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// Copyright 2013 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_ARM64
#include "src/arm64/assembler-arm64-inl.h"
#include "src/codegen.h"
#include "src/ic/ic.h"
#include "src/ic/stub-cache.h"
#include "src/objects-inl.h"
namespace v8 {
namespace internal {
Condition CompareIC::ComputeCondition(Token::Value op) {
switch (op) {
case Token::EQ_STRICT:
case Token::EQ:
return eq;
case Token::LT:
return lt;
case Token::GT:
return gt;
case Token::LTE:
return le;
case Token::GTE:
return ge;
default:
UNREACHABLE();
}
}
bool CompareIC::HasInlinedSmiCode(Address address) {
// The address of the instruction following the call.
Address info_address = Assembler::return_address_from_call_start(address);
InstructionSequence* patch_info = InstructionSequence::At(info_address);
return patch_info->IsInlineData();
}
// Activate a SMI fast-path by patching the instructions generated by
// JumpPatchSite::EmitJumpIf(Not)Smi(), using the information encoded by
// JumpPatchSite::EmitPatchInfo().
void PatchInlinedSmiCode(Isolate* isolate, Address address,
InlinedSmiCheck check) {
// The patch information is encoded in the instruction stream using
// instructions which have no side effects, so we can safely execute them.
// The patch information is encoded directly after the call to the helper
// function which is requesting this patch operation.
Address info_address = Assembler::return_address_from_call_start(address);
InlineSmiCheckInfo info(info_address);
// Check and decode the patch information instruction.
if (!info.HasSmiCheck()) {
return;
}
if (FLAG_trace_ic) {
LOG(isolate, PatchIC(address, info_address, info.SmiCheckDelta()));
}
// Patch and activate code generated by JumpPatchSite::EmitJumpIfNotSmi()
// and JumpPatchSite::EmitJumpIfSmi().
// Changing
// tb(n)z xzr, #0, <target>
// to
// tb(!n)z test_reg, #0, <target>
Instruction* to_patch = info.SmiCheck();
PatchingAssembler patcher(isolate, reinterpret_cast<byte*>(to_patch), 1);
DCHECK(to_patch->IsTestBranch());
DCHECK(to_patch->ImmTestBranchBit5() == 0);
DCHECK(to_patch->ImmTestBranchBit40() == 0);
STATIC_ASSERT(kSmiTag == 0);
STATIC_ASSERT(kSmiTagMask == 1);
int branch_imm = to_patch->ImmTestBranch();
Register smi_reg;
if (check == ENABLE_INLINED_SMI_CHECK) {
DCHECK(to_patch->Rt() == xzr.code());
smi_reg = info.SmiRegister();
} else {
DCHECK(check == DISABLE_INLINED_SMI_CHECK);
DCHECK(to_patch->Rt() != xzr.code());
smi_reg = xzr;
}
if (to_patch->Mask(TestBranchMask) == TBZ) {
// This is JumpIfNotSmi(smi_reg, branch_imm).
patcher.tbnz(smi_reg, 0, branch_imm);
} else {
DCHECK(to_patch->Mask(TestBranchMask) == TBNZ);
// This is JumpIfSmi(smi_reg, branch_imm).
patcher.tbz(smi_reg, 0, branch_imm);
}
}
} // namespace internal
} // namespace v8
#endif // V8_TARGET_ARCH_ARM64
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