| File: | jdk/src/hotspot/share/opto/loopTransform.cpp |
| Warning: | line 1525, column 9 Value stored to 'pre_header' during its initialization is never read |
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| 1 | /* |
| 2 | * Copyright (c) 2000, 2021, Oracle and/or its affiliates. All rights reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. |
| 8 | * |
| 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 12 | * version 2 for more details (a copy is included in the LICENSE file that |
| 13 | * accompanied this code). |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License version |
| 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 18 | * |
| 19 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| 20 | * or visit www.oracle.com if you need additional information or have any |
| 21 | * questions. |
| 22 | * |
| 23 | */ |
| 24 | |
| 25 | #include "precompiled.hpp" |
| 26 | #include "compiler/compileLog.hpp" |
| 27 | #include "memory/allocation.inline.hpp" |
| 28 | #include "opto/addnode.hpp" |
| 29 | #include "opto/callnode.hpp" |
| 30 | #include "opto/castnode.hpp" |
| 31 | #include "opto/connode.hpp" |
| 32 | #include "opto/convertnode.hpp" |
| 33 | #include "opto/divnode.hpp" |
| 34 | #include "opto/loopnode.hpp" |
| 35 | #include "opto/mulnode.hpp" |
| 36 | #include "opto/movenode.hpp" |
| 37 | #include "opto/opaquenode.hpp" |
| 38 | #include "opto/rootnode.hpp" |
| 39 | #include "opto/runtime.hpp" |
| 40 | #include "opto/subnode.hpp" |
| 41 | #include "opto/superword.hpp" |
| 42 | #include "opto/vectornode.hpp" |
| 43 | #include "runtime/globals_extension.hpp" |
| 44 | #include "runtime/stubRoutines.hpp" |
| 45 | |
| 46 | //------------------------------is_loop_exit----------------------------------- |
| 47 | // Given an IfNode, return the loop-exiting projection or NULL if both |
| 48 | // arms remain in the loop. |
| 49 | Node *IdealLoopTree::is_loop_exit(Node *iff) const { |
| 50 | if (iff->outcnt() != 2) return NULL__null; // Ignore partially dead tests |
| 51 | PhaseIdealLoop *phase = _phase; |
| 52 | // Test is an IfNode, has 2 projections. If BOTH are in the loop |
| 53 | // we need loop unswitching instead of peeling. |
| 54 | if (!is_member(phase->get_loop(iff->raw_out(0)))) |
| 55 | return iff->raw_out(0); |
| 56 | if (!is_member(phase->get_loop(iff->raw_out(1)))) |
| 57 | return iff->raw_out(1); |
| 58 | return NULL__null; |
| 59 | } |
| 60 | |
| 61 | |
| 62 | //============================================================================= |
| 63 | |
| 64 | |
| 65 | //------------------------------record_for_igvn---------------------------- |
| 66 | // Put loop body on igvn work list |
| 67 | void IdealLoopTree::record_for_igvn() { |
| 68 | for (uint i = 0; i < _body.size(); i++) { |
| 69 | Node *n = _body.at(i); |
| 70 | _phase->_igvn._worklist.push(n); |
| 71 | } |
| 72 | // put body of outer strip mined loop on igvn work list as well |
| 73 | if (_head->is_CountedLoop() && _head->as_Loop()->is_strip_mined()) { |
| 74 | CountedLoopNode* l = _head->as_CountedLoop(); |
| 75 | Node* outer_loop = l->outer_loop(); |
| 76 | assert(outer_loop != NULL, "missing piece of strip mined loop")do { if (!(outer_loop != __null)) { (*g_assert_poison) = 'X'; ; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 76, "assert(" "outer_loop != __null" ") failed", "missing piece of strip mined loop" ); ::breakpoint(); } } while (0); |
| 77 | _phase->_igvn._worklist.push(outer_loop); |
| 78 | Node* outer_loop_tail = l->outer_loop_tail(); |
| 79 | assert(outer_loop_tail != NULL, "missing piece of strip mined loop")do { if (!(outer_loop_tail != __null)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 79, "assert(" "outer_loop_tail != __null" ") failed", "missing piece of strip mined loop" ); ::breakpoint(); } } while (0); |
| 80 | _phase->_igvn._worklist.push(outer_loop_tail); |
| 81 | Node* outer_loop_end = l->outer_loop_end(); |
| 82 | assert(outer_loop_end != NULL, "missing piece of strip mined loop")do { if (!(outer_loop_end != __null)) { (*g_assert_poison) = 'X' ;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 82, "assert(" "outer_loop_end != __null" ") failed", "missing piece of strip mined loop" ); ::breakpoint(); } } while (0); |
| 83 | _phase->_igvn._worklist.push(outer_loop_end); |
| 84 | Node* outer_safepoint = l->outer_safepoint(); |
| 85 | assert(outer_safepoint != NULL, "missing piece of strip mined loop")do { if (!(outer_safepoint != __null)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 85, "assert(" "outer_safepoint != __null" ") failed", "missing piece of strip mined loop" ); ::breakpoint(); } } while (0); |
| 86 | _phase->_igvn._worklist.push(outer_safepoint); |
| 87 | Node* cle_out = _head->as_CountedLoop()->loopexit()->proj_out(false); |
| 88 | assert(cle_out != NULL, "missing piece of strip mined loop")do { if (!(cle_out != __null)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 88, "assert(" "cle_out != __null" ") failed", "missing piece of strip mined loop" ); ::breakpoint(); } } while (0); |
| 89 | _phase->_igvn._worklist.push(cle_out); |
| 90 | } |
| 91 | } |
| 92 | |
| 93 | //------------------------------compute_exact_trip_count----------------------- |
| 94 | // Compute loop trip count if possible. Do not recalculate trip count for |
| 95 | // split loops (pre-main-post) which have their limits and inits behind Opaque node. |
| 96 | void IdealLoopTree::compute_trip_count(PhaseIdealLoop* phase) { |
| 97 | if (!_head->as_Loop()->is_valid_counted_loop(T_INT)) { |
| 98 | return; |
| 99 | } |
| 100 | CountedLoopNode* cl = _head->as_CountedLoop(); |
| 101 | // Trip count may become nonexact for iteration split loops since |
| 102 | // RCE modifies limits. Note, _trip_count value is not reset since |
| 103 | // it is used to limit unrolling of main loop. |
| 104 | cl->set_nonexact_trip_count(); |
| 105 | |
| 106 | // Loop's test should be part of loop. |
| 107 | if (!phase->is_member(this, phase->get_ctrl(cl->loopexit()->in(CountedLoopEndNode::TestValue)))) |
| 108 | return; // Infinite loop |
| 109 | |
| 110 | #ifdef ASSERT1 |
| 111 | BoolTest::mask bt = cl->loopexit()->test_trip(); |
| 112 | assert(bt == BoolTest::lt || bt == BoolTest::gt ||do { if (!(bt == BoolTest::lt || bt == BoolTest::gt || bt == BoolTest ::ne)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 113, "assert(" "bt == BoolTest::lt || bt == BoolTest::gt || bt == BoolTest::ne" ") failed", "canonical test is expected"); ::breakpoint(); } } while (0) |
| 113 | bt == BoolTest::ne, "canonical test is expected")do { if (!(bt == BoolTest::lt || bt == BoolTest::gt || bt == BoolTest ::ne)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 113, "assert(" "bt == BoolTest::lt || bt == BoolTest::gt || bt == BoolTest::ne" ") failed", "canonical test is expected"); ::breakpoint(); } } while (0); |
| 114 | #endif |
| 115 | |
| 116 | Node* init_n = cl->init_trip(); |
| 117 | Node* limit_n = cl->limit(); |
| 118 | if (init_n != NULL__null && limit_n != NULL__null) { |
| 119 | // Use longs to avoid integer overflow. |
| 120 | int stride_con = cl->stride_con(); |
| 121 | const TypeInt* init_type = phase->_igvn.type(init_n)->is_int(); |
| 122 | const TypeInt* limit_type = phase->_igvn.type(limit_n)->is_int(); |
| 123 | jlong init_con = (stride_con > 0) ? init_type->_lo : init_type->_hi; |
| 124 | jlong limit_con = (stride_con > 0) ? limit_type->_hi : limit_type->_lo; |
| 125 | int stride_m = stride_con - (stride_con > 0 ? 1 : -1); |
| 126 | jlong trip_count = (limit_con - init_con + stride_m)/stride_con; |
| 127 | // The loop body is always executed at least once even if init >= limit (for stride_con > 0) or |
| 128 | // init <= limit (for stride_con < 0). |
| 129 | trip_count = MAX2(trip_count, (jlong)1); |
| 130 | if (trip_count < (jlong)max_juint) { |
| 131 | if (init_n->is_Con() && limit_n->is_Con()) { |
| 132 | // Set exact trip count. |
| 133 | cl->set_exact_trip_count((uint)trip_count); |
| 134 | } else if (cl->unrolled_count() == 1) { |
| 135 | // Set maximum trip count before unrolling. |
| 136 | cl->set_trip_count((uint)trip_count); |
| 137 | } |
| 138 | } |
| 139 | } |
| 140 | } |
| 141 | |
| 142 | //------------------------------compute_profile_trip_cnt---------------------------- |
| 143 | // Compute loop trip count from profile data as |
| 144 | // (backedge_count + loop_exit_count) / loop_exit_count |
| 145 | |
| 146 | float IdealLoopTree::compute_profile_trip_cnt_helper(Node* n) { |
| 147 | if (n->is_If()) { |
| 148 | IfNode *iff = n->as_If(); |
| 149 | if (iff->_fcnt != COUNT_UNKNOWN(-1.0f) && iff->_prob != PROB_UNKNOWN(-1.0f)) { |
| 150 | Node *exit = is_loop_exit(iff); |
| 151 | if (exit) { |
| 152 | float exit_prob = iff->_prob; |
| 153 | if (exit->Opcode() == Op_IfFalse) { |
| 154 | exit_prob = 1.0 - exit_prob; |
| 155 | } |
| 156 | if (exit_prob > PROB_MIN(1e-6f)) { |
| 157 | float exit_cnt = iff->_fcnt * exit_prob; |
| 158 | return exit_cnt; |
| 159 | } |
| 160 | } |
| 161 | } |
| 162 | } |
| 163 | if (n->is_Jump()) { |
| 164 | JumpNode *jmp = n->as_Jump(); |
| 165 | if (jmp->_fcnt != COUNT_UNKNOWN(-1.0f)) { |
| 166 | float* probs = jmp->_probs; |
| 167 | float exit_prob = 0; |
| 168 | PhaseIdealLoop *phase = _phase; |
| 169 | for (DUIterator_Fast imax, i = jmp->fast_outs(imax); i < imax; i++) { |
| 170 | JumpProjNode* u = jmp->fast_out(i)->as_JumpProj(); |
| 171 | if (!is_member(_phase->get_loop(u))) { |
| 172 | exit_prob += probs[u->_con]; |
| 173 | } |
| 174 | } |
| 175 | return exit_prob * jmp->_fcnt; |
| 176 | } |
| 177 | } |
| 178 | return 0; |
| 179 | } |
| 180 | |
| 181 | void IdealLoopTree::compute_profile_trip_cnt(PhaseIdealLoop *phase) { |
| 182 | if (!_head->is_Loop()) { |
| 183 | return; |
| 184 | } |
| 185 | LoopNode* head = _head->as_Loop(); |
| 186 | if (head->profile_trip_cnt() != COUNT_UNKNOWN(-1.0f)) { |
| 187 | return; // Already computed |
| 188 | } |
| 189 | float trip_cnt = (float)max_jint; // default is big |
| 190 | |
| 191 | Node* back = head->in(LoopNode::LoopBackControl); |
| 192 | while (back != head) { |
| 193 | if ((back->Opcode() == Op_IfTrue || back->Opcode() == Op_IfFalse) && |
| 194 | back->in(0) && |
| 195 | back->in(0)->is_If() && |
| 196 | back->in(0)->as_If()->_fcnt != COUNT_UNKNOWN(-1.0f) && |
| 197 | back->in(0)->as_If()->_prob != PROB_UNKNOWN(-1.0f) && |
| 198 | (back->Opcode() == Op_IfTrue ? 1-back->in(0)->as_If()->_prob : back->in(0)->as_If()->_prob) > PROB_MIN(1e-6f)) { |
| 199 | break; |
| 200 | } |
| 201 | back = phase->idom(back); |
| 202 | } |
| 203 | if (back != head) { |
| 204 | assert((back->Opcode() == Op_IfTrue || back->Opcode() == Op_IfFalse) &&do { if (!((back->Opcode() == Op_IfTrue || back->Opcode () == Op_IfFalse) && back->in(0))) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 205, "assert(" "(back->Opcode() == Op_IfTrue || back->Opcode() == Op_IfFalse) && back->in(0)" ") failed", "if-projection exists"); ::breakpoint(); } } while (0) |
| 205 | back->in(0), "if-projection exists")do { if (!((back->Opcode() == Op_IfTrue || back->Opcode () == Op_IfFalse) && back->in(0))) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 205, "assert(" "(back->Opcode() == Op_IfTrue || back->Opcode() == Op_IfFalse) && back->in(0)" ") failed", "if-projection exists"); ::breakpoint(); } } while (0); |
| 206 | IfNode* back_if = back->in(0)->as_If(); |
| 207 | float loop_back_cnt = back_if->_fcnt * (back->Opcode() == Op_IfTrue ? back_if->_prob : (1 - back_if->_prob)); |
| 208 | |
| 209 | // Now compute a loop exit count |
| 210 | float loop_exit_cnt = 0.0f; |
| 211 | if (_child == NULL__null) { |
| 212 | for (uint i = 0; i < _body.size(); i++) { |
| 213 | Node *n = _body[i]; |
| 214 | loop_exit_cnt += compute_profile_trip_cnt_helper(n); |
| 215 | } |
| 216 | } else { |
| 217 | ResourceMark rm; |
| 218 | Unique_Node_List wq; |
| 219 | wq.push(back); |
| 220 | for (uint i = 0; i < wq.size(); i++) { |
| 221 | Node *n = wq.at(i); |
| 222 | assert(n->is_CFG(), "only control nodes")do { if (!(n->is_CFG())) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 222, "assert(" "n->is_CFG()" ") failed", "only control nodes" ); ::breakpoint(); } } while (0); |
| 223 | if (n != head) { |
| 224 | if (n->is_Region()) { |
| 225 | for (uint j = 1; j < n->req(); j++) { |
| 226 | wq.push(n->in(j)); |
| 227 | } |
| 228 | } else { |
| 229 | loop_exit_cnt += compute_profile_trip_cnt_helper(n); |
| 230 | wq.push(n->in(0)); |
| 231 | } |
| 232 | } |
| 233 | } |
| 234 | |
| 235 | } |
| 236 | if (loop_exit_cnt > 0.0f) { |
| 237 | trip_cnt = (loop_back_cnt + loop_exit_cnt) / loop_exit_cnt; |
| 238 | } else { |
| 239 | // No exit count so use |
| 240 | trip_cnt = loop_back_cnt; |
| 241 | } |
| 242 | } else { |
| 243 | head->mark_profile_trip_failed(); |
| 244 | } |
| 245 | #ifndef PRODUCT |
| 246 | if (TraceProfileTripCount) { |
| 247 | tty->print_cr("compute_profile_trip_cnt lp: %d cnt: %f\n", head->_idx, trip_cnt); |
| 248 | } |
| 249 | #endif |
| 250 | head->set_profile_trip_cnt(trip_cnt); |
| 251 | } |
| 252 | |
| 253 | //---------------------find_invariant----------------------------- |
| 254 | // Return nonzero index of invariant operand for an associative |
| 255 | // binary operation of (nonconstant) invariant and variant values. |
| 256 | // Helper for reassociate_invariants. |
| 257 | int IdealLoopTree::find_invariant(Node* n, PhaseIdealLoop *phase) { |
| 258 | bool in1_invar = this->is_invariant(n->in(1)); |
| 259 | bool in2_invar = this->is_invariant(n->in(2)); |
| 260 | if (in1_invar && !in2_invar) return 1; |
| 261 | if (!in1_invar && in2_invar) return 2; |
| 262 | return 0; |
| 263 | } |
| 264 | |
| 265 | //---------------------is_associative----------------------------- |
| 266 | // Return TRUE if "n" is an associative binary node. If "base" is |
| 267 | // not NULL, "n" must be re-associative with it. |
| 268 | bool IdealLoopTree::is_associative(Node* n, Node* base) { |
| 269 | int op = n->Opcode(); |
| 270 | if (base != NULL__null) { |
| 271 | assert(is_associative(base), "Base node should be associative")do { if (!(is_associative(base))) { (*g_assert_poison) = 'X'; ; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 271, "assert(" "is_associative(base)" ") failed", "Base node should be associative" ); ::breakpoint(); } } while (0); |
| 272 | int base_op = base->Opcode(); |
| 273 | if (base_op == Op_AddI || base_op == Op_SubI) { |
| 274 | return op == Op_AddI || op == Op_SubI; |
| 275 | } |
| 276 | if (base_op == Op_AddL || base_op == Op_SubL) { |
| 277 | return op == Op_AddL || op == Op_SubL; |
| 278 | } |
| 279 | return op == base_op; |
| 280 | } else { |
| 281 | // Integer "add/sub/mul/and/or/xor" operations are associative. |
| 282 | return op == Op_AddI || op == Op_AddL |
| 283 | || op == Op_SubI || op == Op_SubL |
| 284 | || op == Op_MulI || op == Op_MulL |
| 285 | || op == Op_AndI || op == Op_AndL |
| 286 | || op == Op_OrI || op == Op_OrL |
| 287 | || op == Op_XorI || op == Op_XorL; |
| 288 | } |
| 289 | } |
| 290 | |
| 291 | //---------------------reassociate_add_sub------------------------ |
| 292 | // Reassociate invariant add and subtract expressions: |
| 293 | // |
| 294 | // inv1 + (x + inv2) => ( inv1 + inv2) + x |
| 295 | // (x + inv2) + inv1 => ( inv1 + inv2) + x |
| 296 | // inv1 + (x - inv2) => ( inv1 - inv2) + x |
| 297 | // inv1 - (inv2 - x) => ( inv1 - inv2) + x |
| 298 | // (x + inv2) - inv1 => (-inv1 + inv2) + x |
| 299 | // (x - inv2) + inv1 => ( inv1 - inv2) + x |
| 300 | // (x - inv2) - inv1 => (-inv1 - inv2) + x |
| 301 | // inv1 + (inv2 - x) => ( inv1 + inv2) - x |
| 302 | // inv1 - (x - inv2) => ( inv1 + inv2) - x |
| 303 | // (inv2 - x) + inv1 => ( inv1 + inv2) - x |
| 304 | // (inv2 - x) - inv1 => (-inv1 + inv2) - x |
| 305 | // inv1 - (x + inv2) => ( inv1 - inv2) - x |
| 306 | // |
| 307 | Node* IdealLoopTree::reassociate_add_sub(Node* n1, int inv1_idx, int inv2_idx, PhaseIdealLoop *phase) { |
| 308 | assert(n1->is_Add() || n1->is_Sub(), "Target node should be add or subtract")do { if (!(n1->is_Add() || n1->is_Sub())) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 308, "assert(" "n1->is_Add() || n1->is_Sub()" ") failed" , "Target node should be add or subtract"); ::breakpoint(); } } while (0); |
| 309 | Node* n2 = n1->in(3 - inv1_idx); |
| 310 | Node* inv1 = n1->in(inv1_idx); |
| 311 | Node* inv2 = n2->in(inv2_idx); |
| 312 | Node* x = n2->in(3 - inv2_idx); |
| 313 | |
| 314 | bool neg_x = n2->is_Sub() && inv2_idx == 1; |
| 315 | bool neg_inv2 = n2->is_Sub() && inv2_idx == 2; |
| 316 | bool neg_inv1 = n1->is_Sub() && inv1_idx == 2; |
| 317 | if (n1->is_Sub() && inv1_idx == 1) { |
| 318 | neg_x = !neg_x; |
| 319 | neg_inv2 = !neg_inv2; |
| 320 | } |
| 321 | |
| 322 | bool is_int = n1->bottom_type()->isa_int() != NULL__null; |
| 323 | Node* inv1_c = phase->get_ctrl(inv1); |
| 324 | Node* n_inv1; |
| 325 | if (neg_inv1) { |
| 326 | Node* zero; |
| 327 | if (is_int) { |
| 328 | zero = phase->_igvn.intcon(0); |
| 329 | n_inv1 = new SubINode(zero, inv1); |
| 330 | } else { |
| 331 | zero = phase->_igvn.longcon(0L); |
| 332 | n_inv1 = new SubLNode(zero, inv1); |
| 333 | } |
| 334 | phase->set_ctrl(zero, phase->C->root()); |
| 335 | phase->register_new_node(n_inv1, inv1_c); |
| 336 | } else { |
| 337 | n_inv1 = inv1; |
| 338 | } |
| 339 | |
| 340 | Node* inv; |
| 341 | if (is_int) { |
| 342 | if (neg_inv2) { |
| 343 | inv = new SubINode(n_inv1, inv2); |
| 344 | } else { |
| 345 | inv = new AddINode(n_inv1, inv2); |
| 346 | } |
| 347 | phase->register_new_node(inv, phase->get_early_ctrl(inv)); |
| 348 | if (neg_x) { |
| 349 | return new SubINode(inv, x); |
| 350 | } else { |
| 351 | return new AddINode(x, inv); |
| 352 | } |
| 353 | } else { |
| 354 | if (neg_inv2) { |
| 355 | inv = new SubLNode(n_inv1, inv2); |
| 356 | } else { |
| 357 | inv = new AddLNode(n_inv1, inv2); |
| 358 | } |
| 359 | phase->register_new_node(inv, phase->get_early_ctrl(inv)); |
| 360 | if (neg_x) { |
| 361 | return new SubLNode(inv, x); |
| 362 | } else { |
| 363 | return new AddLNode(x, inv); |
| 364 | } |
| 365 | } |
| 366 | } |
| 367 | |
| 368 | //---------------------reassociate----------------------------- |
| 369 | // Reassociate invariant binary expressions with add/sub/mul/ |
| 370 | // and/or/xor operators. |
| 371 | // For add/sub expressions: see "reassociate_add_sub" |
| 372 | // |
| 373 | // For mul/and/or/xor expressions: |
| 374 | // |
| 375 | // inv1 op (x op inv2) => (inv1 op inv2) op x |
| 376 | // |
| 377 | Node* IdealLoopTree::reassociate(Node* n1, PhaseIdealLoop *phase) { |
| 378 | if (!is_associative(n1) || n1->outcnt() == 0) return NULL__null; |
| 379 | if (is_invariant(n1)) return NULL__null; |
| 380 | // Don't mess with add of constant (igvn moves them to expression tree root.) |
| 381 | if (n1->is_Add() && n1->in(2)->is_Con()) return NULL__null; |
| 382 | |
| 383 | int inv1_idx = find_invariant(n1, phase); |
| 384 | if (!inv1_idx) return NULL__null; |
| 385 | Node* n2 = n1->in(3 - inv1_idx); |
| 386 | if (!is_associative(n2, n1)) return NULL__null; |
| 387 | int inv2_idx = find_invariant(n2, phase); |
| 388 | if (!inv2_idx) return NULL__null; |
| 389 | |
| 390 | if (!phase->may_require_nodes(10, 10)) return NULL__null; |
| 391 | |
| 392 | Node* result = NULL__null; |
| 393 | switch (n1->Opcode()) { |
| 394 | case Op_AddI: |
| 395 | case Op_AddL: |
| 396 | case Op_SubI: |
| 397 | case Op_SubL: |
| 398 | result = reassociate_add_sub(n1, inv1_idx, inv2_idx, phase); |
| 399 | break; |
| 400 | case Op_MulI: |
| 401 | case Op_MulL: |
| 402 | case Op_AndI: |
| 403 | case Op_AndL: |
| 404 | case Op_OrI: |
| 405 | case Op_OrL: |
| 406 | case Op_XorI: |
| 407 | case Op_XorL: { |
| 408 | Node* inv1 = n1->in(inv1_idx); |
| 409 | Node* inv2 = n2->in(inv2_idx); |
| 410 | Node* x = n2->in(3 - inv2_idx); |
| 411 | Node* inv = n2->clone_with_data_edge(inv1, inv2); |
| 412 | phase->register_new_node(inv, phase->get_early_ctrl(inv)); |
| 413 | result = n1->clone_with_data_edge(x, inv); |
| 414 | break; |
| 415 | } |
| 416 | default: |
| 417 | ShouldNotReachHere()do { (*g_assert_poison) = 'X';; report_should_not_reach_here( "/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 417); ::breakpoint(); } while (0); |
| 418 | } |
| 419 | |
| 420 | assert(result != NULL, "")do { if (!(result != __null)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 420, "assert(" "result != __null" ") failed", ""); ::breakpoint (); } } while (0); |
| 421 | phase->register_new_node(result, phase->get_ctrl(n1)); |
| 422 | phase->_igvn.replace_node(n1, result); |
| 423 | assert(phase->get_loop(phase->get_ctrl(n1)) == this, "")do { if (!(phase->get_loop(phase->get_ctrl(n1)) == this )) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 423, "assert(" "phase->get_loop(phase->get_ctrl(n1)) == this" ") failed", ""); ::breakpoint(); } } while (0); |
| 424 | _body.yank(n1); |
| 425 | return result; |
| 426 | } |
| 427 | |
| 428 | //---------------------reassociate_invariants----------------------------- |
| 429 | // Reassociate invariant expressions: |
| 430 | void IdealLoopTree::reassociate_invariants(PhaseIdealLoop *phase) { |
| 431 | for (int i = _body.size() - 1; i >= 0; i--) { |
| 432 | Node *n = _body.at(i); |
| 433 | for (int j = 0; j < 5; j++) { |
| 434 | Node* nn = reassociate(n, phase); |
| 435 | if (nn == NULL__null) break; |
| 436 | n = nn; // again |
| 437 | } |
| 438 | } |
| 439 | } |
| 440 | |
| 441 | //------------------------------policy_peeling--------------------------------- |
| 442 | // Return TRUE if the loop should be peeled, otherwise return FALSE. Peeling |
| 443 | // is applicable if we can make a loop-invariant test (usually a null-check) |
| 444 | // execute before we enter the loop. When TRUE, the estimated node budget is |
| 445 | // also requested. |
| 446 | bool IdealLoopTree::policy_peeling(PhaseIdealLoop *phase) { |
| 447 | uint estimate = estimate_peeling(phase); |
| 448 | |
| 449 | return estimate == 0 ? false : phase->may_require_nodes(estimate); |
| 450 | } |
| 451 | |
| 452 | // Perform actual policy and size estimate for the loop peeling transform, and |
| 453 | // return the estimated loop size if peeling is applicable, otherwise return |
| 454 | // zero. No node budget is allocated. |
| 455 | uint IdealLoopTree::estimate_peeling(PhaseIdealLoop *phase) { |
| 456 | |
| 457 | // If nodes are depleted, some transform has miscalculated its needs. |
| 458 | assert(!phase->exceeding_node_budget(), "sanity")do { if (!(!phase->exceeding_node_budget())) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 458, "assert(" "!phase->exceeding_node_budget()" ") failed" , "sanity"); ::breakpoint(); } } while (0); |
| 459 | |
| 460 | // Peeling does loop cloning which can result in O(N^2) node construction. |
| 461 | if (_body.size() > 255) { |
| 462 | return 0; // Suppress too large body size. |
| 463 | } |
| 464 | // Optimistic estimate that approximates loop body complexity via data and |
| 465 | // control flow fan-out (instead of using the more pessimistic: BodySize^2). |
| 466 | uint estimate = est_loop_clone_sz(2); |
| 467 | |
| 468 | if (phase->exceeding_node_budget(estimate)) { |
| 469 | return 0; // Too large to safely clone. |
| 470 | } |
| 471 | |
| 472 | // Check for vectorized loops, any peeling done was already applied. |
| 473 | if (_head->is_CountedLoop()) { |
| 474 | CountedLoopNode* cl = _head->as_CountedLoop(); |
| 475 | if (cl->is_unroll_only() || cl->trip_count() == 1) { |
| 476 | return 0; |
| 477 | } |
| 478 | } |
| 479 | |
| 480 | Node* test = tail(); |
| 481 | |
| 482 | while (test != _head) { // Scan till run off top of loop |
| 483 | if (test->is_If()) { // Test? |
| 484 | Node *ctrl = phase->get_ctrl(test->in(1)); |
| 485 | if (ctrl->is_top()) { |
| 486 | return 0; // Found dead test on live IF? No peeling! |
| 487 | } |
| 488 | // Standard IF only has one input value to check for loop invariance. |
| 489 | assert(test->Opcode() == Op_If ||do { if (!(test->Opcode() == Op_If || test->Opcode() == Op_CountedLoopEnd || test->Opcode() == Op_LongCountedLoopEnd || test->Opcode() == Op_RangeCheck)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 493, "assert(" "test->Opcode() == Op_If || test->Opcode() == Op_CountedLoopEnd || test->Opcode() == Op_LongCountedLoopEnd || test->Opcode() == Op_RangeCheck" ") failed", "Check this code when new subtype is added"); :: breakpoint(); } } while (0) |
| 490 | test->Opcode() == Op_CountedLoopEnd ||do { if (!(test->Opcode() == Op_If || test->Opcode() == Op_CountedLoopEnd || test->Opcode() == Op_LongCountedLoopEnd || test->Opcode() == Op_RangeCheck)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 493, "assert(" "test->Opcode() == Op_If || test->Opcode() == Op_CountedLoopEnd || test->Opcode() == Op_LongCountedLoopEnd || test->Opcode() == Op_RangeCheck" ") failed", "Check this code when new subtype is added"); :: breakpoint(); } } while (0) |
| 491 | test->Opcode() == Op_LongCountedLoopEnd ||do { if (!(test->Opcode() == Op_If || test->Opcode() == Op_CountedLoopEnd || test->Opcode() == Op_LongCountedLoopEnd || test->Opcode() == Op_RangeCheck)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 493, "assert(" "test->Opcode() == Op_If || test->Opcode() == Op_CountedLoopEnd || test->Opcode() == Op_LongCountedLoopEnd || test->Opcode() == Op_RangeCheck" ") failed", "Check this code when new subtype is added"); :: breakpoint(); } } while (0) |
| 492 | test->Opcode() == Op_RangeCheck,do { if (!(test->Opcode() == Op_If || test->Opcode() == Op_CountedLoopEnd || test->Opcode() == Op_LongCountedLoopEnd || test->Opcode() == Op_RangeCheck)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 493, "assert(" "test->Opcode() == Op_If || test->Opcode() == Op_CountedLoopEnd || test->Opcode() == Op_LongCountedLoopEnd || test->Opcode() == Op_RangeCheck" ") failed", "Check this code when new subtype is added"); :: breakpoint(); } } while (0) |
| 493 | "Check this code when new subtype is added")do { if (!(test->Opcode() == Op_If || test->Opcode() == Op_CountedLoopEnd || test->Opcode() == Op_LongCountedLoopEnd || test->Opcode() == Op_RangeCheck)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 493, "assert(" "test->Opcode() == Op_If || test->Opcode() == Op_CountedLoopEnd || test->Opcode() == Op_LongCountedLoopEnd || test->Opcode() == Op_RangeCheck" ") failed", "Check this code when new subtype is added"); :: breakpoint(); } } while (0); |
| 494 | // Condition is not a member of this loop? |
| 495 | if (!is_member(phase->get_loop(ctrl)) && is_loop_exit(test)) { |
| 496 | return estimate; // Found reason to peel! |
| 497 | } |
| 498 | } |
| 499 | // Walk up dominators to loop _head looking for test which is executed on |
| 500 | // every path through the loop. |
| 501 | test = phase->idom(test); |
| 502 | } |
| 503 | return 0; |
| 504 | } |
| 505 | |
| 506 | //------------------------------peeled_dom_test_elim--------------------------- |
| 507 | // If we got the effect of peeling, either by actually peeling or by making |
| 508 | // a pre-loop which must execute at least once, we can remove all |
| 509 | // loop-invariant dominated tests in the main body. |
| 510 | void PhaseIdealLoop::peeled_dom_test_elim(IdealLoopTree* loop, Node_List& old_new) { |
| 511 | bool progress = true; |
| 512 | while (progress) { |
| 513 | progress = false; // Reset for next iteration |
| 514 | Node* prev = loop->_head->in(LoopNode::LoopBackControl); // loop->tail(); |
| 515 | Node* test = prev->in(0); |
| 516 | while (test != loop->_head) { // Scan till run off top of loop |
| 517 | int p_op = prev->Opcode(); |
| 518 | assert(test != NULL, "test cannot be NULL")do { if (!(test != __null)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 518, "assert(" "test != __null" ") failed", "test cannot be NULL" ); ::breakpoint(); } } while (0); |
| 519 | Node* test_cond = NULL__null; |
| 520 | if ((p_op == Op_IfFalse || p_op == Op_IfTrue) && test->is_If()) { |
| 521 | test_cond = test->in(1); |
| 522 | } |
| 523 | if (test_cond != NULL__null && // Test? |
| 524 | !test_cond->is_Con() && // And not already obvious? |
| 525 | // And condition is not a member of this loop? |
| 526 | !loop->is_member(get_loop(get_ctrl(test_cond)))) { |
| 527 | // Walk loop body looking for instances of this test |
| 528 | for (uint i = 0; i < loop->_body.size(); i++) { |
| 529 | Node* n = loop->_body.at(i); |
| 530 | // Check against cached test condition because dominated_by() |
| 531 | // replaces the test condition with a constant. |
| 532 | if (n->is_If() && n->in(1) == test_cond) { |
| 533 | // IfNode was dominated by version in peeled loop body |
| 534 | progress = true; |
| 535 | dominated_by(old_new[prev->_idx], n); |
| 536 | } |
| 537 | } |
| 538 | } |
| 539 | prev = test; |
| 540 | test = idom(test); |
| 541 | } // End of scan tests in loop |
| 542 | } // End of while (progress) |
| 543 | } |
| 544 | |
| 545 | //------------------------------do_peeling------------------------------------- |
| 546 | // Peel the first iteration of the given loop. |
| 547 | // Step 1: Clone the loop body. The clone becomes the peeled iteration. |
| 548 | // The pre-loop illegally has 2 control users (old & new loops). |
| 549 | // Step 2: Make the old-loop fall-in edges point to the peeled iteration. |
| 550 | // Do this by making the old-loop fall-in edges act as if they came |
| 551 | // around the loopback from the prior iteration (follow the old-loop |
| 552 | // backedges) and then map to the new peeled iteration. This leaves |
| 553 | // the pre-loop with only 1 user (the new peeled iteration), but the |
| 554 | // peeled-loop backedge has 2 users. |
| 555 | // Step 3: Cut the backedge on the clone (so its not a loop) and remove the |
| 556 | // extra backedge user. |
| 557 | // |
| 558 | // orig |
| 559 | // |
| 560 | // stmt1 |
| 561 | // | |
| 562 | // v |
| 563 | // loop predicate |
| 564 | // | |
| 565 | // v |
| 566 | // loop<----+ |
| 567 | // | | |
| 568 | // stmt2 | |
| 569 | // | | |
| 570 | // v | |
| 571 | // if ^ |
| 572 | // / \ | |
| 573 | // / \ | |
| 574 | // v v | |
| 575 | // false true | |
| 576 | // / \ | |
| 577 | // / ----+ |
| 578 | // | |
| 579 | // v |
| 580 | // exit |
| 581 | // |
| 582 | // |
| 583 | // after clone loop |
| 584 | // |
| 585 | // stmt1 |
| 586 | // | |
| 587 | // v |
| 588 | // loop predicate |
| 589 | // / \ |
| 590 | // clone / \ orig |
| 591 | // / \ |
| 592 | // / \ |
| 593 | // v v |
| 594 | // +---->loop clone loop<----+ |
| 595 | // | | | | |
| 596 | // | stmt2 clone stmt2 | |
| 597 | // | | | | |
| 598 | // | v v | |
| 599 | // ^ if clone If ^ |
| 600 | // | / \ / \ | |
| 601 | // | / \ / \ | |
| 602 | // | v v v v | |
| 603 | // | true false false true | |
| 604 | // | / \ / \ | |
| 605 | // +---- \ / ----+ |
| 606 | // \ / |
| 607 | // 1v v2 |
| 608 | // region |
| 609 | // | |
| 610 | // v |
| 611 | // exit |
| 612 | // |
| 613 | // |
| 614 | // after peel and predicate move |
| 615 | // |
| 616 | // stmt1 |
| 617 | // / |
| 618 | // / |
| 619 | // clone / orig |
| 620 | // / |
| 621 | // / +----------+ |
| 622 | // / | | |
| 623 | // / loop predicate | |
| 624 | // / | | |
| 625 | // v v | |
| 626 | // TOP-->loop clone loop<----+ | |
| 627 | // | | | | |
| 628 | // stmt2 clone stmt2 | | |
| 629 | // | | | ^ |
| 630 | // v v | | |
| 631 | // if clone If ^ | |
| 632 | // / \ / \ | | |
| 633 | // / \ / \ | | |
| 634 | // v v v v | | |
| 635 | // true false false true | | |
| 636 | // | \ / \ | | |
| 637 | // | \ / ----+ ^ |
| 638 | // | \ / | |
| 639 | // | 1v v2 | |
| 640 | // v region | |
| 641 | // | | | |
| 642 | // | v | |
| 643 | // | exit | |
| 644 | // | | |
| 645 | // +--------------->-----------------+ |
| 646 | // |
| 647 | // |
| 648 | // final graph |
| 649 | // |
| 650 | // stmt1 |
| 651 | // | |
| 652 | // v |
| 653 | // stmt2 clone |
| 654 | // | |
| 655 | // v |
| 656 | // if clone |
| 657 | // / | |
| 658 | // / | |
| 659 | // v v |
| 660 | // false true |
| 661 | // | | |
| 662 | // | v |
| 663 | // | loop predicate |
| 664 | // | | |
| 665 | // | v |
| 666 | // | loop<----+ |
| 667 | // | | | |
| 668 | // | stmt2 | |
| 669 | // | | | |
| 670 | // | v | |
| 671 | // v if ^ |
| 672 | // | / \ | |
| 673 | // | / \ | |
| 674 | // | v v | |
| 675 | // | false true | |
| 676 | // | | \ | |
| 677 | // v v --+ |
| 678 | // region |
| 679 | // | |
| 680 | // v |
| 681 | // exit |
| 682 | // |
| 683 | void PhaseIdealLoop::do_peeling(IdealLoopTree *loop, Node_List &old_new) { |
| 684 | |
| 685 | C->set_major_progress(); |
| 686 | // Peeling a 'main' loop in a pre/main/post situation obfuscates the |
| 687 | // 'pre' loop from the main and the 'pre' can no longer have its |
| 688 | // iterations adjusted. Therefore, we need to declare this loop as |
| 689 | // no longer a 'main' loop; it will need new pre and post loops before |
| 690 | // we can do further RCE. |
| 691 | #ifndef PRODUCT |
| 692 | if (TraceLoopOpts) { |
| 693 | tty->print("Peel "); |
| 694 | loop->dump_head(); |
| 695 | } |
| 696 | #endif |
| 697 | LoopNode* head = loop->_head->as_Loop(); |
| 698 | bool counted_loop = head->is_CountedLoop(); |
| 699 | if (counted_loop) { |
| 700 | CountedLoopNode *cl = head->as_CountedLoop(); |
| 701 | assert(cl->trip_count() > 0, "peeling a fully unrolled loop")do { if (!(cl->trip_count() > 0)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 701, "assert(" "cl->trip_count() > 0" ") failed", "peeling a fully unrolled loop" ); ::breakpoint(); } } while (0); |
| 702 | cl->set_trip_count(cl->trip_count() - 1); |
| 703 | if (cl->is_main_loop()) { |
| 704 | cl->set_normal_loop(); |
| 705 | #ifndef PRODUCT |
| 706 | if (PrintOpto && VerifyLoopOptimizations) { |
| 707 | tty->print("Peeling a 'main' loop; resetting to 'normal' "); |
| 708 | loop->dump_head(); |
| 709 | } |
| 710 | #endif |
| 711 | } |
| 712 | } |
| 713 | Node* entry = head->in(LoopNode::EntryControl); |
| 714 | |
| 715 | // Step 1: Clone the loop body. The clone becomes the peeled iteration. |
| 716 | // The pre-loop illegally has 2 control users (old & new loops). |
| 717 | clone_loop(loop, old_new, dom_depth(head->skip_strip_mined()), ControlAroundStripMined); |
| 718 | |
| 719 | // Step 2: Make the old-loop fall-in edges point to the peeled iteration. |
| 720 | // Do this by making the old-loop fall-in edges act as if they came |
| 721 | // around the loopback from the prior iteration (follow the old-loop |
| 722 | // backedges) and then map to the new peeled iteration. This leaves |
| 723 | // the pre-loop with only 1 user (the new peeled iteration), but the |
| 724 | // peeled-loop backedge has 2 users. |
| 725 | Node* new_entry = old_new[head->in(LoopNode::LoopBackControl)->_idx]; |
| 726 | _igvn.hash_delete(head->skip_strip_mined()); |
| 727 | head->skip_strip_mined()->set_req(LoopNode::EntryControl, new_entry); |
| 728 | for (DUIterator_Fast jmax, j = head->fast_outs(jmax); j < jmax; j++) { |
| 729 | Node* old = head->fast_out(j); |
| 730 | if (old->in(0) == loop->_head && old->req() == 3 && old->is_Phi()) { |
| 731 | Node* new_exit_value = old_new[old->in(LoopNode::LoopBackControl)->_idx]; |
| 732 | if (!new_exit_value) // Backedge value is ALSO loop invariant? |
| 733 | // Then loop body backedge value remains the same. |
| 734 | new_exit_value = old->in(LoopNode::LoopBackControl); |
| 735 | _igvn.hash_delete(old); |
| 736 | old->set_req(LoopNode::EntryControl, new_exit_value); |
| 737 | } |
| 738 | } |
| 739 | |
| 740 | |
| 741 | // Step 3: Cut the backedge on the clone (so its not a loop) and remove the |
| 742 | // extra backedge user. |
| 743 | Node* new_head = old_new[head->_idx]; |
| 744 | _igvn.hash_delete(new_head); |
| 745 | new_head->set_req(LoopNode::LoopBackControl, C->top()); |
| 746 | for (DUIterator_Fast j2max, j2 = new_head->fast_outs(j2max); j2 < j2max; j2++) { |
| 747 | Node* use = new_head->fast_out(j2); |
| 748 | if (use->in(0) == new_head && use->req() == 3 && use->is_Phi()) { |
| 749 | _igvn.hash_delete(use); |
| 750 | use->set_req(LoopNode::LoopBackControl, C->top()); |
| 751 | } |
| 752 | } |
| 753 | |
| 754 | // Step 4: Correct dom-depth info. Set to loop-head depth. |
| 755 | |
| 756 | int dd = dom_depth(head->skip_strip_mined()); |
| 757 | set_idom(head->skip_strip_mined(), head->skip_strip_mined()->in(LoopNode::EntryControl), dd); |
| 758 | for (uint j3 = 0; j3 < loop->_body.size(); j3++) { |
| 759 | Node *old = loop->_body.at(j3); |
| 760 | Node *nnn = old_new[old->_idx]; |
| 761 | if (!has_ctrl(nnn)) { |
| 762 | set_idom(nnn, idom(nnn), dd-1); |
| 763 | } |
| 764 | } |
| 765 | |
| 766 | // Now force out all loop-invariant dominating tests. The optimizer |
| 767 | // finds some, but we _know_ they are all useless. |
| 768 | peeled_dom_test_elim(loop,old_new); |
| 769 | |
| 770 | loop->record_for_igvn(); |
| 771 | } |
| 772 | |
| 773 | //------------------------------policy_maximally_unroll------------------------ |
| 774 | // Calculate the exact loop trip-count and return TRUE if loop can be fully, |
| 775 | // i.e. maximally, unrolled, otherwise return FALSE. When TRUE, the estimated |
| 776 | // node budget is also requested. |
| 777 | bool IdealLoopTree::policy_maximally_unroll(PhaseIdealLoop* phase) const { |
| 778 | CountedLoopNode* cl = _head->as_CountedLoop(); |
| 779 | assert(cl->is_normal_loop(), "")do { if (!(cl->is_normal_loop())) { (*g_assert_poison) = 'X' ;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 779, "assert(" "cl->is_normal_loop()" ") failed", ""); :: breakpoint(); } } while (0); |
| 780 | if (!cl->is_valid_counted_loop(T_INT)) { |
| 781 | return false; // Malformed counted loop. |
| 782 | } |
| 783 | if (!cl->has_exact_trip_count()) { |
| 784 | return false; // Trip count is not exact. |
| 785 | } |
| 786 | |
| 787 | uint trip_count = cl->trip_count(); |
| 788 | // Note, max_juint is used to indicate unknown trip count. |
| 789 | assert(trip_count > 1, "one iteration loop should be optimized out already")do { if (!(trip_count > 1)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 789, "assert(" "trip_count > 1" ") failed", "one iteration loop should be optimized out already" ); ::breakpoint(); } } while (0); |
| 790 | assert(trip_count < max_juint, "exact trip_count should be less than max_juint.")do { if (!(trip_count < max_juint)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 790, "assert(" "trip_count < max_juint" ") failed", "exact trip_count should be less than max_juint." ); ::breakpoint(); } } while (0); |
| 791 | |
| 792 | // If nodes are depleted, some transform has miscalculated its needs. |
| 793 | assert(!phase->exceeding_node_budget(), "sanity")do { if (!(!phase->exceeding_node_budget())) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 793, "assert(" "!phase->exceeding_node_budget()" ") failed" , "sanity"); ::breakpoint(); } } while (0); |
| 794 | |
| 795 | // Allow the unrolled body to get larger than the standard loop size limit. |
| 796 | uint unroll_limit = (uint)LoopUnrollLimit * 4; |
| 797 | assert((intx)unroll_limit == LoopUnrollLimit * 4, "LoopUnrollLimit must fit in 32bits")do { if (!((intx)unroll_limit == LoopUnrollLimit * 4)) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 797, "assert(" "(intx)unroll_limit == LoopUnrollLimit * 4" ") failed" , "LoopUnrollLimit must fit in 32bits"); ::breakpoint(); } } while (0); |
| 798 | if (trip_count > unroll_limit || _body.size() > unroll_limit) { |
| 799 | return false; |
| 800 | } |
| 801 | |
| 802 | uint new_body_size = est_loop_unroll_sz(trip_count); |
| 803 | |
| 804 | if (new_body_size == UINT_MAX(2147483647 *2U +1U)) { // Check for bad estimate (overflow). |
| 805 | return false; |
| 806 | } |
| 807 | |
| 808 | // Fully unroll a loop with few iterations, regardless of other conditions, |
| 809 | // since the following (general) loop optimizations will split such loop in |
| 810 | // any case (into pre-main-post). |
| 811 | if (trip_count <= 3) { |
| 812 | return phase->may_require_nodes(new_body_size); |
| 813 | } |
| 814 | |
| 815 | // Reject if unrolling will result in too much node construction. |
| 816 | if (new_body_size > unroll_limit || phase->exceeding_node_budget(new_body_size)) { |
| 817 | return false; |
| 818 | } |
| 819 | |
| 820 | // Do not unroll a loop with String intrinsics code. |
| 821 | // String intrinsics are large and have loops. |
| 822 | for (uint k = 0; k < _body.size(); k++) { |
| 823 | Node* n = _body.at(k); |
| 824 | switch (n->Opcode()) { |
| 825 | case Op_StrComp: |
| 826 | case Op_StrEquals: |
| 827 | case Op_StrIndexOf: |
| 828 | case Op_StrIndexOfChar: |
| 829 | case Op_EncodeISOArray: |
| 830 | case Op_AryEq: |
| 831 | case Op_HasNegatives: { |
| 832 | return false; |
| 833 | } |
| 834 | #if INCLUDE_RTM_OPT1 |
| 835 | case Op_FastLock: |
| 836 | case Op_FastUnlock: { |
| 837 | // Don't unroll RTM locking code because it is large. |
| 838 | if (UseRTMLocking) { |
| 839 | return false; |
| 840 | } |
| 841 | } |
| 842 | #endif |
| 843 | } // switch |
| 844 | } |
| 845 | |
| 846 | return phase->may_require_nodes(new_body_size); |
| 847 | } |
| 848 | |
| 849 | |
| 850 | //------------------------------policy_unroll---------------------------------- |
| 851 | // Return TRUE or FALSE if the loop should be unrolled or not. Apply unroll if |
| 852 | // the loop is a counted loop and the loop body is small enough. When TRUE, |
| 853 | // the estimated node budget is also requested. |
| 854 | bool IdealLoopTree::policy_unroll(PhaseIdealLoop *phase) { |
| 855 | |
| 856 | CountedLoopNode *cl = _head->as_CountedLoop(); |
| 857 | assert(cl->is_normal_loop() || cl->is_main_loop(), "")do { if (!(cl->is_normal_loop() || cl->is_main_loop())) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 857, "assert(" "cl->is_normal_loop() || cl->is_main_loop()" ") failed", ""); ::breakpoint(); } } while (0); |
| 858 | |
| 859 | if (!cl->is_valid_counted_loop(T_INT)) { |
| 860 | return false; // Malformed counted loop |
| 861 | } |
| 862 | |
| 863 | // If nodes are depleted, some transform has miscalculated its needs. |
| 864 | assert(!phase->exceeding_node_budget(), "sanity")do { if (!(!phase->exceeding_node_budget())) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 864, "assert(" "!phase->exceeding_node_budget()" ") failed" , "sanity"); ::breakpoint(); } } while (0); |
| 865 | |
| 866 | // Protect against over-unrolling. |
| 867 | // After split at least one iteration will be executed in pre-loop. |
| 868 | if (cl->trip_count() <= (cl->is_normal_loop() ? 2u : 1u)) { |
| 869 | return false; |
| 870 | } |
| 871 | _local_loop_unroll_limit = LoopUnrollLimit; |
| 872 | _local_loop_unroll_factor = 4; |
| 873 | int future_unroll_cnt = cl->unrolled_count() * 2; |
| 874 | if (!cl->is_vectorized_loop()) { |
| 875 | if (future_unroll_cnt > LoopMaxUnroll) return false; |
| 876 | } else { |
| 877 | // obey user constraints on vector mapped loops with additional unrolling applied |
| 878 | int unroll_constraint = (cl->slp_max_unroll()) ? cl->slp_max_unroll() : 1; |
| 879 | if ((future_unroll_cnt / unroll_constraint) > LoopMaxUnroll) return false; |
| 880 | } |
| 881 | |
| 882 | const int stride_con = cl->stride_con(); |
| 883 | |
| 884 | // Check for initial stride being a small enough constant |
| 885 | const int initial_stride_sz = MAX2(1<<2, Matcher::max_vector_size(T_BYTE) / 2); |
| 886 | // Maximum stride size should protect against overflow, when doubling stride unroll_count times |
| 887 | const int max_stride_size = MIN2<int>(max_jint / 2 - 2, initial_stride_sz * future_unroll_cnt); |
| 888 | // No abs() use; abs(min_jint) = min_jint |
| 889 | if (stride_con < -max_stride_size || stride_con > max_stride_size) return false; |
| 890 | |
| 891 | // Don't unroll if the next round of unrolling would push us |
| 892 | // over the expected trip count of the loop. One is subtracted |
| 893 | // from the expected trip count because the pre-loop normally |
| 894 | // executes 1 iteration. |
| 895 | if (UnrollLimitForProfileCheck > 0 && |
| 896 | cl->profile_trip_cnt() != COUNT_UNKNOWN(-1.0f) && |
| 897 | future_unroll_cnt > UnrollLimitForProfileCheck && |
| 898 | (float)future_unroll_cnt > cl->profile_trip_cnt() - 1.0) { |
| 899 | return false; |
| 900 | } |
| 901 | |
| 902 | // When unroll count is greater than LoopUnrollMin, don't unroll if: |
| 903 | // the residual iterations are more than 10% of the trip count |
| 904 | // and rounds of "unroll,optimize" are not making significant progress |
| 905 | // Progress defined as current size less than 20% larger than previous size. |
| 906 | if (UseSuperWord && cl->node_count_before_unroll() > 0 && |
| 907 | future_unroll_cnt > LoopUnrollMin && |
| 908 | (future_unroll_cnt - 1) * (100.0 / LoopPercentProfileLimit) > cl->profile_trip_cnt() && |
| 909 | 1.2 * cl->node_count_before_unroll() < (double)_body.size()) { |
| 910 | return false; |
| 911 | } |
| 912 | |
| 913 | Node *init_n = cl->init_trip(); |
| 914 | Node *limit_n = cl->limit(); |
| 915 | if (limit_n == NULL__null) return false; // We will dereference it below. |
| 916 | |
| 917 | // Non-constant bounds. |
| 918 | // Protect against over-unrolling when init or/and limit are not constant |
| 919 | // (so that trip_count's init value is maxint) but iv range is known. |
| 920 | if (init_n == NULL__null || !init_n->is_Con() || !limit_n->is_Con()) { |
| 921 | Node* phi = cl->phi(); |
| 922 | if (phi != NULL__null) { |
| 923 | assert(phi->is_Phi() && phi->in(0) == _head, "Counted loop should have iv phi.")do { if (!(phi->is_Phi() && phi->in(0) == _head )) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 923, "assert(" "phi->is_Phi() && phi->in(0) == _head" ") failed", "Counted loop should have iv phi."); ::breakpoint (); } } while (0); |
| 924 | const TypeInt* iv_type = phase->_igvn.type(phi)->is_int(); |
| 925 | int next_stride = stride_con * 2; // stride after this unroll |
| 926 | if (next_stride > 0) { |
| 927 | if (iv_type->_lo > max_jint - next_stride || // overflow |
| 928 | iv_type->_lo + next_stride > iv_type->_hi) { |
| 929 | return false; // over-unrolling |
| 930 | } |
| 931 | } else if (next_stride < 0) { |
| 932 | if (iv_type->_hi < min_jint - next_stride || // overflow |
| 933 | iv_type->_hi + next_stride < iv_type->_lo) { |
| 934 | return false; // over-unrolling |
| 935 | } |
| 936 | } |
| 937 | } |
| 938 | } |
| 939 | |
| 940 | // After unroll limit will be adjusted: new_limit = limit-stride. |
| 941 | // Bailout if adjustment overflow. |
| 942 | const TypeInt* limit_type = phase->_igvn.type(limit_n)->is_int(); |
| 943 | if ((stride_con > 0 && ((min_jint + stride_con) > limit_type->_hi)) || |
| 944 | (stride_con < 0 && ((max_jint + stride_con) < limit_type->_lo))) |
| 945 | return false; // overflow |
| 946 | |
| 947 | // Adjust body_size to determine if we unroll or not |
| 948 | uint body_size = _body.size(); |
| 949 | // Key test to unroll loop in CRC32 java code |
| 950 | int xors_in_loop = 0; |
| 951 | // Also count ModL, DivL and MulL which expand mightly |
| 952 | for (uint k = 0; k < _body.size(); k++) { |
| 953 | Node* n = _body.at(k); |
| 954 | switch (n->Opcode()) { |
| 955 | case Op_XorI: xors_in_loop++; break; // CRC32 java code |
| 956 | case Op_ModL: body_size += 30; break; |
| 957 | case Op_DivL: body_size += 30; break; |
| 958 | case Op_MulL: body_size += 10; break; |
| 959 | case Op_StrComp: |
| 960 | case Op_StrEquals: |
| 961 | case Op_StrIndexOf: |
| 962 | case Op_StrIndexOfChar: |
| 963 | case Op_EncodeISOArray: |
| 964 | case Op_AryEq: |
| 965 | case Op_HasNegatives: { |
| 966 | // Do not unroll a loop with String intrinsics code. |
| 967 | // String intrinsics are large and have loops. |
| 968 | return false; |
| 969 | } |
| 970 | #if INCLUDE_RTM_OPT1 |
| 971 | case Op_FastLock: |
| 972 | case Op_FastUnlock: { |
| 973 | // Don't unroll RTM locking code because it is large. |
| 974 | if (UseRTMLocking) { |
| 975 | return false; |
| 976 | } |
| 977 | } |
| 978 | #endif |
| 979 | } // switch |
| 980 | } |
| 981 | |
| 982 | if (UseSuperWord) { |
| 983 | if (!cl->is_reduction_loop()) { |
| 984 | phase->mark_reductions(this); |
| 985 | } |
| 986 | |
| 987 | // Only attempt slp analysis when user controls do not prohibit it |
| 988 | if (LoopMaxUnroll > _local_loop_unroll_factor) { |
| 989 | // Once policy_slp_analysis succeeds, mark the loop with the |
| 990 | // maximal unroll factor so that we minimize analysis passes |
| 991 | if (future_unroll_cnt >= _local_loop_unroll_factor) { |
| 992 | policy_unroll_slp_analysis(cl, phase, future_unroll_cnt); |
| 993 | } |
| 994 | } |
| 995 | } |
| 996 | |
| 997 | int slp_max_unroll_factor = cl->slp_max_unroll(); |
| 998 | if ((LoopMaxUnroll < slp_max_unroll_factor) && FLAG_IS_DEFAULT(LoopMaxUnroll)(JVMFlag::is_default(Flag_LoopMaxUnroll_enum)) && UseSubwordForMaxVector) { |
| 999 | LoopMaxUnroll = slp_max_unroll_factor; |
| 1000 | } |
| 1001 | |
| 1002 | uint estimate = est_loop_clone_sz(2); |
| 1003 | |
| 1004 | if (cl->has_passed_slp()) { |
| 1005 | if (slp_max_unroll_factor >= future_unroll_cnt) { |
| 1006 | return phase->may_require_nodes(estimate); |
| 1007 | } |
| 1008 | return false; // Loop too big. |
| 1009 | } |
| 1010 | |
| 1011 | // Check for being too big |
| 1012 | if (body_size > (uint)_local_loop_unroll_limit) { |
| 1013 | if ((cl->is_subword_loop() || xors_in_loop >= 4) && body_size < 4u * LoopUnrollLimit) { |
| 1014 | return phase->may_require_nodes(estimate); |
| 1015 | } |
| 1016 | return false; // Loop too big. |
| 1017 | } |
| 1018 | |
| 1019 | if (cl->is_unroll_only()) { |
| 1020 | if (TraceSuperWordLoopUnrollAnalysis) { |
| 1021 | tty->print_cr("policy_unroll passed vector loop(vlen=%d, factor=%d)\n", |
| 1022 | slp_max_unroll_factor, future_unroll_cnt); |
| 1023 | } |
| 1024 | } |
| 1025 | |
| 1026 | // Unroll once! (Each trip will soon do double iterations) |
| 1027 | return phase->may_require_nodes(estimate); |
| 1028 | } |
| 1029 | |
| 1030 | void IdealLoopTree::policy_unroll_slp_analysis(CountedLoopNode *cl, PhaseIdealLoop *phase, int future_unroll_cnt) { |
| 1031 | |
| 1032 | // If nodes are depleted, some transform has miscalculated its needs. |
| 1033 | assert(!phase->exceeding_node_budget(), "sanity")do { if (!(!phase->exceeding_node_budget())) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1033, "assert(" "!phase->exceeding_node_budget()" ") failed" , "sanity"); ::breakpoint(); } } while (0); |
| 1034 | |
| 1035 | // Enable this functionality target by target as needed |
| 1036 | if (SuperWordLoopUnrollAnalysis) { |
| 1037 | if (!cl->was_slp_analyzed()) { |
| 1038 | SuperWord sw(phase); |
| 1039 | sw.transform_loop(this, false); |
| 1040 | |
| 1041 | // If the loop is slp canonical analyze it |
| 1042 | if (sw.early_return() == false) { |
| 1043 | sw.unrolling_analysis(_local_loop_unroll_factor); |
| 1044 | } |
| 1045 | } |
| 1046 | |
| 1047 | if (cl->has_passed_slp()) { |
| 1048 | int slp_max_unroll_factor = cl->slp_max_unroll(); |
| 1049 | if (slp_max_unroll_factor >= future_unroll_cnt) { |
| 1050 | int new_limit = cl->node_count_before_unroll() * slp_max_unroll_factor; |
| 1051 | if (new_limit > LoopUnrollLimit) { |
| 1052 | if (TraceSuperWordLoopUnrollAnalysis) { |
| 1053 | tty->print_cr("slp analysis unroll=%d, default limit=%d\n", new_limit, _local_loop_unroll_limit); |
| 1054 | } |
| 1055 | _local_loop_unroll_limit = new_limit; |
| 1056 | } |
| 1057 | } |
| 1058 | } |
| 1059 | } |
| 1060 | } |
| 1061 | |
| 1062 | |
| 1063 | //------------------------------policy_range_check----------------------------- |
| 1064 | // Return TRUE or FALSE if the loop should be range-check-eliminated or not. |
| 1065 | // When TRUE, the estimated node budget is also requested. |
| 1066 | // |
| 1067 | // We will actually perform iteration-splitting, a more powerful form of RCE. |
| 1068 | bool IdealLoopTree::policy_range_check(PhaseIdealLoop* phase, bool provisional, BasicType bt) const { |
| 1069 | if (!provisional && !RangeCheckElimination) return false; |
| 1070 | |
| 1071 | // If nodes are depleted, some transform has miscalculated its needs. |
| 1072 | assert(provisional || !phase->exceeding_node_budget(), "sanity")do { if (!(provisional || !phase->exceeding_node_budget()) ) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1072, "assert(" "provisional || !phase->exceeding_node_budget()" ") failed", "sanity"); ::breakpoint(); } } while (0); |
| 1073 | |
| 1074 | if (_head->is_CountedLoop()) { |
| 1075 | CountedLoopNode *cl = _head->as_CountedLoop(); |
| 1076 | // If we unrolled with no intention of doing RCE and we later changed our |
| 1077 | // minds, we got no pre-loop. Either we need to make a new pre-loop, or we |
| 1078 | // have to disallow RCE. |
| 1079 | if (cl->is_main_no_pre_loop()) return false; // Disallowed for now. |
| 1080 | |
| 1081 | // check for vectorized loops, some opts are no longer needed |
| 1082 | // RCE needs pre/main/post loops. Don't apply it on a single iteration loop. |
| 1083 | if (cl->is_unroll_only() || (cl->is_normal_loop() && cl->trip_count() == 1)) return false; |
| 1084 | } else { |
| 1085 | assert(provisional, "no long counted loop expected")do { if (!(provisional)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1085, "assert(" "provisional" ") failed", "no long counted loop expected" ); ::breakpoint(); } } while (0); |
| 1086 | } |
| 1087 | |
| 1088 | BaseCountedLoopNode* cl = _head->as_BaseCountedLoop(); |
| 1089 | Node *trip_counter = cl->phi(); |
| 1090 | assert(!cl->is_LongCountedLoop() || bt == T_LONG, "only long range checks in long counted loops")do { if (!(!cl->is_LongCountedLoop() || bt == T_LONG)) { ( *g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1090, "assert(" "!cl->is_LongCountedLoop() || bt == T_LONG" ") failed", "only long range checks in long counted loops"); ::breakpoint(); } } while (0); |
| 1091 | |
| 1092 | // Check loop body for tests of trip-counter plus loop-invariant vs |
| 1093 | // loop-invariant. |
| 1094 | for (uint i = 0; i < _body.size(); i++) { |
| 1095 | Node *iff = _body[i]; |
| 1096 | if (iff->Opcode() == Op_If || |
| 1097 | iff->Opcode() == Op_RangeCheck) { // Test? |
| 1098 | |
| 1099 | // Comparing trip+off vs limit |
| 1100 | Node *bol = iff->in(1); |
| 1101 | if (bol->req() != 2) { |
| 1102 | continue; // dead constant test |
| 1103 | } |
| 1104 | if (!bol->is_Bool()) { |
| 1105 | assert(bol->Opcode() == Op_Conv2B, "predicate check only")do { if (!(bol->Opcode() == Op_Conv2B)) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1105, "assert(" "bol->Opcode() == Op_Conv2B" ") failed", "predicate check only"); ::breakpoint(); } } while (0); |
| 1106 | continue; |
| 1107 | } |
| 1108 | if (bol->as_Bool()->_test._test == BoolTest::ne) { |
| 1109 | continue; // not RC |
| 1110 | } |
| 1111 | Node *cmp = bol->in(1); |
| 1112 | Node *rc_exp = cmp->in(1); |
| 1113 | Node *limit = cmp->in(2); |
| 1114 | |
| 1115 | if (provisional) { |
| 1116 | // Try to pattern match with either cmp inputs, do not check |
| 1117 | // whether one of the inputs is loop independent as it may not |
| 1118 | // have had a chance to be hoisted yet. |
| 1119 | if (!phase->is_scaled_iv_plus_offset(cmp->in(1), trip_counter, NULL__null, NULL__null, bt) && |
| 1120 | !phase->is_scaled_iv_plus_offset(cmp->in(2), trip_counter, NULL__null, NULL__null, bt)) { |
| 1121 | continue; |
| 1122 | } |
| 1123 | } else { |
| 1124 | Node *limit_c = phase->get_ctrl(limit); |
| 1125 | if (limit_c == phase->C->top()) { |
| 1126 | return false; // Found dead test on live IF? No RCE! |
| 1127 | } |
| 1128 | if (is_member(phase->get_loop(limit_c))) { |
| 1129 | // Compare might have operands swapped; commute them |
| 1130 | rc_exp = cmp->in(2); |
| 1131 | limit = cmp->in(1); |
| 1132 | limit_c = phase->get_ctrl(limit); |
| 1133 | if (is_member(phase->get_loop(limit_c))) { |
| 1134 | continue; // Both inputs are loop varying; cannot RCE |
| 1135 | } |
| 1136 | } |
| 1137 | |
| 1138 | if (!phase->is_scaled_iv_plus_offset(rc_exp, trip_counter, NULL__null, NULL__null, bt)) { |
| 1139 | continue; |
| 1140 | } |
| 1141 | } |
| 1142 | // Found a test like 'trip+off vs limit'. Test is an IfNode, has two (2) |
| 1143 | // projections. If BOTH are in the loop we need loop unswitching instead |
| 1144 | // of iteration splitting. |
| 1145 | if (is_loop_exit(iff)) { |
| 1146 | // Found valid reason to split iterations (if there is room). |
| 1147 | // NOTE: Usually a gross overestimate. |
| 1148 | // Long range checks cause the loop to be transformed in a loop nest which only causes a fixed number of nodes |
| 1149 | // to be added |
| 1150 | return provisional || bt == T_LONG || phase->may_require_nodes(est_loop_clone_sz(2)); |
| 1151 | } |
| 1152 | } // End of is IF |
| 1153 | } |
| 1154 | |
| 1155 | return false; |
| 1156 | } |
| 1157 | |
| 1158 | //------------------------------policy_peel_only------------------------------- |
| 1159 | // Return TRUE or FALSE if the loop should NEVER be RCE'd or aligned. Useful |
| 1160 | // for unrolling loops with NO array accesses. |
| 1161 | bool IdealLoopTree::policy_peel_only(PhaseIdealLoop *phase) const { |
| 1162 | |
| 1163 | // If nodes are depleted, some transform has miscalculated its needs. |
| 1164 | assert(!phase->exceeding_node_budget(), "sanity")do { if (!(!phase->exceeding_node_budget())) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1164, "assert(" "!phase->exceeding_node_budget()" ") failed" , "sanity"); ::breakpoint(); } } while (0); |
| 1165 | |
| 1166 | // check for vectorized loops, any peeling done was already applied |
| 1167 | if (_head->is_CountedLoop() && _head->as_CountedLoop()->is_unroll_only()) { |
| 1168 | return false; |
| 1169 | } |
| 1170 | |
| 1171 | for (uint i = 0; i < _body.size(); i++) { |
| 1172 | if (_body[i]->is_Mem()) { |
| 1173 | return false; |
| 1174 | } |
| 1175 | } |
| 1176 | // No memory accesses at all! |
| 1177 | return true; |
| 1178 | } |
| 1179 | |
| 1180 | //------------------------------clone_up_backedge_goo-------------------------- |
| 1181 | // If Node n lives in the back_ctrl block and cannot float, we clone a private |
| 1182 | // version of n in preheader_ctrl block and return that, otherwise return n. |
| 1183 | Node *PhaseIdealLoop::clone_up_backedge_goo(Node *back_ctrl, Node *preheader_ctrl, Node *n, VectorSet &visited, Node_Stack &clones) { |
| 1184 | if (get_ctrl(n) != back_ctrl) return n; |
| 1185 | |
| 1186 | // Only visit once |
| 1187 | if (visited.test_set(n->_idx)) { |
| 1188 | Node *x = clones.find(n->_idx); |
| 1189 | return (x != NULL__null) ? x : n; |
| 1190 | } |
| 1191 | |
| 1192 | Node *x = NULL__null; // If required, a clone of 'n' |
| 1193 | // Check for 'n' being pinned in the backedge. |
| 1194 | if (n->in(0) && n->in(0) == back_ctrl) { |
| 1195 | assert(clones.find(n->_idx) == NULL, "dead loop")do { if (!(clones.find(n->_idx) == __null)) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1195, "assert(" "clones.find(n->_idx) == __null" ") failed" , "dead loop"); ::breakpoint(); } } while (0); |
| 1196 | x = n->clone(); // Clone a copy of 'n' to preheader |
| 1197 | clones.push(x, n->_idx); |
| 1198 | x->set_req(0, preheader_ctrl); // Fix x's control input to preheader |
| 1199 | } |
| 1200 | |
| 1201 | // Recursive fixup any other input edges into x. |
| 1202 | // If there are no changes we can just return 'n', otherwise |
| 1203 | // we need to clone a private copy and change it. |
| 1204 | for (uint i = 1; i < n->req(); i++) { |
| 1205 | Node *g = clone_up_backedge_goo(back_ctrl, preheader_ctrl, n->in(i), visited, clones); |
| 1206 | if (g != n->in(i)) { |
| 1207 | if (!x) { |
| 1208 | assert(clones.find(n->_idx) == NULL, "dead loop")do { if (!(clones.find(n->_idx) == __null)) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1208, "assert(" "clones.find(n->_idx) == __null" ") failed" , "dead loop"); ::breakpoint(); } } while (0); |
| 1209 | x = n->clone(); |
| 1210 | clones.push(x, n->_idx); |
| 1211 | } |
| 1212 | x->set_req(i, g); |
| 1213 | } |
| 1214 | } |
| 1215 | if (x) { // x can legally float to pre-header location |
| 1216 | register_new_node(x, preheader_ctrl); |
| 1217 | return x; |
| 1218 | } else { // raise n to cover LCA of uses |
| 1219 | set_ctrl(n, find_non_split_ctrl(back_ctrl->in(0))); |
| 1220 | } |
| 1221 | return n; |
| 1222 | } |
| 1223 | |
| 1224 | Node* PhaseIdealLoop::cast_incr_before_loop(Node* incr, Node* ctrl, Node* loop) { |
| 1225 | Node* castii = new CastIINode(incr, TypeInt::INT, ConstraintCastNode::StrongDependency); |
| 1226 | castii->set_req(0, ctrl); |
| 1227 | register_new_node(castii, ctrl); |
| 1228 | for (DUIterator_Fast imax, i = incr->fast_outs(imax); i < imax; i++) { |
| 1229 | Node* n = incr->fast_out(i); |
| 1230 | if (n->is_Phi() && n->in(0) == loop) { |
| 1231 | int nrep = n->replace_edge(incr, castii, &_igvn); |
| 1232 | return castii; |
| 1233 | } |
| 1234 | } |
| 1235 | return NULL__null; |
| 1236 | } |
| 1237 | |
| 1238 | #ifdef ASSERT1 |
| 1239 | void PhaseIdealLoop::ensure_zero_trip_guard_proj(Node* node, bool is_main_loop) { |
| 1240 | assert(node->is_IfProj(), "must be the zero trip guard If node")do { if (!(node->is_IfProj())) { (*g_assert_poison) = 'X'; ; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1240, "assert(" "node->is_IfProj()" ") failed", "must be the zero trip guard If node" ); ::breakpoint(); } } while (0); |
| 1241 | Node* zer_bol = node->in(0)->in(1); |
| 1242 | assert(zer_bol != NULL && zer_bol->is_Bool(), "must be Bool")do { if (!(zer_bol != __null && zer_bol->is_Bool() )) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1242, "assert(" "zer_bol != __null && zer_bol->is_Bool()" ") failed", "must be Bool"); ::breakpoint(); } } while (0); |
| 1243 | Node* zer_cmp = zer_bol->in(1); |
| 1244 | assert(zer_cmp != NULL && zer_cmp->Opcode() == Op_CmpI, "must be CmpI")do { if (!(zer_cmp != __null && zer_cmp->Opcode() == Op_CmpI)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1244, "assert(" "zer_cmp != __null && zer_cmp->Opcode() == Op_CmpI" ") failed", "must be CmpI"); ::breakpoint(); } } while (0); |
| 1245 | // For the main loop, the opaque node is the second input to zer_cmp, for the post loop it's the first input node |
| 1246 | Node* zer_opaq = zer_cmp->in(is_main_loop ? 2 : 1); |
| 1247 | assert(zer_opaq != NULL && zer_opaq->Opcode() == Op_Opaque1, "must be Opaque1")do { if (!(zer_opaq != __null && zer_opaq->Opcode( ) == Op_Opaque1)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1247, "assert(" "zer_opaq != __null && zer_opaq->Opcode() == Op_Opaque1" ") failed", "must be Opaque1"); ::breakpoint(); } } while (0 ); |
| 1248 | } |
| 1249 | #endif |
| 1250 | |
| 1251 | // Make a copy of the skeleton range check predicates before the main |
| 1252 | // loop and set the initial value of loop as input. After unrolling, |
| 1253 | // the range of values for the induction variable in the main loop can |
| 1254 | // fall outside the allowed range of values by the array access (main |
| 1255 | // loop is never executed). When that happens, range check |
| 1256 | // CastII/ConvI2L nodes cause some data paths to die. For consistency, |
| 1257 | // the control paths must die too but the range checks were removed by |
| 1258 | // predication. The range checks that we add here guarantee that they do. |
| 1259 | void PhaseIdealLoop::copy_skeleton_predicates_to_main_loop_helper(Node* predicate, Node* init, Node* stride, |
| 1260 | IdealLoopTree* outer_loop, LoopNode* outer_main_head, |
| 1261 | uint dd_main_head, const uint idx_before_pre_post, |
| 1262 | const uint idx_after_post_before_pre, Node* zero_trip_guard_proj_main, |
| 1263 | Node* zero_trip_guard_proj_post, const Node_List &old_new) { |
| 1264 | if (predicate != NULL__null) { |
| 1265 | #ifdef ASSERT1 |
| 1266 | ensure_zero_trip_guard_proj(zero_trip_guard_proj_main, true); |
| 1267 | ensure_zero_trip_guard_proj(zero_trip_guard_proj_post, false); |
| 1268 | #endif |
| 1269 | IfNode* iff = predicate->in(0)->as_If(); |
| 1270 | ProjNode* uncommon_proj = iff->proj_out(1 - predicate->as_Proj()->_con); |
| 1271 | Node* rgn = uncommon_proj->unique_ctrl_out(); |
| 1272 | assert(rgn->is_Region() || rgn->is_Call(), "must be a region or call uct")do { if (!(rgn->is_Region() || rgn->is_Call())) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1272, "assert(" "rgn->is_Region() || rgn->is_Call()" ") failed" , "must be a region or call uct"); ::breakpoint(); } } while ( 0); |
| 1273 | assert(iff->in(1)->in(1)->Opcode() == Op_Opaque1, "unexpected predicate shape")do { if (!(iff->in(1)->in(1)->Opcode() == Op_Opaque1 )) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1273, "assert(" "iff->in(1)->in(1)->Opcode() == Op_Opaque1" ") failed", "unexpected predicate shape"); ::breakpoint(); } } while (0); |
| 1274 | predicate = iff->in(0); |
| 1275 | Node* current_proj = outer_main_head->in(LoopNode::EntryControl); |
| 1276 | Node* prev_proj = current_proj; |
| 1277 | Node* opaque_init = new OpaqueLoopInitNode(C, init); |
| 1278 | register_new_node(opaque_init, outer_main_head->in(LoopNode::EntryControl)); |
| 1279 | Node* opaque_stride = new OpaqueLoopStrideNode(C, stride); |
| 1280 | register_new_node(opaque_stride, outer_main_head->in(LoopNode::EntryControl)); |
| 1281 | |
| 1282 | while (predicate != NULL__null && predicate->is_Proj() && predicate->in(0)->is_If()) { |
| 1283 | iff = predicate->in(0)->as_If(); |
| 1284 | uncommon_proj = iff->proj_out(1 - predicate->as_Proj()->_con); |
| 1285 | if (uncommon_proj->unique_ctrl_out() != rgn) |
| 1286 | break; |
| 1287 | if (iff->in(1)->Opcode() == Op_Opaque4) { |
| 1288 | assert(skeleton_predicate_has_opaque(iff), "unexpected")do { if (!(skeleton_predicate_has_opaque(iff))) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1288, "assert(" "skeleton_predicate_has_opaque(iff)" ") failed" , "unexpected"); ::breakpoint(); } } while (0); |
| 1289 | // Clone the skeleton predicate twice and initialize one with the initial |
| 1290 | // value of the loop induction variable. Leave the other predicate |
| 1291 | // to be initialized when increasing the stride during loop unrolling. |
| 1292 | prev_proj = clone_skeleton_predicate_for_main_or_post_loop(iff, opaque_init, NULL__null, predicate, uncommon_proj, |
| 1293 | current_proj, outer_loop, prev_proj); |
| 1294 | assert(skeleton_predicate_has_opaque(prev_proj->in(0)->as_If()), "")do { if (!(skeleton_predicate_has_opaque(prev_proj->in(0)-> as_If()))) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1294, "assert(" "skeleton_predicate_has_opaque(prev_proj->in(0)->as_If())" ") failed", ""); ::breakpoint(); } } while (0); |
| 1295 | |
| 1296 | prev_proj = clone_skeleton_predicate_for_main_or_post_loop(iff, init, stride, predicate, uncommon_proj, |
| 1297 | current_proj, outer_loop, prev_proj); |
| 1298 | assert(!skeleton_predicate_has_opaque(prev_proj->in(0)->as_If()), "")do { if (!(!skeleton_predicate_has_opaque(prev_proj->in(0) ->as_If()))) { (*g_assert_poison) = 'X';; report_vm_error( "/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1298, "assert(" "!skeleton_predicate_has_opaque(prev_proj->in(0)->as_If())" ") failed", ""); ::breakpoint(); } } while (0); |
| 1299 | |
| 1300 | // Rewire any control inputs from the cloned skeleton predicates down to the main and post loop for data nodes that are part of the |
| 1301 | // main loop (and were cloned to the pre and post loop). |
| 1302 | for (DUIterator i = predicate->outs(); predicate->has_out(i); i++) { |
| 1303 | Node* loop_node = predicate->out(i); |
| 1304 | Node* pre_loop_node = old_new[loop_node->_idx]; |
| 1305 | // Change the control if 'loop_node' is part of the main loop. If there is an old->new mapping and the index of |
| 1306 | // 'pre_loop_node' is greater than idx_before_pre_post, then we know that 'loop_node' was cloned and is part of |
| 1307 | // the main loop (and 'pre_loop_node' is part of the pre loop). |
| 1308 | if (!loop_node->is_CFG() && (pre_loop_node != NULL__null && pre_loop_node->_idx > idx_after_post_before_pre)) { |
| 1309 | // 'loop_node' is a data node and part of the main loop. Rewire the control to the projection of the zero-trip guard if node |
| 1310 | // of the main loop that is immediately preceding the cloned predicates. |
| 1311 | _igvn.replace_input_of(loop_node, 0, zero_trip_guard_proj_main); |
| 1312 | --i; |
| 1313 | } else if (loop_node->_idx > idx_before_pre_post && loop_node->_idx < idx_after_post_before_pre) { |
| 1314 | // 'loop_node' is a data node and part of the post loop. Rewire the control to the projection of the zero-trip guard if node |
| 1315 | // of the post loop that is immediately preceding the post loop header node (there are no cloned predicates for the post loop). |
| 1316 | assert(pre_loop_node == NULL, "a node belonging to the post loop should not have an old_new mapping at this stage")do { if (!(pre_loop_node == __null)) { (*g_assert_poison) = 'X' ;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1316, "assert(" "pre_loop_node == __null" ") failed", "a node belonging to the post loop should not have an old_new mapping at this stage" ); ::breakpoint(); } } while (0); |
| 1317 | _igvn.replace_input_of(loop_node, 0, zero_trip_guard_proj_post); |
| 1318 | --i; |
| 1319 | } |
| 1320 | } |
| 1321 | |
| 1322 | // Remove the skeleton predicate from the pre-loop |
| 1323 | _igvn.replace_input_of(iff, 1, _igvn.intcon(1)); |
| 1324 | } |
| 1325 | predicate = predicate->in(0)->in(0); |
| 1326 | } |
| 1327 | _igvn.replace_input_of(outer_main_head, LoopNode::EntryControl, prev_proj); |
| 1328 | set_idom(outer_main_head, prev_proj, dd_main_head); |
| 1329 | } |
| 1330 | } |
| 1331 | |
| 1332 | static bool skeleton_follow_inputs(Node* n, int op) { |
| 1333 | return (n->is_Bool() || |
| 1334 | n->is_Cmp() || |
| 1335 | op == Op_AndL || |
| 1336 | op == Op_OrL || |
| 1337 | op == Op_RShiftL || |
| 1338 | op == Op_LShiftL || |
| 1339 | op == Op_AddL || |
| 1340 | op == Op_AddI || |
| 1341 | op == Op_MulL || |
| 1342 | op == Op_MulI || |
| 1343 | op == Op_SubL || |
| 1344 | op == Op_SubI || |
| 1345 | op == Op_ConvI2L); |
| 1346 | } |
| 1347 | |
| 1348 | bool PhaseIdealLoop::skeleton_predicate_has_opaque(IfNode* iff) { |
| 1349 | ResourceMark rm; |
| 1350 | Unique_Node_List wq; |
| 1351 | wq.push(iff->in(1)->in(1)); |
| 1352 | for (uint i = 0; i < wq.size(); i++) { |
| 1353 | Node* n = wq.at(i); |
| 1354 | int op = n->Opcode(); |
| 1355 | if (skeleton_follow_inputs(n, op)) { |
| 1356 | for (uint j = 1; j < n->req(); j++) { |
| 1357 | Node* m = n->in(j); |
| 1358 | if (m != NULL__null) { |
| 1359 | wq.push(m); |
| 1360 | } |
| 1361 | } |
| 1362 | continue; |
| 1363 | } |
| 1364 | if (n->is_Opaque1()) { |
| 1365 | return true; |
| 1366 | } |
| 1367 | } |
| 1368 | return false; |
| 1369 | } |
| 1370 | |
| 1371 | // Clone the skeleton predicate bool for a main or unswitched loop: |
| 1372 | // Main loop: Set new_init and new_stride nodes as new inputs. |
| 1373 | // Unswitched loop: new_init and new_stride are both NULL. Clone OpaqueLoopInit and OpaqueLoopStride instead. |
| 1374 | Node* PhaseIdealLoop::clone_skeleton_predicate_bool(Node* iff, Node* new_init, Node* new_stride, Node* control) { |
| 1375 | Node_Stack to_clone(2); |
| 1376 | to_clone.push(iff->in(1), 1); |
| 1377 | uint current = C->unique(); |
| 1378 | Node* result = NULL__null; |
| 1379 | bool is_unswitched_loop = new_init == NULL__null && new_stride == NULL__null; |
| 1380 | assert(new_init != NULL || is_unswitched_loop, "new_init must be set when new_stride is non-null")do { if (!(new_init != __null || is_unswitched_loop)) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1380, "assert(" "new_init != __null || is_unswitched_loop" ") failed" , "new_init must be set when new_stride is non-null"); ::breakpoint (); } } while (0); |
| 1381 | // Look for the opaque node to replace with the new value |
| 1382 | // and clone everything in between. We keep the Opaque4 node |
| 1383 | // so the duplicated predicates are eliminated once loop |
| 1384 | // opts are over: they are here only to keep the IR graph |
| 1385 | // consistent. |
| 1386 | do { |
| 1387 | Node* n = to_clone.node(); |
| 1388 | uint i = to_clone.index(); |
| 1389 | Node* m = n->in(i); |
| 1390 | int op = m->Opcode(); |
| 1391 | if (skeleton_follow_inputs(m, op)) { |
| 1392 | to_clone.push(m, 1); |
| 1393 | continue; |
| 1394 | } |
| 1395 | if (m->is_Opaque1()) { |
| 1396 | if (n->_idx < current) { |
| 1397 | n = n->clone(); |
| 1398 | register_new_node(n, control); |
| 1399 | } |
| 1400 | if (op == Op_OpaqueLoopInit) { |
| 1401 | if (is_unswitched_loop && m->_idx < current && new_init == NULL__null) { |
| 1402 | new_init = m->clone(); |
| 1403 | register_new_node(new_init, control); |
| 1404 | } |
| 1405 | n->set_req(i, new_init); |
| 1406 | } else { |
| 1407 | assert(op == Op_OpaqueLoopStride, "unexpected opaque node")do { if (!(op == Op_OpaqueLoopStride)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1407, "assert(" "op == Op_OpaqueLoopStride" ") failed", "unexpected opaque node" ); ::breakpoint(); } } while (0); |
| 1408 | if (is_unswitched_loop && m->_idx < current && new_stride == NULL__null) { |
| 1409 | new_stride = m->clone(); |
| 1410 | register_new_node(new_stride, control); |
| 1411 | } |
| 1412 | if (new_stride != NULL__null) { |
| 1413 | n->set_req(i, new_stride); |
| 1414 | } |
| 1415 | } |
| 1416 | to_clone.set_node(n); |
| 1417 | } |
| 1418 | while (true) { |
| 1419 | Node* cur = to_clone.node(); |
| 1420 | uint j = to_clone.index(); |
| 1421 | if (j+1 < cur->req()) { |
| 1422 | to_clone.set_index(j+1); |
| 1423 | break; |
| 1424 | } |
| 1425 | to_clone.pop(); |
| 1426 | if (to_clone.size() == 0) { |
| 1427 | result = cur; |
| 1428 | break; |
| 1429 | } |
| 1430 | Node* next = to_clone.node(); |
| 1431 | j = to_clone.index(); |
| 1432 | if (next->in(j) != cur) { |
| 1433 | assert(cur->_idx >= current || next->in(j)->Opcode() == Op_Opaque1, "new node or Opaque1 being replaced")do { if (!(cur->_idx >= current || next->in(j)->Opcode () == Op_Opaque1)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1433, "assert(" "cur->_idx >= current || next->in(j)->Opcode() == Op_Opaque1" ") failed", "new node or Opaque1 being replaced"); ::breakpoint (); } } while (0); |
| 1434 | if (next->_idx < current) { |
| 1435 | next = next->clone(); |
| 1436 | register_new_node(next, control); |
| 1437 | to_clone.set_node(next); |
| 1438 | } |
| 1439 | next->set_req(j, cur); |
| 1440 | } |
| 1441 | } |
| 1442 | } while (result == NULL__null); |
| 1443 | assert(result->_idx >= current, "new node expected")do { if (!(result->_idx >= current)) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1443, "assert(" "result->_idx >= current" ") failed", "new node expected"); ::breakpoint(); } } while (0); |
| 1444 | assert(!is_unswitched_loop || new_init != NULL, "new_init must always be found and cloned")do { if (!(!is_unswitched_loop || new_init != __null)) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1444, "assert(" "!is_unswitched_loop || new_init != __null" ") failed", "new_init must always be found and cloned"); ::breakpoint (); } } while (0); |
| 1445 | return result; |
| 1446 | } |
| 1447 | |
| 1448 | // Clone a skeleton predicate for the main loop. new_init and new_stride are set as new inputs. Since the predicates cannot fail at runtime, |
| 1449 | // Halt nodes are inserted instead of uncommon traps. |
| 1450 | Node* PhaseIdealLoop::clone_skeleton_predicate_for_main_or_post_loop(Node* iff, Node* new_init, Node* new_stride, Node* predicate, Node* uncommon_proj, |
| 1451 | Node* control, IdealLoopTree* outer_loop, Node* input_proj) { |
| 1452 | Node* result = clone_skeleton_predicate_bool(iff, new_init, new_stride, control); |
| 1453 | Node* proj = predicate->clone(); |
| 1454 | Node* other_proj = uncommon_proj->clone(); |
| 1455 | Node* new_iff = iff->clone(); |
| 1456 | new_iff->set_req(1, result); |
| 1457 | proj->set_req(0, new_iff); |
| 1458 | other_proj->set_req(0, new_iff); |
| 1459 | Node* frame = new ParmNode(C->start(), TypeFunc::FramePtr); |
| 1460 | register_new_node(frame, C->start()); |
| 1461 | // It's impossible for the predicate to fail at runtime. Use an Halt node. |
| 1462 | Node* halt = new HaltNode(other_proj, frame, "duplicated predicate failed which is impossible"); |
| 1463 | C->root()->add_req(halt); |
| 1464 | new_iff->set_req(0, input_proj); |
| 1465 | |
| 1466 | register_control(new_iff, outer_loop == _ltree_root ? _ltree_root : outer_loop->_parent, input_proj); |
| 1467 | register_control(proj, outer_loop == _ltree_root ? _ltree_root : outer_loop->_parent, new_iff); |
| 1468 | register_control(other_proj, _ltree_root, new_iff); |
| 1469 | register_control(halt, _ltree_root, other_proj); |
| 1470 | return proj; |
| 1471 | } |
| 1472 | |
| 1473 | void PhaseIdealLoop::copy_skeleton_predicates_to_main_loop(CountedLoopNode* pre_head, Node* init, Node* stride, |
| 1474 | IdealLoopTree* outer_loop, LoopNode* outer_main_head, |
| 1475 | uint dd_main_head, const uint idx_before_pre_post, |
| 1476 | const uint idx_after_post_before_pre, Node* zero_trip_guard_proj_main, |
| 1477 | Node* zero_trip_guard_proj_post, const Node_List &old_new) { |
| 1478 | if (UseLoopPredicate) { |
| 1479 | Node* entry = pre_head->in(LoopNode::EntryControl); |
| 1480 | Node* predicate = NULL__null; |
| 1481 | predicate = find_predicate_insertion_point(entry, Deoptimization::Reason_loop_limit_check); |
| 1482 | if (predicate != NULL__null) { |
| 1483 | entry = skip_loop_predicates(entry); |
| 1484 | } |
| 1485 | Node* profile_predicate = NULL__null; |
| 1486 | if (UseProfiledLoopPredicate) { |
| 1487 | profile_predicate = find_predicate_insertion_point(entry, Deoptimization::Reason_profile_predicate); |
| 1488 | if (profile_predicate != NULL__null) { |
| 1489 | entry = skip_loop_predicates(entry); |
| 1490 | } |
| 1491 | } |
| 1492 | predicate = find_predicate_insertion_point(entry, Deoptimization::Reason_predicate); |
| 1493 | copy_skeleton_predicates_to_main_loop_helper(predicate, init, stride, outer_loop, outer_main_head, dd_main_head, |
| 1494 | idx_before_pre_post, idx_after_post_before_pre, zero_trip_guard_proj_main, |
| 1495 | zero_trip_guard_proj_post, old_new); |
| 1496 | copy_skeleton_predicates_to_main_loop_helper(profile_predicate, init, stride, outer_loop, outer_main_head, dd_main_head, |
| 1497 | idx_before_pre_post, idx_after_post_before_pre, zero_trip_guard_proj_main, |
| 1498 | zero_trip_guard_proj_post, old_new); |
| 1499 | } |
| 1500 | } |
| 1501 | |
| 1502 | //------------------------------insert_pre_post_loops-------------------------- |
| 1503 | // Insert pre and post loops. If peel_only is set, the pre-loop can not have |
| 1504 | // more iterations added. It acts as a 'peel' only, no lower-bound RCE, no |
| 1505 | // alignment. Useful to unroll loops that do no array accesses. |
| 1506 | void PhaseIdealLoop::insert_pre_post_loops(IdealLoopTree *loop, Node_List &old_new, bool peel_only) { |
| 1507 | |
| 1508 | #ifndef PRODUCT |
| 1509 | if (TraceLoopOpts) { |
| 1510 | if (peel_only) |
| 1511 | tty->print("PeelMainPost "); |
| 1512 | else |
| 1513 | tty->print("PreMainPost "); |
| 1514 | loop->dump_head(); |
| 1515 | } |
| 1516 | #endif |
| 1517 | C->set_major_progress(); |
| 1518 | |
| 1519 | // Find common pieces of the loop being guarded with pre & post loops |
| 1520 | CountedLoopNode *main_head = loop->_head->as_CountedLoop(); |
| 1521 | assert(main_head->is_normal_loop(), "")do { if (!(main_head->is_normal_loop())) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1521, "assert(" "main_head->is_normal_loop()" ") failed" , ""); ::breakpoint(); } } while (0); |
| 1522 | CountedLoopEndNode *main_end = main_head->loopexit(); |
| 1523 | assert(main_end->outcnt() == 2, "1 true, 1 false path only")do { if (!(main_end->outcnt() == 2)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1523, "assert(" "main_end->outcnt() == 2" ") failed", "1 true, 1 false path only" ); ::breakpoint(); } } while (0); |
| 1524 | |
| 1525 | Node *pre_header= main_head->in(LoopNode::EntryControl); |
Value stored to 'pre_header' during its initialization is never read | |
| 1526 | Node *init = main_head->init_trip(); |
| 1527 | Node *incr = main_end ->incr(); |
| 1528 | Node *limit = main_end ->limit(); |
| 1529 | Node *stride = main_end ->stride(); |
| 1530 | Node *cmp = main_end ->cmp_node(); |
| 1531 | BoolTest::mask b_test = main_end->test_trip(); |
| 1532 | |
| 1533 | // Need only 1 user of 'bol' because I will be hacking the loop bounds. |
| 1534 | Node *bol = main_end->in(CountedLoopEndNode::TestValue); |
| 1535 | if (bol->outcnt() != 1) { |
| 1536 | bol = bol->clone(); |
| 1537 | register_new_node(bol,main_end->in(CountedLoopEndNode::TestControl)); |
| 1538 | _igvn.replace_input_of(main_end, CountedLoopEndNode::TestValue, bol); |
| 1539 | } |
| 1540 | // Need only 1 user of 'cmp' because I will be hacking the loop bounds. |
| 1541 | if (cmp->outcnt() != 1) { |
| 1542 | cmp = cmp->clone(); |
| 1543 | register_new_node(cmp,main_end->in(CountedLoopEndNode::TestControl)); |
| 1544 | _igvn.replace_input_of(bol, 1, cmp); |
| 1545 | } |
| 1546 | |
| 1547 | // Add the post loop |
| 1548 | const uint idx_before_pre_post = Compile::current()->unique(); |
| 1549 | CountedLoopNode *post_head = NULL__null; |
| 1550 | Node* post_incr = incr; |
| 1551 | Node* main_exit = insert_post_loop(loop, old_new, main_head, main_end, post_incr, limit, post_head); |
| 1552 | const uint idx_after_post_before_pre = Compile::current()->unique(); |
| 1553 | |
| 1554 | //------------------------------ |
| 1555 | // Step B: Create Pre-Loop. |
| 1556 | |
| 1557 | // Step B1: Clone the loop body. The clone becomes the pre-loop. The main |
| 1558 | // loop pre-header illegally has 2 control users (old & new loops). |
| 1559 | LoopNode* outer_main_head = main_head; |
| 1560 | IdealLoopTree* outer_loop = loop; |
| 1561 | if (main_head->is_strip_mined()) { |
| 1562 | main_head->verify_strip_mined(1); |
| 1563 | outer_main_head = main_head->outer_loop(); |
| 1564 | outer_loop = loop->_parent; |
| 1565 | assert(outer_loop->_head == outer_main_head, "broken loop tree")do { if (!(outer_loop->_head == outer_main_head)) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1565, "assert(" "outer_loop->_head == outer_main_head" ") failed" , "broken loop tree"); ::breakpoint(); } } while (0); |
| 1566 | } |
| 1567 | uint dd_main_head = dom_depth(outer_main_head); |
| 1568 | clone_loop(loop, old_new, dd_main_head, ControlAroundStripMined); |
| 1569 | CountedLoopNode* pre_head = old_new[main_head->_idx]->as_CountedLoop(); |
| 1570 | CountedLoopEndNode* pre_end = old_new[main_end ->_idx]->as_CountedLoopEnd(); |
| 1571 | pre_head->set_pre_loop(main_head); |
| 1572 | Node *pre_incr = old_new[incr->_idx]; |
| 1573 | |
| 1574 | // Reduce the pre-loop trip count. |
| 1575 | pre_end->_prob = PROB_FAIR(0.5f); |
| 1576 | |
| 1577 | // Find the pre-loop normal exit. |
| 1578 | Node* pre_exit = pre_end->proj_out(false); |
| 1579 | assert(pre_exit->Opcode() == Op_IfFalse, "")do { if (!(pre_exit->Opcode() == Op_IfFalse)) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1579, "assert(" "pre_exit->Opcode() == Op_IfFalse" ") failed" , ""); ::breakpoint(); } } while (0); |
| 1580 | IfFalseNode *new_pre_exit = new IfFalseNode(pre_end); |
| 1581 | _igvn.register_new_node_with_optimizer(new_pre_exit); |
| 1582 | set_idom(new_pre_exit, pre_end, dd_main_head); |
| 1583 | set_loop(new_pre_exit, outer_loop->_parent); |
| 1584 | |
| 1585 | // Step B2: Build a zero-trip guard for the main-loop. After leaving the |
| 1586 | // pre-loop, the main-loop may not execute at all. Later in life this |
| 1587 | // zero-trip guard will become the minimum-trip guard when we unroll |
| 1588 | // the main-loop. |
| 1589 | Node *min_opaq = new Opaque1Node(C, limit); |
| 1590 | Node *min_cmp = new CmpINode(pre_incr, min_opaq); |
| 1591 | Node *min_bol = new BoolNode(min_cmp, b_test); |
| 1592 | register_new_node(min_opaq, new_pre_exit); |
| 1593 | register_new_node(min_cmp , new_pre_exit); |
| 1594 | register_new_node(min_bol , new_pre_exit); |
| 1595 | |
| 1596 | // Build the IfNode (assume the main-loop is executed always). |
| 1597 | IfNode *min_iff = new IfNode(new_pre_exit, min_bol, PROB_ALWAYS(1.0f-(1e-6f)), COUNT_UNKNOWN(-1.0f)); |
| 1598 | _igvn.register_new_node_with_optimizer(min_iff); |
| 1599 | set_idom(min_iff, new_pre_exit, dd_main_head); |
| 1600 | set_loop(min_iff, outer_loop->_parent); |
| 1601 | |
| 1602 | // Plug in the false-path, taken if we need to skip main-loop |
| 1603 | _igvn.hash_delete(pre_exit); |
| 1604 | pre_exit->set_req(0, min_iff); |
| 1605 | set_idom(pre_exit, min_iff, dd_main_head); |
| 1606 | set_idom(pre_exit->unique_ctrl_out(), min_iff, dd_main_head); |
| 1607 | // Make the true-path, must enter the main loop |
| 1608 | Node *min_taken = new IfTrueNode(min_iff); |
| 1609 | _igvn.register_new_node_with_optimizer(min_taken); |
| 1610 | set_idom(min_taken, min_iff, dd_main_head); |
| 1611 | set_loop(min_taken, outer_loop->_parent); |
| 1612 | // Plug in the true path |
| 1613 | _igvn.hash_delete(outer_main_head); |
| 1614 | outer_main_head->set_req(LoopNode::EntryControl, min_taken); |
| 1615 | set_idom(outer_main_head, min_taken, dd_main_head); |
| 1616 | |
| 1617 | VectorSet visited; |
| 1618 | Node_Stack clones(main_head->back_control()->outcnt()); |
| 1619 | // Step B3: Make the fall-in values to the main-loop come from the |
| 1620 | // fall-out values of the pre-loop. |
| 1621 | for (DUIterator i2 = main_head->outs(); main_head->has_out(i2); i2++) { |
| 1622 | Node* main_phi = main_head->out(i2); |
| 1623 | if (main_phi->is_Phi() && main_phi->in(0) == main_head && main_phi->outcnt() > 0) { |
| 1624 | Node* pre_phi = old_new[main_phi->_idx]; |
| 1625 | Node* fallpre = clone_up_backedge_goo(pre_head->back_control(), |
| 1626 | main_head->skip_strip_mined()->in(LoopNode::EntryControl), |
| 1627 | pre_phi->in(LoopNode::LoopBackControl), |
| 1628 | visited, clones); |
| 1629 | _igvn.hash_delete(main_phi); |
| 1630 | main_phi->set_req(LoopNode::EntryControl, fallpre); |
| 1631 | } |
| 1632 | } |
| 1633 | |
| 1634 | // Nodes inside the loop may be control dependent on a predicate |
| 1635 | // that was moved before the preloop. If the back branch of the main |
| 1636 | // or post loops becomes dead, those nodes won't be dependent on the |
| 1637 | // test that guards that loop nest anymore which could lead to an |
| 1638 | // incorrect array access because it executes independently of the |
| 1639 | // test that was guarding the loop nest. We add a special CastII on |
| 1640 | // the if branch that enters the loop, between the input induction |
| 1641 | // variable value and the induction variable Phi to preserve correct |
| 1642 | // dependencies. |
| 1643 | |
| 1644 | // CastII for the main loop: |
| 1645 | Node* castii = cast_incr_before_loop(pre_incr, min_taken, main_head); |
| 1646 | assert(castii != NULL, "no castII inserted")do { if (!(castii != __null)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1646, "assert(" "castii != __null" ") failed", "no castII inserted" ); ::breakpoint(); } } while (0); |
| 1647 | assert(post_head->in(1)->is_IfProj(), "must be zero-trip guard If node projection of the post loop")do { if (!(post_head->in(1)->is_IfProj())) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1647, "assert(" "post_head->in(1)->is_IfProj()" ") failed" , "must be zero-trip guard If node projection of the post loop" ); ::breakpoint(); } } while (0); |
| 1648 | copy_skeleton_predicates_to_main_loop(pre_head, castii, stride, outer_loop, outer_main_head, dd_main_head, |
| 1649 | idx_before_pre_post, idx_after_post_before_pre, min_taken, post_head->in(1), old_new); |
| 1650 | copy_skeleton_predicates_to_post_loop(outer_main_head, post_head, post_incr, stride); |
| 1651 | |
| 1652 | // Step B4: Shorten the pre-loop to run only 1 iteration (for now). |
| 1653 | // RCE and alignment may change this later. |
| 1654 | Node *cmp_end = pre_end->cmp_node(); |
| 1655 | assert(cmp_end->in(2) == limit, "")do { if (!(cmp_end->in(2) == limit)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1655, "assert(" "cmp_end->in(2) == limit" ") failed", "" ); ::breakpoint(); } } while (0); |
| 1656 | Node *pre_limit = new AddINode(init, stride); |
| 1657 | |
| 1658 | // Save the original loop limit in this Opaque1 node for |
| 1659 | // use by range check elimination. |
| 1660 | Node *pre_opaq = new Opaque1Node(C, pre_limit, limit); |
| 1661 | |
| 1662 | register_new_node(pre_limit, pre_head->in(0)); |
| 1663 | register_new_node(pre_opaq , pre_head->in(0)); |
| 1664 | |
| 1665 | // Since no other users of pre-loop compare, I can hack limit directly |
| 1666 | assert(cmp_end->outcnt() == 1, "no other users")do { if (!(cmp_end->outcnt() == 1)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1666, "assert(" "cmp_end->outcnt() == 1" ") failed", "no other users" ); ::breakpoint(); } } while (0); |
| 1667 | _igvn.hash_delete(cmp_end); |
| 1668 | cmp_end->set_req(2, peel_only ? pre_limit : pre_opaq); |
| 1669 | |
| 1670 | // Special case for not-equal loop bounds: |
| 1671 | // Change pre loop test, main loop test, and the |
| 1672 | // main loop guard test to use lt or gt depending on stride |
| 1673 | // direction: |
| 1674 | // positive stride use < |
| 1675 | // negative stride use > |
| 1676 | // |
| 1677 | // not-equal test is kept for post loop to handle case |
| 1678 | // when init > limit when stride > 0 (and reverse). |
| 1679 | |
| 1680 | if (pre_end->in(CountedLoopEndNode::TestValue)->as_Bool()->_test._test == BoolTest::ne) { |
| 1681 | |
| 1682 | BoolTest::mask new_test = (main_end->stride_con() > 0) ? BoolTest::lt : BoolTest::gt; |
| 1683 | // Modify pre loop end condition |
| 1684 | Node* pre_bol = pre_end->in(CountedLoopEndNode::TestValue)->as_Bool(); |
| 1685 | BoolNode* new_bol0 = new BoolNode(pre_bol->in(1), new_test); |
| 1686 | register_new_node(new_bol0, pre_head->in(0)); |
| 1687 | _igvn.replace_input_of(pre_end, CountedLoopEndNode::TestValue, new_bol0); |
| 1688 | // Modify main loop guard condition |
| 1689 | assert(min_iff->in(CountedLoopEndNode::TestValue) == min_bol, "guard okay")do { if (!(min_iff->in(CountedLoopEndNode::TestValue) == min_bol )) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1689, "assert(" "min_iff->in(CountedLoopEndNode::TestValue) == min_bol" ") failed", "guard okay"); ::breakpoint(); } } while (0); |
| 1690 | BoolNode* new_bol1 = new BoolNode(min_bol->in(1), new_test); |
| 1691 | register_new_node(new_bol1, new_pre_exit); |
| 1692 | _igvn.hash_delete(min_iff); |
| 1693 | min_iff->set_req(CountedLoopEndNode::TestValue, new_bol1); |
| 1694 | // Modify main loop end condition |
| 1695 | BoolNode* main_bol = main_end->in(CountedLoopEndNode::TestValue)->as_Bool(); |
| 1696 | BoolNode* new_bol2 = new BoolNode(main_bol->in(1), new_test); |
| 1697 | register_new_node(new_bol2, main_end->in(CountedLoopEndNode::TestControl)); |
| 1698 | _igvn.replace_input_of(main_end, CountedLoopEndNode::TestValue, new_bol2); |
| 1699 | } |
| 1700 | |
| 1701 | // Flag main loop |
| 1702 | main_head->set_main_loop(); |
| 1703 | if (peel_only) { |
| 1704 | main_head->set_main_no_pre_loop(); |
| 1705 | } |
| 1706 | |
| 1707 | // Subtract a trip count for the pre-loop. |
| 1708 | main_head->set_trip_count(main_head->trip_count() - 1); |
| 1709 | |
| 1710 | // It's difficult to be precise about the trip-counts |
| 1711 | // for the pre/post loops. They are usually very short, |
| 1712 | // so guess that 4 trips is a reasonable value. |
| 1713 | post_head->set_profile_trip_cnt(4.0); |
| 1714 | pre_head->set_profile_trip_cnt(4.0); |
| 1715 | |
| 1716 | // Now force out all loop-invariant dominating tests. The optimizer |
| 1717 | // finds some, but we _know_ they are all useless. |
| 1718 | peeled_dom_test_elim(loop,old_new); |
| 1719 | loop->record_for_igvn(); |
| 1720 | } |
| 1721 | |
| 1722 | //------------------------------insert_vector_post_loop------------------------ |
| 1723 | // Insert a copy of the atomic unrolled vectorized main loop as a post loop, |
| 1724 | // unroll_policy has already informed us that more unrolling is about to |
| 1725 | // happen to the main loop. The resultant post loop will serve as a |
| 1726 | // vectorized drain loop. |
| 1727 | void PhaseIdealLoop::insert_vector_post_loop(IdealLoopTree *loop, Node_List &old_new) { |
| 1728 | if (!loop->_head->is_CountedLoop()) return; |
| 1729 | |
| 1730 | CountedLoopNode *cl = loop->_head->as_CountedLoop(); |
| 1731 | |
| 1732 | // only process vectorized main loops |
| 1733 | if (!cl->is_vectorized_loop() || !cl->is_main_loop()) return; |
| 1734 | |
| 1735 | int slp_max_unroll_factor = cl->slp_max_unroll(); |
| 1736 | int cur_unroll = cl->unrolled_count(); |
| 1737 | |
| 1738 | if (slp_max_unroll_factor == 0) return; |
| 1739 | |
| 1740 | // only process atomic unroll vector loops (not super unrolled after vectorization) |
| 1741 | if (cur_unroll != slp_max_unroll_factor) return; |
| 1742 | |
| 1743 | // we only ever process this one time |
| 1744 | if (cl->has_atomic_post_loop()) return; |
| 1745 | |
| 1746 | if (!may_require_nodes(loop->est_loop_clone_sz(2))) { |
| 1747 | return; |
| 1748 | } |
| 1749 | |
| 1750 | #ifndef PRODUCT |
| 1751 | if (TraceLoopOpts) { |
| 1752 | tty->print("PostVector "); |
| 1753 | loop->dump_head(); |
| 1754 | } |
| 1755 | #endif |
| 1756 | C->set_major_progress(); |
| 1757 | |
| 1758 | // Find common pieces of the loop being guarded with pre & post loops |
| 1759 | CountedLoopNode *main_head = loop->_head->as_CountedLoop(); |
| 1760 | CountedLoopEndNode *main_end = main_head->loopexit(); |
| 1761 | // diagnostic to show loop end is not properly formed |
| 1762 | assert(main_end->outcnt() == 2, "1 true, 1 false path only")do { if (!(main_end->outcnt() == 2)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1762, "assert(" "main_end->outcnt() == 2" ") failed", "1 true, 1 false path only" ); ::breakpoint(); } } while (0); |
| 1763 | |
| 1764 | // mark this loop as processed |
| 1765 | main_head->mark_has_atomic_post_loop(); |
| 1766 | |
| 1767 | Node *incr = main_end->incr(); |
| 1768 | Node *limit = main_end->limit(); |
| 1769 | |
| 1770 | // In this case we throw away the result as we are not using it to connect anything else. |
| 1771 | CountedLoopNode *post_head = NULL__null; |
| 1772 | insert_post_loop(loop, old_new, main_head, main_end, incr, limit, post_head); |
| 1773 | copy_skeleton_predicates_to_post_loop(main_head->skip_strip_mined(), post_head, incr, main_head->stride()); |
| 1774 | |
| 1775 | // It's difficult to be precise about the trip-counts |
| 1776 | // for post loops. They are usually very short, |
| 1777 | // so guess that unit vector trips is a reasonable value. |
| 1778 | post_head->set_profile_trip_cnt(cur_unroll); |
| 1779 | |
| 1780 | // Now force out all loop-invariant dominating tests. The optimizer |
| 1781 | // finds some, but we _know_ they are all useless. |
| 1782 | peeled_dom_test_elim(loop, old_new); |
| 1783 | loop->record_for_igvn(); |
| 1784 | } |
| 1785 | |
| 1786 | |
| 1787 | //-------------------------insert_scalar_rced_post_loop------------------------ |
| 1788 | // Insert a copy of the rce'd main loop as a post loop, |
| 1789 | // We have not unrolled the main loop, so this is the right time to inject this. |
| 1790 | // Later we will examine the partner of this post loop pair which still has range checks |
| 1791 | // to see inject code which tests at runtime if the range checks are applicable. |
| 1792 | void PhaseIdealLoop::insert_scalar_rced_post_loop(IdealLoopTree *loop, Node_List &old_new) { |
| 1793 | if (!loop->_head->is_CountedLoop()) return; |
| 1794 | |
| 1795 | CountedLoopNode *cl = loop->_head->as_CountedLoop(); |
| 1796 | |
| 1797 | // only process RCE'd main loops |
| 1798 | if (!cl->is_main_loop() || cl->range_checks_present()) return; |
| 1799 | |
| 1800 | #ifndef PRODUCT |
| 1801 | if (TraceLoopOpts) { |
| 1802 | tty->print("PostScalarRce "); |
| 1803 | loop->dump_head(); |
| 1804 | } |
| 1805 | #endif |
| 1806 | C->set_major_progress(); |
| 1807 | |
| 1808 | // Find common pieces of the loop being guarded with pre & post loops |
| 1809 | CountedLoopNode *main_head = loop->_head->as_CountedLoop(); |
| 1810 | CountedLoopEndNode *main_end = main_head->loopexit(); |
| 1811 | // diagnostic to show loop end is not properly formed |
| 1812 | assert(main_end->outcnt() == 2, "1 true, 1 false path only")do { if (!(main_end->outcnt() == 2)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1812, "assert(" "main_end->outcnt() == 2" ") failed", "1 true, 1 false path only" ); ::breakpoint(); } } while (0); |
| 1813 | |
| 1814 | Node *incr = main_end->incr(); |
| 1815 | Node *limit = main_end->limit(); |
| 1816 | |
| 1817 | // In this case we throw away the result as we are not using it to connect anything else. |
| 1818 | CountedLoopNode *post_head = NULL__null; |
| 1819 | insert_post_loop(loop, old_new, main_head, main_end, incr, limit, post_head); |
| 1820 | copy_skeleton_predicates_to_post_loop(main_head->skip_strip_mined(), post_head, incr, main_head->stride()); |
| 1821 | |
| 1822 | // It's difficult to be precise about the trip-counts |
| 1823 | // for post loops. They are usually very short, |
| 1824 | // so guess that unit vector trips is a reasonable value. |
| 1825 | post_head->set_profile_trip_cnt(4.0); |
| 1826 | post_head->set_is_rce_post_loop(); |
| 1827 | |
| 1828 | // Now force out all loop-invariant dominating tests. The optimizer |
| 1829 | // finds some, but we _know_ they are all useless. |
| 1830 | peeled_dom_test_elim(loop, old_new); |
| 1831 | loop->record_for_igvn(); |
| 1832 | } |
| 1833 | |
| 1834 | |
| 1835 | //------------------------------insert_post_loop------------------------------- |
| 1836 | // Insert post loops. Add a post loop to the given loop passed. |
| 1837 | Node *PhaseIdealLoop::insert_post_loop(IdealLoopTree* loop, Node_List& old_new, |
| 1838 | CountedLoopNode* main_head, CountedLoopEndNode* main_end, |
| 1839 | Node*& incr, Node* limit, CountedLoopNode*& post_head) { |
| 1840 | IfNode* outer_main_end = main_end; |
| 1841 | IdealLoopTree* outer_loop = loop; |
| 1842 | if (main_head->is_strip_mined()) { |
| 1843 | main_head->verify_strip_mined(1); |
| 1844 | outer_main_end = main_head->outer_loop_end(); |
| 1845 | outer_loop = loop->_parent; |
| 1846 | assert(outer_loop->_head == main_head->in(LoopNode::EntryControl), "broken loop tree")do { if (!(outer_loop->_head == main_head->in(LoopNode:: EntryControl))) { (*g_assert_poison) = 'X';; report_vm_error( "/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1846, "assert(" "outer_loop->_head == main_head->in(LoopNode::EntryControl)" ") failed", "broken loop tree"); ::breakpoint(); } } while ( 0); |
| 1847 | } |
| 1848 | |
| 1849 | //------------------------------ |
| 1850 | // Step A: Create a new post-Loop. |
| 1851 | Node* main_exit = outer_main_end->proj_out(false); |
| 1852 | assert(main_exit->Opcode() == Op_IfFalse, "")do { if (!(main_exit->Opcode() == Op_IfFalse)) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1852, "assert(" "main_exit->Opcode() == Op_IfFalse" ") failed" , ""); ::breakpoint(); } } while (0); |
| 1853 | int dd_main_exit = dom_depth(main_exit); |
| 1854 | |
| 1855 | // Step A1: Clone the loop body of main. The clone becomes the post-loop. |
| 1856 | // The main loop pre-header illegally has 2 control users (old & new loops). |
| 1857 | clone_loop(loop, old_new, dd_main_exit, ControlAroundStripMined); |
| 1858 | assert(old_new[main_end->_idx]->Opcode() == Op_CountedLoopEnd, "")do { if (!(old_new[main_end->_idx]->Opcode() == Op_CountedLoopEnd )) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1858, "assert(" "old_new[main_end->_idx]->Opcode() == Op_CountedLoopEnd" ") failed", ""); ::breakpoint(); } } while (0); |
| 1859 | post_head = old_new[main_head->_idx]->as_CountedLoop(); |
| 1860 | post_head->set_normal_loop(); |
| 1861 | post_head->set_post_loop(main_head); |
| 1862 | |
| 1863 | // Reduce the post-loop trip count. |
| 1864 | CountedLoopEndNode* post_end = old_new[main_end->_idx]->as_CountedLoopEnd(); |
| 1865 | post_end->_prob = PROB_FAIR(0.5f); |
| 1866 | |
| 1867 | // Build the main-loop normal exit. |
| 1868 | IfFalseNode *new_main_exit = new IfFalseNode(outer_main_end); |
| 1869 | _igvn.register_new_node_with_optimizer(new_main_exit); |
| 1870 | set_idom(new_main_exit, outer_main_end, dd_main_exit); |
| 1871 | set_loop(new_main_exit, outer_loop->_parent); |
| 1872 | |
| 1873 | // Step A2: Build a zero-trip guard for the post-loop. After leaving the |
| 1874 | // main-loop, the post-loop may not execute at all. We 'opaque' the incr |
| 1875 | // (the previous loop trip-counter exit value) because we will be changing |
| 1876 | // the exit value (via additional unrolling) so we cannot constant-fold away the zero |
| 1877 | // trip guard until all unrolling is done. |
| 1878 | Node *zer_opaq = new Opaque1Node(C, incr); |
| 1879 | Node *zer_cmp = new CmpINode(zer_opaq, limit); |
| 1880 | Node *zer_bol = new BoolNode(zer_cmp, main_end->test_trip()); |
| 1881 | register_new_node(zer_opaq, new_main_exit); |
| 1882 | register_new_node(zer_cmp, new_main_exit); |
| 1883 | register_new_node(zer_bol, new_main_exit); |
| 1884 | |
| 1885 | // Build the IfNode |
| 1886 | IfNode *zer_iff = new IfNode(new_main_exit, zer_bol, PROB_FAIR(0.5f), COUNT_UNKNOWN(-1.0f)); |
| 1887 | _igvn.register_new_node_with_optimizer(zer_iff); |
| 1888 | set_idom(zer_iff, new_main_exit, dd_main_exit); |
| 1889 | set_loop(zer_iff, outer_loop->_parent); |
| 1890 | |
| 1891 | // Plug in the false-path, taken if we need to skip this post-loop |
| 1892 | _igvn.replace_input_of(main_exit, 0, zer_iff); |
| 1893 | set_idom(main_exit, zer_iff, dd_main_exit); |
| 1894 | set_idom(main_exit->unique_out(), zer_iff, dd_main_exit); |
| 1895 | // Make the true-path, must enter this post loop |
| 1896 | Node *zer_taken = new IfTrueNode(zer_iff); |
| 1897 | _igvn.register_new_node_with_optimizer(zer_taken); |
| 1898 | set_idom(zer_taken, zer_iff, dd_main_exit); |
| 1899 | set_loop(zer_taken, outer_loop->_parent); |
| 1900 | // Plug in the true path |
| 1901 | _igvn.hash_delete(post_head); |
| 1902 | post_head->set_req(LoopNode::EntryControl, zer_taken); |
| 1903 | set_idom(post_head, zer_taken, dd_main_exit); |
| 1904 | |
| 1905 | VectorSet visited; |
| 1906 | Node_Stack clones(main_head->back_control()->outcnt()); |
| 1907 | // Step A3: Make the fall-in values to the post-loop come from the |
| 1908 | // fall-out values of the main-loop. |
| 1909 | for (DUIterator i = main_head->outs(); main_head->has_out(i); i++) { |
| 1910 | Node* main_phi = main_head->out(i); |
| 1911 | if (main_phi->is_Phi() && main_phi->in(0) == main_head && main_phi->outcnt() > 0) { |
| 1912 | Node* cur_phi = old_new[main_phi->_idx]; |
| 1913 | Node* fallnew = clone_up_backedge_goo(main_head->back_control(), |
| 1914 | post_head->init_control(), |
| 1915 | main_phi->in(LoopNode::LoopBackControl), |
| 1916 | visited, clones); |
| 1917 | _igvn.hash_delete(cur_phi); |
| 1918 | cur_phi->set_req(LoopNode::EntryControl, fallnew); |
| 1919 | } |
| 1920 | } |
| 1921 | |
| 1922 | // CastII for the new post loop: |
| 1923 | incr = cast_incr_before_loop(zer_opaq->in(1), zer_taken, post_head); |
| 1924 | assert(incr != NULL, "no castII inserted")do { if (!(incr != __null)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1924, "assert(" "incr != __null" ") failed", "no castII inserted" ); ::breakpoint(); } } while (0); |
| 1925 | |
| 1926 | return new_main_exit; |
| 1927 | } |
| 1928 | |
| 1929 | //------------------------------is_invariant----------------------------- |
| 1930 | // Return true if n is invariant |
| 1931 | bool IdealLoopTree::is_invariant(Node* n) const { |
| 1932 | Node *n_c = _phase->has_ctrl(n) ? _phase->get_ctrl(n) : n; |
| 1933 | if (n_c->is_top()) return false; |
| 1934 | return !is_member(_phase->get_loop(n_c)); |
| 1935 | } |
| 1936 | |
| 1937 | void PhaseIdealLoop::update_main_loop_skeleton_predicates(Node* ctrl, CountedLoopNode* loop_head, Node* init, int stride_con) { |
| 1938 | // Search for skeleton predicates and update them according to the new stride |
| 1939 | Node* entry = ctrl; |
| 1940 | Node* prev_proj = ctrl; |
| 1941 | LoopNode* outer_loop_head = loop_head->skip_strip_mined(); |
| 1942 | IdealLoopTree* outer_loop = get_loop(outer_loop_head); |
| 1943 | |
| 1944 | // Compute the value of the loop induction variable at the end of the |
| 1945 | // first iteration of the unrolled loop: init + new_stride_con - init_inc |
| 1946 | int new_stride_con = stride_con * 2; |
| 1947 | Node* max_value = _igvn.intcon(new_stride_con); |
| 1948 | set_ctrl(max_value, C->root()); |
| 1949 | |
| 1950 | while (entry != NULL__null && entry->is_Proj() && entry->in(0)->is_If()) { |
| 1951 | IfNode* iff = entry->in(0)->as_If(); |
| 1952 | ProjNode* proj = iff->proj_out(1 - entry->as_Proj()->_con); |
| 1953 | if (proj->unique_ctrl_out()->Opcode() != Op_Halt) { |
| 1954 | break; |
| 1955 | } |
| 1956 | if (iff->in(1)->Opcode() == Op_Opaque4) { |
| 1957 | // Look for predicate with an Opaque1 node that can be used as a template |
| 1958 | if (!skeleton_predicate_has_opaque(iff)) { |
| 1959 | // No Opaque1 node? It's either the check for the first value |
| 1960 | // of the first iteration or the check for the last value of |
| 1961 | // the first iteration of an unrolled loop. We can't |
| 1962 | // tell. Kill it in any case. |
| 1963 | _igvn.replace_input_of(iff, 1, iff->in(1)->in(2)); |
| 1964 | } else { |
| 1965 | // Add back predicates updated for the new stride. |
| 1966 | prev_proj = clone_skeleton_predicate_for_main_or_post_loop(iff, init, max_value, entry, proj, ctrl, outer_loop, |
| 1967 | prev_proj); |
| 1968 | assert(!skeleton_predicate_has_opaque(prev_proj->in(0)->as_If()), "unexpected")do { if (!(!skeleton_predicate_has_opaque(prev_proj->in(0) ->as_If()))) { (*g_assert_poison) = 'X';; report_vm_error( "/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1968, "assert(" "!skeleton_predicate_has_opaque(prev_proj->in(0)->as_If())" ") failed", "unexpected"); ::breakpoint(); } } while (0); |
| 1969 | } |
| 1970 | } |
| 1971 | entry = entry->in(0)->in(0); |
| 1972 | } |
| 1973 | if (prev_proj != ctrl) { |
| 1974 | _igvn.replace_input_of(outer_loop_head, LoopNode::EntryControl, prev_proj); |
| 1975 | set_idom(outer_loop_head, prev_proj, dom_depth(outer_loop_head)); |
| 1976 | } |
| 1977 | } |
| 1978 | |
| 1979 | void PhaseIdealLoop::copy_skeleton_predicates_to_post_loop(LoopNode* main_loop_head, CountedLoopNode* post_loop_head, Node* init, Node* stride) { |
| 1980 | // Go over the skeleton predicates of the main loop and make a copy for the post loop with its initial iv value and |
| 1981 | // stride as inputs. |
| 1982 | Node* post_loop_entry = post_loop_head->in(LoopNode::EntryControl); |
| 1983 | Node* main_loop_entry = main_loop_head->in(LoopNode::EntryControl); |
| 1984 | IdealLoopTree* post_loop = get_loop(post_loop_head); |
| 1985 | |
| 1986 | Node* ctrl = main_loop_entry; |
| 1987 | Node* prev_proj = post_loop_entry; |
| 1988 | while (ctrl != NULL__null && ctrl->is_Proj() && ctrl->in(0)->is_If()) { |
| 1989 | IfNode* iff = ctrl->in(0)->as_If(); |
| 1990 | ProjNode* proj = iff->proj_out(1 - ctrl->as_Proj()->_con); |
| 1991 | if (proj->unique_ctrl_out()->Opcode() != Op_Halt) { |
| 1992 | break; |
| 1993 | } |
| 1994 | if (iff->in(1)->Opcode() == Op_Opaque4 && skeleton_predicate_has_opaque(iff)) { |
| 1995 | prev_proj = clone_skeleton_predicate_for_main_or_post_loop(iff, init, stride, ctrl, proj, post_loop_entry, |
| 1996 | post_loop, prev_proj); |
| 1997 | assert(!skeleton_predicate_has_opaque(prev_proj->in(0)->as_If()), "unexpected")do { if (!(!skeleton_predicate_has_opaque(prev_proj->in(0) ->as_If()))) { (*g_assert_poison) = 'X';; report_vm_error( "/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 1997, "assert(" "!skeleton_predicate_has_opaque(prev_proj->in(0)->as_If())" ") failed", "unexpected"); ::breakpoint(); } } while (0); |
| 1998 | } |
| 1999 | ctrl = ctrl->in(0)->in(0); |
| 2000 | } |
| 2001 | if (prev_proj != post_loop_entry) { |
| 2002 | _igvn.replace_input_of(post_loop_head, LoopNode::EntryControl, prev_proj); |
| 2003 | set_idom(post_loop_head, prev_proj, dom_depth(post_loop_head)); |
| 2004 | } |
| 2005 | } |
| 2006 | |
| 2007 | //------------------------------do_unroll-------------------------------------- |
| 2008 | // Unroll the loop body one step - make each trip do 2 iterations. |
| 2009 | void PhaseIdealLoop::do_unroll(IdealLoopTree *loop, Node_List &old_new, bool adjust_min_trip) { |
| 2010 | assert(LoopUnrollLimit, "")do { if (!(LoopUnrollLimit)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2010, "assert(" "LoopUnrollLimit" ") failed", ""); ::breakpoint (); } } while (0); |
| 2011 | CountedLoopNode *loop_head = loop->_head->as_CountedLoop(); |
| 2012 | CountedLoopEndNode *loop_end = loop_head->loopexit(); |
| 2013 | #ifndef PRODUCT |
| 2014 | if (PrintOpto && VerifyLoopOptimizations) { |
| 2015 | tty->print("Unrolling "); |
| 2016 | loop->dump_head(); |
| 2017 | } else if (TraceLoopOpts) { |
| 2018 | if (loop_head->trip_count() < (uint)LoopUnrollLimit) { |
| 2019 | tty->print("Unroll %d(%2d) ", loop_head->unrolled_count()*2, loop_head->trip_count()); |
| 2020 | } else { |
| 2021 | tty->print("Unroll %d ", loop_head->unrolled_count()*2); |
| 2022 | } |
| 2023 | loop->dump_head(); |
| 2024 | } |
| 2025 | |
| 2026 | if (C->do_vector_loop() && (PrintOpto && (VerifyLoopOptimizations || TraceLoopOpts))) { |
| 2027 | Node_Stack stack(C->live_nodes() >> 2); |
| 2028 | Node_List rpo_list; |
| 2029 | VectorSet visited; |
| 2030 | visited.set(loop_head->_idx); |
| 2031 | rpo(loop_head, stack, visited, rpo_list); |
| 2032 | dump(loop, rpo_list.size(), rpo_list); |
| 2033 | } |
| 2034 | #endif |
| 2035 | |
| 2036 | // Remember loop node count before unrolling to detect |
| 2037 | // if rounds of unroll,optimize are making progress |
| 2038 | loop_head->set_node_count_before_unroll(loop->_body.size()); |
| 2039 | |
| 2040 | Node *ctrl = loop_head->skip_strip_mined()->in(LoopNode::EntryControl); |
| 2041 | Node *limit = loop_head->limit(); |
| 2042 | Node *init = loop_head->init_trip(); |
| 2043 | Node *stride = loop_head->stride(); |
| 2044 | |
| 2045 | Node *opaq = NULL__null; |
| 2046 | if (adjust_min_trip) { // If not maximally unrolling, need adjustment |
| 2047 | // Search for zero-trip guard. |
| 2048 | |
| 2049 | // Check the shape of the graph at the loop entry. If an inappropriate |
| 2050 | // graph shape is encountered, the compiler bails out loop unrolling; |
| 2051 | // compilation of the method will still succeed. |
| 2052 | opaq = loop_head->is_canonical_loop_entry(); |
| 2053 | if (opaq == NULL__null) { |
| 2054 | return; |
| 2055 | } |
| 2056 | // Zero-trip test uses an 'opaque' node which is not shared. |
| 2057 | assert(opaq->outcnt() == 1 && opaq->in(1) == limit, "")do { if (!(opaq->outcnt() == 1 && opaq->in(1) == limit)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2057, "assert(" "opaq->outcnt() == 1 && opaq->in(1) == limit" ") failed", ""); ::breakpoint(); } } while (0); |
| 2058 | } |
| 2059 | |
| 2060 | C->set_major_progress(); |
| 2061 | |
| 2062 | Node* new_limit = NULL__null; |
| 2063 | int stride_con = stride->get_int(); |
| 2064 | int stride_p = (stride_con > 0) ? stride_con : -stride_con; |
| 2065 | uint old_trip_count = loop_head->trip_count(); |
| 2066 | // Verify that unroll policy result is still valid. |
| 2067 | assert(old_trip_count > 1 && (!adjust_min_trip || stride_p <=do { if (!(old_trip_count > 1 && (!adjust_min_trip || stride_p <= MIN2<int>(max_jint / 2 - 2, MAX2(1<< 3, Matcher::max_vector_size(T_BYTE)) * loop_head->unrolled_count ())))) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2068, "assert(" "old_trip_count > 1 && (!adjust_min_trip || stride_p <= MIN2<int>(max_jint / 2 - 2, MAX2(1<<3, Matcher::max_vector_size(T_BYTE)) * loop_head->unrolled_count()))" ") failed", "sanity"); ::breakpoint(); } } while (0) |
| 2068 | MIN2<int>(max_jint / 2 - 2, MAX2(1<<3, Matcher::max_vector_size(T_BYTE)) * loop_head->unrolled_count())), "sanity")do { if (!(old_trip_count > 1 && (!adjust_min_trip || stride_p <= MIN2<int>(max_jint / 2 - 2, MAX2(1<< 3, Matcher::max_vector_size(T_BYTE)) * loop_head->unrolled_count ())))) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2068, "assert(" "old_trip_count > 1 && (!adjust_min_trip || stride_p <= MIN2<int>(max_jint / 2 - 2, MAX2(1<<3, Matcher::max_vector_size(T_BYTE)) * loop_head->unrolled_count()))" ") failed", "sanity"); ::breakpoint(); } } while (0); |
| 2069 | |
| 2070 | update_main_loop_skeleton_predicates(ctrl, loop_head, init, stride_con); |
| 2071 | |
| 2072 | // Adjust loop limit to keep valid iterations number after unroll. |
| 2073 | // Use (limit - stride) instead of (((limit - init)/stride) & (-2))*stride |
| 2074 | // which may overflow. |
| 2075 | if (!adjust_min_trip) { |
| 2076 | assert(old_trip_count > 1 && (old_trip_count & 1) == 0,do { if (!(old_trip_count > 1 && (old_trip_count & 1) == 0)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2077, "assert(" "old_trip_count > 1 && (old_trip_count & 1) == 0" ") failed", "odd trip count for maximally unroll"); ::breakpoint (); } } while (0) |
| 2077 | "odd trip count for maximally unroll")do { if (!(old_trip_count > 1 && (old_trip_count & 1) == 0)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2077, "assert(" "old_trip_count > 1 && (old_trip_count & 1) == 0" ") failed", "odd trip count for maximally unroll"); ::breakpoint (); } } while (0); |
| 2078 | // Don't need to adjust limit for maximally unroll since trip count is even. |
| 2079 | } else if (loop_head->has_exact_trip_count() && init->is_Con()) { |
| 2080 | // Loop's limit is constant. Loop's init could be constant when pre-loop |
| 2081 | // become peeled iteration. |
| 2082 | jlong init_con = init->get_int(); |
| 2083 | // We can keep old loop limit if iterations count stays the same: |
| 2084 | // old_trip_count == new_trip_count * 2 |
| 2085 | // Note: since old_trip_count >= 2 then new_trip_count >= 1 |
| 2086 | // so we also don't need to adjust zero trip test. |
| 2087 | jlong limit_con = limit->get_int(); |
| 2088 | // (stride_con*2) not overflow since stride_con <= 8. |
| 2089 | int new_stride_con = stride_con * 2; |
| 2090 | int stride_m = new_stride_con - (stride_con > 0 ? 1 : -1); |
| 2091 | jlong trip_count = (limit_con - init_con + stride_m)/new_stride_con; |
| 2092 | // New trip count should satisfy next conditions. |
| 2093 | assert(trip_count > 0 && (julong)trip_count < (julong)max_juint/2, "sanity")do { if (!(trip_count > 0 && (julong)trip_count < (julong)max_juint/2)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2093, "assert(" "trip_count > 0 && (julong)trip_count < (julong)max_juint/2" ") failed", "sanity"); ::breakpoint(); } } while (0); |
| 2094 | uint new_trip_count = (uint)trip_count; |
| 2095 | adjust_min_trip = (old_trip_count != new_trip_count*2); |
| 2096 | } |
| 2097 | |
| 2098 | if (adjust_min_trip) { |
| 2099 | // Step 2: Adjust the trip limit if it is called for. |
| 2100 | // The adjustment amount is -stride. Need to make sure if the |
| 2101 | // adjustment underflows or overflows, then the main loop is skipped. |
| 2102 | Node* cmp = loop_end->cmp_node(); |
| 2103 | assert(cmp->in(2) == limit, "sanity")do { if (!(cmp->in(2) == limit)) { (*g_assert_poison) = 'X' ;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2103, "assert(" "cmp->in(2) == limit" ") failed", "sanity" ); ::breakpoint(); } } while (0); |
| 2104 | assert(opaq != NULL && opaq->in(1) == limit, "sanity")do { if (!(opaq != __null && opaq->in(1) == limit) ) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2104, "assert(" "opaq != __null && opaq->in(1) == limit" ") failed", "sanity"); ::breakpoint(); } } while (0); |
| 2105 | |
| 2106 | // Verify that policy_unroll result is still valid. |
| 2107 | const TypeInt* limit_type = _igvn.type(limit)->is_int(); |
| 2108 | assert(stride_con > 0 && ((limit_type->_hi - stride_con) < limit_type->_hi) ||do { if (!(stride_con > 0 && ((limit_type->_hi - stride_con) < limit_type->_hi) || stride_con < 0 && ((limit_type->_lo - stride_con) > limit_type->_lo)) ) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2110, "assert(" "stride_con > 0 && ((limit_type->_hi - stride_con) < limit_type->_hi) || stride_con < 0 && ((limit_type->_lo - stride_con) > limit_type->_lo)" ") failed", "sanity"); ::breakpoint(); } } while (0) |
| 2109 | stride_con < 0 && ((limit_type->_lo - stride_con) > limit_type->_lo),do { if (!(stride_con > 0 && ((limit_type->_hi - stride_con) < limit_type->_hi) || stride_con < 0 && ((limit_type->_lo - stride_con) > limit_type->_lo)) ) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2110, "assert(" "stride_con > 0 && ((limit_type->_hi - stride_con) < limit_type->_hi) || stride_con < 0 && ((limit_type->_lo - stride_con) > limit_type->_lo)" ") failed", "sanity"); ::breakpoint(); } } while (0) |
| 2110 | "sanity")do { if (!(stride_con > 0 && ((limit_type->_hi - stride_con) < limit_type->_hi) || stride_con < 0 && ((limit_type->_lo - stride_con) > limit_type->_lo)) ) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2110, "assert(" "stride_con > 0 && ((limit_type->_hi - stride_con) < limit_type->_hi) || stride_con < 0 && ((limit_type->_lo - stride_con) > limit_type->_lo)" ") failed", "sanity"); ::breakpoint(); } } while (0); |
| 2111 | |
| 2112 | if (limit->is_Con()) { |
| 2113 | // The check in policy_unroll and the assert above guarantee |
| 2114 | // no underflow if limit is constant. |
| 2115 | new_limit = _igvn.intcon(limit->get_int() - stride_con); |
| 2116 | set_ctrl(new_limit, C->root()); |
| 2117 | } else { |
| 2118 | // Limit is not constant. |
| 2119 | if (loop_head->unrolled_count() == 1) { // only for first unroll |
| 2120 | // Separate limit by Opaque node in case it is an incremented |
| 2121 | // variable from previous loop to avoid using pre-incremented |
| 2122 | // value which could increase register pressure. |
| 2123 | // Otherwise reorg_offsets() optimization will create a separate |
| 2124 | // Opaque node for each use of trip-counter and as result |
| 2125 | // zero trip guard limit will be different from loop limit. |
| 2126 | assert(has_ctrl(opaq), "should have it")do { if (!(has_ctrl(opaq))) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2126, "assert(" "has_ctrl(opaq)" ") failed", "should have it" ); ::breakpoint(); } } while (0); |
| 2127 | Node* opaq_ctrl = get_ctrl(opaq); |
| 2128 | limit = new Opaque2Node(C, limit); |
| 2129 | register_new_node(limit, opaq_ctrl); |
| 2130 | } |
| 2131 | if ((stride_con > 0 && (java_subtract(limit_type->_lo, stride_con) < limit_type->_lo)) || |
| 2132 | (stride_con < 0 && (java_subtract(limit_type->_hi, stride_con) > limit_type->_hi))) { |
| 2133 | // No underflow. |
| 2134 | new_limit = new SubINode(limit, stride); |
| 2135 | } else { |
| 2136 | // (limit - stride) may underflow. |
| 2137 | // Clamp the adjustment value with MININT or MAXINT: |
| 2138 | // |
| 2139 | // new_limit = limit-stride |
| 2140 | // if (stride > 0) |
| 2141 | // new_limit = (limit < new_limit) ? MININT : new_limit; |
| 2142 | // else |
| 2143 | // new_limit = (limit > new_limit) ? MAXINT : new_limit; |
| 2144 | // |
| 2145 | BoolTest::mask bt = loop_end->test_trip(); |
| 2146 | assert(bt == BoolTest::lt || bt == BoolTest::gt, "canonical test is expected")do { if (!(bt == BoolTest::lt || bt == BoolTest::gt)) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2146, "assert(" "bt == BoolTest::lt || bt == BoolTest::gt" ") failed" , "canonical test is expected"); ::breakpoint(); } } while (0 ); |
| 2147 | Node* adj_max = _igvn.intcon((stride_con > 0) ? min_jint : max_jint); |
| 2148 | set_ctrl(adj_max, C->root()); |
| 2149 | Node* old_limit = NULL__null; |
| 2150 | Node* adj_limit = NULL__null; |
| 2151 | Node* bol = limit->is_CMove() ? limit->in(CMoveNode::Condition) : NULL__null; |
| 2152 | if (loop_head->unrolled_count() > 1 && |
| 2153 | limit->is_CMove() && limit->Opcode() == Op_CMoveI && |
| 2154 | limit->in(CMoveNode::IfTrue) == adj_max && |
| 2155 | bol->as_Bool()->_test._test == bt && |
| 2156 | bol->in(1)->Opcode() == Op_CmpI && |
| 2157 | bol->in(1)->in(2) == limit->in(CMoveNode::IfFalse)) { |
| 2158 | // Loop was unrolled before. |
| 2159 | // Optimize the limit to avoid nested CMove: |
| 2160 | // use original limit as old limit. |
| 2161 | old_limit = bol->in(1)->in(1); |
| 2162 | // Adjust previous adjusted limit. |
| 2163 | adj_limit = limit->in(CMoveNode::IfFalse); |
| 2164 | adj_limit = new SubINode(adj_limit, stride); |
| 2165 | } else { |
| 2166 | old_limit = limit; |
| 2167 | adj_limit = new SubINode(limit, stride); |
| 2168 | } |
| 2169 | assert(old_limit != NULL && adj_limit != NULL, "")do { if (!(old_limit != __null && adj_limit != __null )) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2169, "assert(" "old_limit != __null && adj_limit != __null" ") failed", ""); ::breakpoint(); } } while (0); |
| 2170 | register_new_node(adj_limit, ctrl); // adjust amount |
| 2171 | Node* adj_cmp = new CmpINode(old_limit, adj_limit); |
| 2172 | register_new_node(adj_cmp, ctrl); |
| 2173 | Node* adj_bool = new BoolNode(adj_cmp, bt); |
| 2174 | register_new_node(adj_bool, ctrl); |
| 2175 | new_limit = new CMoveINode(adj_bool, adj_limit, adj_max, TypeInt::INT); |
| 2176 | } |
| 2177 | register_new_node(new_limit, ctrl); |
| 2178 | } |
| 2179 | |
| 2180 | assert(new_limit != NULL, "")do { if (!(new_limit != __null)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2180, "assert(" "new_limit != __null" ") failed", ""); ::breakpoint (); } } while (0); |
| 2181 | // Replace in loop test. |
| 2182 | assert(loop_end->in(1)->in(1) == cmp, "sanity")do { if (!(loop_end->in(1)->in(1) == cmp)) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2182, "assert(" "loop_end->in(1)->in(1) == cmp" ") failed" , "sanity"); ::breakpoint(); } } while (0); |
| 2183 | if (cmp->outcnt() == 1 && loop_end->in(1)->outcnt() == 1) { |
| 2184 | // Don't need to create new test since only one user. |
| 2185 | _igvn.hash_delete(cmp); |
| 2186 | cmp->set_req(2, new_limit); |
| 2187 | } else { |
| 2188 | // Create new test since it is shared. |
| 2189 | Node* ctrl2 = loop_end->in(0); |
| 2190 | Node* cmp2 = cmp->clone(); |
| 2191 | cmp2->set_req(2, new_limit); |
| 2192 | register_new_node(cmp2, ctrl2); |
| 2193 | Node* bol2 = loop_end->in(1)->clone(); |
| 2194 | bol2->set_req(1, cmp2); |
| 2195 | register_new_node(bol2, ctrl2); |
| 2196 | _igvn.replace_input_of(loop_end, 1, bol2); |
| 2197 | } |
| 2198 | // Step 3: Find the min-trip test guaranteed before a 'main' loop. |
| 2199 | // Make it a 1-trip test (means at least 2 trips). |
| 2200 | |
| 2201 | // Guard test uses an 'opaque' node which is not shared. Hence I |
| 2202 | // can edit it's inputs directly. Hammer in the new limit for the |
| 2203 | // minimum-trip guard. |
| 2204 | assert(opaq->outcnt() == 1, "")do { if (!(opaq->outcnt() == 1)) { (*g_assert_poison) = 'X' ;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2204, "assert(" "opaq->outcnt() == 1" ") failed", ""); :: breakpoint(); } } while (0); |
| 2205 | _igvn.replace_input_of(opaq, 1, new_limit); |
| 2206 | } |
| 2207 | |
| 2208 | // Adjust max trip count. The trip count is intentionally rounded |
| 2209 | // down here (e.g. 15-> 7-> 3-> 1) because if we unwittingly over-unroll, |
| 2210 | // the main, unrolled, part of the loop will never execute as it is protected |
| 2211 | // by the min-trip test. See bug 4834191 for a case where we over-unrolled |
| 2212 | // and later determined that part of the unrolled loop was dead. |
| 2213 | loop_head->set_trip_count(old_trip_count / 2); |
| 2214 | |
| 2215 | // Double the count of original iterations in the unrolled loop body. |
| 2216 | loop_head->double_unrolled_count(); |
| 2217 | |
| 2218 | // --------- |
| 2219 | // Step 4: Clone the loop body. Move it inside the loop. This loop body |
| 2220 | // represents the odd iterations; since the loop trips an even number of |
| 2221 | // times its backedge is never taken. Kill the backedge. |
| 2222 | uint dd = dom_depth(loop_head); |
| 2223 | clone_loop(loop, old_new, dd, IgnoreStripMined); |
| 2224 | |
| 2225 | // Make backedges of the clone equal to backedges of the original. |
| 2226 | // Make the fall-in from the original come from the fall-out of the clone. |
| 2227 | for (DUIterator_Fast jmax, j = loop_head->fast_outs(jmax); j < jmax; j++) { |
| 2228 | Node* phi = loop_head->fast_out(j); |
| 2229 | if (phi->is_Phi() && phi->in(0) == loop_head && phi->outcnt() > 0) { |
| 2230 | Node *newphi = old_new[phi->_idx]; |
| 2231 | _igvn.hash_delete(phi); |
| 2232 | _igvn.hash_delete(newphi); |
| 2233 | |
| 2234 | phi ->set_req(LoopNode:: EntryControl, newphi->in(LoopNode::LoopBackControl)); |
| 2235 | newphi->set_req(LoopNode::LoopBackControl, phi ->in(LoopNode::LoopBackControl)); |
| 2236 | phi ->set_req(LoopNode::LoopBackControl, C->top()); |
| 2237 | } |
| 2238 | } |
| 2239 | Node *clone_head = old_new[loop_head->_idx]; |
| 2240 | _igvn.hash_delete(clone_head); |
| 2241 | loop_head ->set_req(LoopNode:: EntryControl, clone_head->in(LoopNode::LoopBackControl)); |
| 2242 | clone_head->set_req(LoopNode::LoopBackControl, loop_head ->in(LoopNode::LoopBackControl)); |
| 2243 | loop_head ->set_req(LoopNode::LoopBackControl, C->top()); |
| 2244 | loop->_head = clone_head; // New loop header |
| 2245 | |
| 2246 | set_idom(loop_head, loop_head ->in(LoopNode::EntryControl), dd); |
| 2247 | set_idom(clone_head, clone_head->in(LoopNode::EntryControl), dd); |
| 2248 | |
| 2249 | // Kill the clone's backedge |
| 2250 | Node *newcle = old_new[loop_end->_idx]; |
| 2251 | _igvn.hash_delete(newcle); |
| 2252 | Node *one = _igvn.intcon(1); |
| 2253 | set_ctrl(one, C->root()); |
| 2254 | newcle->set_req(1, one); |
| 2255 | // Force clone into same loop body |
| 2256 | uint max = loop->_body.size(); |
| 2257 | for (uint k = 0; k < max; k++) { |
| 2258 | Node *old = loop->_body.at(k); |
| 2259 | Node *nnn = old_new[old->_idx]; |
| 2260 | loop->_body.push(nnn); |
| 2261 | if (!has_ctrl(old)) { |
| 2262 | set_loop(nnn, loop); |
| 2263 | } |
| 2264 | } |
| 2265 | |
| 2266 | loop->record_for_igvn(); |
| 2267 | loop_head->clear_strip_mined(); |
| 2268 | |
| 2269 | #ifndef PRODUCT |
| 2270 | if (C->do_vector_loop() && (PrintOpto && (VerifyLoopOptimizations || TraceLoopOpts))) { |
| 2271 | tty->print("\nnew loop after unroll\n"); loop->dump_head(); |
| 2272 | for (uint i = 0; i < loop->_body.size(); i++) { |
| 2273 | loop->_body.at(i)->dump(); |
| 2274 | } |
| 2275 | if (C->clone_map().is_debug()) { |
| 2276 | tty->print("\nCloneMap\n"); |
| 2277 | Dict* dict = C->clone_map().dict(); |
| 2278 | DictI i(dict); |
| 2279 | tty->print_cr("Dict@%p[%d] = ", dict, dict->Size()); |
| 2280 | for (int ii = 0; i.test(); ++i, ++ii) { |
| 2281 | NodeCloneInfo cl((uint64_t)dict->operator[]((void*)i._key)); |
| 2282 | tty->print("%d->%d:%d,", (int)(intptr_t)i._key, cl.idx(), cl.gen()); |
| 2283 | if (ii % 10 == 9) { |
| 2284 | tty->print_cr(" "); |
| 2285 | } |
| 2286 | } |
| 2287 | tty->print_cr(" "); |
| 2288 | } |
| 2289 | } |
| 2290 | #endif |
| 2291 | } |
| 2292 | |
| 2293 | //------------------------------do_maximally_unroll---------------------------- |
| 2294 | |
| 2295 | void PhaseIdealLoop::do_maximally_unroll(IdealLoopTree *loop, Node_List &old_new) { |
| 2296 | CountedLoopNode *cl = loop->_head->as_CountedLoop(); |
| 2297 | assert(cl->has_exact_trip_count(), "trip count is not exact")do { if (!(cl->has_exact_trip_count())) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2297, "assert(" "cl->has_exact_trip_count()" ") failed", "trip count is not exact"); ::breakpoint(); } } while (0); |
| 2298 | assert(cl->trip_count() > 0, "")do { if (!(cl->trip_count() > 0)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2298, "assert(" "cl->trip_count() > 0" ") failed", "" ); ::breakpoint(); } } while (0); |
| 2299 | #ifndef PRODUCT |
| 2300 | if (TraceLoopOpts) { |
| 2301 | tty->print("MaxUnroll %d ", cl->trip_count()); |
| 2302 | loop->dump_head(); |
| 2303 | } |
| 2304 | #endif |
| 2305 | |
| 2306 | // If loop is tripping an odd number of times, peel odd iteration |
| 2307 | if ((cl->trip_count() & 1) == 1) { |
| 2308 | do_peeling(loop, old_new); |
| 2309 | } |
| 2310 | |
| 2311 | // Now its tripping an even number of times remaining. Double loop body. |
| 2312 | // Do not adjust pre-guards; they are not needed and do not exist. |
| 2313 | if (cl->trip_count() > 0) { |
| 2314 | assert((cl->trip_count() & 1) == 0, "missed peeling")do { if (!((cl->trip_count() & 1) == 0)) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2314, "assert(" "(cl->trip_count() & 1) == 0" ") failed" , "missed peeling"); ::breakpoint(); } } while (0); |
| 2315 | do_unroll(loop, old_new, false); |
| 2316 | } |
| 2317 | } |
| 2318 | |
| 2319 | void PhaseIdealLoop::mark_reductions(IdealLoopTree *loop) { |
| 2320 | if (SuperWordReductions == false) return; |
| 2321 | |
| 2322 | CountedLoopNode* loop_head = loop->_head->as_CountedLoop(); |
| 2323 | if (loop_head->unrolled_count() > 1) { |
| 2324 | return; |
| 2325 | } |
| 2326 | |
| 2327 | Node* trip_phi = loop_head->phi(); |
| 2328 | for (DUIterator_Fast imax, i = loop_head->fast_outs(imax); i < imax; i++) { |
| 2329 | Node* phi = loop_head->fast_out(i); |
| 2330 | if (phi->is_Phi() && phi->outcnt() > 0 && phi != trip_phi) { |
| 2331 | // For definitions which are loop inclusive and not tripcounts. |
| 2332 | Node* def_node = phi->in(LoopNode::LoopBackControl); |
| 2333 | |
| 2334 | if (def_node != NULL__null) { |
| 2335 | Node* n_ctrl = get_ctrl(def_node); |
| 2336 | if (n_ctrl != NULL__null && loop->is_member(get_loop(n_ctrl))) { |
| 2337 | // Now test it to see if it fits the standard pattern for a reduction operator. |
| 2338 | int opc = def_node->Opcode(); |
| 2339 | if (opc != ReductionNode::opcode(opc, def_node->bottom_type()->basic_type()) |
| 2340 | || opc == Op_MinD || opc == Op_MinF || opc == Op_MaxD || opc == Op_MaxF) { |
| 2341 | if (!def_node->is_reduction()) { // Not marked yet |
| 2342 | // To be a reduction, the arithmetic node must have the phi as input and provide a def to it |
| 2343 | bool ok = false; |
| 2344 | for (unsigned j = 1; j < def_node->req(); j++) { |
| 2345 | Node* in = def_node->in(j); |
| 2346 | if (in == phi) { |
| 2347 | ok = true; |
| 2348 | break; |
| 2349 | } |
| 2350 | } |
| 2351 | |
| 2352 | // do nothing if we did not match the initial criteria |
| 2353 | if (ok == false) { |
| 2354 | continue; |
| 2355 | } |
| 2356 | |
| 2357 | // The result of the reduction must not be used in the loop |
| 2358 | for (DUIterator_Fast imax, i = def_node->fast_outs(imax); i < imax && ok; i++) { |
| 2359 | Node* u = def_node->fast_out(i); |
| 2360 | if (!loop->is_member(get_loop(ctrl_or_self(u)))) { |
| 2361 | continue; |
| 2362 | } |
| 2363 | if (u == phi) { |
| 2364 | continue; |
| 2365 | } |
| 2366 | ok = false; |
| 2367 | } |
| 2368 | |
| 2369 | // iff the uses conform |
| 2370 | if (ok) { |
| 2371 | def_node->add_flag(Node::Flag_is_reduction); |
| 2372 | loop_head->mark_has_reductions(); |
| 2373 | } |
| 2374 | } |
| 2375 | } |
| 2376 | } |
| 2377 | } |
| 2378 | } |
| 2379 | } |
| 2380 | } |
| 2381 | |
| 2382 | //------------------------------adjust_limit----------------------------------- |
| 2383 | // Helper function that computes new loop limit as (rc_limit-offset)/scale |
| 2384 | Node* PhaseIdealLoop::adjust_limit(bool is_positive_stride, Node* scale, Node* offset, Node* rc_limit, Node* old_limit, Node* pre_ctrl, bool round) { |
| 2385 | Node* sub = new SubLNode(rc_limit, offset); |
| 2386 | register_new_node(sub, pre_ctrl); |
| 2387 | Node* limit = new DivLNode(NULL__null, sub, scale); |
| 2388 | register_new_node(limit, pre_ctrl); |
| 2389 | |
| 2390 | // When the absolute value of scale is greater than one, the division |
| 2391 | // may round limit down/up, so add/sub one to/from the limit. |
| 2392 | if (round) { |
| 2393 | limit = new AddLNode(limit, _igvn.longcon(is_positive_stride ? -1 : 1)); |
| 2394 | register_new_node(limit, pre_ctrl); |
| 2395 | } |
| 2396 | |
| 2397 | // Clamp the limit to handle integer under-/overflows by using long values. |
| 2398 | // We only convert the limit back to int when we handled under-/overflows. |
| 2399 | // Note that all values are longs in the following computations. |
| 2400 | // When reducing the limit, clamp to [min_jint, old_limit]: |
| 2401 | // INT(MINL(old_limit, MAXL(limit, min_jint))) |
| 2402 | // - integer underflow of limit: MAXL chooses min_jint. |
| 2403 | // - integer overflow of limit: MINL chooses old_limit (<= MAX_INT < limit) |
| 2404 | // When increasing the limit, clamp to [old_limit, max_jint]: |
| 2405 | // INT(MAXL(old_limit, MINL(limit, max_jint))) |
| 2406 | // - integer overflow of limit: MINL chooses max_jint. |
| 2407 | // - integer underflow of limit: MAXL chooses old_limit (>= MIN_INT > limit) |
| 2408 | // INT() is finally converting the limit back to an integer value. |
| 2409 | |
| 2410 | // We use CMove nodes to implement long versions of min/max (MINL/MAXL). |
| 2411 | // We use helper methods for inner MINL/MAXL which return CMoveL nodes to keep a long value for the outer MINL/MAXL comparison: |
| 2412 | Node* inner_result_long; |
| 2413 | if (is_positive_stride) { |
| 2414 | inner_result_long = MaxNode::signed_max(limit, _igvn.longcon(min_jint), TypeLong::LONG, _igvn); |
| 2415 | } else { |
| 2416 | inner_result_long = MaxNode::signed_min(limit, _igvn.longcon(max_jint), TypeLong::LONG, _igvn); |
| 2417 | } |
| 2418 | set_subtree_ctrl(inner_result_long, false); |
| 2419 | |
| 2420 | // Outer MINL/MAXL: |
| 2421 | // The comparison is done with long values but the result is the converted back to int by using CmovI. |
| 2422 | Node* old_limit_long = new ConvI2LNode(old_limit); |
| 2423 | register_new_node(old_limit_long, pre_ctrl); |
| 2424 | Node* cmp = new CmpLNode(old_limit_long, limit); |
| 2425 | register_new_node(cmp, pre_ctrl); |
| 2426 | Node* bol = new BoolNode(cmp, is_positive_stride ? BoolTest::gt : BoolTest::lt); |
| 2427 | register_new_node(bol, pre_ctrl); |
| 2428 | Node* inner_result_int = new ConvL2INode(inner_result_long); // Could under-/overflow but that's fine as comparison was done with CmpL |
| 2429 | register_new_node(inner_result_int, pre_ctrl); |
| 2430 | limit = new CMoveINode(bol, old_limit, inner_result_int, TypeInt::INT); |
| 2431 | register_new_node(limit, pre_ctrl); |
| 2432 | return limit; |
| 2433 | } |
| 2434 | |
| 2435 | //------------------------------add_constraint--------------------------------- |
| 2436 | // Constrain the main loop iterations so the conditions: |
| 2437 | // low_limit <= scale_con*I + offset < upper_limit |
| 2438 | // always hold true. That is, either increase the number of iterations in the |
| 2439 | // pre-loop or reduce the number of iterations in the main-loop until the condition |
| 2440 | // holds true in the main-loop. Stride, scale, offset and limit are all loop |
| 2441 | // invariant. Further, stride and scale are constants (offset and limit often are). |
| 2442 | void PhaseIdealLoop::add_constraint(jlong stride_con, jlong scale_con, Node* offset, Node* low_limit, Node* upper_limit, Node* pre_ctrl, Node** pre_limit, Node** main_limit) { |
| 2443 | assert(_igvn.type(offset)->isa_long() != NULL && _igvn.type(low_limit)->isa_long() != NULL &&do { if (!(_igvn.type(offset)->isa_long() != __null && _igvn.type(low_limit)->isa_long() != __null && _igvn .type(upper_limit)->isa_long() != __null)) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2444, "assert(" "_igvn.type(offset)->isa_long() != __null && _igvn.type(low_limit)->isa_long() != __null && _igvn.type(upper_limit)->isa_long() != __null" ") failed", "arguments should be long values"); ::breakpoint (); } } while (0) |
| 2444 | _igvn.type(upper_limit)->isa_long() != NULL, "arguments should be long values")do { if (!(_igvn.type(offset)->isa_long() != __null && _igvn.type(low_limit)->isa_long() != __null && _igvn .type(upper_limit)->isa_long() != __null)) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2444, "assert(" "_igvn.type(offset)->isa_long() != __null && _igvn.type(low_limit)->isa_long() != __null && _igvn.type(upper_limit)->isa_long() != __null" ") failed", "arguments should be long values"); ::breakpoint (); } } while (0); |
| 2445 | |
| 2446 | // For a positive stride, we need to reduce the main-loop limit and |
| 2447 | // increase the pre-loop limit. This is reversed for a negative stride. |
| 2448 | bool is_positive_stride = (stride_con > 0); |
| 2449 | |
| 2450 | // If the absolute scale value is greater one, division in 'adjust_limit' may require |
| 2451 | // rounding. Make sure the ABS method correctly handles min_jint. |
| 2452 | // Only do this for the pre-loop, one less iteration of the main loop doesn't hurt. |
| 2453 | bool round = ABS(scale_con) > 1; |
| 2454 | |
| 2455 | Node* scale = _igvn.longcon(scale_con); |
| 2456 | set_ctrl(scale, C->root()); |
| 2457 | |
| 2458 | if ((stride_con^scale_con) >= 0) { // Use XOR to avoid overflow |
| 2459 | // Positive stride*scale: the affine function is increasing, |
| 2460 | // the pre-loop checks for underflow and the post-loop for overflow. |
| 2461 | |
| 2462 | // The overflow limit: scale*I+offset < upper_limit |
| 2463 | // For the main-loop limit compute: |
| 2464 | // ( if (scale > 0) /* and stride > 0 */ |
| 2465 | // I < (upper_limit-offset)/scale |
| 2466 | // else /* scale < 0 and stride < 0 */ |
| 2467 | // I > (upper_limit-offset)/scale |
| 2468 | // ) |
| 2469 | *main_limit = adjust_limit(is_positive_stride, scale, offset, upper_limit, *main_limit, pre_ctrl, false); |
| 2470 | |
| 2471 | // The underflow limit: low_limit <= scale*I+offset |
| 2472 | // For the pre-loop limit compute: |
| 2473 | // NOT(scale*I+offset >= low_limit) |
| 2474 | // scale*I+offset < low_limit |
| 2475 | // ( if (scale > 0) /* and stride > 0 */ |
| 2476 | // I < (low_limit-offset)/scale |
| 2477 | // else /* scale < 0 and stride < 0 */ |
| 2478 | // I > (low_limit-offset)/scale |
| 2479 | // ) |
| 2480 | *pre_limit = adjust_limit(!is_positive_stride, scale, offset, low_limit, *pre_limit, pre_ctrl, round); |
| 2481 | } else { |
| 2482 | // Negative stride*scale: the affine function is decreasing, |
| 2483 | // the pre-loop checks for overflow and the post-loop for underflow. |
| 2484 | |
| 2485 | // The overflow limit: scale*I+offset < upper_limit |
| 2486 | // For the pre-loop limit compute: |
| 2487 | // NOT(scale*I+offset < upper_limit) |
| 2488 | // scale*I+offset >= upper_limit |
| 2489 | // scale*I+offset+1 > upper_limit |
| 2490 | // ( if (scale < 0) /* and stride > 0 */ |
| 2491 | // I < (upper_limit-(offset+1))/scale |
| 2492 | // else /* scale > 0 and stride < 0 */ |
| 2493 | // I > (upper_limit-(offset+1))/scale |
| 2494 | // ) |
| 2495 | Node* one = _igvn.longcon(1); |
| 2496 | set_ctrl(one, C->root()); |
| 2497 | Node* plus_one = new AddLNode(offset, one); |
| 2498 | register_new_node(plus_one, pre_ctrl); |
| 2499 | *pre_limit = adjust_limit(!is_positive_stride, scale, plus_one, upper_limit, *pre_limit, pre_ctrl, round); |
| 2500 | |
| 2501 | // The underflow limit: low_limit <= scale*I+offset |
| 2502 | // For the main-loop limit compute: |
| 2503 | // scale*I+offset+1 > low_limit |
| 2504 | // ( if (scale < 0) /* and stride > 0 */ |
| 2505 | // I < (low_limit-(offset+1))/scale |
| 2506 | // else /* scale > 0 and stride < 0 */ |
| 2507 | // I > (low_limit-(offset+1))/scale |
| 2508 | // ) |
| 2509 | *main_limit = adjust_limit(is_positive_stride, scale, plus_one, low_limit, *main_limit, pre_ctrl, false); |
| 2510 | } |
| 2511 | } |
| 2512 | |
| 2513 | bool PhaseIdealLoop::is_iv(Node* exp, Node* iv, BasicType bt) { |
| 2514 | if (exp == iv) { |
| 2515 | return true; |
| 2516 | } |
| 2517 | |
| 2518 | if (bt == T_LONG && iv->bottom_type()->isa_int() && exp->Opcode() == Op_ConvI2L && exp->in(1) == iv) { |
| 2519 | return true; |
| 2520 | } |
| 2521 | return false; |
| 2522 | } |
| 2523 | |
| 2524 | //------------------------------is_scaled_iv--------------------------------- |
| 2525 | // Return true if exp is a constant times an induction var |
| 2526 | bool PhaseIdealLoop::is_scaled_iv(Node* exp, Node* iv, jlong* p_scale, BasicType bt, bool* converted) { |
| 2527 | exp = exp->uncast(); |
| 2528 | assert(bt == T_INT || bt == T_LONG, "unexpected int type")do { if (!(bt == T_INT || bt == T_LONG)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2528, "assert(" "bt == T_INT || bt == T_LONG" ") failed", "unexpected int type" ); ::breakpoint(); } } while (0); |
| 2529 | if (is_iv(exp, iv, bt)) { |
| 2530 | if (p_scale != NULL__null) { |
| 2531 | *p_scale = 1; |
| 2532 | } |
| 2533 | return true; |
| 2534 | } |
| 2535 | if (bt == T_LONG && iv->bottom_type()->isa_int() && exp->Opcode() == Op_ConvI2L) { |
| 2536 | exp = exp->in(1); |
| 2537 | bt = T_INT; |
| 2538 | if (converted != NULL__null) { |
| 2539 | *converted = true; |
| 2540 | } |
| 2541 | } |
| 2542 | int opc = exp->Opcode(); |
| 2543 | // Can't use is_Mul() here as it's true for AndI and AndL |
| 2544 | if (opc == Op_Mul(bt)) { |
| 2545 | if (is_iv(exp->in(1)->uncast(), iv, bt) && exp->in(2)->is_Con()) { |
| 2546 | if (p_scale != NULL__null) { |
| 2547 | *p_scale = exp->in(2)->get_integer_as_long(bt); |
| 2548 | } |
| 2549 | return true; |
| 2550 | } |
| 2551 | if (is_iv(exp->in(2)->uncast(), iv, bt) && exp->in(1)->is_Con()) { |
| 2552 | if (p_scale != NULL__null) { |
| 2553 | *p_scale = exp->in(1)->get_integer_as_long(bt); |
| 2554 | } |
| 2555 | return true; |
| 2556 | } |
| 2557 | } else if (opc == Op_LShift(bt)) { |
| 2558 | if (is_iv(exp->in(1)->uncast(), iv, bt) && exp->in(2)->is_Con()) { |
| 2559 | if (p_scale != NULL__null) { |
| 2560 | jint shift_amount = exp->in(2)->get_int(); |
| 2561 | if (bt == T_INT) { |
| 2562 | *p_scale = java_shift_left((jint)1, (juint)shift_amount); |
| 2563 | } else if (bt == T_LONG) { |
| 2564 | *p_scale = java_shift_left((jlong)1, (julong)shift_amount); |
| 2565 | } |
| 2566 | } |
| 2567 | return true; |
| 2568 | } |
| 2569 | } |
| 2570 | return false; |
| 2571 | } |
| 2572 | |
| 2573 | //-----------------------------is_scaled_iv_plus_offset------------------------------ |
| 2574 | // Return true if exp is a simple induction variable expression: k1*iv + (invar + k2) |
| 2575 | bool PhaseIdealLoop::is_scaled_iv_plus_offset(Node* exp, Node* iv, jlong* p_scale, Node** p_offset, BasicType bt, bool* converted, int depth) { |
| 2576 | assert(bt == T_INT || bt == T_LONG, "unexpected int type")do { if (!(bt == T_INT || bt == T_LONG)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2576, "assert(" "bt == T_INT || bt == T_LONG" ") failed", "unexpected int type" ); ::breakpoint(); } } while (0); |
| 2577 | if (is_scaled_iv(exp, iv, p_scale, bt, converted)) { |
| 2578 | if (p_offset != NULL__null) { |
| 2579 | Node *zero = _igvn.integercon(0, bt); |
| 2580 | set_ctrl(zero, C->root()); |
| 2581 | *p_offset = zero; |
| 2582 | } |
| 2583 | return true; |
| 2584 | } |
| 2585 | exp = exp->uncast(); |
| 2586 | int opc = exp->Opcode(); |
| 2587 | if (opc == Op_Add(bt)) { |
| 2588 | if (is_scaled_iv(exp->in(1), iv, p_scale, bt, converted)) { |
| 2589 | if (p_offset != NULL__null) { |
| 2590 | *p_offset = exp->in(2); |
| 2591 | } |
| 2592 | return true; |
| 2593 | } |
| 2594 | if (is_scaled_iv(exp->in(2), iv, p_scale, bt, converted)) { |
| 2595 | if (p_offset != NULL__null) { |
| 2596 | *p_offset = exp->in(1); |
| 2597 | } |
| 2598 | return true; |
| 2599 | } |
| 2600 | if (exp->in(2)->is_Con()) { |
| 2601 | Node* offset2 = NULL__null; |
| 2602 | if (depth < 2 && |
| 2603 | is_scaled_iv_plus_offset(exp->in(1), iv, p_scale, |
| 2604 | p_offset != NULL__null ? &offset2 : NULL__null, bt, converted, depth+1)) { |
| 2605 | if (p_offset != NULL__null) { |
| 2606 | Node *ctrl_off2 = get_ctrl(offset2); |
| 2607 | Node* offset = AddNode::make(offset2, exp->in(2), bt); |
| 2608 | register_new_node(offset, ctrl_off2); |
| 2609 | *p_offset = offset; |
| 2610 | } |
| 2611 | return true; |
| 2612 | } |
| 2613 | } |
| 2614 | } else if (opc == Op_Sub(bt)) { |
| 2615 | if (is_scaled_iv(exp->in(1), iv, p_scale, bt, converted)) { |
| 2616 | if (p_offset != NULL__null) { |
| 2617 | Node *zero = _igvn.integercon(0, bt); |
| 2618 | set_ctrl(zero, C->root()); |
| 2619 | Node *ctrl_off = get_ctrl(exp->in(2)); |
| 2620 | Node* offset = SubNode::make(zero, exp->in(2), bt); |
| 2621 | register_new_node(offset, ctrl_off); |
| 2622 | *p_offset = offset; |
| 2623 | } |
| 2624 | return true; |
| 2625 | } |
| 2626 | if (is_scaled_iv(exp->in(2), iv, p_scale, bt, converted)) { |
| 2627 | if (p_offset != NULL__null) { |
| 2628 | // We can't handle a scale of min_jint (or min_jlong) here as -1 * min_jint = min_jint |
| 2629 | if (*p_scale == min_signed_integer(bt)) { |
| 2630 | return false; |
| 2631 | } |
| 2632 | *p_scale *= -1; |
| 2633 | *p_offset = exp->in(1); |
| 2634 | } |
| 2635 | return true; |
| 2636 | } |
| 2637 | } |
| 2638 | return false; |
| 2639 | } |
| 2640 | |
| 2641 | // Same as PhaseIdealLoop::duplicate_predicates() but for range checks |
| 2642 | // eliminated by iteration splitting. |
| 2643 | Node* PhaseIdealLoop::add_range_check_predicate(IdealLoopTree* loop, CountedLoopNode* cl, |
| 2644 | Node* predicate_proj, int scale_con, Node* offset, |
| 2645 | Node* limit, jint stride_con, Node* value) { |
| 2646 | bool overflow = false; |
| 2647 | BoolNode* bol = rc_predicate(loop, predicate_proj, scale_con, offset, value, NULL__null, stride_con, limit, (stride_con > 0) != (scale_con > 0), overflow, false); |
| 2648 | Node* opaque_bol = new Opaque4Node(C, bol, _igvn.intcon(1)); |
| 2649 | register_new_node(opaque_bol, predicate_proj); |
| 2650 | IfNode* new_iff = NULL__null; |
| 2651 | if (overflow) { |
| 2652 | new_iff = new IfNode(predicate_proj, opaque_bol, PROB_MAX(1.0f-(1e-6f)), COUNT_UNKNOWN(-1.0f)); |
| 2653 | } else { |
| 2654 | new_iff = new RangeCheckNode(predicate_proj, opaque_bol, PROB_MAX(1.0f-(1e-6f)), COUNT_UNKNOWN(-1.0f)); |
| 2655 | } |
| 2656 | register_control(new_iff, loop->_parent, predicate_proj); |
| 2657 | Node* iffalse = new IfFalseNode(new_iff); |
| 2658 | register_control(iffalse, _ltree_root, new_iff); |
| 2659 | ProjNode* iftrue = new IfTrueNode(new_iff); |
| 2660 | register_control(iftrue, loop->_parent, new_iff); |
| 2661 | Node *frame = new ParmNode(C->start(), TypeFunc::FramePtr); |
| 2662 | register_new_node(frame, C->start()); |
| 2663 | Node* halt = new HaltNode(iffalse, frame, "range check predicate failed which is impossible"); |
| 2664 | register_control(halt, _ltree_root, iffalse); |
| 2665 | C->root()->add_req(halt); |
| 2666 | return iftrue; |
| 2667 | } |
| 2668 | |
| 2669 | //------------------------------do_range_check--------------------------------- |
| 2670 | // Eliminate range-checks and other trip-counter vs loop-invariant tests. |
| 2671 | int PhaseIdealLoop::do_range_check(IdealLoopTree *loop, Node_List &old_new) { |
| 2672 | #ifndef PRODUCT |
| 2673 | if (PrintOpto && VerifyLoopOptimizations) { |
| 2674 | tty->print("Range Check Elimination "); |
| 2675 | loop->dump_head(); |
| 2676 | } else if (TraceLoopOpts) { |
| 2677 | tty->print("RangeCheck "); |
| 2678 | loop->dump_head(); |
| 2679 | } |
| 2680 | #endif |
| 2681 | |
| 2682 | assert(RangeCheckElimination, "")do { if (!(RangeCheckElimination)) { (*g_assert_poison) = 'X' ;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2682, "assert(" "RangeCheckElimination" ") failed", ""); :: breakpoint(); } } while (0); |
| 2683 | CountedLoopNode *cl = loop->_head->as_CountedLoop(); |
| 2684 | // If we fail before trying to eliminate range checks, set multiversion state |
| 2685 | int closed_range_checks = 1; |
| 2686 | |
| 2687 | // protect against stride not being a constant |
| 2688 | if (!cl->stride_is_con()) { |
| 2689 | return closed_range_checks; |
| 2690 | } |
| 2691 | // Find the trip counter; we are iteration splitting based on it |
| 2692 | Node *trip_counter = cl->phi(); |
| 2693 | // Find the main loop limit; we will trim it's iterations |
| 2694 | // to not ever trip end tests |
| 2695 | Node *main_limit = cl->limit(); |
| 2696 | |
| 2697 | // Check graph shape. Cannot optimize a loop if zero-trip |
| 2698 | // Opaque1 node is optimized away and then another round |
| 2699 | // of loop opts attempted. |
| 2700 | if (cl->is_canonical_loop_entry() == NULL__null) { |
| 2701 | return closed_range_checks; |
| 2702 | } |
| 2703 | |
| 2704 | // Need to find the main-loop zero-trip guard |
| 2705 | Node *ctrl = cl->skip_predicates(); |
| 2706 | Node *iffm = ctrl->in(0); |
| 2707 | Node *opqzm = iffm->in(1)->in(1)->in(2); |
| 2708 | assert(opqzm->in(1) == main_limit, "do not understand situation")do { if (!(opqzm->in(1) == main_limit)) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2708, "assert(" "opqzm->in(1) == main_limit" ") failed", "do not understand situation"); ::breakpoint(); } } while (0 ); |
| 2709 | |
| 2710 | // Find the pre-loop limit; we will expand its iterations to |
| 2711 | // not ever trip low tests. |
| 2712 | Node *p_f = iffm->in(0); |
| 2713 | // pre loop may have been optimized out |
| 2714 | if (p_f->Opcode() != Op_IfFalse) { |
| 2715 | return closed_range_checks; |
| 2716 | } |
| 2717 | CountedLoopEndNode *pre_end = p_f->in(0)->as_CountedLoopEnd(); |
| 2718 | assert(pre_end->loopnode()->is_pre_loop(), "")do { if (!(pre_end->loopnode()->is_pre_loop())) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2718, "assert(" "pre_end->loopnode()->is_pre_loop()" ") failed" , ""); ::breakpoint(); } } while (0); |
| 2719 | Node *pre_opaq1 = pre_end->limit(); |
| 2720 | // Occasionally it's possible for a pre-loop Opaque1 node to be |
| 2721 | // optimized away and then another round of loop opts attempted. |
| 2722 | // We can not optimize this particular loop in that case. |
| 2723 | if (pre_opaq1->Opcode() != Op_Opaque1) { |
| 2724 | return closed_range_checks; |
| 2725 | } |
| 2726 | Opaque1Node *pre_opaq = (Opaque1Node*)pre_opaq1; |
| 2727 | Node *pre_limit = pre_opaq->in(1); |
| 2728 | |
| 2729 | // Where do we put new limit calculations |
| 2730 | Node *pre_ctrl = pre_end->loopnode()->in(LoopNode::EntryControl); |
| 2731 | |
| 2732 | // Ensure the original loop limit is available from the |
| 2733 | // pre-loop Opaque1 node. |
| 2734 | Node *orig_limit = pre_opaq->original_loop_limit(); |
| 2735 | if (orig_limit == NULL__null || _igvn.type(orig_limit) == Type::TOP) { |
| 2736 | return closed_range_checks; |
| 2737 | } |
| 2738 | // Must know if its a count-up or count-down loop |
| 2739 | |
| 2740 | int stride_con = cl->stride_con(); |
| 2741 | Node* zero = _igvn.longcon(0); |
| 2742 | Node* one = _igvn.longcon(1); |
| 2743 | // Use symmetrical int range [-max_jint,max_jint] |
| 2744 | Node* mini = _igvn.longcon(-max_jint); |
| 2745 | set_ctrl(zero, C->root()); |
| 2746 | set_ctrl(one, C->root()); |
| 2747 | set_ctrl(mini, C->root()); |
| 2748 | |
| 2749 | // Count number of range checks and reduce by load range limits, if zero, |
| 2750 | // the loop is in canonical form to multiversion. |
| 2751 | closed_range_checks = 0; |
| 2752 | |
| 2753 | Node* predicate_proj = cl->skip_strip_mined()->in(LoopNode::EntryControl); |
| 2754 | assert(predicate_proj->is_Proj() && predicate_proj->in(0)->is_If(), "if projection only")do { if (!(predicate_proj->is_Proj() && predicate_proj ->in(0)->is_If())) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2754, "assert(" "predicate_proj->is_Proj() && predicate_proj->in(0)->is_If()" ") failed", "if projection only"); ::breakpoint(); } } while (0); |
| 2755 | |
| 2756 | // Check loop body for tests of trip-counter plus loop-invariant vs loop-variant. |
| 2757 | for (uint i = 0; i < loop->_body.size(); i++) { |
| 2758 | Node *iff = loop->_body[i]; |
| 2759 | if (iff->Opcode() == Op_If || |
| 2760 | iff->Opcode() == Op_RangeCheck) { // Test? |
| 2761 | // Test is an IfNode, has 2 projections. If BOTH are in the loop |
| 2762 | // we need loop unswitching instead of iteration splitting. |
| 2763 | closed_range_checks++; |
| 2764 | Node *exit = loop->is_loop_exit(iff); |
| 2765 | if (!exit) continue; |
| 2766 | int flip = (exit->Opcode() == Op_IfTrue) ? 1 : 0; |
| 2767 | |
| 2768 | // Get boolean condition to test |
| 2769 | Node *i1 = iff->in(1); |
| 2770 | if (!i1->is_Bool()) continue; |
| 2771 | BoolNode *bol = i1->as_Bool(); |
| 2772 | BoolTest b_test = bol->_test; |
| 2773 | // Flip sense of test if exit condition is flipped |
| 2774 | if (flip) { |
| 2775 | b_test = b_test.negate(); |
| 2776 | } |
| 2777 | // Get compare |
| 2778 | Node *cmp = bol->in(1); |
| 2779 | |
| 2780 | // Look for trip_counter + offset vs limit |
| 2781 | Node *rc_exp = cmp->in(1); |
| 2782 | Node *limit = cmp->in(2); |
| 2783 | int scale_con= 1; // Assume trip counter not scaled |
| 2784 | |
| 2785 | Node *limit_c = get_ctrl(limit); |
| 2786 | if (loop->is_member(get_loop(limit_c))) { |
| 2787 | // Compare might have operands swapped; commute them |
| 2788 | b_test = b_test.commute(); |
| 2789 | rc_exp = cmp->in(2); |
| 2790 | limit = cmp->in(1); |
| 2791 | limit_c = get_ctrl(limit); |
| 2792 | if (loop->is_member(get_loop(limit_c))) { |
| 2793 | continue; // Both inputs are loop varying; cannot RCE |
| 2794 | } |
| 2795 | } |
| 2796 | // Here we know 'limit' is loop invariant |
| 2797 | |
| 2798 | // 'limit' maybe pinned below the zero trip test (probably from a |
| 2799 | // previous round of rce), in which case, it can't be used in the |
| 2800 | // zero trip test expression which must occur before the zero test's if. |
| 2801 | if (is_dominator(ctrl, limit_c)) { |
| 2802 | continue; // Don't rce this check but continue looking for other candidates. |
| 2803 | } |
| 2804 | |
| 2805 | // Check for scaled induction variable plus an offset |
| 2806 | Node *offset = NULL__null; |
| 2807 | |
| 2808 | if (!is_scaled_iv_plus_offset(rc_exp, trip_counter, &scale_con, &offset)) { |
| 2809 | continue; |
| 2810 | } |
| 2811 | |
| 2812 | Node *offset_c = get_ctrl(offset); |
| 2813 | if (loop->is_member(get_loop(offset_c))) { |
| 2814 | continue; // Offset is not really loop invariant |
| 2815 | } |
| 2816 | // Here we know 'offset' is loop invariant. |
| 2817 | |
| 2818 | // As above for the 'limit', the 'offset' maybe pinned below the |
| 2819 | // zero trip test. |
| 2820 | if (is_dominator(ctrl, offset_c)) { |
| 2821 | continue; // Don't rce this check but continue looking for other candidates. |
| 2822 | } |
| 2823 | #ifdef ASSERT1 |
| 2824 | if (TraceRangeLimitCheck) { |
| 2825 | tty->print_cr("RC bool node%s", flip ? " flipped:" : ":"); |
| 2826 | bol->dump(2); |
| 2827 | } |
| 2828 | #endif |
| 2829 | // At this point we have the expression as: |
| 2830 | // scale_con * trip_counter + offset :: limit |
| 2831 | // where scale_con, offset and limit are loop invariant. Trip_counter |
| 2832 | // monotonically increases by stride_con, a constant. Both (or either) |
| 2833 | // stride_con and scale_con can be negative which will flip about the |
| 2834 | // sense of the test. |
| 2835 | |
| 2836 | // Perform the limit computations in jlong to avoid overflow |
| 2837 | jlong lscale_con = scale_con; |
| 2838 | Node* int_offset = offset; |
| 2839 | offset = new ConvI2LNode(offset); |
| 2840 | register_new_node(offset, pre_ctrl); |
| 2841 | Node* int_limit = limit; |
| 2842 | limit = new ConvI2LNode(limit); |
| 2843 | register_new_node(limit, pre_ctrl); |
| 2844 | |
| 2845 | // Adjust pre and main loop limits to guard the correct iteration set |
| 2846 | if (cmp->Opcode() == Op_CmpU) { // Unsigned compare is really 2 tests |
| 2847 | if (b_test._test == BoolTest::lt) { // Range checks always use lt |
| 2848 | // The underflow and overflow limits: 0 <= scale*I+offset < limit |
| 2849 | add_constraint(stride_con, lscale_con, offset, zero, limit, pre_ctrl, &pre_limit, &main_limit); |
| 2850 | Node* init = cl->init_trip(); |
| 2851 | Node* opaque_init = new OpaqueLoopInitNode(C, init); |
| 2852 | register_new_node(opaque_init, predicate_proj); |
| 2853 | |
| 2854 | // predicate on first value of first iteration |
| 2855 | predicate_proj = add_range_check_predicate(loop, cl, predicate_proj, scale_con, int_offset, int_limit, stride_con, init); |
| 2856 | assert(!skeleton_predicate_has_opaque(predicate_proj->in(0)->as_If()), "unexpected")do { if (!(!skeleton_predicate_has_opaque(predicate_proj-> in(0)->as_If()))) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2856, "assert(" "!skeleton_predicate_has_opaque(predicate_proj->in(0)->as_If())" ") failed", "unexpected"); ::breakpoint(); } } while (0); |
| 2857 | |
| 2858 | // template predicate so it can be updated on next unrolling |
| 2859 | predicate_proj = add_range_check_predicate(loop, cl, predicate_proj, scale_con, int_offset, int_limit, stride_con, opaque_init); |
| 2860 | assert(skeleton_predicate_has_opaque(predicate_proj->in(0)->as_If()), "unexpected")do { if (!(skeleton_predicate_has_opaque(predicate_proj->in (0)->as_If()))) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2860, "assert(" "skeleton_predicate_has_opaque(predicate_proj->in(0)->as_If())" ") failed", "unexpected"); ::breakpoint(); } } while (0); |
| 2861 | |
| 2862 | Node* opaque_stride = new OpaqueLoopStrideNode(C, cl->stride()); |
| 2863 | register_new_node(opaque_stride, predicate_proj); |
| 2864 | Node* max_value = new SubINode(opaque_stride, cl->stride()); |
| 2865 | register_new_node(max_value, predicate_proj); |
| 2866 | max_value = new AddINode(opaque_init, max_value); |
| 2867 | register_new_node(max_value, predicate_proj); |
| 2868 | predicate_proj = add_range_check_predicate(loop, cl, predicate_proj, scale_con, int_offset, int_limit, stride_con, max_value); |
| 2869 | assert(skeleton_predicate_has_opaque(predicate_proj->in(0)->as_If()), "unexpected")do { if (!(skeleton_predicate_has_opaque(predicate_proj->in (0)->as_If()))) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2869, "assert(" "skeleton_predicate_has_opaque(predicate_proj->in(0)->as_If())" ") failed", "unexpected"); ::breakpoint(); } } while (0); |
| 2870 | |
| 2871 | } else { |
| 2872 | if (PrintOpto) { |
| 2873 | tty->print_cr("missed RCE opportunity"); |
| 2874 | } |
| 2875 | continue; // In release mode, ignore it |
| 2876 | } |
| 2877 | } else { // Otherwise work on normal compares |
| 2878 | switch(b_test._test) { |
| 2879 | case BoolTest::gt: |
| 2880 | // Fall into GE case |
| 2881 | case BoolTest::ge: |
| 2882 | // Convert (I*scale+offset) >= Limit to (I*(-scale)+(-offset)) <= -Limit |
| 2883 | lscale_con = -lscale_con; |
| 2884 | offset = new SubLNode(zero, offset); |
| 2885 | register_new_node(offset, pre_ctrl); |
| 2886 | limit = new SubLNode(zero, limit); |
| 2887 | register_new_node(limit, pre_ctrl); |
| 2888 | // Fall into LE case |
| 2889 | case BoolTest::le: |
| 2890 | if (b_test._test != BoolTest::gt) { |
| 2891 | // Convert X <= Y to X < Y+1 |
| 2892 | limit = new AddLNode(limit, one); |
| 2893 | register_new_node(limit, pre_ctrl); |
| 2894 | } |
| 2895 | // Fall into LT case |
| 2896 | case BoolTest::lt: |
| 2897 | // The underflow and overflow limits: MIN_INT <= scale*I+offset < limit |
| 2898 | // Note: (MIN_INT+1 == -MAX_INT) is used instead of MIN_INT here |
| 2899 | // to avoid problem with scale == -1: MIN_INT/(-1) == MIN_INT. |
| 2900 | add_constraint(stride_con, lscale_con, offset, mini, limit, pre_ctrl, &pre_limit, &main_limit); |
| 2901 | break; |
| 2902 | default: |
| 2903 | if (PrintOpto) { |
| 2904 | tty->print_cr("missed RCE opportunity"); |
| 2905 | } |
| 2906 | continue; // Unhandled case |
| 2907 | } |
| 2908 | } |
| 2909 | |
| 2910 | // Kill the eliminated test |
| 2911 | C->set_major_progress(); |
| 2912 | Node *kill_con = _igvn.intcon(1-flip); |
| 2913 | set_ctrl(kill_con, C->root()); |
| 2914 | _igvn.replace_input_of(iff, 1, kill_con); |
| 2915 | // Find surviving projection |
| 2916 | assert(iff->is_If(), "")do { if (!(iff->is_If())) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2916, "assert(" "iff->is_If()" ") failed", ""); ::breakpoint (); } } while (0); |
| 2917 | ProjNode* dp = ((IfNode*)iff)->proj_out(1-flip); |
| 2918 | // Find loads off the surviving projection; remove their control edge |
| 2919 | for (DUIterator_Fast imax, i = dp->fast_outs(imax); i < imax; i++) { |
| 2920 | Node* cd = dp->fast_out(i); // Control-dependent node |
| 2921 | if (cd->is_Load() && cd->depends_only_on_test()) { // Loads can now float around in the loop |
| 2922 | // Allow the load to float around in the loop, or before it |
| 2923 | // but NOT before the pre-loop. |
| 2924 | _igvn.replace_input_of(cd, 0, ctrl); // ctrl, not NULL |
| 2925 | --i; |
| 2926 | --imax; |
| 2927 | } |
| 2928 | } |
| 2929 | if (int_limit->Opcode() == Op_LoadRange) { |
| 2930 | closed_range_checks--; |
| 2931 | } |
| 2932 | } // End of is IF |
| 2933 | } |
| 2934 | if (predicate_proj != cl->skip_strip_mined()->in(LoopNode::EntryControl)) { |
| 2935 | _igvn.replace_input_of(cl->skip_strip_mined(), LoopNode::EntryControl, predicate_proj); |
| 2936 | set_idom(cl->skip_strip_mined(), predicate_proj, dom_depth(cl->skip_strip_mined())); |
| 2937 | } |
| 2938 | |
| 2939 | // Update loop limits |
| 2940 | if (pre_limit != orig_limit) { |
| 2941 | // Computed pre-loop limit can be outside of loop iterations range. |
| 2942 | pre_limit = (stride_con > 0) ? (Node*)new MinINode(pre_limit, orig_limit) |
| 2943 | : (Node*)new MaxINode(pre_limit, orig_limit); |
| 2944 | register_new_node(pre_limit, pre_ctrl); |
| 2945 | } |
| 2946 | _igvn.replace_input_of(pre_opaq, 1, pre_limit); |
| 2947 | |
| 2948 | // Note:: we are making the main loop limit no longer precise; |
| 2949 | // need to round up based on stride. |
| 2950 | cl->set_nonexact_trip_count(); |
| 2951 | Node *main_cle = cl->loopexit(); |
| 2952 | Node *main_bol = main_cle->in(1); |
| 2953 | // Hacking loop bounds; need private copies of exit test |
| 2954 | if (main_bol->outcnt() > 1) { // BoolNode shared? |
| 2955 | main_bol = main_bol->clone(); // Clone a private BoolNode |
| 2956 | register_new_node(main_bol, main_cle->in(0)); |
| 2957 | _igvn.replace_input_of(main_cle, 1, main_bol); |
| 2958 | } |
| 2959 | Node *main_cmp = main_bol->in(1); |
| 2960 | if (main_cmp->outcnt() > 1) { // CmpNode shared? |
| 2961 | main_cmp = main_cmp->clone(); // Clone a private CmpNode |
| 2962 | register_new_node(main_cmp, main_cle->in(0)); |
| 2963 | _igvn.replace_input_of(main_bol, 1, main_cmp); |
| 2964 | } |
| 2965 | assert(main_limit == cl->limit() || get_ctrl(main_limit) == pre_ctrl, "wrong control for added limit")do { if (!(main_limit == cl->limit() || get_ctrl(main_limit ) == pre_ctrl)) { (*g_assert_poison) = 'X';; report_vm_error( "/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2965, "assert(" "main_limit == cl->limit() || get_ctrl(main_limit) == pre_ctrl" ") failed", "wrong control for added limit"); ::breakpoint() ; } } while (0); |
| 2966 | const TypeInt* orig_limit_t = _igvn.type(orig_limit)->is_int(); |
| 2967 | bool upward = cl->stride_con() > 0; |
| 2968 | // The new loop limit is <= (for an upward loop) >= (for a downward loop) than the orig limit. |
| 2969 | // The expression that computes the new limit may be too complicated and the computed type of the new limit |
| 2970 | // may be too pessimistic. A CastII here guarantees it's not lost. |
| 2971 | main_limit = new CastIINode(main_limit, TypeInt::make(upward ? min_jint : orig_limit_t->_lo, |
| 2972 | upward ? orig_limit_t->_hi : max_jint, Type::WidenMax)); |
| 2973 | main_limit->init_req(0, pre_ctrl); |
| 2974 | register_new_node(main_limit, pre_ctrl); |
| 2975 | // Hack the now-private loop bounds |
| 2976 | _igvn.replace_input_of(main_cmp, 2, main_limit); |
| 2977 | // The OpaqueNode is unshared by design |
| 2978 | assert(opqzm->outcnt() == 1, "cannot hack shared node")do { if (!(opqzm->outcnt() == 1)) { (*g_assert_poison) = 'X' ;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2978, "assert(" "opqzm->outcnt() == 1" ") failed", "cannot hack shared node" ); ::breakpoint(); } } while (0); |
| 2979 | _igvn.replace_input_of(opqzm, 1, main_limit); |
| 2980 | |
| 2981 | return closed_range_checks; |
| 2982 | } |
| 2983 | |
| 2984 | //------------------------------has_range_checks------------------------------- |
| 2985 | // Check to see if RCE cleaned the current loop of range-checks. |
| 2986 | void PhaseIdealLoop::has_range_checks(IdealLoopTree *loop) { |
| 2987 | assert(RangeCheckElimination, "")do { if (!(RangeCheckElimination)) { (*g_assert_poison) = 'X' ;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 2987, "assert(" "RangeCheckElimination" ") failed", ""); :: breakpoint(); } } while (0); |
| 2988 | |
| 2989 | // skip if not a counted loop |
| 2990 | if (!loop->is_counted()) return; |
| 2991 | |
| 2992 | CountedLoopNode *cl = loop->_head->as_CountedLoop(); |
| 2993 | |
| 2994 | // skip this loop if it is already checked |
| 2995 | if (cl->has_been_range_checked()) return; |
| 2996 | |
| 2997 | // Now check for existence of range checks |
| 2998 | for (uint i = 0; i < loop->_body.size(); i++) { |
| 2999 | Node *iff = loop->_body[i]; |
| 3000 | int iff_opc = iff->Opcode(); |
| 3001 | if (iff_opc == Op_If || iff_opc == Op_RangeCheck) { |
| 3002 | cl->mark_has_range_checks(); |
| 3003 | break; |
| 3004 | } |
| 3005 | } |
| 3006 | cl->set_has_been_range_checked(); |
| 3007 | } |
| 3008 | |
| 3009 | //-------------------------multi_version_post_loops---------------------------- |
| 3010 | // Check the range checks that remain, if simple, use the bounds to guard |
| 3011 | // which version to a post loop we execute, one with range checks or one without |
| 3012 | bool PhaseIdealLoop::multi_version_post_loops(IdealLoopTree *rce_loop, IdealLoopTree *legacy_loop) { |
| 3013 | bool multi_version_succeeded = false; |
| 3014 | assert(RangeCheckElimination, "")do { if (!(RangeCheckElimination)) { (*g_assert_poison) = 'X' ;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 3014, "assert(" "RangeCheckElimination" ") failed", ""); :: breakpoint(); } } while (0); |
| 3015 | CountedLoopNode *legacy_cl = legacy_loop->_head->as_CountedLoop(); |
| 3016 | assert(legacy_cl->is_post_loop(), "")do { if (!(legacy_cl->is_post_loop())) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 3016, "assert(" "legacy_cl->is_post_loop()" ") failed", "" ); ::breakpoint(); } } while (0); |
| 3017 | |
| 3018 | // Check for existence of range checks using the unique instance to make a guard with |
| 3019 | Unique_Node_List worklist; |
| 3020 | for (uint i = 0; i < legacy_loop->_body.size(); i++) { |
| 3021 | Node *iff = legacy_loop->_body[i]; |
| 3022 | int iff_opc = iff->Opcode(); |
| 3023 | if (iff_opc == Op_If || iff_opc == Op_RangeCheck) { |
| 3024 | worklist.push(iff); |
| 3025 | } |
| 3026 | } |
| 3027 | |
| 3028 | // Find RCE'd post loop so that we can stage its guard. |
| 3029 | if (legacy_cl->is_canonical_loop_entry() == NULL__null) { |
| 3030 | return multi_version_succeeded; |
| 3031 | } |
| 3032 | Node* ctrl = legacy_cl->in(LoopNode::EntryControl); |
| 3033 | Node* iffm = ctrl->in(0); |
| 3034 | |
| 3035 | // Now we test that both the post loops are connected |
| 3036 | Node* post_loop_region = iffm->in(0); |
| 3037 | if (post_loop_region == NULL__null) return multi_version_succeeded; |
| 3038 | if (!post_loop_region->is_Region()) return multi_version_succeeded; |
| 3039 | Node* covering_region = post_loop_region->in(RegionNode::Control+1); |
| 3040 | if (covering_region == NULL__null) return multi_version_succeeded; |
| 3041 | if (!covering_region->is_Region()) return multi_version_succeeded; |
| 3042 | Node* p_f = covering_region->in(RegionNode::Control); |
| 3043 | if (p_f == NULL__null) return multi_version_succeeded; |
| 3044 | if (!p_f->is_IfFalse()) return multi_version_succeeded; |
| 3045 | if (!p_f->in(0)->is_CountedLoopEnd()) return multi_version_succeeded; |
| 3046 | CountedLoopEndNode* rce_loop_end = p_f->in(0)->as_CountedLoopEnd(); |
| 3047 | if (rce_loop_end == NULL__null) return multi_version_succeeded; |
| 3048 | CountedLoopNode* rce_cl = rce_loop_end->loopnode(); |
| 3049 | if (rce_cl == NULL__null || !rce_cl->is_post_loop()) return multi_version_succeeded; |
| 3050 | CountedLoopNode *known_rce_cl = rce_loop->_head->as_CountedLoop(); |
| 3051 | if (rce_cl != known_rce_cl) return multi_version_succeeded; |
| 3052 | |
| 3053 | // Then we fetch the cover entry test |
| 3054 | ctrl = rce_cl->in(LoopNode::EntryControl); |
| 3055 | if (!ctrl->is_IfTrue() && !ctrl->is_IfFalse()) return multi_version_succeeded; |
| 3056 | |
| 3057 | #ifndef PRODUCT |
| 3058 | if (TraceLoopOpts) { |
| 3059 | tty->print("PostMultiVersion\n"); |
| 3060 | rce_loop->dump_head(); |
| 3061 | legacy_loop->dump_head(); |
| 3062 | } |
| 3063 | #endif |
| 3064 | |
| 3065 | // Now fetch the limit we want to compare against |
| 3066 | Node *limit = rce_cl->limit(); |
| 3067 | bool first_time = true; |
| 3068 | |
| 3069 | // If we got this far, we identified the post loop which has been RCE'd and |
| 3070 | // we have a work list. Now we will try to transform the if guard to cause |
| 3071 | // the loop pair to be multi version executed with the determination left to runtime |
| 3072 | // or the optimizer if full information is known about the given arrays at compile time. |
| 3073 | Node *last_min = NULL__null; |
| 3074 | multi_version_succeeded = true; |
| 3075 | while (worklist.size()) { |
| 3076 | Node* rc_iffm = worklist.pop(); |
| 3077 | if (rc_iffm->is_If()) { |
| 3078 | Node *rc_bolzm = rc_iffm->in(1); |
| 3079 | if (rc_bolzm->is_Bool()) { |
| 3080 | Node *rc_cmpzm = rc_bolzm->in(1); |
| 3081 | if (rc_cmpzm->is_Cmp()) { |
| 3082 | Node *rc_left = rc_cmpzm->in(2); |
| 3083 | if (rc_left->Opcode() != Op_LoadRange) { |
| 3084 | multi_version_succeeded = false; |
| 3085 | break; |
| 3086 | } |
| 3087 | if (first_time) { |
| 3088 | last_min = rc_left; |
| 3089 | first_time = false; |
| 3090 | } else { |
| 3091 | Node *cur_min = new MinINode(last_min, rc_left); |
| 3092 | last_min = cur_min; |
| 3093 | _igvn.register_new_node_with_optimizer(last_min); |
| 3094 | } |
| 3095 | } |
| 3096 | } |
| 3097 | } |
| 3098 | } |
| 3099 | |
| 3100 | // All we have to do is update the limit of the rce loop |
| 3101 | // with the min of our expression and the current limit. |
| 3102 | // We will use this expression to replace the current limit. |
| 3103 | if (last_min && multi_version_succeeded) { |
| 3104 | Node *cur_min = new MinINode(last_min, limit); |
| 3105 | _igvn.register_new_node_with_optimizer(cur_min); |
| 3106 | Node *cmp_node = rce_loop_end->cmp_node(); |
| 3107 | _igvn.replace_input_of(cmp_node, 2, cur_min); |
| 3108 | set_ctrl(cur_min, ctrl); |
| 3109 | set_loop(cur_min, rce_loop->_parent); |
| 3110 | |
| 3111 | legacy_cl->mark_is_multiversioned(); |
| 3112 | rce_cl->mark_is_multiversioned(); |
| 3113 | multi_version_succeeded = true; |
| 3114 | |
| 3115 | C->set_major_progress(); |
| 3116 | } |
| 3117 | |
| 3118 | return multi_version_succeeded; |
| 3119 | } |
| 3120 | |
| 3121 | //-------------------------poison_rce_post_loop-------------------------------- |
| 3122 | // Causes the rce'd post loop to be optimized away if multiversioning fails |
| 3123 | void PhaseIdealLoop::poison_rce_post_loop(IdealLoopTree *rce_loop) { |
| 3124 | CountedLoopNode *rce_cl = rce_loop->_head->as_CountedLoop(); |
| 3125 | Node* ctrl = rce_cl->in(LoopNode::EntryControl); |
| 3126 | if (ctrl->is_IfTrue() || ctrl->is_IfFalse()) { |
| 3127 | Node* iffm = ctrl->in(0); |
| 3128 | if (iffm->is_If()) { |
| 3129 | Node* cur_bool = iffm->in(1); |
| 3130 | if (cur_bool->is_Bool()) { |
| 3131 | Node* cur_cmp = cur_bool->in(1); |
| 3132 | if (cur_cmp->is_Cmp()) { |
| 3133 | BoolTest::mask new_test = BoolTest::gt; |
| 3134 | BoolNode *new_bool = new BoolNode(cur_cmp, new_test); |
| 3135 | _igvn.replace_node(cur_bool, new_bool); |
| 3136 | _igvn._worklist.push(new_bool); |
| 3137 | Node* left_op = cur_cmp->in(1); |
| 3138 | _igvn.replace_input_of(cur_cmp, 2, left_op); |
| 3139 | C->set_major_progress(); |
| 3140 | } |
| 3141 | } |
| 3142 | } |
| 3143 | } |
| 3144 | } |
| 3145 | |
| 3146 | //------------------------------DCE_loop_body---------------------------------- |
| 3147 | // Remove simplistic dead code from loop body |
| 3148 | void IdealLoopTree::DCE_loop_body() { |
| 3149 | for (uint i = 0; i < _body.size(); i++) { |
| 3150 | if (_body.at(i)->outcnt() == 0) { |
| 3151 | _body.map(i, _body.pop()); |
| 3152 | i--; // Ensure we revisit the updated index. |
| 3153 | } |
| 3154 | } |
| 3155 | } |
| 3156 | |
| 3157 | |
| 3158 | //------------------------------adjust_loop_exit_prob-------------------------- |
| 3159 | // Look for loop-exit tests with the 50/50 (or worse) guesses from the parsing stage. |
| 3160 | // Replace with a 1-in-10 exit guess. |
| 3161 | void IdealLoopTree::adjust_loop_exit_prob(PhaseIdealLoop *phase) { |
| 3162 | Node *test = tail(); |
| 3163 | while (test != _head) { |
| 3164 | uint top = test->Opcode(); |
| 3165 | if (top == Op_IfTrue || top == Op_IfFalse) { |
| 3166 | int test_con = ((ProjNode*)test)->_con; |
| 3167 | assert(top == (uint)(test_con? Op_IfTrue: Op_IfFalse), "sanity")do { if (!(top == (uint)(test_con? Op_IfTrue: Op_IfFalse))) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 3167, "assert(" "top == (uint)(test_con? Op_IfTrue: Op_IfFalse)" ") failed", "sanity"); ::breakpoint(); } } while (0); |
| 3168 | IfNode *iff = test->in(0)->as_If(); |
| 3169 | if (iff->outcnt() == 2) { // Ignore dead tests |
| 3170 | Node *bol = iff->in(1); |
| 3171 | if (bol && bol->req() > 1 && bol->in(1) && |
| 3172 | ((bol->in(1)->Opcode() == Op_StorePConditional) || |
| 3173 | (bol->in(1)->Opcode() == Op_StoreIConditional) || |
| 3174 | (bol->in(1)->Opcode() == Op_StoreLConditional) || |
| 3175 | (bol->in(1)->Opcode() == Op_CompareAndExchangeB) || |
| 3176 | (bol->in(1)->Opcode() == Op_CompareAndExchangeS) || |
| 3177 | (bol->in(1)->Opcode() == Op_CompareAndExchangeI) || |
| 3178 | (bol->in(1)->Opcode() == Op_CompareAndExchangeL) || |
| 3179 | (bol->in(1)->Opcode() == Op_CompareAndExchangeP) || |
| 3180 | (bol->in(1)->Opcode() == Op_CompareAndExchangeN) || |
| 3181 | (bol->in(1)->Opcode() == Op_WeakCompareAndSwapB) || |
| 3182 | (bol->in(1)->Opcode() == Op_WeakCompareAndSwapS) || |
| 3183 | (bol->in(1)->Opcode() == Op_WeakCompareAndSwapI) || |
| 3184 | (bol->in(1)->Opcode() == Op_WeakCompareAndSwapL) || |
| 3185 | (bol->in(1)->Opcode() == Op_WeakCompareAndSwapP) || |
| 3186 | (bol->in(1)->Opcode() == Op_WeakCompareAndSwapN) || |
| 3187 | (bol->in(1)->Opcode() == Op_CompareAndSwapB) || |
| 3188 | (bol->in(1)->Opcode() == Op_CompareAndSwapS) || |
| 3189 | (bol->in(1)->Opcode() == Op_CompareAndSwapI) || |
| 3190 | (bol->in(1)->Opcode() == Op_CompareAndSwapL) || |
| 3191 | (bol->in(1)->Opcode() == Op_CompareAndSwapP) || |
| 3192 | (bol->in(1)->Opcode() == Op_CompareAndSwapN) || |
| 3193 | (bol->in(1)->Opcode() == Op_ShenandoahCompareAndExchangeP) || |
| 3194 | (bol->in(1)->Opcode() == Op_ShenandoahCompareAndExchangeN) || |
| 3195 | (bol->in(1)->Opcode() == Op_ShenandoahWeakCompareAndSwapP) || |
| 3196 | (bol->in(1)->Opcode() == Op_ShenandoahWeakCompareAndSwapN) || |
| 3197 | (bol->in(1)->Opcode() == Op_ShenandoahCompareAndSwapP) || |
| 3198 | (bol->in(1)->Opcode() == Op_ShenandoahCompareAndSwapN))) |
| 3199 | return; // Allocation loops RARELY take backedge |
| 3200 | // Find the OTHER exit path from the IF |
| 3201 | Node* ex = iff->proj_out(1-test_con); |
| 3202 | float p = iff->_prob; |
| 3203 | if (!phase->is_member(this, ex) && iff->_fcnt == COUNT_UNKNOWN(-1.0f)) { |
| 3204 | if (top == Op_IfTrue) { |
| 3205 | if (p < (PROB_FAIR(0.5f) + PROB_UNLIKELY_MAG(3)(1e-3f))) { |
| 3206 | iff->_prob = PROB_STATIC_FREQUENT(1.0f-(1e-1f)); |
| 3207 | } |
| 3208 | } else { |
| 3209 | if (p > (PROB_FAIR(0.5f) - PROB_UNLIKELY_MAG(3)(1e-3f))) { |
| 3210 | iff->_prob = PROB_STATIC_INFREQUENT(1e-1f); |
| 3211 | } |
| 3212 | } |
| 3213 | } |
| 3214 | } |
| 3215 | } |
| 3216 | test = phase->idom(test); |
| 3217 | } |
| 3218 | } |
| 3219 | |
| 3220 | #ifdef ASSERT1 |
| 3221 | static CountedLoopNode* locate_pre_from_main(CountedLoopNode* main_loop) { |
| 3222 | assert(!main_loop->is_main_no_pre_loop(), "Does not have a pre loop")do { if (!(!main_loop->is_main_no_pre_loop())) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 3222, "assert(" "!main_loop->is_main_no_pre_loop()" ") failed" , "Does not have a pre loop"); ::breakpoint(); } } while (0); |
| 3223 | Node* ctrl = main_loop->skip_predicates(); |
| 3224 | assert(ctrl->Opcode() == Op_IfTrue || ctrl->Opcode() == Op_IfFalse, "")do { if (!(ctrl->Opcode() == Op_IfTrue || ctrl->Opcode( ) == Op_IfFalse)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 3224, "assert(" "ctrl->Opcode() == Op_IfTrue || ctrl->Opcode() == Op_IfFalse" ") failed", ""); ::breakpoint(); } } while (0); |
| 3225 | Node* iffm = ctrl->in(0); |
| 3226 | assert(iffm->Opcode() == Op_If, "")do { if (!(iffm->Opcode() == Op_If)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 3226, "assert(" "iffm->Opcode() == Op_If" ") failed", "" ); ::breakpoint(); } } while (0); |
| 3227 | Node* p_f = iffm->in(0); |
| 3228 | assert(p_f->Opcode() == Op_IfFalse, "")do { if (!(p_f->Opcode() == Op_IfFalse)) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 3228, "assert(" "p_f->Opcode() == Op_IfFalse" ") failed" , ""); ::breakpoint(); } } while (0); |
| 3229 | CountedLoopNode* pre_loop = p_f->in(0)->as_CountedLoopEnd()->loopnode(); |
| 3230 | assert(pre_loop->is_pre_loop(), "No pre loop found")do { if (!(pre_loop->is_pre_loop())) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 3230, "assert(" "pre_loop->is_pre_loop()" ") failed", "No pre loop found" ); ::breakpoint(); } } while (0); |
| 3231 | return pre_loop; |
| 3232 | } |
| 3233 | #endif |
| 3234 | |
| 3235 | // Remove the main and post loops and make the pre loop execute all |
| 3236 | // iterations. Useful when the pre loop is found empty. |
| 3237 | void IdealLoopTree::remove_main_post_loops(CountedLoopNode *cl, PhaseIdealLoop *phase) { |
| 3238 | CountedLoopEndNode* pre_end = cl->loopexit(); |
| 3239 | Node* pre_cmp = pre_end->cmp_node(); |
| 3240 | if (pre_cmp->in(2)->Opcode() != Op_Opaque1) { |
| 3241 | // Only safe to remove the main loop if the compiler optimized it |
| 3242 | // out based on an unknown number of iterations |
| 3243 | return; |
| 3244 | } |
| 3245 | |
| 3246 | // Can we find the main loop? |
| 3247 | if (_next == NULL__null) { |
| 3248 | return; |
| 3249 | } |
| 3250 | |
| 3251 | Node* next_head = _next->_head; |
| 3252 | if (!next_head->is_CountedLoop()) { |
| 3253 | return; |
| 3254 | } |
| 3255 | |
| 3256 | CountedLoopNode* main_head = next_head->as_CountedLoop(); |
| 3257 | if (!main_head->is_main_loop() || main_head->is_main_no_pre_loop()) { |
| 3258 | return; |
| 3259 | } |
| 3260 | |
| 3261 | assert(locate_pre_from_main(main_head) == cl, "bad main loop")do { if (!(locate_pre_from_main(main_head) == cl)) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 3261, "assert(" "locate_pre_from_main(main_head) == cl" ") failed" , "bad main loop"); ::breakpoint(); } } while (0); |
| 3262 | Node* main_iff = main_head->skip_predicates()->in(0); |
| 3263 | |
| 3264 | // Remove the Opaque1Node of the pre loop and make it execute all iterations |
| 3265 | phase->_igvn.replace_input_of(pre_cmp, 2, pre_cmp->in(2)->in(2)); |
| 3266 | // Remove the Opaque1Node of the main loop so it can be optimized out |
| 3267 | Node* main_cmp = main_iff->in(1)->in(1); |
| 3268 | assert(main_cmp->in(2)->Opcode() == Op_Opaque1, "main loop has no opaque node?")do { if (!(main_cmp->in(2)->Opcode() == Op_Opaque1)) { ( *g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 3268, "assert(" "main_cmp->in(2)->Opcode() == Op_Opaque1" ") failed", "main loop has no opaque node?"); ::breakpoint() ; } } while (0); |
| 3269 | phase->_igvn.replace_input_of(main_cmp, 2, main_cmp->in(2)->in(1)); |
| 3270 | } |
| 3271 | |
| 3272 | //------------------------------do_remove_empty_loop--------------------------- |
| 3273 | // We always attempt remove empty loops. The approach is to replace the trip |
| 3274 | // counter with the value it will have on the last iteration. This will break |
| 3275 | // the loop. |
| 3276 | bool IdealLoopTree::do_remove_empty_loop(PhaseIdealLoop *phase) { |
| 3277 | // Minimum size must be empty loop |
| 3278 | if (_body.size() > EMPTY_LOOP_SIZE) { |
| 3279 | return false; |
| 3280 | } |
| 3281 | if (!_head->is_CountedLoop()) { |
| 3282 | return false; // Dead loop |
| 3283 | } |
| 3284 | CountedLoopNode *cl = _head->as_CountedLoop(); |
| 3285 | if (!cl->is_valid_counted_loop(T_INT)) { |
| 3286 | return false; // Malformed loop |
| 3287 | } |
| 3288 | if (!phase->is_member(this, phase->get_ctrl(cl->loopexit()->in(CountedLoopEndNode::TestValue)))) { |
| 3289 | return false; // Infinite loop |
| 3290 | } |
| 3291 | if (cl->is_pre_loop()) { |
| 3292 | // If the loop we are removing is a pre-loop then the main and post loop |
| 3293 | // can be removed as well. |
| 3294 | remove_main_post_loops(cl, phase); |
| 3295 | } |
| 3296 | |
| 3297 | #ifdef ASSERT1 |
| 3298 | // Ensure only one phi which is the iv. |
| 3299 | Node* iv = NULL__null; |
| 3300 | for (DUIterator_Fast imax, i = cl->fast_outs(imax); i < imax; i++) { |
| 3301 | Node* n = cl->fast_out(i); |
| 3302 | if (n->Opcode() == Op_Phi) { |
| 3303 | assert(iv == NULL, "Too many phis")do { if (!(iv == __null)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 3303, "assert(" "iv == __null" ") failed", "Too many phis") ; ::breakpoint(); } } while (0); |
| 3304 | iv = n; |
| 3305 | } |
| 3306 | } |
| 3307 | assert(iv == cl->phi(), "Wrong phi")do { if (!(iv == cl->phi())) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 3307, "assert(" "iv == cl->phi()" ") failed", "Wrong phi" ); ::breakpoint(); } } while (0); |
| 3308 | #endif |
| 3309 | |
| 3310 | // main and post loops have explicitly created zero trip guard |
| 3311 | bool needs_guard = !cl->is_main_loop() && !cl->is_post_loop(); |
| 3312 | if (needs_guard) { |
| 3313 | // Skip guard if values not overlap. |
| 3314 | const TypeInt* init_t = phase->_igvn.type(cl->init_trip())->is_int(); |
| 3315 | const TypeInt* limit_t = phase->_igvn.type(cl->limit())->is_int(); |
| 3316 | int stride_con = cl->stride_con(); |
| 3317 | if (stride_con > 0) { |
| 3318 | needs_guard = (init_t->_hi >= limit_t->_lo); |
| 3319 | } else { |
| 3320 | needs_guard = (init_t->_lo <= limit_t->_hi); |
| 3321 | } |
| 3322 | } |
| 3323 | if (needs_guard) { |
| 3324 | // Check for an obvious zero trip guard. |
| 3325 | Node* inctrl = PhaseIdealLoop::skip_all_loop_predicates(cl->skip_predicates()); |
| 3326 | if (inctrl->Opcode() == Op_IfTrue || inctrl->Opcode() == Op_IfFalse) { |
| 3327 | bool maybe_swapped = (inctrl->Opcode() == Op_IfFalse); |
| 3328 | // The test should look like just the backedge of a CountedLoop |
| 3329 | Node* iff = inctrl->in(0); |
| 3330 | if (iff->is_If()) { |
| 3331 | Node* bol = iff->in(1); |
| 3332 | if (bol->is_Bool()) { |
| 3333 | BoolTest test = bol->as_Bool()->_test; |
| 3334 | if (maybe_swapped) { |
| 3335 | test._test = test.commute(); |
| 3336 | test._test = test.negate(); |
| 3337 | } |
| 3338 | if (test._test == cl->loopexit()->test_trip()) { |
| 3339 | Node* cmp = bol->in(1); |
| 3340 | int init_idx = maybe_swapped ? 2 : 1; |
| 3341 | int limit_idx = maybe_swapped ? 1 : 2; |
| 3342 | if (cmp->is_Cmp() && cmp->in(init_idx) == cl->init_trip() && cmp->in(limit_idx) == cl->limit()) { |
| 3343 | needs_guard = false; |
| 3344 | } |
| 3345 | } |
| 3346 | } |
| 3347 | } |
| 3348 | } |
| 3349 | } |
| 3350 | |
| 3351 | #ifndef PRODUCT |
| 3352 | if (PrintOpto) { |
| 3353 | tty->print("Removing empty loop with%s zero trip guard", needs_guard ? "out" : ""); |
| 3354 | this->dump_head(); |
| 3355 | } else if (TraceLoopOpts) { |
| 3356 | tty->print("Empty with%s zero trip guard ", needs_guard ? "out" : ""); |
| 3357 | this->dump_head(); |
| 3358 | } |
| 3359 | #endif |
| 3360 | |
| 3361 | if (needs_guard) { |
| 3362 | // Peel the loop to ensure there's a zero trip guard |
| 3363 | Node_List old_new; |
| 3364 | phase->do_peeling(this, old_new); |
| 3365 | } |
| 3366 | |
| 3367 | // Replace the phi at loop head with the final value of the last |
| 3368 | // iteration. Then the CountedLoopEnd will collapse (backedge never |
| 3369 | // taken) and all loop-invariant uses of the exit values will be correct. |
| 3370 | Node *phi = cl->phi(); |
| 3371 | Node *exact_limit = phase->exact_limit(this); |
| 3372 | if (exact_limit != cl->limit()) { |
| 3373 | // We also need to replace the original limit to collapse loop exit. |
| 3374 | Node* cmp = cl->loopexit()->cmp_node(); |
| 3375 | assert(cl->limit() == cmp->in(2), "sanity")do { if (!(cl->limit() == cmp->in(2))) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 3375, "assert(" "cl->limit() == cmp->in(2)" ") failed" , "sanity"); ::breakpoint(); } } while (0); |
| 3376 | // Duplicate cmp node if it has other users |
| 3377 | if (cmp->outcnt() > 1) { |
| 3378 | cmp = cmp->clone(); |
| 3379 | cmp = phase->_igvn.register_new_node_with_optimizer(cmp); |
| 3380 | BoolNode *bol = cl->loopexit()->in(CountedLoopEndNode::TestValue)->as_Bool(); |
| 3381 | phase->_igvn.replace_input_of(bol, 1, cmp); // put bol on worklist |
| 3382 | } |
| 3383 | phase->_igvn._worklist.push(cmp->in(2)); // put limit on worklist |
| 3384 | phase->_igvn.replace_input_of(cmp, 2, exact_limit); // put cmp on worklist |
| 3385 | } |
| 3386 | // Note: the final value after increment should not overflow since |
| 3387 | // counted loop has limit check predicate. |
| 3388 | Node *final = new SubINode(exact_limit, cl->stride()); |
| 3389 | phase->register_new_node(final,cl->in(LoopNode::EntryControl)); |
| 3390 | phase->_igvn.replace_node(phi,final); |
| 3391 | phase->C->set_major_progress(); |
| 3392 | return true; |
| 3393 | } |
| 3394 | |
| 3395 | //------------------------------do_one_iteration_loop-------------------------- |
| 3396 | // Convert one iteration loop into normal code. |
| 3397 | bool IdealLoopTree::do_one_iteration_loop(PhaseIdealLoop *phase) { |
| 3398 | if (!_head->as_Loop()->is_valid_counted_loop(T_INT)) { |
| 3399 | return false; // Only for counted loop |
| 3400 | } |
| 3401 | CountedLoopNode *cl = _head->as_CountedLoop(); |
| 3402 | if (!cl->has_exact_trip_count() || cl->trip_count() != 1) { |
| 3403 | return false; |
| 3404 | } |
| 3405 | |
| 3406 | #ifndef PRODUCT |
| 3407 | if (TraceLoopOpts) { |
| 3408 | tty->print("OneIteration "); |
| 3409 | this->dump_head(); |
| 3410 | } |
| 3411 | #endif |
| 3412 | |
| 3413 | Node *init_n = cl->init_trip(); |
| 3414 | // Loop boundaries should be constant since trip count is exact. |
| 3415 | assert((cl->stride_con() > 0 && init_n->get_int() + cl->stride_con() >= cl->limit()->get_int()) ||do { if (!((cl->stride_con() > 0 && init_n-> get_int() + cl->stride_con() >= cl->limit()->get_int ()) || (cl->stride_con() < 0 && init_n->get_int () + cl->stride_con() <= cl->limit()->get_int())) ) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 3416, "assert(" "(cl->stride_con() > 0 && init_n->get_int() + cl->stride_con() >= cl->limit()->get_int()) || (cl->stride_con() < 0 && init_n->get_int() + cl->stride_con() <= cl->limit()->get_int())" ") failed", "should be one iteration"); ::breakpoint(); } } while (0) |
| 3416 | (cl->stride_con() < 0 && init_n->get_int() + cl->stride_con() <= cl->limit()->get_int()), "should be one iteration")do { if (!((cl->stride_con() > 0 && init_n-> get_int() + cl->stride_con() >= cl->limit()->get_int ()) || (cl->stride_con() < 0 && init_n->get_int () + cl->stride_con() <= cl->limit()->get_int())) ) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 3416, "assert(" "(cl->stride_con() > 0 && init_n->get_int() + cl->stride_con() >= cl->limit()->get_int()) || (cl->stride_con() < 0 && init_n->get_int() + cl->stride_con() <= cl->limit()->get_int())" ") failed", "should be one iteration"); ::breakpoint(); } } while (0); |
| 3417 | // Replace the phi at loop head with the value of the init_trip. |
| 3418 | // Then the CountedLoopEnd will collapse (backedge will not be taken) |
| 3419 | // and all loop-invariant uses of the exit values will be correct. |
| 3420 | phase->_igvn.replace_node(cl->phi(), cl->init_trip()); |
| 3421 | phase->C->set_major_progress(); |
| 3422 | return true; |
| 3423 | } |
| 3424 | |
| 3425 | //============================================================================= |
| 3426 | //------------------------------iteration_split_impl--------------------------- |
| 3427 | bool IdealLoopTree::iteration_split_impl(PhaseIdealLoop *phase, Node_List &old_new) { |
| 3428 | // Compute loop trip count if possible. |
| 3429 | compute_trip_count(phase); |
| 3430 | |
| 3431 | // Convert one iteration loop into normal code. |
| 3432 | if (do_one_iteration_loop(phase)) { |
| 3433 | return true; |
| 3434 | } |
| 3435 | // Check and remove empty loops (spam micro-benchmarks) |
| 3436 | if (do_remove_empty_loop(phase)) { |
| 3437 | return true; // Here we removed an empty loop |
| 3438 | } |
| 3439 | |
| 3440 | AutoNodeBudget node_budget(phase); |
| 3441 | |
| 3442 | // Non-counted loops may be peeled; exactly 1 iteration is peeled. |
| 3443 | // This removes loop-invariant tests (usually null checks). |
| 3444 | if (!_head->is_CountedLoop()) { // Non-counted loop |
| 3445 | if (PartialPeelLoop && phase->partial_peel(this, old_new)) { |
| 3446 | // Partial peel succeeded so terminate this round of loop opts |
| 3447 | return false; |
| 3448 | } |
| 3449 | if (policy_peeling(phase)) { // Should we peel? |
| 3450 | if (PrintOpto) { tty->print_cr("should_peel"); } |
| 3451 | phase->do_peeling(this, old_new); |
| 3452 | } else if (policy_unswitching(phase)) { |
| 3453 | phase->do_unswitching(this, old_new); |
| 3454 | return false; // need to recalculate idom data |
| 3455 | } else if (_head->is_LongCountedLoop()) { |
| 3456 | phase->create_loop_nest(this, old_new); |
| 3457 | } |
| 3458 | return true; |
| 3459 | } |
| 3460 | CountedLoopNode *cl = _head->as_CountedLoop(); |
| 3461 | |
| 3462 | if (!cl->is_valid_counted_loop(T_INT)) return true; // Ignore various kinds of broken loops |
| 3463 | |
| 3464 | // Do nothing special to pre- and post- loops |
| 3465 | if (cl->is_pre_loop() || cl->is_post_loop()) return true; |
| 3466 | |
| 3467 | // Compute loop trip count from profile data |
| 3468 | compute_profile_trip_cnt(phase); |
| 3469 | |
| 3470 | // Before attempting fancy unrolling, RCE or alignment, see if we want |
| 3471 | // to completely unroll this loop or do loop unswitching. |
| 3472 | if (cl->is_normal_loop()) { |
| 3473 | if (policy_unswitching(phase)) { |
| 3474 | phase->do_unswitching(this, old_new); |
| 3475 | return false; // need to recalculate idom data |
| 3476 | } |
| 3477 | if (policy_maximally_unroll(phase)) { |
| 3478 | // Here we did some unrolling and peeling. Eventually we will |
| 3479 | // completely unroll this loop and it will no longer be a loop. |
| 3480 | phase->do_maximally_unroll(this, old_new); |
| 3481 | return true; |
| 3482 | } |
| 3483 | } |
| 3484 | |
| 3485 | uint est_peeling = estimate_peeling(phase); |
| 3486 | bool should_peel = 0 < est_peeling; |
| 3487 | |
| 3488 | // Counted loops may be peeled, or may need some iterations run up |
| 3489 | // front for RCE. Thus we clone a full loop up front whose trip count is |
| 3490 | // at least 1 (if peeling), but may be several more. |
| 3491 | |
| 3492 | // The main loop will start cache-line aligned with at least 1 |
| 3493 | // iteration of the unrolled body (zero-trip test required) and |
| 3494 | // will have some range checks removed. |
| 3495 | |
| 3496 | // A post-loop will finish any odd iterations (leftover after |
| 3497 | // unrolling), plus any needed for RCE purposes. |
| 3498 | |
| 3499 | bool should_unroll = policy_unroll(phase); |
| 3500 | bool should_rce = policy_range_check(phase, false, T_INT); |
| 3501 | bool should_rce_long = policy_range_check(phase, false, T_LONG); |
| 3502 | |
| 3503 | // If not RCE'ing (iteration splitting), then we do not need a pre-loop. |
| 3504 | // We may still need to peel an initial iteration but we will not |
| 3505 | // be needing an unknown number of pre-iterations. |
| 3506 | // |
| 3507 | // Basically, if peel_only reports TRUE first time through, we will not |
| 3508 | // be able to later do RCE on this loop. |
| 3509 | bool peel_only = policy_peel_only(phase) && !should_rce; |
| 3510 | |
| 3511 | // If we have any of these conditions (RCE, unrolling) met, then |
| 3512 | // we switch to the pre-/main-/post-loop model. This model also covers |
| 3513 | // peeling. |
| 3514 | if (should_rce || should_unroll) { |
| 3515 | if (cl->is_normal_loop()) { // Convert to 'pre/main/post' loops |
| 3516 | if (should_rce_long && phase->create_loop_nest(this, old_new)) { |
| 3517 | return true; |
| 3518 | } |
| 3519 | uint estimate = est_loop_clone_sz(3); |
| 3520 | if (!phase->may_require_nodes(estimate)) { |
| 3521 | return false; |
| 3522 | } |
| 3523 | phase->insert_pre_post_loops(this, old_new, peel_only); |
| 3524 | } |
| 3525 | // Adjust the pre- and main-loop limits to let the pre and post loops run |
| 3526 | // with full checks, but the main-loop with no checks. Remove said checks |
| 3527 | // from the main body. |
| 3528 | if (should_rce) { |
| 3529 | if (phase->do_range_check(this, old_new) != 0) { |
| 3530 | cl->mark_has_range_checks(); |
| 3531 | } |
| 3532 | } else if (PostLoopMultiversioning) { |
| 3533 | phase->has_range_checks(this); |
| 3534 | } |
| 3535 | |
| 3536 | if (should_unroll && !should_peel && PostLoopMultiversioning) { |
| 3537 | // Try to setup multiversioning on main loops before they are unrolled |
| 3538 | if (cl->is_main_loop() && (cl->unrolled_count() == 1)) { |
| 3539 | phase->insert_scalar_rced_post_loop(this, old_new); |
| 3540 | } |
| 3541 | } |
| 3542 | |
| 3543 | // Double loop body for unrolling. Adjust the minimum-trip test (will do |
| 3544 | // twice as many iterations as before) and the main body limit (only do |
| 3545 | // an even number of trips). If we are peeling, we might enable some RCE |
| 3546 | // and we'd rather unroll the post-RCE'd loop SO... do not unroll if |
| 3547 | // peeling. |
| 3548 | if (should_unroll && !should_peel) { |
| 3549 | if (SuperWordLoopUnrollAnalysis) { |
| 3550 | phase->insert_vector_post_loop(this, old_new); |
| 3551 | } |
| 3552 | phase->do_unroll(this, old_new, true); |
| 3553 | } |
| 3554 | } else { // Else we have an unchanged counted loop |
| 3555 | if (should_peel) { // Might want to peel but do nothing else |
| 3556 | if (phase->may_require_nodes(est_peeling)) { |
| 3557 | phase->do_peeling(this, old_new); |
| 3558 | } |
| 3559 | } |
| 3560 | if (should_rce_long) { |
| 3561 | phase->create_loop_nest(this, old_new); |
| 3562 | } |
| 3563 | } |
| 3564 | return true; |
| 3565 | } |
| 3566 | |
| 3567 | |
| 3568 | //============================================================================= |
| 3569 | //------------------------------iteration_split-------------------------------- |
| 3570 | bool IdealLoopTree::iteration_split(PhaseIdealLoop* phase, Node_List &old_new) { |
| 3571 | // Recursively iteration split nested loops |
| 3572 | if (_child && !_child->iteration_split(phase, old_new)) { |
| 3573 | return false; |
| 3574 | } |
| 3575 | |
| 3576 | // Clean out prior deadwood |
| 3577 | DCE_loop_body(); |
| 3578 | |
| 3579 | // Look for loop-exit tests with my 50/50 guesses from the Parsing stage. |
| 3580 | // Replace with a 1-in-10 exit guess. |
| 3581 | if (!is_root() && is_loop()) { |
| 3582 | adjust_loop_exit_prob(phase); |
| 3583 | } |
| 3584 | |
| 3585 | // Unrolling, RCE and peeling efforts, iff innermost loop. |
| 3586 | if (_allow_optimizations && is_innermost()) { |
| 3587 | if (!_has_call) { |
| 3588 | if (!iteration_split_impl(phase, old_new)) { |
| 3589 | return false; |
| 3590 | } |
| 3591 | } else { |
| 3592 | AutoNodeBudget node_budget(phase); |
| 3593 | if (policy_unswitching(phase)) { |
| 3594 | phase->do_unswitching(this, old_new); |
| 3595 | return false; // need to recalculate idom data |
| 3596 | } |
| 3597 | } |
| 3598 | } |
| 3599 | |
| 3600 | // Minor offset re-organization to remove loop-fallout uses of |
| 3601 | // trip counter when there was no major reshaping. |
| 3602 | phase->reorg_offsets(this); |
| 3603 | |
| 3604 | if (_next && !_next->iteration_split(phase, old_new)) { |
| 3605 | return false; |
| 3606 | } |
| 3607 | return true; |
| 3608 | } |
| 3609 | |
| 3610 | |
| 3611 | //============================================================================= |
| 3612 | // Process all the loops in the loop tree and replace any fill |
| 3613 | // patterns with an intrinsic version. |
| 3614 | bool PhaseIdealLoop::do_intrinsify_fill() { |
| 3615 | bool changed = false; |
| 3616 | for (LoopTreeIterator iter(_ltree_root); !iter.done(); iter.next()) { |
| 3617 | IdealLoopTree* lpt = iter.current(); |
| 3618 | changed |= intrinsify_fill(lpt); |
| 3619 | } |
| 3620 | return changed; |
| 3621 | } |
| 3622 | |
| 3623 | |
| 3624 | // Examine an inner loop looking for a a single store of an invariant |
| 3625 | // value in a unit stride loop, |
| 3626 | bool PhaseIdealLoop::match_fill_loop(IdealLoopTree* lpt, Node*& store, Node*& store_value, |
| 3627 | Node*& shift, Node*& con) { |
| 3628 | const char* msg = NULL__null; |
| 3629 | Node* msg_node = NULL__null; |
| 3630 | |
| 3631 | store_value = NULL__null; |
| 3632 | con = NULL__null; |
| 3633 | shift = NULL__null; |
| 3634 | |
| 3635 | // Process the loop looking for stores. If there are multiple |
| 3636 | // stores or extra control flow give at this point. |
| 3637 | CountedLoopNode* head = lpt->_head->as_CountedLoop(); |
| 3638 | for (uint i = 0; msg == NULL__null && i < lpt->_body.size(); i++) { |
| 3639 | Node* n = lpt->_body.at(i); |
| 3640 | if (n->outcnt() == 0) continue; // Ignore dead |
| 3641 | if (n->is_Store()) { |
| 3642 | if (store != NULL__null) { |
| 3643 | msg = "multiple stores"; |
| 3644 | break; |
| 3645 | } |
| 3646 | int opc = n->Opcode(); |
| 3647 | if (opc == Op_StoreP || opc == Op_StoreN || opc == Op_StoreNKlass || opc == Op_StoreCM) { |
| 3648 | msg = "oop fills not handled"; |
| 3649 | break; |
| 3650 | } |
| 3651 | Node* value = n->in(MemNode::ValueIn); |
| 3652 | if (!lpt->is_invariant(value)) { |
| 3653 | msg = "variant store value"; |
| 3654 | } else if (!_igvn.type(n->in(MemNode::Address))->isa_aryptr()) { |
| 3655 | msg = "not array address"; |
| 3656 | } |
| 3657 | store = n; |
| 3658 | store_value = value; |
| 3659 | } else if (n->is_If() && n != head->loopexit_or_null()) { |
| 3660 | msg = "extra control flow"; |
| 3661 | msg_node = n; |
| 3662 | } |
| 3663 | } |
| 3664 | |
| 3665 | if (store == NULL__null) { |
| 3666 | // No store in loop |
| 3667 | return false; |
| 3668 | } |
| 3669 | |
| 3670 | if (msg == NULL__null && head->stride_con() != 1) { |
| 3671 | // could handle negative strides too |
| 3672 | if (head->stride_con() < 0) { |
| 3673 | msg = "negative stride"; |
| 3674 | } else { |
| 3675 | msg = "non-unit stride"; |
| 3676 | } |
| 3677 | } |
| 3678 | |
| 3679 | if (msg == NULL__null && !store->in(MemNode::Address)->is_AddP()) { |
| 3680 | msg = "can't handle store address"; |
| 3681 | msg_node = store->in(MemNode::Address); |
| 3682 | } |
| 3683 | |
| 3684 | if (msg == NULL__null && |
| 3685 | (!store->in(MemNode::Memory)->is_Phi() || |
| 3686 | store->in(MemNode::Memory)->in(LoopNode::LoopBackControl) != store)) { |
| 3687 | msg = "store memory isn't proper phi"; |
| 3688 | msg_node = store->in(MemNode::Memory); |
| 3689 | } |
| 3690 | |
| 3691 | // Make sure there is an appropriate fill routine |
| 3692 | BasicType t = store->as_Mem()->memory_type(); |
| 3693 | const char* fill_name; |
| 3694 | if (msg == NULL__null && |
| 3695 | StubRoutines::select_fill_function(t, false, fill_name) == NULL__null) { |
| 3696 | msg = "unsupported store"; |
| 3697 | msg_node = store; |
| 3698 | } |
| 3699 | |
| 3700 | if (msg != NULL__null) { |
| 3701 | #ifndef PRODUCT |
| 3702 | if (TraceOptimizeFill) { |
| 3703 | tty->print_cr("not fill intrinsic candidate: %s", msg); |
| 3704 | if (msg_node != NULL__null) msg_node->dump(); |
| 3705 | } |
| 3706 | #endif |
| 3707 | return false; |
| 3708 | } |
| 3709 | |
| 3710 | // Make sure the address expression can be handled. It should be |
| 3711 | // head->phi * elsize + con. head->phi might have a ConvI2L(CastII()). |
| 3712 | Node* elements[4]; |
| 3713 | Node* cast = NULL__null; |
| 3714 | Node* conv = NULL__null; |
| 3715 | bool found_index = false; |
| 3716 | int count = store->in(MemNode::Address)->as_AddP()->unpack_offsets(elements, ARRAY_SIZE(elements)sizeof(array_size_impl(elements))); |
| 3717 | for (int e = 0; e < count; e++) { |
| 3718 | Node* n = elements[e]; |
| 3719 | if (n->is_Con() && con == NULL__null) { |
| 3720 | con = n; |
| 3721 | } else if (n->Opcode() == Op_LShiftXOp_LShiftL && shift == NULL__null) { |
| 3722 | Node* value = n->in(1); |
| 3723 | #ifdef _LP641 |
| 3724 | if (value->Opcode() == Op_ConvI2L) { |
| 3725 | conv = value; |
| 3726 | value = value->in(1); |
| 3727 | } |
| 3728 | if (value->Opcode() == Op_CastII && |
| 3729 | value->as_CastII()->has_range_check()) { |
| 3730 | // Skip range check dependent CastII nodes |
| 3731 | cast = value; |
| 3732 | value = value->in(1); |
| 3733 | } |
| 3734 | #endif |
| 3735 | if (value != head->phi()) { |
| 3736 | msg = "unhandled shift in address"; |
| 3737 | } else { |
| 3738 | if (type2aelembytes(store->as_Mem()->memory_type(), true) != (1 << n->in(2)->get_int())) { |
| 3739 | msg = "scale doesn't match"; |
| 3740 | } else { |
| 3741 | found_index = true; |
| 3742 | shift = n; |
| 3743 | } |
| 3744 | } |
| 3745 | } else if (n->Opcode() == Op_ConvI2L && conv == NULL__null) { |
| 3746 | conv = n; |
| 3747 | n = n->in(1); |
| 3748 | if (n->Opcode() == Op_CastII && |
| 3749 | n->as_CastII()->has_range_check()) { |
| 3750 | // Skip range check dependent CastII nodes |
| 3751 | cast = n; |
| 3752 | n = n->in(1); |
| 3753 | } |
| 3754 | if (n == head->phi()) { |
| 3755 | found_index = true; |
| 3756 | } else { |
| 3757 | msg = "unhandled input to ConvI2L"; |
| 3758 | } |
| 3759 | } else if (n == head->phi()) { |
| 3760 | // no shift, check below for allowed cases |
| 3761 | found_index = true; |
| 3762 | } else { |
| 3763 | msg = "unhandled node in address"; |
| 3764 | msg_node = n; |
| 3765 | } |
| 3766 | } |
| 3767 | |
| 3768 | if (count == -1) { |
| 3769 | msg = "malformed address expression"; |
| 3770 | msg_node = store; |
| 3771 | } |
| 3772 | |
| 3773 | if (!found_index) { |
| 3774 | msg = "missing use of index"; |
| 3775 | } |
| 3776 | |
| 3777 | // byte sized items won't have a shift |
| 3778 | if (msg == NULL__null && shift == NULL__null && t != T_BYTE && t != T_BOOLEAN) { |
| 3779 | msg = "can't find shift"; |
| 3780 | msg_node = store; |
| 3781 | } |
| 3782 | |
| 3783 | if (msg != NULL__null) { |
| 3784 | #ifndef PRODUCT |
| 3785 | if (TraceOptimizeFill) { |
| 3786 | tty->print_cr("not fill intrinsic: %s", msg); |
| 3787 | if (msg_node != NULL__null) msg_node->dump(); |
| 3788 | } |
| 3789 | #endif |
| 3790 | return false; |
| 3791 | } |
| 3792 | |
| 3793 | // No make sure all the other nodes in the loop can be handled |
| 3794 | VectorSet ok; |
| 3795 | |
| 3796 | // store related values are ok |
| 3797 | ok.set(store->_idx); |
| 3798 | ok.set(store->in(MemNode::Memory)->_idx); |
| 3799 | |
| 3800 | CountedLoopEndNode* loop_exit = head->loopexit(); |
| 3801 | |
| 3802 | // Loop structure is ok |
| 3803 | ok.set(head->_idx); |
| 3804 | ok.set(loop_exit->_idx); |
| 3805 | ok.set(head->phi()->_idx); |
| 3806 | ok.set(head->incr()->_idx); |
| 3807 | ok.set(loop_exit->cmp_node()->_idx); |
| 3808 | ok.set(loop_exit->in(1)->_idx); |
| 3809 | |
| 3810 | // Address elements are ok |
| 3811 | if (con) ok.set(con->_idx); |
| 3812 | if (shift) ok.set(shift->_idx); |
| 3813 | if (cast) ok.set(cast->_idx); |
| 3814 | if (conv) ok.set(conv->_idx); |
| 3815 | |
| 3816 | for (uint i = 0; msg == NULL__null && i < lpt->_body.size(); i++) { |
| 3817 | Node* n = lpt->_body.at(i); |
| 3818 | if (n->outcnt() == 0) continue; // Ignore dead |
| 3819 | if (ok.test(n->_idx)) continue; |
| 3820 | // Backedge projection is ok |
| 3821 | if (n->is_IfTrue() && n->in(0) == loop_exit) continue; |
| 3822 | if (!n->is_AddP()) { |
| 3823 | msg = "unhandled node"; |
| 3824 | msg_node = n; |
| 3825 | break; |
| 3826 | } |
| 3827 | } |
| 3828 | |
| 3829 | // Make sure no unexpected values are used outside the loop |
| 3830 | for (uint i = 0; msg == NULL__null && i < lpt->_body.size(); i++) { |
| 3831 | Node* n = lpt->_body.at(i); |
| 3832 | // These values can be replaced with other nodes if they are used |
| 3833 | // outside the loop. |
| 3834 | if (n == store || n == loop_exit || n == head->incr() || n == store->in(MemNode::Memory)) continue; |
| 3835 | for (SimpleDUIterator iter(n); iter.has_next(); iter.next()) { |
| 3836 | Node* use = iter.get(); |
| 3837 | if (!lpt->_body.contains(use)) { |
| 3838 | msg = "node is used outside loop"; |
| 3839 | msg_node = n; |
| 3840 | break; |
| 3841 | } |
| 3842 | } |
| 3843 | } |
| 3844 | |
| 3845 | #ifdef ASSERT1 |
| 3846 | if (TraceOptimizeFill) { |
| 3847 | if (msg != NULL__null) { |
| 3848 | tty->print_cr("no fill intrinsic: %s", msg); |
| 3849 | if (msg_node != NULL__null) msg_node->dump(); |
| 3850 | } else { |
| 3851 | tty->print_cr("fill intrinsic for:"); |
| 3852 | } |
| 3853 | store->dump(); |
| 3854 | if (Verbose) { |
| 3855 | lpt->_body.dump(); |
| 3856 | } |
| 3857 | } |
| 3858 | #endif |
| 3859 | |
| 3860 | return msg == NULL__null; |
| 3861 | } |
| 3862 | |
| 3863 | |
| 3864 | |
| 3865 | bool PhaseIdealLoop::intrinsify_fill(IdealLoopTree* lpt) { |
| 3866 | // Only for counted inner loops |
| 3867 | if (!lpt->is_counted() || !lpt->is_innermost()) { |
| 3868 | return false; |
| 3869 | } |
| 3870 | |
| 3871 | // Must have constant stride |
| 3872 | CountedLoopNode* head = lpt->_head->as_CountedLoop(); |
| 3873 | if (!head->is_valid_counted_loop(T_INT) || !head->is_normal_loop()) { |
| 3874 | return false; |
| 3875 | } |
| 3876 | |
| 3877 | head->verify_strip_mined(1); |
| 3878 | |
| 3879 | // Check that the body only contains a store of a loop invariant |
| 3880 | // value that is indexed by the loop phi. |
| 3881 | Node* store = NULL__null; |
| 3882 | Node* store_value = NULL__null; |
| 3883 | Node* shift = NULL__null; |
| 3884 | Node* offset = NULL__null; |
| 3885 | if (!match_fill_loop(lpt, store, store_value, shift, offset)) { |
| 3886 | return false; |
| 3887 | } |
| 3888 | |
| 3889 | Node* exit = head->loopexit()->proj_out_or_null(0); |
| 3890 | if (exit == NULL__null) { |
| 3891 | return false; |
| 3892 | } |
| 3893 | |
| 3894 | #ifndef PRODUCT |
| 3895 | if (TraceLoopOpts) { |
| 3896 | tty->print("ArrayFill "); |
| 3897 | lpt->dump_head(); |
| 3898 | } |
| 3899 | #endif |
| 3900 | |
| 3901 | // Now replace the whole loop body by a call to a fill routine that |
| 3902 | // covers the same region as the loop. |
| 3903 | Node* base = store->in(MemNode::Address)->as_AddP()->in(AddPNode::Base); |
| 3904 | |
| 3905 | // Build an expression for the beginning of the copy region |
| 3906 | Node* index = head->init_trip(); |
| 3907 | #ifdef _LP641 |
| 3908 | index = new ConvI2LNode(index); |
| 3909 | _igvn.register_new_node_with_optimizer(index); |
| 3910 | #endif |
| 3911 | if (shift != NULL__null) { |
| 3912 | // byte arrays don't require a shift but others do. |
| 3913 | index = new LShiftXNodeLShiftLNode(index, shift->in(2)); |
| 3914 | _igvn.register_new_node_with_optimizer(index); |
| 3915 | } |
| 3916 | index = new AddPNode(base, base, index); |
| 3917 | _igvn.register_new_node_with_optimizer(index); |
| 3918 | Node* from = new AddPNode(base, index, offset); |
| 3919 | _igvn.register_new_node_with_optimizer(from); |
| 3920 | // Compute the number of elements to copy |
| 3921 | Node* len = new SubINode(head->limit(), head->init_trip()); |
| 3922 | _igvn.register_new_node_with_optimizer(len); |
| 3923 | |
| 3924 | BasicType t = store->as_Mem()->memory_type(); |
| 3925 | bool aligned = false; |
| 3926 | if (offset != NULL__null && head->init_trip()->is_Con()) { |
| 3927 | int element_size = type2aelembytes(t); |
| 3928 | aligned = (offset->find_intptr_t_typefind_long_type()->get_con() + head->init_trip()->get_int() * element_size) % HeapWordSize == 0; |
| 3929 | } |
| 3930 | |
| 3931 | // Build a call to the fill routine |
| 3932 | const char* fill_name; |
| 3933 | address fill = StubRoutines::select_fill_function(t, aligned, fill_name); |
| 3934 | assert(fill != NULL, "what?")do { if (!(fill != __null)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/loopTransform.cpp" , 3934, "assert(" "fill != __null" ") failed", "what?"); ::breakpoint (); } } while (0); |
| 3935 | |
| 3936 | // Convert float/double to int/long for fill routines |
| 3937 | if (t == T_FLOAT) { |
| 3938 | store_value = new MoveF2INode(store_value); |
| 3939 | _igvn.register_new_node_with_optimizer(store_value); |
| 3940 | } else if (t == T_DOUBLE) { |
| 3941 | store_value = new MoveD2LNode(store_value); |
| 3942 | _igvn.register_new_node_with_optimizer(store_value); |
| 3943 | } |
| 3944 | |
| 3945 | Node* mem_phi = store->in(MemNode::Memory); |
| 3946 | Node* result_ctrl; |
| 3947 | Node* result_mem; |
| 3948 | const TypeFunc* call_type = OptoRuntime::array_fill_Type(); |
| 3949 | CallLeafNode *call = new CallLeafNoFPNode(call_type, fill, |
| 3950 | fill_name, TypeAryPtr::get_array_body_type(t)); |
| 3951 | uint cnt = 0; |
| 3952 | call->init_req(TypeFunc::Parms + cnt++, from); |
| 3953 | call->init_req(TypeFunc::Parms + cnt++, store_value); |
| 3954 | #ifdef _LP641 |
| 3955 | len = new ConvI2LNode(len); |
| 3956 | _igvn.register_new_node_with_optimizer(len); |
| 3957 | #endif |
| 3958 | call->init_req(TypeFunc::Parms + cnt++, len); |
| 3959 | #ifdef _LP641 |
| 3960 | call->init_req(TypeFunc::Parms + cnt++, C->top()); |
| 3961 | #endif |
| 3962 | call->init_req(TypeFunc::Control, head->init_control()); |
| 3963 | call->init_req(TypeFunc::I_O, C->top()); // Does no I/O. |
| 3964 | call->init_req(TypeFunc::Memory, mem_phi->in(LoopNode::EntryControl)); |
| 3965 | call->init_req(TypeFunc::ReturnAdr, C->start()->proj_out_or_null(TypeFunc::ReturnAdr)); |
| 3966 | call->init_req(TypeFunc::FramePtr, C->start()->proj_out_or_null(TypeFunc::FramePtr)); |
| 3967 | _igvn.register_new_node_with_optimizer(call); |
| 3968 | result_ctrl = new ProjNode(call,TypeFunc::Control); |
| 3969 | _igvn.register_new_node_with_optimizer(result_ctrl); |
| 3970 | result_mem = new ProjNode(call,TypeFunc::Memory); |
| 3971 | _igvn.register_new_node_with_optimizer(result_mem); |
| 3972 | |
| 3973 | /* Disable following optimization until proper fix (add missing checks). |
| 3974 | |
| 3975 | // If this fill is tightly coupled to an allocation and overwrites |
| 3976 | // the whole body, allow it to take over the zeroing. |
| 3977 | AllocateNode* alloc = AllocateNode::Ideal_allocation(base, this); |
| 3978 | if (alloc != NULL && alloc->is_AllocateArray()) { |
| 3979 | Node* length = alloc->as_AllocateArray()->Ideal_length(); |
| 3980 | if (head->limit() == length && |
| 3981 | head->init_trip() == _igvn.intcon(0)) { |
| 3982 | if (TraceOptimizeFill) { |
| 3983 | tty->print_cr("Eliminated zeroing in allocation"); |
| 3984 | } |
| 3985 | alloc->maybe_set_complete(&_igvn); |
| 3986 | } else { |
| 3987 | #ifdef ASSERT |
| 3988 | if (TraceOptimizeFill) { |
| 3989 | tty->print_cr("filling array but bounds don't match"); |
| 3990 | alloc->dump(); |
| 3991 | head->init_trip()->dump(); |
| 3992 | head->limit()->dump(); |
| 3993 | length->dump(); |
| 3994 | } |
| 3995 | #endif |
| 3996 | } |
| 3997 | } |
| 3998 | */ |
| 3999 | |
| 4000 | if (head->is_strip_mined()) { |
| 4001 | // Inner strip mined loop goes away so get rid of outer strip |
| 4002 | // mined loop |
| 4003 | Node* outer_sfpt = head->outer_safepoint(); |
| 4004 | Node* in = outer_sfpt->in(0); |
| 4005 | Node* outer_out = head->outer_loop_exit(); |
| 4006 | lazy_replace(outer_out, in); |
| 4007 | _igvn.replace_input_of(outer_sfpt, 0, C->top()); |
| 4008 | } |
| 4009 | |
| 4010 | // Redirect the old control and memory edges that are outside the loop. |
| 4011 | // Sometimes the memory phi of the head is used as the outgoing |
| 4012 | // state of the loop. It's safe in this case to replace it with the |
| 4013 | // result_mem. |
| 4014 | _igvn.replace_node(store->in(MemNode::Memory), result_mem); |
| 4015 | lazy_replace(exit, result_ctrl); |
| 4016 | _igvn.replace_node(store, result_mem); |
| 4017 | // Any uses the increment outside of the loop become the loop limit. |
| 4018 | _igvn.replace_node(head->incr(), head->limit()); |
| 4019 | |
| 4020 | // Disconnect the head from the loop. |
| 4021 | for (uint i = 0; i < lpt->_body.size(); i++) { |
| 4022 | Node* n = lpt->_body.at(i); |
| 4023 | _igvn.replace_node(n, C->top()); |
| 4024 | } |
| 4025 | |
| 4026 | return true; |
| 4027 | } |