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[codegen][x64] Add an in place version of Smi(Un)Tag

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The current version of SmiTag and SmiUntag was checking if the
registers were the same, copying them if not and then untagging.
We can avoid a branch and a check by having two versions of
SmiTag and SmiUntag.

Change-Id: Id89213e073cefc9f8e46fcf0e79d0c1d349342ae
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1826730
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64021}
This commit is contained in:
Santiago Aboy Solanes 2019-09-26 20:54:05 +01:00 committed by Commit Bot
parent 249567589a
commit ea6844a665
4 changed files with 59 additions and 43 deletions
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23
src/builtins/x64/builtins-x64.cc
View File

@ -1201,8 +1201,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
Operand(rbp, InterpreterFrameConstants::kBytecodeArrayFromFp));
__ movq(kInterpreterBytecodeOffsetRegister,
Operand(rbp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
__ SmiUntag(kInterpreterBytecodeOffsetRegister,
kInterpreterBytecodeOffsetRegister);
__ SmiUntag(kInterpreterBytecodeOffsetRegister);
// Either return, or advance to the next bytecode and dispatch.
Label do_return;
@ -1429,8 +1428,7 @@ static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
// Get the target bytecode offset from the frame.
__ movq(kInterpreterBytecodeOffsetRegister,
Operand(rbp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
__ SmiUntag(kInterpreterBytecodeOffsetRegister,
kInterpreterBytecodeOffsetRegister);
__ SmiUntag(kInterpreterBytecodeOffsetRegister);
// Dispatch to the target bytecode.
__ movzxbq(r11, Operand(kInterpreterBytecodeArrayRegister,
@ -1447,8 +1445,7 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
Operand(rbp, InterpreterFrameConstants::kBytecodeArrayFromFp));
__ movq(kInterpreterBytecodeOffsetRegister,
Operand(rbp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
__ SmiUntag(kInterpreterBytecodeOffsetRegister,
kInterpreterBytecodeOffsetRegister);
__ SmiUntag(kInterpreterBytecodeOffsetRegister);
// Load the current bytecode.
__ movzxbq(rbx, Operand(kInterpreterBytecodeArrayRegister,
@ -1487,7 +1484,7 @@ void Builtins::Generate_InstantiateAsmJs(MacroAssembler* masm) {
// Preserve argument count for later compare.
__ movq(rcx, rax);
// Push the number of arguments to the callee.
__ SmiTag(rax, rax);
__ SmiTag(rax);
__ Push(rax);
// Push a copy of the target function and the new target.
__ Push(rdi);
@ -1524,7 +1521,7 @@ void Builtins::Generate_InstantiateAsmJs(MacroAssembler* masm) {
__ Drop(2);
__ Pop(rcx);
__ SmiUntag(rcx, rcx);
__ SmiUntag(rcx);
scope.GenerateLeaveFrame();
__ PopReturnAddressTo(rbx);
@ -1538,7 +1535,7 @@ void Builtins::Generate_InstantiateAsmJs(MacroAssembler* masm) {
__ Pop(rdx);
__ Pop(rdi);
__ Pop(rax);
__ SmiUntag(rax, rax);
__ SmiUntag(rax);
}
// On failure, tail call back to regular js by re-calling the function
// which has be reset to the compile lazy builtin.
@ -1565,7 +1562,7 @@ void Generate_ContinueToBuiltinHelper(MacroAssembler* masm,
int code = config->GetAllocatableGeneralCode(i);
__ popq(Register::from_code(code));
if (java_script_builtin && code == kJavaScriptCallArgCountRegister.code()) {
__ SmiUntag(Register::from_code(code), Register::from_code(code));
__ SmiUntag(Register::from_code(code));
}
}
__ movq(
@ -2276,7 +2273,7 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm,
// TODO(bmeurer): Inline the allocation here to avoid building the frame
// in the fast case? (fall back to AllocateInNewSpace?)
FrameScope scope(masm, StackFrame::INTERNAL);
__ SmiTag(rax, rax);
__ SmiTag(rax);
__ Push(rax);
__ Push(rdi);
__ movq(rax, rcx);
@ -2287,7 +2284,7 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm,
__ movq(rcx, rax);
__ Pop(rdi);
__ Pop(rax);
__ SmiUntag(rax, rax);
__ SmiUntag(rax);
}
__ LoadTaggedPointerField(
rdx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
@ -2649,7 +2646,7 @@ void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
// The function index was pushed to the stack by the caller as int32.
__ Pop(r11);
// Convert to Smi for the runtime call.
__ SmiTag(r11, r11);
__ SmiTag(r11);
{
HardAbortScope hard_abort(masm); // Avoid calls to Abort.
FrameScope scope(masm, StackFrame::WASM_COMPILE_LAZY);

57
src/codegen/x64/macro-assembler-x64.cc
View File

@ -1133,34 +1133,49 @@ void TurboAssembler::Move(Register dst, ExternalReference ext) {
movq(dst, Immediate64(ext.address(), RelocInfo::EXTERNAL_REFERENCE));
}
void MacroAssembler::SmiTag(Register dst, Register src) {
void MacroAssembler::SmiTag(Register reg) {
STATIC_ASSERT(kSmiTag == 0);
DCHECK(SmiValuesAre32Bits() || SmiValuesAre31Bits());
if (COMPRESS_POINTERS_BOOL) {
if (dst != src) {
movl(dst, src);
}
shll(dst, Immediate(kSmiShift));
shll(reg, Immediate(kSmiShift));
} else {
if (dst != src) {
movq(dst, src);
}
shlq(dst, Immediate(kSmiShift));
shlq(reg, Immediate(kSmiShift));
}
}
void TurboAssembler::SmiUntag(Register dst, Register src) {
void MacroAssembler::SmiTag(Register dst, Register src) {
DCHECK(dst != src);
if (COMPRESS_POINTERS_BOOL) {
movl(dst, src);
} else {
movq(dst, src);
}
SmiTag(dst);
}
void TurboAssembler::SmiUntag(Register reg) {
STATIC_ASSERT(kSmiTag == 0);
DCHECK(SmiValuesAre32Bits() || SmiValuesAre31Bits());
// TODO(v8:7703): Is there a way to avoid this sign extension when pointer
// compression is enabled?
if (COMPRESS_POINTERS_BOOL) {
movsxlq(reg, reg);
}
sarq(reg, Immediate(kSmiShift));
}
void TurboAssembler::SmiUntag(Register dst, Register src) {
DCHECK(dst != src);
if (COMPRESS_POINTERS_BOOL) {
movsxlq(dst, src);
sarq(dst, Immediate(kSmiShift));
} else {
if (dst != src) {
movq(dst, src);
}
sarq(dst, Immediate(kSmiShift));
movq(dst, src);
}
// TODO(v8:7703): Call SmiUntag(reg) if we can find a way to avoid the extra
// mov when pointer compression is enabled.
STATIC_ASSERT(kSmiTag == 0);
DCHECK(SmiValuesAre32Bits() || SmiValuesAre31Bits());
sarq(dst, Immediate(kSmiShift));
}
void TurboAssembler::SmiUntag(Register dst, Operand src) {
@ -1617,7 +1632,7 @@ void TurboAssembler::Call(Handle<Code> code_object, RelocInfo::Mode rmode) {
Operand TurboAssembler::EntryFromBuiltinIndexAsOperand(Register builtin_index) {
if (SmiValuesAre32Bits()) {
// The builtin_index register contains the builtin index as a Smi.
SmiUntag(builtin_index, builtin_index);
SmiUntag(builtin_index);
return Operand(kRootRegister, builtin_index, times_system_pointer_size,
IsolateData::builtin_entry_table_offset());
} else {
@ -2387,13 +2402,13 @@ void MacroAssembler::CheckDebugHook(Register fun, Register new_target,
FrameScope frame(this,
has_frame() ? StackFrame::NONE : StackFrame::INTERNAL);
if (expected.is_reg()) {
SmiTag(expected.reg(), expected.reg());
SmiTag(expected.reg());
Push(expected.reg());
}
if (actual.is_reg()) {
SmiTag(actual.reg(), actual.reg());
SmiTag(actual.reg());
Push(actual.reg());
SmiUntag(actual.reg(), actual.reg());
SmiUntag(actual.reg());
}
if (new_target.is_valid()) {
Push(new_target);
@ -2408,11 +2423,11 @@ void MacroAssembler::CheckDebugHook(Register fun, Register new_target,
}
if (actual.is_reg()) {
Pop(actual.reg());
SmiUntag(actual.reg(), actual.reg());
SmiUntag(actual.reg());
}
if (expected.is_reg()) {
Pop(expected.reg());
SmiUntag(expected.reg(), expected.reg());
SmiUntag(expected.reg());
}
}
bind(&skip_hook);

4
src/codegen/x64/macro-assembler-x64.h
View File

@ -314,6 +314,8 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
RelocInfo::Mode rmode = RelocInfo::FULL_EMBEDDED_OBJECT);
// Convert smi to word-size sign-extended value.
void SmiUntag(Register reg);
// Requires dst != src
void SmiUntag(Register dst, Register src);
void SmiUntag(Register dst, Operand src);
@ -665,6 +667,8 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
// Conversions between tagged smi values and non-tagged integer values.
// Tag an word-size value. The result must be known to be a valid smi value.
void SmiTag(Register reg);
// Requires dst != src
void SmiTag(Register dst, Register src);
// Simple comparison of smis. Both sides must be known smis to use these,

18
test/cctest/test-macro-assembler-x64.cc
View File

@ -242,35 +242,35 @@ TEST(SmiTag) {
__ movq(rax, Immediate(1)); // Test number.
__ movq(rcx, Immediate(0));
__ SmiTag(rcx, rcx);
__ SmiTag(rcx);
__ Set(rdx, Smi::kZero.ptr());
__ cmp_tagged(rcx, rdx);
__ j(not_equal, &exit);
__ movq(rax, Immediate(2)); // Test number.
__ movq(rcx, Immediate(1024));
__ SmiTag(rcx, rcx);
__ SmiTag(rcx);
__ Set(rdx, Smi::FromInt(1024).ptr());
__ cmp_tagged(rcx, rdx);
__ j(not_equal, &exit);
__ movq(rax, Immediate(3)); // Test number.
__ movq(rcx, Immediate(-1));
__ SmiTag(rcx, rcx);
__ SmiTag(rcx);
__ Set(rdx, Smi::FromInt(-1).ptr());
__ cmp_tagged(rcx, rdx);
__ j(not_equal, &exit);
__ movq(rax, Immediate(4)); // Test number.
__ movq(rcx, Immediate(Smi::kMaxValue));
__ SmiTag(rcx, rcx);
__ SmiTag(rcx);
__ Set(rdx, Smi::FromInt(Smi::kMaxValue).ptr());
__ cmp_tagged(rcx, rdx);
__ j(not_equal, &exit);
__ movq(rax, Immediate(5)); // Test number.
__ movq(rcx, Immediate(Smi::kMinValue));
__ SmiTag(rcx, rcx);
__ SmiTag(rcx);
__ Set(rdx, Smi::FromInt(Smi::kMinValue).ptr());
__ cmp_tagged(rcx, rdx);
__ j(not_equal, &exit);
@ -344,7 +344,7 @@ TEST(SmiCheck) {
// CheckSmi
__ movl(rcx, Immediate(0));
__ SmiTag(rcx, rcx);
__ SmiTag(rcx);
cond = masm->CheckSmi(rcx);
__ j(NegateCondition(cond), &exit);
@ -355,7 +355,7 @@ TEST(SmiCheck) {
__ incq(rax);
__ movl(rcx, Immediate(-1));
__ SmiTag(rcx, rcx);
__ SmiTag(rcx);
cond = masm->CheckSmi(rcx);
__ j(NegateCondition(cond), &exit);
@ -366,7 +366,7 @@ TEST(SmiCheck) {
__ incq(rax);
__ movl(rcx, Immediate(Smi::kMaxValue));
__ SmiTag(rcx, rcx);
__ SmiTag(rcx);
cond = masm->CheckSmi(rcx);
__ j(NegateCondition(cond), &exit);
@ -377,7 +377,7 @@ TEST(SmiCheck) {
__ incq(rax);
__ movl(rcx, Immediate(Smi::kMinValue));
__ SmiTag(rcx, rcx);
__ SmiTag(rcx);
cond = masm->CheckSmi(rcx);
__ j(NegateCondition(cond), &exit);