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// Copyright 2012 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#if V8_TARGET_ARCH_X87
#include "src/codegen.h"
#include "src/ic/ic.h"
#include "src/ic/stub-cache.h"
namespace v8 {
namespace internal {
Condition CompareIC::ComputeCondition(Token::Value op) {
switch (op) {
case Token::EQ_STRICT:
case Token::EQ:
return equal;
case Token::LT:
return less;
case Token::GT:
return greater;
case Token::LTE:
return less_equal;
case Token::GTE:
return greater_equal;
default:
UNREACHABLE();
return no_condition;
}
}
bool CompareIC::HasInlinedSmiCode(Address address) {
// The address of the instruction following the call.
Address test_instruction_address =
address + Assembler::kCallTargetAddressOffset;
// If the instruction following the call is not a test al, nothing
// was inlined.
return *test_instruction_address == Assembler::kTestAlByte;
}
void PatchInlinedSmiCode(Isolate* isolate, Address address,
InlinedSmiCheck check) {
// The address of the instruction following the call.
Address test_instruction_address =
address + Assembler::kCallTargetAddressOffset;
// If the instruction following the call is not a test al, nothing
// was inlined.
if (*test_instruction_address != Assembler::kTestAlByte) {
DCHECK(*test_instruction_address == Assembler::kNopByte);
return;
}
Address delta_address = test_instruction_address + 1;
// The delta to the start of the map check instruction and the
// condition code uses at the patched jump.
uint8_t delta = *reinterpret_cast<uint8_t*>(delta_address);
if (FLAG_trace_ic) {
LOG(isolate, PatchIC(address, test_instruction_address, delta));
}
// Patch with a short conditional jump. Enabling means switching from a short
// jump-if-carry/not-carry to jump-if-zero/not-zero, whereas disabling is the
// reverse operation of that.
Address jmp_address = test_instruction_address - delta;
DCHECK((check == ENABLE_INLINED_SMI_CHECK)
? (*jmp_address == Assembler::kJncShortOpcode ||
*jmp_address == Assembler::kJcShortOpcode)
: (*jmp_address == Assembler::kJnzShortOpcode ||
*jmp_address == Assembler::kJzShortOpcode));
Condition cc =
(check == ENABLE_INLINED_SMI_CHECK)
? (*jmp_address == Assembler::kJncShortOpcode ? not_zero : zero)
: (*jmp_address == Assembler::kJnzShortOpcode ? not_carry : carry);
*jmp_address = static_cast<byte>(Assembler::kJccShortPrefix | cc);
}
} // namespace internal
} // namespace v8
#endif // V8_TARGET_ARCH_X87
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