| File: | jdk/src/hotspot/cpu/x86/icBuffer_x86.cpp |
| Warning: | line 88, column 24 Value stored to 'jump' during its initialization is never read |
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| 1 | /* |
| 2 | * Copyright (c) 1997, 2015, 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 "asm/macroAssembler.hpp" |
| 27 | #include "asm/macroAssembler.inline.hpp" |
| 28 | #include "code/icBuffer.hpp" |
| 29 | #include "gc/shared/collectedHeap.inline.hpp" |
| 30 | #include "interpreter/bytecodes.hpp" |
| 31 | #include "memory/resourceArea.hpp" |
| 32 | #include "nativeInst_x86.hpp" |
| 33 | #include "oops/oop.inline.hpp" |
| 34 | |
| 35 | int InlineCacheBuffer::ic_stub_code_size() { |
| 36 | // Worst case, if destination is not a near call: |
| 37 | // lea rax, lit1 |
| 38 | // lea scratch, lit2 |
| 39 | // jmp scratch |
| 40 | |
| 41 | // Best case |
| 42 | // lea rax, lit1 |
| 43 | // jmp lit2 |
| 44 | |
| 45 | int best = NativeMovConstReg::instruction_size + NativeJump::instruction_size; |
| 46 | int worst = 2 * NativeMovConstReg::instruction_size + 3; |
| 47 | return MAX2(best, worst); |
| 48 | } |
| 49 | |
| 50 | |
| 51 | |
| 52 | void InlineCacheBuffer::assemble_ic_buffer_code(address code_begin, void* cached_value, address entry_point) { |
| 53 | ResourceMark rm; |
| 54 | CodeBuffer code(code_begin, ic_stub_code_size()); |
| 55 | MacroAssembler* masm = new MacroAssembler(&code); |
| 56 | // note: even though the code contains an embedded value, we do not need reloc info |
| 57 | // because |
| 58 | // (1) the value is old (i.e., doesn't matter for scavenges) |
| 59 | // (2) these ICStubs are removed *before* a GC happens, so the roots disappear |
| 60 | // assert(cached_value == NULL || cached_oop->is_perm(), "must be perm oop"); |
| 61 | masm->lea(rax, AddressLiteral((address) cached_value, relocInfo::metadata_type)); |
| 62 | masm->jump(ExternalAddress(entry_point)); |
| 63 | } |
| 64 | |
| 65 | |
| 66 | address InlineCacheBuffer::ic_buffer_entry_point(address code_begin) { |
| 67 | NativeMovConstReg* move = nativeMovConstReg_at(code_begin); // creation also verifies the object |
| 68 | address jmp = move->next_instruction_address(); |
| 69 | NativeInstruction* ni = nativeInstruction_at(jmp); |
| 70 | if (ni->is_jump()) { |
| 71 | NativeJump* jump = nativeJump_at(jmp); |
| 72 | return jump->jump_destination(); |
| 73 | } else { |
| 74 | assert(ni->is_far_jump(), "unexpected instruction")do { if (!(ni->is_far_jump())) { (*g_assert_poison) = 'X'; ; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/cpu/x86/icBuffer_x86.cpp" , 74, "assert(" "ni->is_far_jump()" ") failed", "unexpected instruction" ); ::breakpoint(); } } while (0); |
| 75 | NativeFarJump* jump = nativeFarJump_at(jmp); |
| 76 | return jump->jump_destination(); |
| 77 | } |
| 78 | } |
| 79 | |
| 80 | |
| 81 | void* InlineCacheBuffer::ic_buffer_cached_value(address code_begin) { |
| 82 | // creation also verifies the object |
| 83 | NativeMovConstReg* move = nativeMovConstReg_at(code_begin); |
| 84 | // Verifies the jump |
| 85 | address jmp = move->next_instruction_address(); |
| 86 | NativeInstruction* ni = nativeInstruction_at(jmp); |
| 87 | if (ni->is_jump()) { |
| 88 | NativeJump* jump = nativeJump_at(jmp); |
Value stored to 'jump' during its initialization is never read | |
| 89 | } else { |
| 90 | assert(ni->is_far_jump(), "unexpected instruction")do { if (!(ni->is_far_jump())) { (*g_assert_poison) = 'X'; ; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/cpu/x86/icBuffer_x86.cpp" , 90, "assert(" "ni->is_far_jump()" ") failed", "unexpected instruction" ); ::breakpoint(); } } while (0); |
| 91 | NativeFarJump* jump = nativeFarJump_at(jmp); |
| 92 | } |
| 93 | void* o = (void*)move->data(); |
| 94 | return o; |
| 95 | } |