| File: | jdk/src/hotspot/share/opto/ifnode.cpp |
| Warning: | line 966, column 5 Value stored to 'cond' 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 "ci/ciTypeFlow.hpp" |
| 27 | #include "memory/allocation.inline.hpp" |
| 28 | #include "memory/resourceArea.hpp" |
| 29 | #include "opto/addnode.hpp" |
| 30 | #include "opto/castnode.hpp" |
| 31 | #include "opto/cfgnode.hpp" |
| 32 | #include "opto/connode.hpp" |
| 33 | #include "opto/loopnode.hpp" |
| 34 | #include "opto/phaseX.hpp" |
| 35 | #include "opto/runtime.hpp" |
| 36 | #include "opto/rootnode.hpp" |
| 37 | #include "opto/subnode.hpp" |
| 38 | |
| 39 | // Portions of code courtesy of Clifford Click |
| 40 | |
| 41 | // Optimization - Graph Style |
| 42 | |
| 43 | |
| 44 | #ifndef PRODUCT |
| 45 | extern int explicit_null_checks_elided; |
| 46 | #endif |
| 47 | |
| 48 | //============================================================================= |
| 49 | //------------------------------Value------------------------------------------ |
| 50 | // Return a tuple for whichever arm of the IF is reachable |
| 51 | const Type* IfNode::Value(PhaseGVN* phase) const { |
| 52 | if( !in(0) ) return Type::TOP; |
| 53 | if( phase->type(in(0)) == Type::TOP ) |
| 54 | return Type::TOP; |
| 55 | const Type *t = phase->type(in(1)); |
| 56 | if( t == Type::TOP ) // data is undefined |
| 57 | return TypeTuple::IFNEITHER; // unreachable altogether |
| 58 | if( t == TypeInt::ZERO ) // zero, or false |
| 59 | return TypeTuple::IFFALSE; // only false branch is reachable |
| 60 | if( t == TypeInt::ONE ) // 1, or true |
| 61 | return TypeTuple::IFTRUE; // only true branch is reachable |
| 62 | assert( t == TypeInt::BOOL, "expected boolean type" )do { if (!(t == TypeInt::BOOL)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 62, "assert(" "t == TypeInt::BOOL" ") failed", "expected boolean type" ); ::breakpoint(); } } while (0); |
| 63 | |
| 64 | return TypeTuple::IFBOTH; // No progress |
| 65 | } |
| 66 | |
| 67 | const RegMask &IfNode::out_RegMask() const { |
| 68 | return RegMask::Empty; |
| 69 | } |
| 70 | |
| 71 | //------------------------------split_if--------------------------------------- |
| 72 | // Look for places where we merge constants, then test on the merged value. |
| 73 | // If the IF test will be constant folded on the path with the constant, we |
| 74 | // win by splitting the IF to before the merge point. |
| 75 | static Node* split_if(IfNode *iff, PhaseIterGVN *igvn) { |
| 76 | // I could be a lot more general here, but I'm trying to squeeze this |
| 77 | // in before the Christmas '98 break so I'm gonna be kinda restrictive |
| 78 | // on the patterns I accept. CNC |
| 79 | |
| 80 | // Look for a compare of a constant and a merged value |
| 81 | Node *i1 = iff->in(1); |
| 82 | if( !i1->is_Bool() ) return NULL__null; |
| 83 | BoolNode *b = i1->as_Bool(); |
| 84 | Node *cmp = b->in(1); |
| 85 | if( !cmp->is_Cmp() ) return NULL__null; |
| 86 | i1 = cmp->in(1); |
| 87 | if( i1 == NULL__null || !i1->is_Phi() ) return NULL__null; |
| 88 | PhiNode *phi = i1->as_Phi(); |
| 89 | Node *con2 = cmp->in(2); |
| 90 | if( !con2->is_Con() ) return NULL__null; |
| 91 | // See that the merge point contains some constants |
| 92 | Node *con1=NULL__null; |
| 93 | uint i4; |
| 94 | for( i4 = 1; i4 < phi->req(); i4++ ) { |
| 95 | con1 = phi->in(i4); |
| 96 | if( !con1 ) return NULL__null; // Do not optimize partially collapsed merges |
| 97 | if( con1->is_Con() ) break; // Found a constant |
| 98 | // Also allow null-vs-not-null checks |
| 99 | const TypePtr *tp = igvn->type(con1)->isa_ptr(); |
| 100 | if( tp && tp->_ptr == TypePtr::NotNull ) |
| 101 | break; |
| 102 | } |
| 103 | if( i4 >= phi->req() ) return NULL__null; // Found no constants |
| 104 | |
| 105 | igvn->C->set_has_split_ifs(true); // Has chance for split-if |
| 106 | |
| 107 | // Make sure that the compare can be constant folded away |
| 108 | Node *cmp2 = cmp->clone(); |
| 109 | cmp2->set_req(1,con1); |
| 110 | cmp2->set_req(2,con2); |
| 111 | const Type *t = cmp2->Value(igvn); |
| 112 | // This compare is dead, so whack it! |
| 113 | igvn->remove_dead_node(cmp2); |
| 114 | if( !t->singleton() ) return NULL__null; |
| 115 | |
| 116 | // No intervening control, like a simple Call |
| 117 | Node* r = iff->in(0); |
| 118 | if (!r->is_Region() || r->is_Loop() || phi->region() != r || r->as_Region()->is_copy()) { |
| 119 | return NULL__null; |
| 120 | } |
| 121 | |
| 122 | // No other users of the cmp/bool |
| 123 | if (b->outcnt() != 1 || cmp->outcnt() != 1) { |
| 124 | //tty->print_cr("many users of cmp/bool"); |
| 125 | return NULL__null; |
| 126 | } |
| 127 | |
| 128 | // Make sure we can determine where all the uses of merged values go |
| 129 | for (DUIterator_Fast jmax, j = r->fast_outs(jmax); j < jmax; j++) { |
| 130 | Node* u = r->fast_out(j); |
| 131 | if( u == r ) continue; |
| 132 | if( u == iff ) continue; |
| 133 | if( u->outcnt() == 0 ) continue; // use is dead & ignorable |
| 134 | if( !u->is_Phi() ) { |
| 135 | /* |
| 136 | if( u->is_Start() ) { |
| 137 | tty->print_cr("Region has inlined start use"); |
| 138 | } else { |
| 139 | tty->print_cr("Region has odd use"); |
| 140 | u->dump(2); |
| 141 | }*/ |
| 142 | return NULL__null; |
| 143 | } |
| 144 | if( u != phi ) { |
| 145 | // CNC - do not allow any other merged value |
| 146 | //tty->print_cr("Merging another value"); |
| 147 | //u->dump(2); |
| 148 | return NULL__null; |
| 149 | } |
| 150 | // Make sure we can account for all Phi uses |
| 151 | for (DUIterator_Fast kmax, k = u->fast_outs(kmax); k < kmax; k++) { |
| 152 | Node* v = u->fast_out(k); // User of the phi |
| 153 | // CNC - Allow only really simple patterns. |
| 154 | // In particular I disallow AddP of the Phi, a fairly common pattern |
| 155 | if (v == cmp) continue; // The compare is OK |
| 156 | if (v->is_ConstraintCast()) { |
| 157 | // If the cast is derived from data flow edges, it may not have a control edge. |
| 158 | // If so, it should be safe to split. But follow-up code can not deal with |
| 159 | // this (l. 359). So skip. |
| 160 | if (v->in(0) == NULL__null) { |
| 161 | return NULL__null; |
| 162 | } |
| 163 | if (v->in(0)->in(0) == iff) { |
| 164 | continue; // CastPP/II of the IfNode is OK |
| 165 | } |
| 166 | } |
| 167 | // Disabled following code because I cannot tell if exactly one |
| 168 | // path dominates without a real dominator check. CNC 9/9/1999 |
| 169 | //uint vop = v->Opcode(); |
| 170 | //if( vop == Op_Phi ) { // Phi from another merge point might be OK |
| 171 | // Node *r = v->in(0); // Get controlling point |
| 172 | // if( !r ) return NULL; // Degraded to a copy |
| 173 | // // Find exactly one path in (either True or False doms, but not IFF) |
| 174 | // int cnt = 0; |
| 175 | // for( uint i = 1; i < r->req(); i++ ) |
| 176 | // if( r->in(i) && r->in(i)->in(0) == iff ) |
| 177 | // cnt++; |
| 178 | // if( cnt == 1 ) continue; // Exactly one of True or False guards Phi |
| 179 | //} |
| 180 | if( !v->is_Call() ) { |
| 181 | /* |
| 182 | if( v->Opcode() == Op_AddP ) { |
| 183 | tty->print_cr("Phi has AddP use"); |
| 184 | } else if( v->Opcode() == Op_CastPP ) { |
| 185 | tty->print_cr("Phi has CastPP use"); |
| 186 | } else if( v->Opcode() == Op_CastII ) { |
| 187 | tty->print_cr("Phi has CastII use"); |
| 188 | } else { |
| 189 | tty->print_cr("Phi has use I cant be bothered with"); |
| 190 | } |
| 191 | */ |
| 192 | } |
| 193 | return NULL__null; |
| 194 | |
| 195 | /* CNC - Cut out all the fancy acceptance tests |
| 196 | // Can we clone this use when doing the transformation? |
| 197 | // If all uses are from Phis at this merge or constants, then YES. |
| 198 | if( !v->in(0) && v != cmp ) { |
| 199 | tty->print_cr("Phi has free-floating use"); |
| 200 | v->dump(2); |
| 201 | return NULL; |
| 202 | } |
| 203 | for( uint l = 1; l < v->req(); l++ ) { |
| 204 | if( (!v->in(l)->is_Phi() || v->in(l)->in(0) != r) && |
| 205 | !v->in(l)->is_Con() ) { |
| 206 | tty->print_cr("Phi has use"); |
| 207 | v->dump(2); |
| 208 | return NULL; |
| 209 | } // End of if Phi-use input is neither Phi nor Constant |
| 210 | } // End of for all inputs to Phi-use |
| 211 | */ |
| 212 | } // End of for all uses of Phi |
| 213 | } // End of for all uses of Region |
| 214 | |
| 215 | // Only do this if the IF node is in a sane state |
| 216 | if (iff->outcnt() != 2) |
| 217 | return NULL__null; |
| 218 | |
| 219 | // Got a hit! Do the Mondo Hack! |
| 220 | // |
| 221 | //ABC a1c def ghi B 1 e h A C a c d f g i |
| 222 | // R - Phi - Phi - Phi Rc - Phi - Phi - Phi Rx - Phi - Phi - Phi |
| 223 | // cmp - 2 cmp - 2 cmp - 2 |
| 224 | // bool bool_c bool_x |
| 225 | // if if_c if_x |
| 226 | // T F T F T F |
| 227 | // ..s.. ..t .. ..s.. ..t.. ..s.. ..t.. |
| 228 | // |
| 229 | // Split the paths coming into the merge point into 2 separate groups of |
| 230 | // merges. On the left will be all the paths feeding constants into the |
| 231 | // Cmp's Phi. On the right will be the remaining paths. The Cmp's Phi |
| 232 | // will fold up into a constant; this will let the Cmp fold up as well as |
| 233 | // all the control flow. Below the original IF we have 2 control |
| 234 | // dependent regions, 's' and 't'. Now we will merge the two paths |
| 235 | // just prior to 's' and 't' from the two IFs. At least 1 path (and quite |
| 236 | // likely 2 or more) will promptly constant fold away. |
| 237 | PhaseGVN *phase = igvn; |
| 238 | |
| 239 | // Make a region merging constants and a region merging the rest |
| 240 | uint req_c = 0; |
| 241 | for (uint ii = 1; ii < r->req(); ii++) { |
| 242 | if (phi->in(ii) == con1) { |
| 243 | req_c++; |
| 244 | } |
| 245 | Node* proj = PhaseIdealLoop::find_predicate(r->in(ii)); |
| 246 | if (proj != NULL__null) { |
| 247 | // Bail out if splitting through a region with a predicate input (could |
| 248 | // also be a loop header before loop opts creates a LoopNode for it). |
| 249 | return NULL__null; |
| 250 | } |
| 251 | } |
| 252 | |
| 253 | // If all the defs of the phi are the same constant, we already have the desired end state. |
| 254 | // Skip the split that would create empty phi and region nodes. |
| 255 | if ((r->req() - req_c) == 1) { |
| 256 | return NULL__null; |
| 257 | } |
| 258 | |
| 259 | // At this point we know that we can apply the split if optimization. If the region is still on the worklist, |
| 260 | // we should wait until it is processed. The region might be removed which makes this optimization redundant. |
| 261 | // This also avoids the creation of dead data loops when rewiring data nodes below when a region is dying. |
| 262 | if (igvn->_worklist.member(r)) { |
| 263 | igvn->_worklist.push(iff); // retry split if later again |
| 264 | return NULL__null; |
| 265 | } |
| 266 | |
| 267 | Node *region_c = new RegionNode(req_c + 1); |
| 268 | Node *phi_c = con1; |
| 269 | uint len = r->req(); |
| 270 | Node *region_x = new RegionNode(len - req_c); |
| 271 | Node *phi_x = PhiNode::make_blank(region_x, phi); |
| 272 | for (uint i = 1, i_c = 1, i_x = 1; i < len; i++) { |
| 273 | if (phi->in(i) == con1) { |
| 274 | region_c->init_req( i_c++, r ->in(i) ); |
| 275 | } else { |
| 276 | region_x->init_req( i_x, r ->in(i) ); |
| 277 | phi_x ->init_req( i_x++, phi->in(i) ); |
| 278 | } |
| 279 | } |
| 280 | |
| 281 | // Register the new RegionNodes but do not transform them. Cannot |
| 282 | // transform until the entire Region/Phi conglomerate has been hacked |
| 283 | // as a single huge transform. |
| 284 | igvn->register_new_node_with_optimizer( region_c ); |
| 285 | igvn->register_new_node_with_optimizer( region_x ); |
| 286 | // Prevent the untimely death of phi_x. Currently he has no uses. He is |
| 287 | // about to get one. If this only use goes away, then phi_x will look dead. |
| 288 | // However, he will be picking up some more uses down below. |
| 289 | Node *hook = new Node(4); |
| 290 | hook->init_req(0, phi_x); |
| 291 | hook->init_req(1, phi_c); |
| 292 | phi_x = phase->transform( phi_x ); |
| 293 | |
| 294 | // Make the compare |
| 295 | Node *cmp_c = phase->makecon(t); |
| 296 | Node *cmp_x = cmp->clone(); |
| 297 | cmp_x->set_req(1,phi_x); |
| 298 | cmp_x->set_req(2,con2); |
| 299 | cmp_x = phase->transform(cmp_x); |
| 300 | // Make the bool |
| 301 | Node *b_c = phase->transform(new BoolNode(cmp_c,b->_test._test)); |
| 302 | Node *b_x = phase->transform(new BoolNode(cmp_x,b->_test._test)); |
| 303 | // Make the IfNode |
| 304 | IfNode* iff_c = iff->clone()->as_If(); |
| 305 | iff_c->set_req(0, region_c); |
| 306 | iff_c->set_req(1, b_c); |
| 307 | igvn->set_type_bottom(iff_c); |
| 308 | igvn->_worklist.push(iff_c); |
| 309 | hook->init_req(2, iff_c); |
| 310 | |
| 311 | IfNode* iff_x = iff->clone()->as_If(); |
| 312 | iff_x->set_req(0, region_x); |
| 313 | iff_x->set_req(1, b_x); |
| 314 | igvn->set_type_bottom(iff_x); |
| 315 | igvn->_worklist.push(iff_x); |
| 316 | hook->init_req(3, iff_x); |
| 317 | |
| 318 | // Make the true/false arms |
| 319 | Node *iff_c_t = phase->transform(new IfTrueNode (iff_c)); |
| 320 | Node *iff_c_f = phase->transform(new IfFalseNode(iff_c)); |
| 321 | Node *iff_x_t = phase->transform(new IfTrueNode (iff_x)); |
| 322 | Node *iff_x_f = phase->transform(new IfFalseNode(iff_x)); |
| 323 | |
| 324 | // Merge the TRUE paths |
| 325 | Node *region_s = new RegionNode(3); |
| 326 | igvn->_worklist.push(region_s); |
| 327 | region_s->init_req(1, iff_c_t); |
| 328 | region_s->init_req(2, iff_x_t); |
| 329 | igvn->register_new_node_with_optimizer( region_s ); |
| 330 | |
| 331 | // Merge the FALSE paths |
| 332 | Node *region_f = new RegionNode(3); |
| 333 | igvn->_worklist.push(region_f); |
| 334 | region_f->init_req(1, iff_c_f); |
| 335 | region_f->init_req(2, iff_x_f); |
| 336 | igvn->register_new_node_with_optimizer( region_f ); |
| 337 | |
| 338 | igvn->hash_delete(cmp);// Remove soon-to-be-dead node from hash table. |
| 339 | cmp->set_req(1,NULL__null); // Whack the inputs to cmp because it will be dead |
| 340 | cmp->set_req(2,NULL__null); |
| 341 | // Check for all uses of the Phi and give them a new home. |
| 342 | // The 'cmp' got cloned, but CastPP/IIs need to be moved. |
| 343 | Node *phi_s = NULL__null; // do not construct unless needed |
| 344 | Node *phi_f = NULL__null; // do not construct unless needed |
| 345 | for (DUIterator_Last i2min, i2 = phi->last_outs(i2min); i2 >= i2min; --i2) { |
| 346 | Node* v = phi->last_out(i2);// User of the phi |
| 347 | igvn->rehash_node_delayed(v); // Have to fixup other Phi users |
| 348 | uint vop = v->Opcode(); |
| 349 | Node *proj = NULL__null; |
| 350 | if( vop == Op_Phi ) { // Remote merge point |
| 351 | Node *r = v->in(0); |
| 352 | for (uint i3 = 1; i3 < r->req(); i3++) |
| 353 | if (r->in(i3) && r->in(i3)->in(0) == iff) { |
| 354 | proj = r->in(i3); |
| 355 | break; |
| 356 | } |
| 357 | } else if( v->is_ConstraintCast() ) { |
| 358 | proj = v->in(0); // Controlling projection |
| 359 | } else { |
| 360 | assert( 0, "do not know how to handle this guy" )do { if (!(0)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 360, "assert(" "0" ") failed", "do not know how to handle this guy" ); ::breakpoint(); } } while (0); |
| 361 | } |
| 362 | guarantee(proj != NULL, "sanity")do { if (!(proj != __null)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 362, "guarantee(" "proj != NULL" ") failed", "sanity"); ::breakpoint (); } } while (0); |
| 363 | |
| 364 | Node *proj_path_data, *proj_path_ctrl; |
| 365 | if( proj->Opcode() == Op_IfTrue ) { |
| 366 | if( phi_s == NULL__null ) { |
| 367 | // Only construct phi_s if needed, otherwise provides |
| 368 | // interfering use. |
| 369 | phi_s = PhiNode::make_blank(region_s,phi); |
| 370 | phi_s->init_req( 1, phi_c ); |
| 371 | phi_s->init_req( 2, phi_x ); |
| 372 | hook->add_req(phi_s); |
| 373 | phi_s = phase->transform(phi_s); |
| 374 | } |
| 375 | proj_path_data = phi_s; |
| 376 | proj_path_ctrl = region_s; |
| 377 | } else { |
| 378 | if( phi_f == NULL__null ) { |
| 379 | // Only construct phi_f if needed, otherwise provides |
| 380 | // interfering use. |
| 381 | phi_f = PhiNode::make_blank(region_f,phi); |
| 382 | phi_f->init_req( 1, phi_c ); |
| 383 | phi_f->init_req( 2, phi_x ); |
| 384 | hook->add_req(phi_f); |
| 385 | phi_f = phase->transform(phi_f); |
| 386 | } |
| 387 | proj_path_data = phi_f; |
| 388 | proj_path_ctrl = region_f; |
| 389 | } |
| 390 | |
| 391 | // Fixup 'v' for for the split |
| 392 | if( vop == Op_Phi ) { // Remote merge point |
| 393 | uint i; |
| 394 | for( i = 1; i < v->req(); i++ ) |
| 395 | if( v->in(i) == phi ) |
| 396 | break; |
| 397 | v->set_req(i, proj_path_data ); |
| 398 | } else if( v->is_ConstraintCast() ) { |
| 399 | v->set_req(0, proj_path_ctrl ); |
| 400 | v->set_req(1, proj_path_data ); |
| 401 | } else |
| 402 | ShouldNotReachHere()do { (*g_assert_poison) = 'X';; report_should_not_reach_here( "/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 402); ::breakpoint(); } while (0); |
| 403 | } |
| 404 | |
| 405 | // Now replace the original iff's True/False with region_s/region_t. |
| 406 | // This makes the original iff go dead. |
| 407 | for (DUIterator_Last i3min, i3 = iff->last_outs(i3min); i3 >= i3min; --i3) { |
| 408 | Node* p = iff->last_out(i3); |
| 409 | assert( p->Opcode() == Op_IfTrue || p->Opcode() == Op_IfFalse, "" )do { if (!(p->Opcode() == Op_IfTrue || p->Opcode() == Op_IfFalse )) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 409, "assert(" "p->Opcode() == Op_IfTrue || p->Opcode() == Op_IfFalse" ") failed", ""); ::breakpoint(); } } while (0); |
| 410 | Node *u = (p->Opcode() == Op_IfTrue) ? region_s : region_f; |
| 411 | // Replace p with u |
| 412 | igvn->add_users_to_worklist(p); |
| 413 | for (DUIterator_Last lmin, l = p->last_outs(lmin); l >= lmin;) { |
| 414 | Node* x = p->last_out(l); |
| 415 | igvn->hash_delete(x); |
| 416 | uint uses_found = 0; |
| 417 | for( uint j = 0; j < x->req(); j++ ) { |
| 418 | if( x->in(j) == p ) { |
| 419 | x->set_req(j, u); |
| 420 | uses_found++; |
| 421 | } |
| 422 | } |
| 423 | l -= uses_found; // we deleted 1 or more copies of this edge |
| 424 | } |
| 425 | igvn->remove_dead_node(p); |
| 426 | } |
| 427 | |
| 428 | // Force the original merge dead |
| 429 | igvn->hash_delete(r); |
| 430 | // First, remove region's dead users. |
| 431 | for (DUIterator_Last lmin, l = r->last_outs(lmin); l >= lmin;) { |
| 432 | Node* u = r->last_out(l); |
| 433 | if( u == r ) { |
| 434 | r->set_req(0, NULL__null); |
| 435 | } else { |
| 436 | assert(u->outcnt() == 0, "only dead users")do { if (!(u->outcnt() == 0)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 436, "assert(" "u->outcnt() == 0" ") failed", "only dead users" ); ::breakpoint(); } } while (0); |
| 437 | igvn->remove_dead_node(u); |
| 438 | } |
| 439 | l -= 1; |
| 440 | } |
| 441 | igvn->remove_dead_node(r); |
| 442 | |
| 443 | // Now remove the bogus extra edges used to keep things alive |
| 444 | igvn->remove_dead_node( hook ); |
| 445 | |
| 446 | // Must return either the original node (now dead) or a new node |
| 447 | // (Do not return a top here, since that would break the uniqueness of top.) |
| 448 | return new ConINode(TypeInt::ZERO); |
| 449 | } |
| 450 | |
| 451 | // if this IfNode follows a range check pattern return the projection |
| 452 | // for the failed path |
| 453 | ProjNode* IfNode::range_check_trap_proj(int& flip_test, Node*& l, Node*& r) { |
| 454 | if (outcnt() != 2) { |
| 455 | return NULL__null; |
| 456 | } |
| 457 | Node* b = in(1); |
| 458 | if (b == NULL__null || !b->is_Bool()) return NULL__null; |
| 459 | BoolNode* bn = b->as_Bool(); |
| 460 | Node* cmp = bn->in(1); |
| 461 | if (cmp == NULL__null) return NULL__null; |
| 462 | if (cmp->Opcode() != Op_CmpU) return NULL__null; |
| 463 | |
| 464 | l = cmp->in(1); |
| 465 | r = cmp->in(2); |
| 466 | flip_test = 1; |
| 467 | if (bn->_test._test == BoolTest::le) { |
| 468 | l = cmp->in(2); |
| 469 | r = cmp->in(1); |
| 470 | flip_test = 2; |
| 471 | } else if (bn->_test._test != BoolTest::lt) { |
| 472 | return NULL__null; |
| 473 | } |
| 474 | if (l->is_top()) return NULL__null; // Top input means dead test |
| 475 | if (r->Opcode() != Op_LoadRange && !is_RangeCheck()) return NULL__null; |
| 476 | |
| 477 | // We have recognized one of these forms: |
| 478 | // Flip 1: If (Bool[<] CmpU(l, LoadRange)) ... |
| 479 | // Flip 2: If (Bool[<=] CmpU(LoadRange, l)) ... |
| 480 | |
| 481 | ProjNode* iftrap = proj_out_or_null(flip_test == 2 ? true : false); |
| 482 | return iftrap; |
| 483 | } |
| 484 | |
| 485 | |
| 486 | //------------------------------is_range_check--------------------------------- |
| 487 | // Return 0 if not a range check. Return 1 if a range check and set index and |
| 488 | // offset. Return 2 if we had to negate the test. Index is NULL if the check |
| 489 | // is versus a constant. |
| 490 | int RangeCheckNode::is_range_check(Node* &range, Node* &index, jint &offset) { |
| 491 | int flip_test = 0; |
| 492 | Node* l = NULL__null; |
| 493 | Node* r = NULL__null; |
| 494 | ProjNode* iftrap = range_check_trap_proj(flip_test, l, r); |
| 495 | |
| 496 | if (iftrap == NULL__null) { |
| 497 | return 0; |
| 498 | } |
| 499 | |
| 500 | // Make sure it's a real range check by requiring an uncommon trap |
| 501 | // along the OOB path. Otherwise, it's possible that the user wrote |
| 502 | // something which optimized to look like a range check but behaves |
| 503 | // in some other way. |
| 504 | if (iftrap->is_uncommon_trap_proj(Deoptimization::Reason_range_check) == NULL__null) { |
| 505 | return 0; |
| 506 | } |
| 507 | |
| 508 | // Look for index+offset form |
| 509 | Node* ind = l; |
| 510 | jint off = 0; |
| 511 | if (l->is_top()) { |
| 512 | return 0; |
| 513 | } else if (l->Opcode() == Op_AddI) { |
| 514 | if ((off = l->in(1)->find_int_con(0)) != 0) { |
| 515 | ind = l->in(2)->uncast(); |
| 516 | } else if ((off = l->in(2)->find_int_con(0)) != 0) { |
| 517 | ind = l->in(1)->uncast(); |
| 518 | } |
| 519 | } else if ((off = l->find_int_con(-1)) >= 0) { |
| 520 | // constant offset with no variable index |
| 521 | ind = NULL__null; |
| 522 | } else { |
| 523 | // variable index with no constant offset (or dead negative index) |
| 524 | off = 0; |
| 525 | } |
| 526 | |
| 527 | // Return all the values: |
| 528 | index = ind; |
| 529 | offset = off; |
| 530 | range = r; |
| 531 | return flip_test; |
| 532 | } |
| 533 | |
| 534 | //------------------------------adjust_check----------------------------------- |
| 535 | // Adjust (widen) a prior range check |
| 536 | static void adjust_check(Node* proj, Node* range, Node* index, |
| 537 | int flip, jint off_lo, PhaseIterGVN* igvn) { |
| 538 | PhaseGVN *gvn = igvn; |
| 539 | // Break apart the old check |
| 540 | Node *iff = proj->in(0); |
| 541 | Node *bol = iff->in(1); |
| 542 | if( bol->is_top() ) return; // In case a partially dead range check appears |
| 543 | // bail (or bomb[ASSERT/DEBUG]) if NOT projection-->IfNode-->BoolNode |
| 544 | DEBUG_ONLY( if( !bol->is_Bool() ) { proj->dump(3); fatal("Expect projection-->IfNode-->BoolNode"); } )if( !bol->is_Bool() ) { proj->dump(3); do { (*g_assert_poison ) = 'X';; report_fatal(INTERNAL_ERROR, "/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 544, "Expect projection-->IfNode-->BoolNode"); ::breakpoint (); } while (0); } |
| 545 | if( !bol->is_Bool() ) return; |
| 546 | |
| 547 | Node *cmp = bol->in(1); |
| 548 | // Compute a new check |
| 549 | Node *new_add = gvn->intcon(off_lo); |
| 550 | if( index ) { |
| 551 | new_add = off_lo ? gvn->transform(new AddINode( index, new_add )) : index; |
| 552 | } |
| 553 | Node *new_cmp = (flip == 1) |
| 554 | ? new CmpUNode( new_add, range ) |
| 555 | : new CmpUNode( range, new_add ); |
| 556 | new_cmp = gvn->transform(new_cmp); |
| 557 | // See if no need to adjust the existing check |
| 558 | if( new_cmp == cmp ) return; |
| 559 | // Else, adjust existing check |
| 560 | Node *new_bol = gvn->transform( new BoolNode( new_cmp, bol->as_Bool()->_test._test ) ); |
| 561 | igvn->rehash_node_delayed( iff ); |
| 562 | iff->set_req_X( 1, new_bol, igvn ); |
| 563 | } |
| 564 | |
| 565 | //------------------------------up_one_dom------------------------------------- |
| 566 | // Walk up the dominator tree one step. Return NULL at root or true |
| 567 | // complex merges. Skips through small diamonds. |
| 568 | Node* IfNode::up_one_dom(Node *curr, bool linear_only) { |
| 569 | Node *dom = curr->in(0); |
| 570 | if( !dom ) // Found a Region degraded to a copy? |
| 571 | return curr->nonnull_req(); // Skip thru it |
| 572 | |
| 573 | if( curr != dom ) // Normal walk up one step? |
| 574 | return dom; |
| 575 | |
| 576 | // Use linear_only if we are still parsing, since we cannot |
| 577 | // trust the regions to be fully filled in. |
| 578 | if (linear_only) |
| 579 | return NULL__null; |
| 580 | |
| 581 | if( dom->is_Root() ) |
| 582 | return NULL__null; |
| 583 | |
| 584 | // Else hit a Region. Check for a loop header |
| 585 | if( dom->is_Loop() ) |
| 586 | return dom->in(1); // Skip up thru loops |
| 587 | |
| 588 | // Check for small diamonds |
| 589 | Node *din1, *din2, *din3, *din4; |
| 590 | if( dom->req() == 3 && // 2-path merge point |
| 591 | (din1 = dom ->in(1)) && // Left path exists |
| 592 | (din2 = dom ->in(2)) && // Right path exists |
| 593 | (din3 = din1->in(0)) && // Left path up one |
| 594 | (din4 = din2->in(0)) ) { // Right path up one |
| 595 | if( din3->is_Call() && // Handle a slow-path call on either arm |
| 596 | (din3 = din3->in(0)) ) |
| 597 | din3 = din3->in(0); |
| 598 | if( din4->is_Call() && // Handle a slow-path call on either arm |
| 599 | (din4 = din4->in(0)) ) |
| 600 | din4 = din4->in(0); |
| 601 | if (din3 != NULL__null && din3 == din4 && din3->is_If()) // Regions not degraded to a copy |
| 602 | return din3; // Skip around diamonds |
| 603 | } |
| 604 | |
| 605 | // Give up the search at true merges |
| 606 | return NULL__null; // Dead loop? Or hit root? |
| 607 | } |
| 608 | |
| 609 | |
| 610 | //------------------------------filtered_int_type-------------------------------- |
| 611 | // Return a possibly more restrictive type for val based on condition control flow for an if |
| 612 | const TypeInt* IfNode::filtered_int_type(PhaseGVN* gvn, Node* val, Node* if_proj) { |
| 613 | assert(if_proj &&do { if (!(if_proj && (if_proj->Opcode() == Op_IfTrue || if_proj->Opcode() == Op_IfFalse))) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 614, "assert(" "if_proj && (if_proj->Opcode() == Op_IfTrue || if_proj->Opcode() == Op_IfFalse)" ") failed", "expecting an if projection"); ::breakpoint(); } } while (0) |
| 614 | (if_proj->Opcode() == Op_IfTrue || if_proj->Opcode() == Op_IfFalse), "expecting an if projection")do { if (!(if_proj && (if_proj->Opcode() == Op_IfTrue || if_proj->Opcode() == Op_IfFalse))) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 614, "assert(" "if_proj && (if_proj->Opcode() == Op_IfTrue || if_proj->Opcode() == Op_IfFalse)" ") failed", "expecting an if projection"); ::breakpoint(); } } while (0); |
| 615 | if (if_proj->in(0) && if_proj->in(0)->is_If()) { |
| 616 | IfNode* iff = if_proj->in(0)->as_If(); |
| 617 | if (iff->in(1) && iff->in(1)->is_Bool()) { |
| 618 | BoolNode* bol = iff->in(1)->as_Bool(); |
| 619 | if (bol->in(1) && bol->in(1)->is_Cmp()) { |
| 620 | const CmpNode* cmp = bol->in(1)->as_Cmp(); |
| 621 | if (cmp->in(1) == val) { |
| 622 | const TypeInt* cmp2_t = gvn->type(cmp->in(2))->isa_int(); |
| 623 | if (cmp2_t != NULL__null) { |
| 624 | jint lo = cmp2_t->_lo; |
| 625 | jint hi = cmp2_t->_hi; |
| 626 | BoolTest::mask msk = if_proj->Opcode() == Op_IfTrue ? bol->_test._test : bol->_test.negate(); |
| 627 | switch (msk) { |
| 628 | case BoolTest::ne: { |
| 629 | // If val is compared to its lower or upper bound, we can narrow the type |
| 630 | const TypeInt* val_t = gvn->type(val)->isa_int(); |
| 631 | if (val_t != NULL__null && !val_t->singleton() && cmp2_t->is_con()) { |
| 632 | if (val_t->_lo == lo) { |
| 633 | return TypeInt::make(val_t->_lo + 1, val_t->_hi, val_t->_widen); |
| 634 | } else if (val_t->_hi == hi) { |
| 635 | return TypeInt::make(val_t->_lo, val_t->_hi - 1, val_t->_widen); |
| 636 | } |
| 637 | } |
| 638 | // Can't refine type |
| 639 | return NULL__null; |
| 640 | } |
| 641 | case BoolTest::eq: |
| 642 | return cmp2_t; |
| 643 | case BoolTest::lt: |
| 644 | lo = TypeInt::INT->_lo; |
| 645 | if (hi != min_jint) { |
| 646 | hi = hi - 1; |
| 647 | } |
| 648 | break; |
| 649 | case BoolTest::le: |
| 650 | lo = TypeInt::INT->_lo; |
| 651 | break; |
| 652 | case BoolTest::gt: |
| 653 | if (lo != max_jint) { |
| 654 | lo = lo + 1; |
| 655 | } |
| 656 | hi = TypeInt::INT->_hi; |
| 657 | break; |
| 658 | case BoolTest::ge: |
| 659 | // lo unchanged |
| 660 | hi = TypeInt::INT->_hi; |
| 661 | break; |
| 662 | default: |
| 663 | break; |
| 664 | } |
| 665 | const TypeInt* rtn_t = TypeInt::make(lo, hi, cmp2_t->_widen); |
| 666 | return rtn_t; |
| 667 | } |
| 668 | } |
| 669 | } |
| 670 | } |
| 671 | } |
| 672 | return NULL__null; |
| 673 | } |
| 674 | |
| 675 | //------------------------------fold_compares---------------------------- |
| 676 | // See if a pair of CmpIs can be converted into a CmpU. In some cases |
| 677 | // the direction of this if is determined by the preceding if so it |
| 678 | // can be eliminate entirely. |
| 679 | // |
| 680 | // Given an if testing (CmpI n v) check for an immediately control |
| 681 | // dependent if that is testing (CmpI n v2) and has one projection |
| 682 | // leading to this if and the other projection leading to a region |
| 683 | // that merges one of this ifs control projections. |
| 684 | // |
| 685 | // If |
| 686 | // / | |
| 687 | // / | |
| 688 | // / | |
| 689 | // If | |
| 690 | // /\ | |
| 691 | // / \ | |
| 692 | // / \ | |
| 693 | // / Region |
| 694 | // |
| 695 | // Or given an if testing (CmpI n v) check for a dominating if that is |
| 696 | // testing (CmpI n v2), both having one projection leading to an |
| 697 | // uncommon trap. Allow Another independent guard in between to cover |
| 698 | // an explicit range check: |
| 699 | // if (index < 0 || index >= array.length) { |
| 700 | // which may need a null check to guard the LoadRange |
| 701 | // |
| 702 | // If |
| 703 | // / \ |
| 704 | // / \ |
| 705 | // / \ |
| 706 | // If unc |
| 707 | // /\ |
| 708 | // / \ |
| 709 | // / \ |
| 710 | // / unc |
| 711 | // |
| 712 | |
| 713 | // Is the comparison for this If suitable for folding? |
| 714 | bool IfNode::cmpi_folds(PhaseIterGVN* igvn, bool fold_ne) { |
| 715 | return in(1) != NULL__null && |
| 716 | in(1)->is_Bool() && |
| 717 | in(1)->in(1) != NULL__null && |
| 718 | in(1)->in(1)->Opcode() == Op_CmpI && |
| 719 | in(1)->in(1)->in(2) != NULL__null && |
| 720 | in(1)->in(1)->in(2) != igvn->C->top() && |
| 721 | (in(1)->as_Bool()->_test.is_less() || |
| 722 | in(1)->as_Bool()->_test.is_greater() || |
| 723 | (fold_ne && in(1)->as_Bool()->_test._test == BoolTest::ne)); |
| 724 | } |
| 725 | |
| 726 | // Is a dominating control suitable for folding with this if? |
| 727 | bool IfNode::is_ctrl_folds(Node* ctrl, PhaseIterGVN* igvn) { |
| 728 | return ctrl != NULL__null && |
| 729 | ctrl->is_Proj() && |
| 730 | ctrl->in(0) != NULL__null && |
| 731 | ctrl->in(0)->Opcode() == Op_If && |
| 732 | ctrl->in(0)->outcnt() == 2 && |
| 733 | ctrl->in(0)->as_If()->cmpi_folds(igvn, true) && |
| 734 | // Must compare same value |
| 735 | ctrl->in(0)->in(1)->in(1)->in(1) != NULL__null && |
| 736 | ctrl->in(0)->in(1)->in(1)->in(1) == in(1)->in(1)->in(1); |
| 737 | } |
| 738 | |
| 739 | // Do this If and the dominating If share a region? |
| 740 | bool IfNode::has_shared_region(ProjNode* proj, ProjNode*& success, ProjNode*& fail) { |
| 741 | ProjNode* otherproj = proj->other_if_proj(); |
| 742 | Node* otherproj_ctrl_use = otherproj->unique_ctrl_out(); |
| 743 | RegionNode* region = (otherproj_ctrl_use != NULL__null && otherproj_ctrl_use->is_Region()) ? otherproj_ctrl_use->as_Region() : NULL__null; |
| 744 | success = NULL__null; |
| 745 | fail = NULL__null; |
| 746 | |
| 747 | if (otherproj->outcnt() == 1 && region != NULL__null && !region->has_phi()) { |
| 748 | for (int i = 0; i < 2; i++) { |
| 749 | ProjNode* proj = proj_out(i); |
| 750 | if (success == NULL__null && proj->outcnt() == 1 && proj->unique_out() == region) { |
| 751 | success = proj; |
| 752 | } else if (fail == NULL__null) { |
| 753 | fail = proj; |
| 754 | } else { |
| 755 | success = fail = NULL__null; |
| 756 | } |
| 757 | } |
| 758 | } |
| 759 | return success != NULL__null && fail != NULL__null; |
| 760 | } |
| 761 | |
| 762 | bool IfNode::is_dominator_unc(CallStaticJavaNode* dom_unc, CallStaticJavaNode* unc) { |
| 763 | // Different methods and methods containing jsrs are not supported. |
| 764 | ciMethod* method = unc->jvms()->method(); |
| 765 | ciMethod* dom_method = dom_unc->jvms()->method(); |
| 766 | if (method != dom_method || method->has_jsrs()) { |
| 767 | return false; |
| 768 | } |
| 769 | // Check that both traps are in the same activation of the method (instead |
| 770 | // of two activations being inlined through different call sites) by verifying |
| 771 | // that the call stacks are equal for both JVMStates. |
| 772 | JVMState* dom_caller = dom_unc->jvms()->caller(); |
| 773 | JVMState* caller = unc->jvms()->caller(); |
| 774 | if ((dom_caller == NULL__null) != (caller == NULL__null)) { |
| 775 | // The current method must either be inlined into both dom_caller and |
| 776 | // caller or must not be inlined at all (top method). Bail out otherwise. |
| 777 | return false; |
| 778 | } else if (dom_caller != NULL__null && !dom_caller->same_calls_as(caller)) { |
| 779 | return false; |
| 780 | } |
| 781 | // Check that the bci of the dominating uncommon trap dominates the bci |
| 782 | // of the dominated uncommon trap. Otherwise we may not re-execute |
| 783 | // the dominated check after deoptimization from the merged uncommon trap. |
| 784 | ciTypeFlow* flow = dom_method->get_flow_analysis(); |
| 785 | int bci = unc->jvms()->bci(); |
| 786 | int dom_bci = dom_unc->jvms()->bci(); |
| 787 | if (!flow->is_dominated_by(bci, dom_bci)) { |
| 788 | return false; |
| 789 | } |
| 790 | |
| 791 | return true; |
| 792 | } |
| 793 | |
| 794 | // Return projection that leads to an uncommon trap if any |
| 795 | ProjNode* IfNode::uncommon_trap_proj(CallStaticJavaNode*& call) const { |
| 796 | for (int i = 0; i < 2; i++) { |
| 797 | call = proj_out(i)->is_uncommon_trap_proj(Deoptimization::Reason_none); |
| 798 | if (call != NULL__null) { |
| 799 | return proj_out(i); |
| 800 | } |
| 801 | } |
| 802 | return NULL__null; |
| 803 | } |
| 804 | |
| 805 | // Do this If and the dominating If both branch out to an uncommon trap |
| 806 | bool IfNode::has_only_uncommon_traps(ProjNode* proj, ProjNode*& success, ProjNode*& fail, PhaseIterGVN* igvn) { |
| 807 | ProjNode* otherproj = proj->other_if_proj(); |
| 808 | CallStaticJavaNode* dom_unc = otherproj->is_uncommon_trap_proj(Deoptimization::Reason_none); |
| 809 | |
| 810 | if (otherproj->outcnt() == 1 && dom_unc != NULL__null) { |
| 811 | // We need to re-execute the folded Ifs after deoptimization from the merged traps |
| 812 | if (!dom_unc->jvms()->should_reexecute()) { |
| 813 | return false; |
| 814 | } |
| 815 | |
| 816 | CallStaticJavaNode* unc = NULL__null; |
| 817 | ProjNode* unc_proj = uncommon_trap_proj(unc); |
| 818 | if (unc_proj != NULL__null && unc_proj->outcnt() == 1) { |
| 819 | if (dom_unc == unc) { |
| 820 | // Allow the uncommon trap to be shared through a region |
| 821 | RegionNode* r = unc->in(0)->as_Region(); |
| 822 | if (r->outcnt() != 2 || r->req() != 3 || r->find_edge(otherproj) == -1 || r->find_edge(unc_proj) == -1) { |
| 823 | return false; |
| 824 | } |
| 825 | assert(r->has_phi() == NULL, "simple region shouldn't have a phi")do { if (!(r->has_phi() == __null)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 825, "assert(" "r->has_phi() == __null" ") failed", "simple region shouldn't have a phi" ); ::breakpoint(); } } while (0); |
| 826 | } else if (dom_unc->in(0) != otherproj || unc->in(0) != unc_proj) { |
| 827 | return false; |
| 828 | } |
| 829 | |
| 830 | if (!is_dominator_unc(dom_unc, unc)) { |
| 831 | return false; |
| 832 | } |
| 833 | |
| 834 | // See merge_uncommon_traps: the reason of the uncommon trap |
| 835 | // will be changed and the state of the dominating If will be |
| 836 | // used. Checked that we didn't apply this transformation in a |
| 837 | // previous compilation and it didn't cause too many traps |
| 838 | ciMethod* dom_method = dom_unc->jvms()->method(); |
| 839 | int dom_bci = dom_unc->jvms()->bci(); |
| 840 | if (!igvn->C->too_many_traps(dom_method, dom_bci, Deoptimization::Reason_unstable_fused_if) && |
| 841 | !igvn->C->too_many_traps(dom_method, dom_bci, Deoptimization::Reason_range_check)) { |
| 842 | success = unc_proj; |
| 843 | fail = unc_proj->other_if_proj(); |
| 844 | return true; |
| 845 | } |
| 846 | } |
| 847 | } |
| 848 | return false; |
| 849 | } |
| 850 | |
| 851 | // Check that the 2 CmpI can be folded into as single CmpU and proceed with the folding |
| 852 | bool IfNode::fold_compares_helper(ProjNode* proj, ProjNode* success, ProjNode* fail, PhaseIterGVN* igvn) { |
| 853 | Node* this_cmp = in(1)->in(1); |
| 854 | BoolNode* this_bool = in(1)->as_Bool(); |
| 855 | IfNode* dom_iff = proj->in(0)->as_If(); |
| 856 | BoolNode* dom_bool = dom_iff->in(1)->as_Bool(); |
| 857 | Node* lo = dom_iff->in(1)->in(1)->in(2); |
| 858 | Node* hi = this_cmp->in(2); |
| 859 | Node* n = this_cmp->in(1); |
| 860 | ProjNode* otherproj = proj->other_if_proj(); |
| 861 | |
| 862 | const TypeInt* lo_type = IfNode::filtered_int_type(igvn, n, otherproj); |
| 863 | const TypeInt* hi_type = IfNode::filtered_int_type(igvn, n, success); |
| 864 | |
| 865 | BoolTest::mask lo_test = dom_bool->_test._test; |
| 866 | BoolTest::mask hi_test = this_bool->_test._test; |
| 867 | BoolTest::mask cond = hi_test; |
| 868 | |
| 869 | // convert: |
| 870 | // |
| 871 | // dom_bool = x {<,<=,>,>=} a |
| 872 | // / \ |
| 873 | // proj = {True,False} / \ otherproj = {False,True} |
| 874 | // / |
| 875 | // this_bool = x {<,<=} b |
| 876 | // / \ |
| 877 | // fail = {True,False} / \ success = {False,True} |
| 878 | // / |
| 879 | // |
| 880 | // (Second test guaranteed canonicalized, first one may not have |
| 881 | // been canonicalized yet) |
| 882 | // |
| 883 | // into: |
| 884 | // |
| 885 | // cond = (x - lo) {<u,<=u,>u,>=u} adjusted_lim |
| 886 | // / \ |
| 887 | // fail / \ success |
| 888 | // / |
| 889 | // |
| 890 | |
| 891 | // Figure out which of the two tests sets the upper bound and which |
| 892 | // sets the lower bound if any. |
| 893 | Node* adjusted_lim = NULL__null; |
| 894 | if (lo_type != NULL__null && hi_type != NULL__null && hi_type->_lo > lo_type->_hi && |
| 895 | hi_type->_hi == max_jint && lo_type->_lo == min_jint && lo_test != BoolTest::ne) { |
| 896 | assert((dom_bool->_test.is_less() && !proj->_con) ||do { if (!((dom_bool->_test.is_less() && !proj-> _con) || (dom_bool->_test.is_greater() && proj-> _con))) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 897, "assert(" "(dom_bool->_test.is_less() && !proj->_con) || (dom_bool->_test.is_greater() && proj->_con)" ") failed", "incorrect test"); ::breakpoint(); } } while (0) |
| 897 | (dom_bool->_test.is_greater() && proj->_con), "incorrect test")do { if (!((dom_bool->_test.is_less() && !proj-> _con) || (dom_bool->_test.is_greater() && proj-> _con))) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 897, "assert(" "(dom_bool->_test.is_less() && !proj->_con) || (dom_bool->_test.is_greater() && proj->_con)" ") failed", "incorrect test"); ::breakpoint(); } } while (0); |
| 898 | |
| 899 | // this_bool = < |
| 900 | // dom_bool = >= (proj = True) or dom_bool = < (proj = False) |
| 901 | // x in [a, b[ on the fail (= True) projection, b > a-1 (because of hi_type->_lo > lo_type->_hi test above): |
| 902 | // lo = a, hi = b, adjusted_lim = b-a, cond = <u |
| 903 | // dom_bool = > (proj = True) or dom_bool = <= (proj = False) |
| 904 | // x in ]a, b[ on the fail (= True) projection, b > a: |
| 905 | // lo = a+1, hi = b, adjusted_lim = b-a-1, cond = <u |
| 906 | // this_bool = <= |
| 907 | // dom_bool = >= (proj = True) or dom_bool = < (proj = False) |
| 908 | // x in [a, b] on the fail (= True) projection, b+1 > a-1: |
| 909 | // lo = a, hi = b, adjusted_lim = b-a+1, cond = <u |
| 910 | // lo = a, hi = b, adjusted_lim = b-a, cond = <=u doesn't work because b = a - 1 is possible, then b-a = -1 |
| 911 | // dom_bool = > (proj = True) or dom_bool = <= (proj = False) |
| 912 | // x in ]a, b] on the fail (= True) projection b+1 > a: |
| 913 | // lo = a+1, hi = b, adjusted_lim = b-a, cond = <u |
| 914 | // lo = a+1, hi = b, adjusted_lim = b-a-1, cond = <=u doesn't work because a = b is possible, then b-a-1 = -1 |
| 915 | |
| 916 | if (hi_test == BoolTest::lt) { |
| 917 | if (lo_test == BoolTest::gt || lo_test == BoolTest::le) { |
| 918 | lo = igvn->transform(new AddINode(lo, igvn->intcon(1))); |
| 919 | } |
| 920 | } else if (hi_test == BoolTest::le) { |
| 921 | if (lo_test == BoolTest::ge || lo_test == BoolTest::lt) { |
| 922 | adjusted_lim = igvn->transform(new SubINode(hi, lo)); |
| 923 | adjusted_lim = igvn->transform(new AddINode(adjusted_lim, igvn->intcon(1))); |
| 924 | cond = BoolTest::lt; |
| 925 | } else if (lo_test == BoolTest::gt || lo_test == BoolTest::le) { |
| 926 | adjusted_lim = igvn->transform(new SubINode(hi, lo)); |
| 927 | lo = igvn->transform(new AddINode(lo, igvn->intcon(1))); |
| 928 | cond = BoolTest::lt; |
| 929 | } else { |
| 930 | assert(false, "unhandled lo_test: %d", lo_test)do { if (!(false)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 930, "assert(" "false" ") failed", "unhandled lo_test: %d", lo_test); ::breakpoint(); } } while (0); |
| 931 | return false; |
| 932 | } |
| 933 | } else { |
| 934 | assert(igvn->_worklist.member(in(1)) && in(1)->Value(igvn) != igvn->type(in(1)), "unhandled hi_test: %d", hi_test)do { if (!(igvn->_worklist.member(in(1)) && in(1)-> Value(igvn) != igvn->type(in(1)))) { (*g_assert_poison) = 'X' ;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 934, "assert(" "igvn->_worklist.member(in(1)) && in(1)->Value(igvn) != igvn->type(in(1))" ") failed", "unhandled hi_test: %d", hi_test); ::breakpoint( ); } } while (0); |
| 935 | return false; |
| 936 | } |
| 937 | // this test was canonicalized |
| 938 | assert(this_bool->_test.is_less() && fail->_con, "incorrect test")do { if (!(this_bool->_test.is_less() && fail-> _con)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 938, "assert(" "this_bool->_test.is_less() && fail->_con" ") failed", "incorrect test"); ::breakpoint(); } } while (0); |
| 939 | } else if (lo_type != NULL__null && hi_type != NULL__null && lo_type->_lo > hi_type->_hi && |
| 940 | lo_type->_hi == max_jint && hi_type->_lo == min_jint && lo_test != BoolTest::ne) { |
| 941 | |
| 942 | // this_bool = < |
| 943 | // dom_bool = < (proj = True) or dom_bool = >= (proj = False) |
| 944 | // x in [b, a[ on the fail (= False) projection, a > b-1 (because of lo_type->_lo > hi_type->_hi above): |
| 945 | // lo = b, hi = a, adjusted_lim = a-b, cond = >=u |
| 946 | // dom_bool = <= (proj = True) or dom_bool = > (proj = False) |
| 947 | // x in [b, a] on the fail (= False) projection, a+1 > b-1: |
| 948 | // lo = b, hi = a, adjusted_lim = a-b+1, cond = >=u |
| 949 | // lo = b, hi = a, adjusted_lim = a-b, cond = >u doesn't work because a = b - 1 is possible, then b-a = -1 |
| 950 | // this_bool = <= |
| 951 | // dom_bool = < (proj = True) or dom_bool = >= (proj = False) |
| 952 | // x in ]b, a[ on the fail (= False) projection, a > b: |
| 953 | // lo = b+1, hi = a, adjusted_lim = a-b-1, cond = >=u |
| 954 | // dom_bool = <= (proj = True) or dom_bool = > (proj = False) |
| 955 | // x in ]b, a] on the fail (= False) projection, a+1 > b: |
| 956 | // lo = b+1, hi = a, adjusted_lim = a-b, cond = >=u |
| 957 | // lo = b+1, hi = a, adjusted_lim = a-b-1, cond = >u doesn't work because a = b is possible, then b-a-1 = -1 |
| 958 | |
| 959 | swap(lo, hi); |
| 960 | swap(lo_type, hi_type); |
| 961 | swap(lo_test, hi_test); |
| 962 | |
| 963 | assert((dom_bool->_test.is_less() && proj->_con) ||do { if (!((dom_bool->_test.is_less() && proj-> _con) || (dom_bool->_test.is_greater() && !proj-> _con))) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 964, "assert(" "(dom_bool->_test.is_less() && proj->_con) || (dom_bool->_test.is_greater() && !proj->_con)" ") failed", "incorrect test"); ::breakpoint(); } } while (0) |
| 964 | (dom_bool->_test.is_greater() && !proj->_con), "incorrect test")do { if (!((dom_bool->_test.is_less() && proj-> _con) || (dom_bool->_test.is_greater() && !proj-> _con))) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 964, "assert(" "(dom_bool->_test.is_less() && proj->_con) || (dom_bool->_test.is_greater() && !proj->_con)" ") failed", "incorrect test"); ::breakpoint(); } } while (0); |
| 965 | |
| 966 | cond = (hi_test == BoolTest::le || hi_test == BoolTest::gt) ? BoolTest::gt : BoolTest::ge; |
Value stored to 'cond' is never read | |
| 967 | |
| 968 | if (lo_test == BoolTest::lt) { |
| 969 | if (hi_test == BoolTest::lt || hi_test == BoolTest::ge) { |
| 970 | cond = BoolTest::ge; |
| 971 | } else if (hi_test == BoolTest::le || hi_test == BoolTest::gt) { |
| 972 | adjusted_lim = igvn->transform(new SubINode(hi, lo)); |
| 973 | adjusted_lim = igvn->transform(new AddINode(adjusted_lim, igvn->intcon(1))); |
| 974 | cond = BoolTest::ge; |
| 975 | } else { |
| 976 | assert(false, "unhandled hi_test: %d", hi_test)do { if (!(false)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 976, "assert(" "false" ") failed", "unhandled hi_test: %d", hi_test); ::breakpoint(); } } while (0); |
| 977 | return false; |
| 978 | } |
| 979 | } else if (lo_test == BoolTest::le) { |
| 980 | if (hi_test == BoolTest::lt || hi_test == BoolTest::ge) { |
| 981 | lo = igvn->transform(new AddINode(lo, igvn->intcon(1))); |
| 982 | cond = BoolTest::ge; |
| 983 | } else if (hi_test == BoolTest::le || hi_test == BoolTest::gt) { |
| 984 | adjusted_lim = igvn->transform(new SubINode(hi, lo)); |
| 985 | lo = igvn->transform(new AddINode(lo, igvn->intcon(1))); |
| 986 | cond = BoolTest::ge; |
| 987 | } else { |
| 988 | assert(false, "unhandled hi_test: %d", hi_test)do { if (!(false)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 988, "assert(" "false" ") failed", "unhandled hi_test: %d", hi_test); ::breakpoint(); } } while (0); |
| 989 | return false; |
| 990 | } |
| 991 | } else { |
| 992 | assert(igvn->_worklist.member(in(1)) && in(1)->Value(igvn) != igvn->type(in(1)), "unhandled lo_test: %d", lo_test)do { if (!(igvn->_worklist.member(in(1)) && in(1)-> Value(igvn) != igvn->type(in(1)))) { (*g_assert_poison) = 'X' ;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 992, "assert(" "igvn->_worklist.member(in(1)) && in(1)->Value(igvn) != igvn->type(in(1))" ") failed", "unhandled lo_test: %d", lo_test); ::breakpoint( ); } } while (0); |
| 993 | return false; |
| 994 | } |
| 995 | // this test was canonicalized |
| 996 | assert(this_bool->_test.is_less() && !fail->_con, "incorrect test")do { if (!(this_bool->_test.is_less() && !fail-> _con)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 996, "assert(" "this_bool->_test.is_less() && !fail->_con" ") failed", "incorrect test"); ::breakpoint(); } } while (0); |
| 997 | } else { |
| 998 | const TypeInt* failtype = filtered_int_type(igvn, n, proj); |
| 999 | if (failtype != NULL__null) { |
| 1000 | const TypeInt* type2 = filtered_int_type(igvn, n, fail); |
| 1001 | if (type2 != NULL__null) { |
| 1002 | failtype = failtype->join(type2)->is_int(); |
| 1003 | if (failtype->_lo > failtype->_hi) { |
| 1004 | // previous if determines the result of this if so |
| 1005 | // replace Bool with constant |
| 1006 | igvn->_worklist.push(in(1)); |
| 1007 | igvn->replace_input_of(this, 1, igvn->intcon(success->_con)); |
| 1008 | return true; |
| 1009 | } |
| 1010 | } |
| 1011 | } |
| 1012 | lo = NULL__null; |
| 1013 | hi = NULL__null; |
| 1014 | } |
| 1015 | |
| 1016 | if (lo && hi) { |
| 1017 | Node* hook = new Node(1); |
| 1018 | hook->init_req(0, lo); // Add a use to lo to prevent him from dying |
| 1019 | // Merge the two compares into a single unsigned compare by building (CmpU (n - lo) (hi - lo)) |
| 1020 | Node* adjusted_val = igvn->transform(new SubINode(n, lo)); |
| 1021 | if (adjusted_lim == NULL__null) { |
| 1022 | adjusted_lim = igvn->transform(new SubINode(hi, lo)); |
| 1023 | } |
| 1024 | hook->destruct(igvn); |
| 1025 | |
| 1026 | int lo = igvn->type(adjusted_lim)->is_int()->_lo; |
| 1027 | if (lo < 0) { |
| 1028 | // If range check elimination applies to this comparison, it includes code to protect from overflows that may |
| 1029 | // cause the main loop to be skipped entirely. Delay this transformation. |
| 1030 | // Example: |
| 1031 | // for (int i = 0; i < limit; i++) { |
| 1032 | // if (i < max_jint && i > min_jint) {... |
| 1033 | // } |
| 1034 | // Comparisons folded as: |
| 1035 | // i - min_jint - 1 <u -2 |
| 1036 | // when RC applies, main loop limit becomes: |
| 1037 | // min(limit, max(-2 + min_jint + 1, min_jint)) |
| 1038 | // = min(limit, min_jint) |
| 1039 | // = min_jint |
| 1040 | if (!igvn->C->post_loop_opts_phase()) { |
| 1041 | if (adjusted_val->outcnt() == 0) { |
| 1042 | igvn->remove_dead_node(adjusted_val); |
| 1043 | } |
| 1044 | if (adjusted_lim->outcnt() == 0) { |
| 1045 | igvn->remove_dead_node(adjusted_lim); |
| 1046 | } |
| 1047 | igvn->C->record_for_post_loop_opts_igvn(this); |
| 1048 | return false; |
| 1049 | } |
| 1050 | } |
| 1051 | |
| 1052 | Node* newcmp = igvn->transform(new CmpUNode(adjusted_val, adjusted_lim)); |
| 1053 | Node* newbool = igvn->transform(new BoolNode(newcmp, cond)); |
| 1054 | |
| 1055 | igvn->replace_input_of(dom_iff, 1, igvn->intcon(proj->_con)); |
| 1056 | igvn->_worklist.push(in(1)); |
| 1057 | igvn->replace_input_of(this, 1, newbool); |
| 1058 | |
| 1059 | return true; |
| 1060 | } |
| 1061 | return false; |
| 1062 | } |
| 1063 | |
| 1064 | // Merge the branches that trap for this If and the dominating If into |
| 1065 | // a single region that branches to the uncommon trap for the |
| 1066 | // dominating If |
| 1067 | Node* IfNode::merge_uncommon_traps(ProjNode* proj, ProjNode* success, ProjNode* fail, PhaseIterGVN* igvn) { |
| 1068 | Node* res = this; |
| 1069 | assert(success->in(0) == this, "bad projection")do { if (!(success->in(0) == this)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 1069, "assert(" "success->in(0) == this" ") failed", "bad projection" ); ::breakpoint(); } } while (0); |
| 1070 | |
| 1071 | ProjNode* otherproj = proj->other_if_proj(); |
| 1072 | |
| 1073 | CallStaticJavaNode* unc = success->is_uncommon_trap_proj(Deoptimization::Reason_none); |
| 1074 | CallStaticJavaNode* dom_unc = otherproj->is_uncommon_trap_proj(Deoptimization::Reason_none); |
| 1075 | |
| 1076 | if (unc != dom_unc) { |
| 1077 | Node* r = new RegionNode(3); |
| 1078 | |
| 1079 | r->set_req(1, otherproj); |
| 1080 | r->set_req(2, success); |
| 1081 | r = igvn->transform(r); |
| 1082 | assert(r->is_Region(), "can't go away")do { if (!(r->is_Region())) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 1082, "assert(" "r->is_Region()" ") failed", "can't go away" ); ::breakpoint(); } } while (0); |
| 1083 | |
| 1084 | // Make both If trap at the state of the first If: once the CmpI |
| 1085 | // nodes are merged, if we trap we don't know which of the CmpI |
| 1086 | // nodes would have caused the trap so we have to restart |
| 1087 | // execution at the first one |
| 1088 | igvn->replace_input_of(dom_unc, 0, r); |
| 1089 | igvn->replace_input_of(unc, 0, igvn->C->top()); |
| 1090 | } |
| 1091 | int trap_request = dom_unc->uncommon_trap_request(); |
| 1092 | Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request); |
| 1093 | Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request); |
| 1094 | |
| 1095 | int flip_test = 0; |
| 1096 | Node* l = NULL__null; |
| 1097 | Node* r = NULL__null; |
| 1098 | |
| 1099 | if (success->in(0)->as_If()->range_check_trap_proj(flip_test, l, r) != NULL__null) { |
| 1100 | // If this looks like a range check, change the trap to |
| 1101 | // Reason_range_check so the compiler recognizes it as a range |
| 1102 | // check and applies the corresponding optimizations |
| 1103 | trap_request = Deoptimization::make_trap_request(Deoptimization::Reason_range_check, action); |
| 1104 | |
| 1105 | improve_address_types(l, r, fail, igvn); |
| 1106 | |
| 1107 | res = igvn->transform(new RangeCheckNode(in(0), in(1), _prob, _fcnt)); |
| 1108 | } else if (unc != dom_unc) { |
| 1109 | // If we trap we won't know what CmpI would have caused the trap |
| 1110 | // so use a special trap reason to mark this pair of CmpI nodes as |
| 1111 | // bad candidate for folding. On recompilation we won't fold them |
| 1112 | // and we may trap again but this time we'll know what branch |
| 1113 | // traps |
| 1114 | trap_request = Deoptimization::make_trap_request(Deoptimization::Reason_unstable_fused_if, action); |
| 1115 | } |
| 1116 | igvn->replace_input_of(dom_unc, TypeFunc::Parms, igvn->intcon(trap_request)); |
| 1117 | return res; |
| 1118 | } |
| 1119 | |
| 1120 | // If we are turning 2 CmpI nodes into a CmpU that follows the pattern |
| 1121 | // of a rangecheck on index i, on 64 bit the compares may be followed |
| 1122 | // by memory accesses using i as index. In that case, the CmpU tells |
| 1123 | // us something about the values taken by i that can help the compiler |
| 1124 | // (see Compile::conv_I2X_index()) |
| 1125 | void IfNode::improve_address_types(Node* l, Node* r, ProjNode* fail, PhaseIterGVN* igvn) { |
| 1126 | #ifdef _LP641 |
| 1127 | ResourceMark rm; |
| 1128 | Node_Stack stack(2); |
| 1129 | |
| 1130 | assert(r->Opcode() == Op_LoadRange, "unexpected range check")do { if (!(r->Opcode() == Op_LoadRange)) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 1130, "assert(" "r->Opcode() == Op_LoadRange" ") failed" , "unexpected range check"); ::breakpoint(); } } while (0); |
| 1131 | const TypeInt* array_size = igvn->type(r)->is_int(); |
| 1132 | |
| 1133 | stack.push(l, 0); |
| 1134 | |
| 1135 | while(stack.size() > 0) { |
| 1136 | Node* n = stack.node(); |
| 1137 | uint start = stack.index(); |
| 1138 | |
| 1139 | uint i = start; |
| 1140 | for (; i < n->outcnt(); i++) { |
| 1141 | Node* use = n->raw_out(i); |
| 1142 | if (stack.size() == 1) { |
| 1143 | if (use->Opcode() == Op_ConvI2L) { |
| 1144 | const TypeLong* bounds = use->as_Type()->type()->is_long(); |
| 1145 | if (bounds->_lo <= array_size->_lo && bounds->_hi >= array_size->_hi && |
| 1146 | (bounds->_lo != array_size->_lo || bounds->_hi != array_size->_hi)) { |
| 1147 | stack.set_index(i+1); |
| 1148 | stack.push(use, 0); |
| 1149 | break; |
| 1150 | } |
| 1151 | } |
| 1152 | } else if (use->is_Mem()) { |
| 1153 | Node* ctrl = use->in(0); |
| 1154 | for (int i = 0; i < 10 && ctrl != NULL__null && ctrl != fail; i++) { |
| 1155 | ctrl = up_one_dom(ctrl); |
| 1156 | } |
| 1157 | if (ctrl == fail) { |
| 1158 | Node* init_n = stack.node_at(1); |
| 1159 | assert(init_n->Opcode() == Op_ConvI2L, "unexpected first node")do { if (!(init_n->Opcode() == Op_ConvI2L)) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 1159, "assert(" "init_n->Opcode() == Op_ConvI2L" ") failed" , "unexpected first node"); ::breakpoint(); } } while (0); |
| 1160 | // Create a new narrow ConvI2L node that is dependent on the range check |
| 1161 | Node* new_n = igvn->C->conv_I2X_index(igvn, l, array_size, fail); |
| 1162 | |
| 1163 | // The type of the ConvI2L may be widen and so the new |
| 1164 | // ConvI2L may not be better than an existing ConvI2L |
| 1165 | if (new_n != init_n) { |
| 1166 | for (uint j = 2; j < stack.size(); j++) { |
| 1167 | Node* n = stack.node_at(j); |
| 1168 | Node* clone = n->clone(); |
| 1169 | int rep = clone->replace_edge(init_n, new_n, igvn); |
| 1170 | assert(rep > 0, "can't find expected node?")do { if (!(rep > 0)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 1170, "assert(" "rep > 0" ") failed", "can't find expected node?" ); ::breakpoint(); } } while (0); |
| 1171 | clone = igvn->transform(clone); |
| 1172 | init_n = n; |
| 1173 | new_n = clone; |
| 1174 | } |
| 1175 | igvn->hash_delete(use); |
| 1176 | int rep = use->replace_edge(init_n, new_n, igvn); |
| 1177 | assert(rep > 0, "can't find expected node?")do { if (!(rep > 0)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 1177, "assert(" "rep > 0" ") failed", "can't find expected node?" ); ::breakpoint(); } } while (0); |
| 1178 | igvn->transform(use); |
| 1179 | if (init_n->outcnt() == 0) { |
| 1180 | igvn->_worklist.push(init_n); |
| 1181 | } |
| 1182 | } |
| 1183 | } |
| 1184 | } else if (use->in(0) == NULL__null && (igvn->type(use)->isa_long() || |
| 1185 | igvn->type(use)->isa_ptr())) { |
| 1186 | stack.set_index(i+1); |
| 1187 | stack.push(use, 0); |
| 1188 | break; |
| 1189 | } |
| 1190 | } |
| 1191 | if (i == n->outcnt()) { |
| 1192 | stack.pop(); |
| 1193 | } |
| 1194 | } |
| 1195 | #endif |
| 1196 | } |
| 1197 | |
| 1198 | bool IfNode::is_cmp_with_loadrange(ProjNode* proj) { |
| 1199 | if (in(1) != NULL__null && |
| 1200 | in(1)->in(1) != NULL__null && |
| 1201 | in(1)->in(1)->in(2) != NULL__null) { |
| 1202 | Node* other = in(1)->in(1)->in(2); |
| 1203 | if (other->Opcode() == Op_LoadRange && |
| 1204 | ((other->in(0) != NULL__null && other->in(0) == proj) || |
| 1205 | (other->in(0) == NULL__null && |
| 1206 | other->in(2) != NULL__null && |
| 1207 | other->in(2)->is_AddP() && |
| 1208 | other->in(2)->in(1) != NULL__null && |
| 1209 | other->in(2)->in(1)->Opcode() == Op_CastPP && |
| 1210 | other->in(2)->in(1)->in(0) == proj))) { |
| 1211 | return true; |
| 1212 | } |
| 1213 | } |
| 1214 | return false; |
| 1215 | } |
| 1216 | |
| 1217 | bool IfNode::is_null_check(ProjNode* proj, PhaseIterGVN* igvn) { |
| 1218 | Node* other = in(1)->in(1)->in(2); |
| 1219 | if (other->in(MemNode::Address) != NULL__null && |
| 1220 | proj->in(0)->in(1) != NULL__null && |
| 1221 | proj->in(0)->in(1)->is_Bool() && |
| 1222 | proj->in(0)->in(1)->in(1) != NULL__null && |
| 1223 | proj->in(0)->in(1)->in(1)->Opcode() == Op_CmpP && |
| 1224 | proj->in(0)->in(1)->in(1)->in(2) != NULL__null && |
| 1225 | proj->in(0)->in(1)->in(1)->in(1) == other->in(MemNode::Address)->in(AddPNode::Address)->uncast() && |
| 1226 | igvn->type(proj->in(0)->in(1)->in(1)->in(2)) == TypePtr::NULL_PTR) { |
| 1227 | return true; |
| 1228 | } |
| 1229 | return false; |
| 1230 | } |
| 1231 | |
| 1232 | // Check that the If that is in between the 2 integer comparisons has |
| 1233 | // no side effect |
| 1234 | bool IfNode::is_side_effect_free_test(ProjNode* proj, PhaseIterGVN* igvn) { |
| 1235 | if (proj == NULL__null) { |
| 1236 | return false; |
| 1237 | } |
| 1238 | CallStaticJavaNode* unc = proj->is_uncommon_trap_if_pattern(Deoptimization::Reason_none); |
| 1239 | if (unc != NULL__null && proj->outcnt() <= 2) { |
| 1240 | if (proj->outcnt() == 1 || |
| 1241 | // Allow simple null check from LoadRange |
| 1242 | (is_cmp_with_loadrange(proj) && is_null_check(proj, igvn))) { |
| 1243 | CallStaticJavaNode* unc = proj->is_uncommon_trap_if_pattern(Deoptimization::Reason_none); |
| 1244 | CallStaticJavaNode* dom_unc = proj->in(0)->in(0)->as_Proj()->is_uncommon_trap_if_pattern(Deoptimization::Reason_none); |
| 1245 | assert(dom_unc != NULL, "is_uncommon_trap_if_pattern returned NULL")do { if (!(dom_unc != __null)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 1245, "assert(" "dom_unc != __null" ") failed", "is_uncommon_trap_if_pattern returned NULL" ); ::breakpoint(); } } while (0); |
| 1246 | |
| 1247 | // reroute_side_effect_free_unc changes the state of this |
| 1248 | // uncommon trap to restart execution at the previous |
| 1249 | // CmpI. Check that this change in a previous compilation didn't |
| 1250 | // cause too many traps. |
| 1251 | int trap_request = unc->uncommon_trap_request(); |
| 1252 | Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request); |
| 1253 | |
| 1254 | if (igvn->C->too_many_traps(dom_unc->jvms()->method(), dom_unc->jvms()->bci(), reason)) { |
| 1255 | return false; |
| 1256 | } |
| 1257 | |
| 1258 | if (!is_dominator_unc(dom_unc, unc)) { |
| 1259 | return false; |
| 1260 | } |
| 1261 | |
| 1262 | return true; |
| 1263 | } |
| 1264 | } |
| 1265 | return false; |
| 1266 | } |
| 1267 | |
| 1268 | // Make the If between the 2 integer comparisons trap at the state of |
| 1269 | // the first If: the last CmpI is the one replaced by a CmpU and the |
| 1270 | // first CmpI is eliminated, so the test between the 2 CmpI nodes |
| 1271 | // won't be guarded by the first CmpI anymore. It can trap in cases |
| 1272 | // where the first CmpI would have prevented it from executing: on a |
| 1273 | // trap, we need to restart execution at the state of the first CmpI |
| 1274 | void IfNode::reroute_side_effect_free_unc(ProjNode* proj, ProjNode* dom_proj, PhaseIterGVN* igvn) { |
| 1275 | CallStaticJavaNode* dom_unc = dom_proj->is_uncommon_trap_if_pattern(Deoptimization::Reason_none); |
| 1276 | ProjNode* otherproj = proj->other_if_proj(); |
| 1277 | CallStaticJavaNode* unc = proj->is_uncommon_trap_if_pattern(Deoptimization::Reason_none); |
| 1278 | Node* call_proj = dom_unc->unique_ctrl_out(); |
| 1279 | Node* halt = call_proj->unique_ctrl_out(); |
| 1280 | |
| 1281 | Node* new_unc = dom_unc->clone(); |
| 1282 | call_proj = call_proj->clone(); |
| 1283 | halt = halt->clone(); |
| 1284 | Node* c = otherproj->clone(); |
| 1285 | |
| 1286 | c = igvn->transform(c); |
| 1287 | new_unc->set_req(TypeFunc::Parms, unc->in(TypeFunc::Parms)); |
| 1288 | new_unc->set_req(0, c); |
| 1289 | new_unc = igvn->transform(new_unc); |
| 1290 | call_proj->set_req(0, new_unc); |
| 1291 | call_proj = igvn->transform(call_proj); |
| 1292 | halt->set_req(0, call_proj); |
| 1293 | halt = igvn->transform(halt); |
| 1294 | |
| 1295 | igvn->replace_node(otherproj, igvn->C->top()); |
| 1296 | igvn->C->root()->add_req(halt); |
| 1297 | } |
| 1298 | |
| 1299 | Node* IfNode::fold_compares(PhaseIterGVN* igvn) { |
| 1300 | if (Opcode() != Op_If) return NULL__null; |
| 1301 | |
| 1302 | if (cmpi_folds(igvn)) { |
| 1303 | Node* ctrl = in(0); |
| 1304 | if (is_ctrl_folds(ctrl, igvn) && ctrl->outcnt() == 1) { |
| 1305 | // A integer comparison immediately dominated by another integer |
| 1306 | // comparison |
| 1307 | ProjNode* success = NULL__null; |
| 1308 | ProjNode* fail = NULL__null; |
| 1309 | ProjNode* dom_cmp = ctrl->as_Proj(); |
| 1310 | if (has_shared_region(dom_cmp, success, fail) && |
| 1311 | // Next call modifies graph so must be last |
| 1312 | fold_compares_helper(dom_cmp, success, fail, igvn)) { |
| 1313 | return this; |
| 1314 | } |
| 1315 | if (has_only_uncommon_traps(dom_cmp, success, fail, igvn) && |
| 1316 | // Next call modifies graph so must be last |
| 1317 | fold_compares_helper(dom_cmp, success, fail, igvn)) { |
| 1318 | return merge_uncommon_traps(dom_cmp, success, fail, igvn); |
| 1319 | } |
| 1320 | return NULL__null; |
| 1321 | } else if (ctrl->in(0) != NULL__null && |
| 1322 | ctrl->in(0)->in(0) != NULL__null) { |
| 1323 | ProjNode* success = NULL__null; |
| 1324 | ProjNode* fail = NULL__null; |
| 1325 | Node* dom = ctrl->in(0)->in(0); |
| 1326 | ProjNode* dom_cmp = dom->isa_Proj(); |
| 1327 | ProjNode* other_cmp = ctrl->isa_Proj(); |
| 1328 | |
| 1329 | // Check if it's an integer comparison dominated by another |
| 1330 | // integer comparison with another test in between |
| 1331 | if (is_ctrl_folds(dom, igvn) && |
| 1332 | has_only_uncommon_traps(dom_cmp, success, fail, igvn) && |
| 1333 | is_side_effect_free_test(other_cmp, igvn) && |
| 1334 | // Next call modifies graph so must be last |
| 1335 | fold_compares_helper(dom_cmp, success, fail, igvn)) { |
| 1336 | reroute_side_effect_free_unc(other_cmp, dom_cmp, igvn); |
| 1337 | return merge_uncommon_traps(dom_cmp, success, fail, igvn); |
| 1338 | } |
| 1339 | } |
| 1340 | } |
| 1341 | return NULL__null; |
| 1342 | } |
| 1343 | |
| 1344 | //------------------------------remove_useless_bool---------------------------- |
| 1345 | // Check for people making a useless boolean: things like |
| 1346 | // if( (x < y ? true : false) ) { ... } |
| 1347 | // Replace with if( x < y ) { ... } |
| 1348 | static Node *remove_useless_bool(IfNode *iff, PhaseGVN *phase) { |
| 1349 | Node *i1 = iff->in(1); |
| 1350 | if( !i1->is_Bool() ) return NULL__null; |
| 1351 | BoolNode *bol = i1->as_Bool(); |
| 1352 | |
| 1353 | Node *cmp = bol->in(1); |
| 1354 | if( cmp->Opcode() != Op_CmpI ) return NULL__null; |
| 1355 | |
| 1356 | // Must be comparing against a bool |
| 1357 | const Type *cmp2_t = phase->type( cmp->in(2) ); |
| 1358 | if( cmp2_t != TypeInt::ZERO && |
| 1359 | cmp2_t != TypeInt::ONE ) |
| 1360 | return NULL__null; |
| 1361 | |
| 1362 | // Find a prior merge point merging the boolean |
| 1363 | i1 = cmp->in(1); |
| 1364 | if( !i1->is_Phi() ) return NULL__null; |
| 1365 | PhiNode *phi = i1->as_Phi(); |
| 1366 | if( phase->type( phi ) != TypeInt::BOOL ) |
| 1367 | return NULL__null; |
| 1368 | |
| 1369 | // Check for diamond pattern |
| 1370 | int true_path = phi->is_diamond_phi(); |
| 1371 | if( true_path == 0 ) return NULL__null; |
| 1372 | |
| 1373 | // Make sure that iff and the control of the phi are different. This |
| 1374 | // should really only happen for dead control flow since it requires |
| 1375 | // an illegal cycle. |
| 1376 | if (phi->in(0)->in(1)->in(0) == iff) return NULL__null; |
| 1377 | |
| 1378 | // phi->region->if_proj->ifnode->bool->cmp |
| 1379 | BoolNode *bol2 = phi->in(0)->in(1)->in(0)->in(1)->as_Bool(); |
| 1380 | |
| 1381 | // Now get the 'sense' of the test correct so we can plug in |
| 1382 | // either iff2->in(1) or its complement. |
| 1383 | int flip = 0; |
| 1384 | if( bol->_test._test == BoolTest::ne ) flip = 1-flip; |
| 1385 | else if( bol->_test._test != BoolTest::eq ) return NULL__null; |
| 1386 | if( cmp2_t == TypeInt::ZERO ) flip = 1-flip; |
| 1387 | |
| 1388 | const Type *phi1_t = phase->type( phi->in(1) ); |
| 1389 | const Type *phi2_t = phase->type( phi->in(2) ); |
| 1390 | // Check for Phi(0,1) and flip |
| 1391 | if( phi1_t == TypeInt::ZERO ) { |
| 1392 | if( phi2_t != TypeInt::ONE ) return NULL__null; |
| 1393 | flip = 1-flip; |
| 1394 | } else { |
| 1395 | // Check for Phi(1,0) |
| 1396 | if( phi1_t != TypeInt::ONE ) return NULL__null; |
| 1397 | if( phi2_t != TypeInt::ZERO ) return NULL__null; |
| 1398 | } |
| 1399 | if( true_path == 2 ) { |
| 1400 | flip = 1-flip; |
| 1401 | } |
| 1402 | |
| 1403 | Node* new_bol = (flip ? phase->transform( bol2->negate(phase) ) : bol2); |
| 1404 | assert(new_bol != iff->in(1), "must make progress")do { if (!(new_bol != iff->in(1))) { (*g_assert_poison) = 'X' ;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 1404, "assert(" "new_bol != iff->in(1)" ") failed", "must make progress" ); ::breakpoint(); } } while (0); |
| 1405 | iff->set_req_X(1, new_bol, phase); |
| 1406 | // Intervening diamond probably goes dead |
| 1407 | phase->C->set_major_progress(); |
| 1408 | return iff; |
| 1409 | } |
| 1410 | |
| 1411 | static IfNode* idealize_test(PhaseGVN* phase, IfNode* iff); |
| 1412 | |
| 1413 | struct RangeCheck { |
| 1414 | Node* ctl; |
| 1415 | jint off; |
| 1416 | }; |
| 1417 | |
| 1418 | Node* IfNode::Ideal_common(PhaseGVN *phase, bool can_reshape) { |
| 1419 | if (remove_dead_region(phase, can_reshape)) return this; |
| 1420 | // No Def-Use info? |
| 1421 | if (!can_reshape) return NULL__null; |
| 1422 | |
| 1423 | // Don't bother trying to transform a dead if |
| 1424 | if (in(0)->is_top()) return NULL__null; |
| 1425 | // Don't bother trying to transform an if with a dead test |
| 1426 | if (in(1)->is_top()) return NULL__null; |
| 1427 | // Another variation of a dead test |
| 1428 | if (in(1)->is_Con()) return NULL__null; |
| 1429 | // Another variation of a dead if |
| 1430 | if (outcnt() < 2) return NULL__null; |
| 1431 | |
| 1432 | // Canonicalize the test. |
| 1433 | Node* idt_if = idealize_test(phase, this); |
| 1434 | if (idt_if != NULL__null) return idt_if; |
| 1435 | |
| 1436 | // Try to split the IF |
| 1437 | PhaseIterGVN *igvn = phase->is_IterGVN(); |
| 1438 | Node *s = split_if(this, igvn); |
| 1439 | if (s != NULL__null) return s; |
| 1440 | |
| 1441 | return NodeSentinel(Node*)-1; |
| 1442 | } |
| 1443 | |
| 1444 | //------------------------------Ideal------------------------------------------ |
| 1445 | // Return a node which is more "ideal" than the current node. Strip out |
| 1446 | // control copies |
| 1447 | Node* IfNode::Ideal(PhaseGVN *phase, bool can_reshape) { |
| 1448 | Node* res = Ideal_common(phase, can_reshape); |
| 1449 | if (res != NodeSentinel(Node*)-1) { |
| 1450 | return res; |
| 1451 | } |
| 1452 | |
| 1453 | // Check for people making a useless boolean: things like |
| 1454 | // if( (x < y ? true : false) ) { ... } |
| 1455 | // Replace with if( x < y ) { ... } |
| 1456 | Node* bol2 = remove_useless_bool(this, phase); |
| 1457 | if (bol2) return bol2; |
| 1458 | |
| 1459 | if (in(0) == NULL__null) return NULL__null; // Dead loop? |
| 1460 | |
| 1461 | PhaseIterGVN* igvn = phase->is_IterGVN(); |
| 1462 | Node* result = fold_compares(igvn); |
| 1463 | if (result != NULL__null) { |
| 1464 | return result; |
| 1465 | } |
| 1466 | |
| 1467 | // Scan for an equivalent test |
| 1468 | int dist = 4; // Cutoff limit for search |
| 1469 | if (is_If() && in(1)->is_Bool()) { |
| 1470 | Node* cmp = in(1)->in(1); |
| 1471 | if (cmp->Opcode() == Op_CmpP && |
| 1472 | cmp->in(2) != NULL__null && // make sure cmp is not already dead |
| 1473 | cmp->in(2)->bottom_type() == TypePtr::NULL_PTR) { |
| 1474 | dist = 64; // Limit for null-pointer scans |
| 1475 | } |
| 1476 | } |
| 1477 | |
| 1478 | Node* prev_dom = search_identical(dist); |
| 1479 | |
| 1480 | if (prev_dom != NULL__null) { |
| 1481 | // Replace dominated IfNode |
| 1482 | return dominated_by(prev_dom, igvn); |
| 1483 | } |
| 1484 | |
| 1485 | return simple_subsuming(igvn); |
| 1486 | } |
| 1487 | |
| 1488 | //------------------------------dominated_by----------------------------------- |
| 1489 | Node* IfNode::dominated_by(Node* prev_dom, PhaseIterGVN *igvn) { |
| 1490 | #ifndef PRODUCT |
| 1491 | if (TraceIterativeGVN) { |
| 1492 | tty->print(" Removing IfNode: "); this->dump(); |
| 1493 | } |
| 1494 | #endif |
| 1495 | |
| 1496 | igvn->hash_delete(this); // Remove self to prevent spurious V-N |
| 1497 | Node *idom = in(0); |
| 1498 | // Need opcode to decide which way 'this' test goes |
| 1499 | int prev_op = prev_dom->Opcode(); |
| 1500 | Node *top = igvn->C->top(); // Shortcut to top |
| 1501 | |
| 1502 | // Loop predicates may have depending checks which should not |
| 1503 | // be skipped. For example, range check predicate has two checks |
| 1504 | // for lower and upper bounds. |
| 1505 | ProjNode* unc_proj = proj_out(1 - prev_dom->as_Proj()->_con)->as_Proj(); |
| 1506 | if (unc_proj->is_uncommon_trap_proj(Deoptimization::Reason_predicate) != NULL__null || |
| 1507 | unc_proj->is_uncommon_trap_proj(Deoptimization::Reason_profile_predicate) != NULL__null) { |
| 1508 | prev_dom = idom; |
| 1509 | } |
| 1510 | |
| 1511 | // Now walk the current IfNode's projections. |
| 1512 | // Loop ends when 'this' has no more uses. |
| 1513 | for (DUIterator_Last imin, i = last_outs(imin); i >= imin; --i) { |
| 1514 | Node *ifp = last_out(i); // Get IfTrue/IfFalse |
| 1515 | igvn->add_users_to_worklist(ifp); |
| 1516 | // Check which projection it is and set target. |
| 1517 | // Data-target is either the dominating projection of the same type |
| 1518 | // or TOP if the dominating projection is of opposite type. |
| 1519 | // Data-target will be used as the new control edge for the non-CFG |
| 1520 | // nodes like Casts and Loads. |
| 1521 | Node *data_target = (ifp->Opcode() == prev_op) ? prev_dom : top; |
| 1522 | // Control-target is just the If's immediate dominator or TOP. |
| 1523 | Node *ctrl_target = (ifp->Opcode() == prev_op) ? idom : top; |
| 1524 | |
| 1525 | // For each child of an IfTrue/IfFalse projection, reroute. |
| 1526 | // Loop ends when projection has no more uses. |
| 1527 | for (DUIterator_Last jmin, j = ifp->last_outs(jmin); j >= jmin; --j) { |
| 1528 | Node* s = ifp->last_out(j); // Get child of IfTrue/IfFalse |
| 1529 | if (s->depends_only_on_test() && igvn->no_dependent_zero_check(s)) { |
| 1530 | // For control producers. |
| 1531 | // Do not rewire Div and Mod nodes which could have a zero divisor to avoid skipping their zero check. |
| 1532 | igvn->replace_input_of(s, 0, data_target); // Move child to data-target |
| 1533 | } else { |
| 1534 | // Find the control input matching this def-use edge. |
| 1535 | // For Regions it may not be in slot 0. |
| 1536 | uint l; |
| 1537 | for (l = 0; s->in(l) != ifp; l++) { } |
| 1538 | igvn->replace_input_of(s, l, ctrl_target); |
| 1539 | } |
| 1540 | } // End for each child of a projection |
| 1541 | |
| 1542 | igvn->remove_dead_node(ifp); |
| 1543 | } // End for each IfTrue/IfFalse child of If |
| 1544 | |
| 1545 | // Kill the IfNode |
| 1546 | igvn->remove_dead_node(this); |
| 1547 | |
| 1548 | // Must return either the original node (now dead) or a new node |
| 1549 | // (Do not return a top here, since that would break the uniqueness of top.) |
| 1550 | return new ConINode(TypeInt::ZERO); |
| 1551 | } |
| 1552 | |
| 1553 | Node* IfNode::search_identical(int dist) { |
| 1554 | // Setup to scan up the CFG looking for a dominating test |
| 1555 | Node* dom = in(0); |
| 1556 | Node* prev_dom = this; |
| 1557 | int op = Opcode(); |
| 1558 | // Search up the dominator tree for an If with an identical test |
| 1559 | while (dom->Opcode() != op || // Not same opcode? |
| 1560 | dom->in(1) != in(1) || // Not same input 1? |
| 1561 | prev_dom->in(0) != dom) { // One path of test does not dominate? |
| 1562 | if (dist < 0) return NULL__null; |
| 1563 | |
| 1564 | dist--; |
| 1565 | prev_dom = dom; |
| 1566 | dom = up_one_dom(dom); |
| 1567 | if (!dom) return NULL__null; |
| 1568 | } |
| 1569 | |
| 1570 | // Check that we did not follow a loop back to ourselves |
| 1571 | if (this == dom) { |
| 1572 | return NULL__null; |
| 1573 | } |
| 1574 | |
| 1575 | #ifndef PRODUCT |
| 1576 | if (dist > 2) { // Add to count of NULL checks elided |
| 1577 | explicit_null_checks_elided++; |
| 1578 | } |
| 1579 | #endif |
| 1580 | |
| 1581 | return prev_dom; |
| 1582 | } |
| 1583 | |
| 1584 | |
| 1585 | static int subsuming_bool_test_encode(Node*); |
| 1586 | |
| 1587 | // Check if dominating test is subsuming 'this' one. |
| 1588 | // |
| 1589 | // cmp |
| 1590 | // / \ |
| 1591 | // (r1) bool \ |
| 1592 | // / bool (r2) |
| 1593 | // (dom) if \ |
| 1594 | // \ ) |
| 1595 | // (pre) if[TF] / |
| 1596 | // \ / |
| 1597 | // if (this) |
| 1598 | // \r1 |
| 1599 | // r2\ eqT eqF neT neF ltT ltF leT leF gtT gtF geT geF |
| 1600 | // eq t f f t f - - f f - - f |
| 1601 | // ne f t t f t - - t t - - t |
| 1602 | // lt f - - f t f - f f - f t |
| 1603 | // le t - - t t - t f f t - t |
| 1604 | // gt f - - f f - f t t f - f |
| 1605 | // ge t - - t f t - t t - t f |
| 1606 | // |
| 1607 | Node* IfNode::simple_subsuming(PhaseIterGVN* igvn) { |
| 1608 | // Table encoding: N/A (na), True-branch (tb), False-branch (fb). |
| 1609 | static enum { na, tb, fb } s_short_circuit_map[6][12] = { |
| 1610 | /*rel: eq+T eq+F ne+T ne+F lt+T lt+F le+T le+F gt+T gt+F ge+T ge+F*/ |
| 1611 | /*eq*/{ tb, fb, fb, tb, fb, na, na, fb, fb, na, na, fb }, |
| 1612 | /*ne*/{ fb, tb, tb, fb, tb, na, na, tb, tb, na, na, tb }, |
| 1613 | /*lt*/{ fb, na, na, fb, tb, fb, na, fb, fb, na, fb, tb }, |
| 1614 | /*le*/{ tb, na, na, tb, tb, na, tb, fb, fb, tb, na, tb }, |
| 1615 | /*gt*/{ fb, na, na, fb, fb, na, fb, tb, tb, fb, na, fb }, |
| 1616 | /*ge*/{ tb, na, na, tb, fb, tb, na, tb, tb, na, tb, fb }}; |
| 1617 | |
| 1618 | Node* pre = in(0); |
| 1619 | if (!pre->is_IfTrue() && !pre->is_IfFalse()) { |
| 1620 | return NULL__null; |
| 1621 | } |
| 1622 | Node* dom = pre->in(0); |
| 1623 | if (!dom->is_If()) { |
| 1624 | return NULL__null; |
| 1625 | } |
| 1626 | Node* bol = in(1); |
| 1627 | if (!bol->is_Bool()) { |
| 1628 | return NULL__null; |
| 1629 | } |
| 1630 | Node* cmp = in(1)->in(1); |
| 1631 | if (!cmp->is_Cmp()) { |
| 1632 | return NULL__null; |
| 1633 | } |
| 1634 | |
| 1635 | if (!dom->in(1)->is_Bool()) { |
| 1636 | return NULL__null; |
| 1637 | } |
| 1638 | if (dom->in(1)->in(1) != cmp) { // Not same cond? |
| 1639 | return NULL__null; |
| 1640 | } |
| 1641 | |
| 1642 | int drel = subsuming_bool_test_encode(dom->in(1)); |
| 1643 | int trel = subsuming_bool_test_encode(bol); |
| 1644 | int bout = pre->is_IfFalse() ? 1 : 0; |
| 1645 | |
| 1646 | if (drel < 0 || trel < 0) { |
| 1647 | return NULL__null; |
| 1648 | } |
| 1649 | int br = s_short_circuit_map[trel][2*drel+bout]; |
| 1650 | if (br == na) { |
| 1651 | return NULL__null; |
| 1652 | } |
| 1653 | #ifndef PRODUCT |
| 1654 | if (TraceIterativeGVN) { |
| 1655 | tty->print(" Subsumed IfNode: "); dump(); |
| 1656 | } |
| 1657 | #endif |
| 1658 | // Replace condition with constant True(1)/False(0). |
| 1659 | bool is_always_true = br == tb; |
| 1660 | set_req(1, igvn->intcon(is_always_true ? 1 : 0)); |
| 1661 | |
| 1662 | // Update any data dependencies to the directly dominating test. This subsumed test is not immediately removed by igvn |
| 1663 | // and therefore subsequent optimizations might miss these data dependencies otherwise. There might be a dead loop |
| 1664 | // ('always_taken_proj' == 'pre') that is cleaned up later. Skip this case to make the iterator work properly. |
| 1665 | Node* always_taken_proj = proj_out(is_always_true); |
| 1666 | if (always_taken_proj != pre) { |
| 1667 | for (DUIterator_Fast imax, i = always_taken_proj->fast_outs(imax); i < imax; i++) { |
| 1668 | Node* u = always_taken_proj->fast_out(i); |
| 1669 | if (!u->is_CFG()) { |
| 1670 | igvn->replace_input_of(u, 0, pre); |
| 1671 | --i; |
| 1672 | --imax; |
| 1673 | } |
| 1674 | } |
| 1675 | } |
| 1676 | |
| 1677 | if (bol->outcnt() == 0) { |
| 1678 | igvn->remove_dead_node(bol); // Kill the BoolNode. |
| 1679 | } |
| 1680 | return this; |
| 1681 | } |
| 1682 | |
| 1683 | // Map BoolTest to local table encoding. The BoolTest (e)numerals |
| 1684 | // { eq = 0, ne = 4, le = 5, ge = 7, lt = 3, gt = 1 } |
| 1685 | // are mapped to table indices, while the remaining (e)numerals in BoolTest |
| 1686 | // { overflow = 2, no_overflow = 6, never = 8, illegal = 9 } |
| 1687 | // are ignored (these are not modeled in the table). |
| 1688 | // |
| 1689 | static int subsuming_bool_test_encode(Node* node) { |
| 1690 | precond(node->is_Bool())do { if (!(node->is_Bool())) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 1690, "assert(" "node->is_Bool()" ") failed", "precond") ; ::breakpoint(); } } while (0); |
| 1691 | BoolTest::mask x = node->as_Bool()->_test._test; |
| 1692 | switch (x) { |
| 1693 | case BoolTest::eq: return 0; |
| 1694 | case BoolTest::ne: return 1; |
| 1695 | case BoolTest::lt: return 2; |
| 1696 | case BoolTest::le: return 3; |
| 1697 | case BoolTest::gt: return 4; |
| 1698 | case BoolTest::ge: return 5; |
| 1699 | case BoolTest::overflow: |
| 1700 | case BoolTest::no_overflow: |
| 1701 | case BoolTest::never: |
| 1702 | case BoolTest::illegal: |
| 1703 | default: |
| 1704 | return -1; |
| 1705 | } |
| 1706 | } |
| 1707 | |
| 1708 | //------------------------------Identity--------------------------------------- |
| 1709 | // If the test is constant & we match, then we are the input Control |
| 1710 | Node* IfProjNode::Identity(PhaseGVN* phase) { |
| 1711 | // Can only optimize if cannot go the other way |
| 1712 | const TypeTuple *t = phase->type(in(0))->is_tuple(); |
| 1713 | if (t == TypeTuple::IFNEITHER || (always_taken(t) && |
| 1714 | // During parsing (GVN) we don't remove dead code aggressively. |
| 1715 | // Cut off dead branch and let PhaseRemoveUseless take care of it. |
| 1716 | (!phase->is_IterGVN() || |
| 1717 | // During IGVN, first wait for the dead branch to be killed. |
| 1718 | // Otherwise, the IfNode's control will have two control uses (the IfNode |
| 1719 | // that doesn't go away because it still has uses and this branch of the |
| 1720 | // If) which breaks other optimizations. Node::has_special_unique_user() |
| 1721 | // will cause this node to be reprocessed once the dead branch is killed. |
| 1722 | in(0)->outcnt() == 1))) { |
| 1723 | // IfNode control |
| 1724 | if (in(0)->is_BaseCountedLoopEnd()) { |
| 1725 | // CountedLoopEndNode may be eliminated by if subsuming, replace CountedLoopNode with LoopNode to |
| 1726 | // avoid mismatching between CountedLoopNode and CountedLoopEndNode in the following optimization. |
| 1727 | Node* head = unique_ctrl_out(); |
| 1728 | if (head != NULL__null && head->is_BaseCountedLoop() && head->in(LoopNode::LoopBackControl) == this) { |
| 1729 | Node* new_head = new LoopNode(head->in(LoopNode::EntryControl), this); |
| 1730 | phase->is_IterGVN()->register_new_node_with_optimizer(new_head); |
| 1731 | phase->is_IterGVN()->replace_node(head, new_head); |
| 1732 | } |
| 1733 | } |
| 1734 | return in(0)->in(0); |
| 1735 | } |
| 1736 | // no progress |
| 1737 | return this; |
| 1738 | } |
| 1739 | |
| 1740 | #ifndef PRODUCT |
| 1741 | //-------------------------------related--------------------------------------- |
| 1742 | // An IfProjNode's related node set consists of its input (an IfNode) including |
| 1743 | // the IfNode's condition, plus all of its outputs at level 1. In compact mode, |
| 1744 | // the restrictions for IfNode apply (see IfNode::rel). |
| 1745 | void IfProjNode::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const { |
| 1746 | Node* ifNode = this->in(0); |
| 1747 | in_rel->append(ifNode); |
| 1748 | if (compact) { |
| 1749 | ifNode->collect_nodes(in_rel, 3, false, true); |
| 1750 | } else { |
| 1751 | ifNode->collect_nodes_in_all_data(in_rel, false); |
| 1752 | } |
| 1753 | this->collect_nodes(out_rel, -1, false, false); |
| 1754 | } |
| 1755 | |
| 1756 | //------------------------------dump_spec-------------------------------------- |
| 1757 | void IfNode::dump_spec(outputStream *st) const { |
| 1758 | st->print("P=%f, C=%f",_prob,_fcnt); |
| 1759 | } |
| 1760 | |
| 1761 | //-------------------------------related--------------------------------------- |
| 1762 | // For an IfNode, the set of related output nodes is just the output nodes till |
| 1763 | // depth 2, i.e, the IfTrue/IfFalse projection nodes plus the nodes they refer. |
| 1764 | // The related input nodes contain no control nodes, but all data nodes |
| 1765 | // pertaining to the condition. In compact mode, the input nodes are collected |
| 1766 | // up to a depth of 3. |
| 1767 | void IfNode::related(GrowableArray <Node *> *in_rel, GrowableArray <Node *> *out_rel, bool compact) const { |
| 1768 | if (compact) { |
| 1769 | this->collect_nodes(in_rel, 3, false, true); |
| 1770 | } else { |
| 1771 | this->collect_nodes_in_all_data(in_rel, false); |
| 1772 | } |
| 1773 | this->collect_nodes(out_rel, -2, false, false); |
| 1774 | } |
| 1775 | #endif |
| 1776 | |
| 1777 | //------------------------------idealize_test---------------------------------- |
| 1778 | // Try to canonicalize tests better. Peek at the Cmp/Bool/If sequence and |
| 1779 | // come up with a canonical sequence. Bools getting 'eq', 'gt' and 'ge' forms |
| 1780 | // converted to 'ne', 'le' and 'lt' forms. IfTrue/IfFalse get swapped as |
| 1781 | // needed. |
| 1782 | static IfNode* idealize_test(PhaseGVN* phase, IfNode* iff) { |
| 1783 | assert(iff->in(0) != NULL, "If must be live")do { if (!(iff->in(0) != __null)) { (*g_assert_poison) = 'X' ;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 1783, "assert(" "iff->in(0) != __null" ") failed", "If must be live" ); ::breakpoint(); } } while (0); |
| 1784 | |
| 1785 | if (iff->outcnt() != 2) return NULL__null; // Malformed projections. |
| 1786 | Node* old_if_f = iff->proj_out(false); |
| 1787 | Node* old_if_t = iff->proj_out(true); |
| 1788 | |
| 1789 | // CountedLoopEnds want the back-control test to be TRUE, irregardless of |
| 1790 | // whether they are testing a 'gt' or 'lt' condition. The 'gt' condition |
| 1791 | // happens in count-down loops |
| 1792 | if (iff->is_BaseCountedLoopEnd()) return NULL__null; |
| 1793 | if (!iff->in(1)->is_Bool()) return NULL__null; // Happens for partially optimized IF tests |
| 1794 | BoolNode *b = iff->in(1)->as_Bool(); |
| 1795 | BoolTest bt = b->_test; |
| 1796 | // Test already in good order? |
| 1797 | if( bt.is_canonical() ) |
| 1798 | return NULL__null; |
| 1799 | |
| 1800 | // Flip test to be canonical. Requires flipping the IfFalse/IfTrue and |
| 1801 | // cloning the IfNode. |
| 1802 | Node* new_b = phase->transform( new BoolNode(b->in(1), bt.negate()) ); |
| 1803 | if( !new_b->is_Bool() ) return NULL__null; |
| 1804 | b = new_b->as_Bool(); |
| 1805 | |
| 1806 | PhaseIterGVN *igvn = phase->is_IterGVN(); |
| 1807 | assert( igvn, "Test is not canonical in parser?" )do { if (!(igvn)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 1807, "assert(" "igvn" ") failed", "Test is not canonical in parser?" ); ::breakpoint(); } } while (0); |
| 1808 | |
| 1809 | // The IF node never really changes, but it needs to be cloned |
| 1810 | iff = iff->clone()->as_If(); |
| 1811 | iff->set_req(1, b); |
| 1812 | iff->_prob = 1.0-iff->_prob; |
| 1813 | |
| 1814 | Node *prior = igvn->hash_find_insert(iff); |
| 1815 | if( prior ) { |
| 1816 | igvn->remove_dead_node(iff); |
| 1817 | iff = (IfNode*)prior; |
| 1818 | } else { |
| 1819 | // Cannot call transform on it just yet |
| 1820 | igvn->set_type_bottom(iff); |
| 1821 | } |
| 1822 | igvn->_worklist.push(iff); |
| 1823 | |
| 1824 | // Now handle projections. Cloning not required. |
| 1825 | Node* new_if_f = (Node*)(new IfFalseNode( iff )); |
| 1826 | Node* new_if_t = (Node*)(new IfTrueNode ( iff )); |
| 1827 | |
| 1828 | igvn->register_new_node_with_optimizer(new_if_f); |
| 1829 | igvn->register_new_node_with_optimizer(new_if_t); |
| 1830 | // Flip test, so flip trailing control |
| 1831 | igvn->replace_node(old_if_f, new_if_t); |
| 1832 | igvn->replace_node(old_if_t, new_if_f); |
| 1833 | |
| 1834 | // Progress |
| 1835 | return iff; |
| 1836 | } |
| 1837 | |
| 1838 | Node* RangeCheckNode::Ideal(PhaseGVN *phase, bool can_reshape) { |
| 1839 | Node* res = Ideal_common(phase, can_reshape); |
| 1840 | if (res != NodeSentinel(Node*)-1) { |
| 1841 | return res; |
| 1842 | } |
| 1843 | |
| 1844 | PhaseIterGVN *igvn = phase->is_IterGVN(); |
| 1845 | // Setup to scan up the CFG looking for a dominating test |
| 1846 | Node* prev_dom = this; |
| 1847 | |
| 1848 | // Check for range-check vs other kinds of tests |
| 1849 | Node* index1; |
| 1850 | Node* range1; |
| 1851 | jint offset1; |
| 1852 | int flip1 = is_range_check(range1, index1, offset1); |
| 1853 | if (flip1) { |
| 1854 | Node* dom = in(0); |
| 1855 | // Try to remove extra range checks. All 'up_one_dom' gives up at merges |
| 1856 | // so all checks we inspect post-dominate the top-most check we find. |
| 1857 | // If we are going to fail the current check and we reach the top check |
| 1858 | // then we are guaranteed to fail, so just start interpreting there. |
| 1859 | // We 'expand' the top 3 range checks to include all post-dominating |
| 1860 | // checks. |
| 1861 | |
| 1862 | // The top 3 range checks seen |
| 1863 | const int NRC = 3; |
| 1864 | RangeCheck prev_checks[NRC]; |
| 1865 | int nb_checks = 0; |
| 1866 | |
| 1867 | // Low and high offsets seen so far |
| 1868 | jint off_lo = offset1; |
| 1869 | jint off_hi = offset1; |
| 1870 | |
| 1871 | bool found_immediate_dominator = false; |
| 1872 | |
| 1873 | // Scan for the top checks and collect range of offsets |
| 1874 | for (int dist = 0; dist < 999; dist++) { // Range-Check scan limit |
| 1875 | if (dom->Opcode() == Op_RangeCheck && // Not same opcode? |
| 1876 | prev_dom->in(0) == dom) { // One path of test does dominate? |
| 1877 | if (dom == this) return NULL__null; // dead loop |
| 1878 | // See if this is a range check |
| 1879 | Node* index2; |
| 1880 | Node* range2; |
| 1881 | jint offset2; |
| 1882 | int flip2 = dom->as_RangeCheck()->is_range_check(range2, index2, offset2); |
| 1883 | // See if this is a _matching_ range check, checking against |
| 1884 | // the same array bounds. |
| 1885 | if (flip2 == flip1 && range2 == range1 && index2 == index1 && |
| 1886 | dom->outcnt() == 2) { |
| 1887 | if (nb_checks == 0 && dom->in(1) == in(1)) { |
| 1888 | // Found an immediately dominating test at the same offset. |
| 1889 | // This kind of back-to-back test can be eliminated locally, |
| 1890 | // and there is no need to search further for dominating tests. |
| 1891 | assert(offset2 == offset1, "Same test but different offsets")do { if (!(offset2 == offset1)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/ifnode.cpp" , 1891, "assert(" "offset2 == offset1" ") failed", "Same test but different offsets" ); ::breakpoint(); } } while (0); |
| 1892 | found_immediate_dominator = true; |
| 1893 | break; |
| 1894 | } |
| 1895 | // Gather expanded bounds |
| 1896 | off_lo = MIN2(off_lo,offset2); |
| 1897 | off_hi = MAX2(off_hi,offset2); |
| 1898 | // Record top NRC range checks |
| 1899 | prev_checks[nb_checks%NRC].ctl = prev_dom; |
| 1900 | prev_checks[nb_checks%NRC].off = offset2; |
| 1901 | nb_checks++; |
| 1902 | } |
| 1903 | } |
| 1904 | prev_dom = dom; |
| 1905 | dom = up_one_dom(dom); |
| 1906 | if (!dom) break; |
| 1907 | } |
| 1908 | |
| 1909 | if (!found_immediate_dominator) { |
| 1910 | // Attempt to widen the dominating range check to cover some later |
| 1911 | // ones. Since range checks "fail" by uncommon-trapping to the |
| 1912 | // interpreter, widening a check can make us speculatively enter |
| 1913 | // the interpreter. If we see range-check deopt's, do not widen! |
| 1914 | if (!phase->C->allow_range_check_smearing()) return NULL__null; |
| 1915 | |
| 1916 | // Didn't find prior covering check, so cannot remove anything. |
| 1917 | if (nb_checks == 0) { |
| 1918 | return NULL__null; |
| 1919 | } |
| 1920 | // Constant indices only need to check the upper bound. |
| 1921 | // Non-constant indices must check both low and high. |
| 1922 | int chk0 = (nb_checks - 1) % NRC; |
| 1923 | if (index1) { |
| 1924 | if (nb_checks == 1) { |
| 1925 | return NULL__null; |
| 1926 | } else { |
| 1927 | // If the top range check's constant is the min or max of |
| 1928 | // all constants we widen the next one to cover the whole |
| 1929 | // range of constants. |
| 1930 | RangeCheck rc0 = prev_checks[chk0]; |
| 1931 | int chk1 = (nb_checks - 2) % NRC; |
| 1932 | RangeCheck rc1 = prev_checks[chk1]; |
| 1933 | if (rc0.off == off_lo) { |
| 1934 | adjust_check(rc1.ctl, range1, index1, flip1, off_hi, igvn); |
| 1935 | prev_dom = rc1.ctl; |
| 1936 | } else if (rc0.off == off_hi) { |
| 1937 | adjust_check(rc1.ctl, range1, index1, flip1, off_lo, igvn); |
| 1938 | prev_dom = rc1.ctl; |
| 1939 | } else { |
| 1940 | // If the top test's constant is not the min or max of all |
| 1941 | // constants, we need 3 range checks. We must leave the |
| 1942 | // top test unchanged because widening it would allow the |
| 1943 | // accesses it protects to successfully read/write out of |
| 1944 | // bounds. |
| 1945 | if (nb_checks == 2) { |
| 1946 | return NULL__null; |
| 1947 | } |
| 1948 | int chk2 = (nb_checks - 3) % NRC; |
| 1949 | RangeCheck rc2 = prev_checks[chk2]; |
| 1950 | // The top range check a+i covers interval: -a <= i < length-a |
| 1951 | // The second range check b+i covers interval: -b <= i < length-b |
| 1952 | if (rc1.off <= rc0.off) { |
| 1953 | // if b <= a, we change the second range check to: |
| 1954 | // -min_of_all_constants <= i < length-min_of_all_constants |
| 1955 | // Together top and second range checks now cover: |
| 1956 | // -min_of_all_constants <= i < length-a |
| 1957 | // which is more restrictive than -b <= i < length-b: |
| 1958 | // -b <= -min_of_all_constants <= i < length-a <= length-b |
| 1959 | // The third check is then changed to: |
| 1960 | // -max_of_all_constants <= i < length-max_of_all_constants |
| 1961 | // so 2nd and 3rd checks restrict allowed values of i to: |
| 1962 | // -min_of_all_constants <= i < length-max_of_all_constants |
| 1963 | adjust_check(rc1.ctl, range1, index1, flip1, off_lo, igvn); |
| 1964 | adjust_check(rc2.ctl, range1, index1, flip1, off_hi, igvn); |
| 1965 | } else { |
| 1966 | // if b > a, we change the second range check to: |
| 1967 | // -max_of_all_constants <= i < length-max_of_all_constants |
| 1968 | // Together top and second range checks now cover: |
| 1969 | // -a <= i < length-max_of_all_constants |
| 1970 | // which is more restrictive than -b <= i < length-b: |
| 1971 | // -b < -a <= i < length-max_of_all_constants <= length-b |
| 1972 | // The third check is then changed to: |
| 1973 | // -max_of_all_constants <= i < length-max_of_all_constants |
| 1974 | // so 2nd and 3rd checks restrict allowed values of i to: |
| 1975 | // -min_of_all_constants <= i < length-max_of_all_constants |
| 1976 | adjust_check(rc1.ctl, range1, index1, flip1, off_hi, igvn); |
| 1977 | adjust_check(rc2.ctl, range1, index1, flip1, off_lo, igvn); |
| 1978 | } |
| 1979 | prev_dom = rc2.ctl; |
| 1980 | } |
| 1981 | } |
| 1982 | } else { |
| 1983 | RangeCheck rc0 = prev_checks[chk0]; |
| 1984 | // 'Widen' the offset of the 1st and only covering check |
| 1985 | adjust_check(rc0.ctl, range1, index1, flip1, off_hi, igvn); |
| 1986 | // Test is now covered by prior checks, dominate it out |
| 1987 | prev_dom = rc0.ctl; |
| 1988 | } |
| 1989 | } |
| 1990 | } else { |
| 1991 | prev_dom = search_identical(4); |
| 1992 | |
| 1993 | if (prev_dom == NULL__null) { |
| 1994 | return NULL__null; |
| 1995 | } |
| 1996 | } |
| 1997 | |
| 1998 | // Replace dominated IfNode |
| 1999 | return dominated_by(prev_dom, igvn); |
| 2000 | } |