deps/v8/src/x87/codegen-x87.cc
// 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.
#include "src/v8.h"
#if V8_TARGET_ARCH_X87
#include "src/codegen.h"
#include "src/heap/heap.h"
#include "src/macro-assembler.h"
namespace v8 {
namespace internal {
// -------------------------------------------------------------------------
// Platform-specific RuntimeCallHelper functions.
void StubRuntimeCallHelper::BeforeCall(MacroAssembler* masm) const {
masm->EnterFrame(StackFrame::INTERNAL);
DCHECK(!masm->has_frame());
masm->set_has_frame(true);
}
void StubRuntimeCallHelper::AfterCall(MacroAssembler* masm) const {
masm->LeaveFrame(StackFrame::INTERNAL);
DCHECK(masm->has_frame());
masm->set_has_frame(false);
}
#define __ masm.
UnaryMathFunction CreateExpFunction() {
// No SSE2 support
return &std::exp;
}
UnaryMathFunction CreateSqrtFunction() {
// No SSE2 support
return &std::sqrt;
}
// Helper functions for CreateMemMoveFunction.
#undef __
#define __ ACCESS_MASM(masm)
enum Direction { FORWARD, BACKWARD };
enum Alignment { MOVE_ALIGNED, MOVE_UNALIGNED };
void MemMoveEmitPopAndReturn(MacroAssembler* masm) {
__ pop(esi);
__ pop(edi);
__ ret(0);
}
#undef __
#define __ masm.
class LabelConverter {
public:
explicit LabelConverter(byte* buffer) : buffer_(buffer) {}
int32_t address(Label* l) const {
return reinterpret_cast<int32_t>(buffer_) + l->pos();
}
private:
byte* buffer_;
};
MemMoveFunction CreateMemMoveFunction() {
size_t actual_size;
// Allocate buffer in executable space.
byte* buffer =
static_cast<byte*>(base::OS::Allocate(1 * KB, &actual_size, true));
if (buffer == NULL) return NULL;
MacroAssembler masm(NULL, buffer, static_cast<int>(actual_size));
LabelConverter conv(buffer);
// Generated code is put into a fixed, unmovable buffer, and not into
// the V8 heap. We can't, and don't, refer to any relocatable addresses
// (e.g. the JavaScript nan-object).
// 32-bit C declaration function calls pass arguments on stack.
// Stack layout:
// esp[12]: Third argument, size.
// esp[8]: Second argument, source pointer.
// esp[4]: First argument, destination pointer.
// esp[0]: return address
const int kDestinationOffset = 1 * kPointerSize;
const int kSourceOffset = 2 * kPointerSize;
const int kSizeOffset = 3 * kPointerSize;
int stack_offset = 0; // Update if we change the stack height.
Label backward, backward_much_overlap;
Label forward_much_overlap, small_size, medium_size, pop_and_return;
__ push(edi);
__ push(esi);
stack_offset += 2 * kPointerSize;
Register dst = edi;
Register src = esi;
Register count = ecx;
__ mov(dst, Operand(esp, stack_offset + kDestinationOffset));
__ mov(src, Operand(esp, stack_offset + kSourceOffset));
__ mov(count, Operand(esp, stack_offset + kSizeOffset));
__ cmp(dst, src);
__ j(equal, &pop_and_return);
// No SSE2.
Label forward;
__ cmp(count, 0);
__ j(equal, &pop_and_return);
__ cmp(dst, src);
__ j(above, &backward);
__ jmp(&forward);
{
// Simple forward copier.
Label forward_loop_1byte, forward_loop_4byte;
__ bind(&forward_loop_4byte);
__ mov(eax, Operand(src, 0));
__ sub(count, Immediate(4));
__ add(src, Immediate(4));
__ mov(Operand(dst, 0), eax);
__ add(dst, Immediate(4));
__ bind(&forward); // Entry point.
__ cmp(count, 3);
__ j(above, &forward_loop_4byte);
__ bind(&forward_loop_1byte);
__ cmp(count, 0);
__ j(below_equal, &pop_and_return);
__ mov_b(eax, Operand(src, 0));
__ dec(count);
__ inc(src);
__ mov_b(Operand(dst, 0), eax);
__ inc(dst);
__ jmp(&forward_loop_1byte);
}
{
// Simple backward copier.
Label backward_loop_1byte, backward_loop_4byte, entry_shortcut;
__ bind(&backward);
__ add(src, count);
__ add(dst, count);
__ cmp(count, 3);
__ j(below_equal, &entry_shortcut);
__ bind(&backward_loop_4byte);
__ sub(src, Immediate(4));
__ sub(count, Immediate(4));
__ mov(eax, Operand(src, 0));
__ sub(dst, Immediate(4));
__ mov(Operand(dst, 0), eax);
__ cmp(count, 3);
__ j(above, &backward_loop_4byte);
__ bind(&backward_loop_1byte);
__ cmp(count, 0);
__ j(below_equal, &pop_and_return);
__ bind(&entry_shortcut);
__ dec(src);
__ dec(count);
__ mov_b(eax, Operand(src, 0));
__ dec(dst);
__ mov_b(Operand(dst, 0), eax);
__ jmp(&backward_loop_1byte);
}
__ bind(&pop_and_return);
MemMoveEmitPopAndReturn(&masm);
CodeDesc desc;
masm.GetCode(&desc);
DCHECK(!RelocInfo::RequiresRelocation(desc));
CpuFeatures::FlushICache(buffer, actual_size);
base::OS::ProtectCode(buffer, actual_size);
// TODO(jkummerow): It would be nice to register this code creation event
// with the PROFILE / GDBJIT system.
return FUNCTION_CAST<MemMoveFunction>(buffer);
}
#undef __
// -------------------------------------------------------------------------
// Code generators
#define __ ACCESS_MASM(masm)
void ElementsTransitionGenerator::GenerateMapChangeElementsTransition(
MacroAssembler* masm,
Register receiver,
Register key,
Register value,
Register target_map,
AllocationSiteMode mode,
Label* allocation_memento_found) {
Register scratch = edi;
DCHECK(!AreAliased(receiver, key, value, target_map, scratch));
if (mode == TRACK_ALLOCATION_SITE) {
DCHECK(allocation_memento_found != NULL);
__ JumpIfJSArrayHasAllocationMemento(
receiver, scratch, allocation_memento_found);
}
// Set transitioned map.
__ mov(FieldOperand(receiver, HeapObject::kMapOffset), target_map);
__ RecordWriteField(receiver,
HeapObject::kMapOffset,
target_map,
scratch,
EMIT_REMEMBERED_SET,
OMIT_SMI_CHECK);
}
void ElementsTransitionGenerator::GenerateSmiToDouble(
MacroAssembler* masm,
Register receiver,
Register key,
Register value,
Register target_map,
AllocationSiteMode mode,
Label* fail) {
// Return address is on the stack.
DCHECK(receiver.is(edx));
DCHECK(key.is(ecx));
DCHECK(value.is(eax));
DCHECK(target_map.is(ebx));
Label loop, entry, convert_hole, gc_required, only_change_map;
if (mode == TRACK_ALLOCATION_SITE) {
__ JumpIfJSArrayHasAllocationMemento(edx, edi, fail);
}
// Check for empty arrays, which only require a map transition and no changes
// to the backing store.
__ mov(edi, FieldOperand(edx, JSObject::kElementsOffset));
__ cmp(edi, Immediate(masm->isolate()->factory()->empty_fixed_array()));
__ j(equal, &only_change_map);
__ push(eax);
__ push(ebx);
__ mov(edi, FieldOperand(edi, FixedArray::kLengthOffset));
// Allocate new FixedDoubleArray.
// edx: receiver
// edi: length of source FixedArray (smi-tagged)
AllocationFlags flags =
static_cast<AllocationFlags>(TAG_OBJECT | DOUBLE_ALIGNMENT);
__ Allocate(FixedDoubleArray::kHeaderSize, times_8, edi,
REGISTER_VALUE_IS_SMI, eax, ebx, no_reg, &gc_required, flags);
// eax: destination FixedDoubleArray
// edi: number of elements
// edx: receiver
__ mov(FieldOperand(eax, HeapObject::kMapOffset),
Immediate(masm->isolate()->factory()->fixed_double_array_map()));
__ mov(FieldOperand(eax, FixedDoubleArray::kLengthOffset), edi);
__ mov(esi, FieldOperand(edx, JSObject::kElementsOffset));
// Replace receiver's backing store with newly created FixedDoubleArray.
__ mov(FieldOperand(edx, JSObject::kElementsOffset), eax);
__ mov(ebx, eax);
__ RecordWriteField(edx,
JSObject::kElementsOffset,
ebx,
edi,
EMIT_REMEMBERED_SET,
OMIT_SMI_CHECK);
__ mov(edi, FieldOperand(esi, FixedArray::kLengthOffset));
// Prepare for conversion loop.
ExternalReference canonical_the_hole_nan_reference =
ExternalReference::address_of_the_hole_nan();
__ jmp(&entry);
// Call into runtime if GC is required.
__ bind(&gc_required);
// Restore registers before jumping into runtime.
__ mov(esi, Operand(ebp, StandardFrameConstants::kContextOffset));
__ pop(ebx);
__ pop(eax);
__ jmp(fail);
// Convert and copy elements
// esi: source FixedArray
__ bind(&loop);
__ mov(ebx, FieldOperand(esi, edi, times_2, FixedArray::kHeaderSize));
// ebx: current element from source
// edi: index of current element
__ JumpIfNotSmi(ebx, &convert_hole);
// Normal smi, convert it to double and store.
__ SmiUntag(ebx);
__ push(ebx);
__ fild_s(Operand(esp, 0));
__ pop(ebx);
__ fstp_d(FieldOperand(eax, edi, times_4, FixedDoubleArray::kHeaderSize));
__ jmp(&entry);
// Found hole, store hole_nan_as_double instead.
__ bind(&convert_hole);
if (FLAG_debug_code) {
__ cmp(ebx, masm->isolate()->factory()->the_hole_value());
__ Assert(equal, kObjectFoundInSmiOnlyArray);
}
__ fld_d(Operand::StaticVariable(canonical_the_hole_nan_reference));
__ fstp_d(FieldOperand(eax, edi, times_4, FixedDoubleArray::kHeaderSize));
__ bind(&entry);
__ sub(edi, Immediate(Smi::FromInt(1)));
__ j(not_sign, &loop);
__ pop(ebx);
__ pop(eax);
// Restore esi.
__ mov(esi, Operand(ebp, StandardFrameConstants::kContextOffset));
__ bind(&only_change_map);
// eax: value
// ebx: target map
// Set transitioned map.
__ mov(FieldOperand(edx, HeapObject::kMapOffset), ebx);
__ RecordWriteField(edx,
HeapObject::kMapOffset,
ebx,
edi,
OMIT_REMEMBERED_SET,
OMIT_SMI_CHECK);
}
void ElementsTransitionGenerator::GenerateDoubleToObject(
MacroAssembler* masm,
Register receiver,
Register key,
Register value,
Register target_map,
AllocationSiteMode mode,
Label* fail) {
// Return address is on the stack.
DCHECK(receiver.is(edx));
DCHECK(key.is(ecx));
DCHECK(value.is(eax));
DCHECK(target_map.is(ebx));
Label loop, entry, convert_hole, gc_required, only_change_map, success;
if (mode == TRACK_ALLOCATION_SITE) {
__ JumpIfJSArrayHasAllocationMemento(edx, edi, fail);
}
// Check for empty arrays, which only require a map transition and no changes
// to the backing store.
__ mov(edi, FieldOperand(edx, JSObject::kElementsOffset));
__ cmp(edi, Immediate(masm->isolate()->factory()->empty_fixed_array()));
__ j(equal, &only_change_map);
__ push(eax);
__ push(edx);
__ push(ebx);
__ mov(ebx, FieldOperand(edi, FixedDoubleArray::kLengthOffset));
// Allocate new FixedArray.
// ebx: length of source FixedDoubleArray (smi-tagged)
__ lea(edi, Operand(ebx, times_2, FixedArray::kHeaderSize));
__ Allocate(edi, eax, esi, no_reg, &gc_required, TAG_OBJECT);
// eax: destination FixedArray
// ebx: number of elements
__ mov(FieldOperand(eax, HeapObject::kMapOffset),
Immediate(masm->isolate()->factory()->fixed_array_map()));
__ mov(FieldOperand(eax, FixedArray::kLengthOffset), ebx);
__ mov(edi, FieldOperand(edx, JSObject::kElementsOffset));
__ jmp(&entry);
// ebx: target map
// edx: receiver
// Set transitioned map.
__ bind(&only_change_map);
__ mov(FieldOperand(edx, HeapObject::kMapOffset), ebx);
__ RecordWriteField(edx,
HeapObject::kMapOffset,
ebx,
edi,
OMIT_REMEMBERED_SET,
OMIT_SMI_CHECK);
__ jmp(&success);
// Call into runtime if GC is required.
__ bind(&gc_required);
__ mov(esi, Operand(ebp, StandardFrameConstants::kContextOffset));
__ pop(ebx);
__ pop(edx);
__ pop(eax);
__ jmp(fail);
// Box doubles into heap numbers.
// edi: source FixedDoubleArray
// eax: destination FixedArray
__ bind(&loop);
// ebx: index of current element (smi-tagged)
uint32_t offset = FixedDoubleArray::kHeaderSize + sizeof(kHoleNanLower32);
__ cmp(FieldOperand(edi, ebx, times_4, offset), Immediate(kHoleNanUpper32));
__ j(equal, &convert_hole);
// Non-hole double, copy value into a heap number.
__ AllocateHeapNumber(edx, esi, no_reg, &gc_required);
// edx: new heap number
__ mov(esi, FieldOperand(edi, ebx, times_4, FixedDoubleArray::kHeaderSize));
__ mov(FieldOperand(edx, HeapNumber::kValueOffset), esi);
__ mov(esi, FieldOperand(edi, ebx, times_4, offset));
__ mov(FieldOperand(edx, HeapNumber::kValueOffset + kPointerSize), esi);
__ mov(FieldOperand(eax, ebx, times_2, FixedArray::kHeaderSize), edx);
__ mov(esi, ebx);
__ RecordWriteArray(eax,
edx,
esi,
EMIT_REMEMBERED_SET,
OMIT_SMI_CHECK);
__ jmp(&entry, Label::kNear);
// Replace the-hole NaN with the-hole pointer.
__ bind(&convert_hole);
__ mov(FieldOperand(eax, ebx, times_2, FixedArray::kHeaderSize),
masm->isolate()->factory()->the_hole_value());
__ bind(&entry);
__ sub(ebx, Immediate(Smi::FromInt(1)));
__ j(not_sign, &loop);
__ pop(ebx);
__ pop(edx);
// ebx: target map
// edx: receiver
// Set transitioned map.
__ mov(FieldOperand(edx, HeapObject::kMapOffset), ebx);
__ RecordWriteField(edx,
HeapObject::kMapOffset,
ebx,
edi,
OMIT_REMEMBERED_SET,
OMIT_SMI_CHECK);
// Replace receiver's backing store with newly created and filled FixedArray.
__ mov(FieldOperand(edx, JSObject::kElementsOffset), eax);
__ RecordWriteField(edx,
JSObject::kElementsOffset,
eax,
edi,
EMIT_REMEMBERED_SET,
OMIT_SMI_CHECK);
// Restore registers.
__ pop(eax);
__ mov(esi, Operand(ebp, StandardFrameConstants::kContextOffset));
__ bind(&success);
}
void StringCharLoadGenerator::Generate(MacroAssembler* masm,
Factory* factory,
Register string,
Register index,
Register result,
Label* call_runtime) {
// Fetch the instance type of the receiver into result register.
__ mov(result, FieldOperand(string, HeapObject::kMapOffset));
__ movzx_b(result, FieldOperand(result, Map::kInstanceTypeOffset));
// We need special handling for indirect strings.
Label check_sequential;
__ test(result, Immediate(kIsIndirectStringMask));
__ j(zero, &check_sequential, Label::kNear);
// Dispatch on the indirect string shape: slice or cons.
Label cons_string;
__ test(result, Immediate(kSlicedNotConsMask));
__ j(zero, &cons_string, Label::kNear);
// Handle slices.
Label indirect_string_loaded;
__ mov(result, FieldOperand(string, SlicedString::kOffsetOffset));
__ SmiUntag(result);
__ add(index, result);
__ mov(string, FieldOperand(string, SlicedString::kParentOffset));
__ jmp(&indirect_string_loaded, Label::kNear);
// Handle cons strings.
// Check whether the right hand side is the empty string (i.e. if
// this is really a flat string in a cons string). If that is not
// the case we would rather go to the runtime system now to flatten
// the string.
__ bind(&cons_string);
__ cmp(FieldOperand(string, ConsString::kSecondOffset),
Immediate(factory->empty_string()));
__ j(not_equal, call_runtime);
__ mov(string, FieldOperand(string, ConsString::kFirstOffset));
__ bind(&indirect_string_loaded);
__ mov(result, FieldOperand(string, HeapObject::kMapOffset));
__ movzx_b(result, FieldOperand(result, Map::kInstanceTypeOffset));
// Distinguish sequential and external strings. Only these two string
// representations can reach here (slices and flat cons strings have been
// reduced to the underlying sequential or external string).
Label seq_string;
__ bind(&check_sequential);
STATIC_ASSERT(kSeqStringTag == 0);
__ test(result, Immediate(kStringRepresentationMask));
__ j(zero, &seq_string, Label::kNear);
// Handle external strings.
Label ascii_external, done;
if (FLAG_debug_code) {
// Assert that we do not have a cons or slice (indirect strings) here.
// Sequential strings have already been ruled out.
__ test(result, Immediate(kIsIndirectStringMask));
__ Assert(zero, kExternalStringExpectedButNotFound);
}
// Rule out short external strings.
STATIC_ASSERT(kShortExternalStringTag != 0);
__ test_b(result, kShortExternalStringMask);
__ j(not_zero, call_runtime);
// Check encoding.
STATIC_ASSERT(kTwoByteStringTag == 0);
__ test_b(result, kStringEncodingMask);
__ mov(result, FieldOperand(string, ExternalString::kResourceDataOffset));
__ j(not_equal, &ascii_external, Label::kNear);
// Two-byte string.
__ movzx_w(result, Operand(result, index, times_2, 0));
__ jmp(&done, Label::kNear);
__ bind(&ascii_external);
// Ascii string.
__ movzx_b(result, Operand(result, index, times_1, 0));
__ jmp(&done, Label::kNear);
// Dispatch on the encoding: ASCII or two-byte.
Label ascii;
__ bind(&seq_string);
STATIC_ASSERT((kStringEncodingMask & kOneByteStringTag) != 0);
STATIC_ASSERT((kStringEncodingMask & kTwoByteStringTag) == 0);
__ test(result, Immediate(kStringEncodingMask));
__ j(not_zero, &ascii, Label::kNear);
// Two-byte string.
// Load the two-byte character code into the result register.
__ movzx_w(result, FieldOperand(string,
index,
times_2,
SeqTwoByteString::kHeaderSize));
__ jmp(&done, Label::kNear);
// Ascii string.
// Load the byte into the result register.
__ bind(&ascii);
__ movzx_b(result, FieldOperand(string,
index,
times_1,
SeqOneByteString::kHeaderSize));
__ bind(&done);
}
#undef __
CodeAgingHelper::CodeAgingHelper() {
DCHECK(young_sequence_.length() == kNoCodeAgeSequenceLength);
CodePatcher patcher(young_sequence_.start(), young_sequence_.length());
patcher.masm()->push(ebp);
patcher.masm()->mov(ebp, esp);
patcher.masm()->push(esi);
patcher.masm()->push(edi);
}
#ifdef DEBUG
bool CodeAgingHelper::IsOld(byte* candidate) const {
return *candidate == kCallOpcode;
}
#endif
bool Code::IsYoungSequence(Isolate* isolate, byte* sequence) {
bool result = isolate->code_aging_helper()->IsYoung(sequence);
DCHECK(result || isolate->code_aging_helper()->IsOld(sequence));
return result;
}
void Code::GetCodeAgeAndParity(Isolate* isolate, byte* sequence, Age* age,
MarkingParity* parity) {
if (IsYoungSequence(isolate, sequence)) {
*age = kNoAgeCodeAge;
*parity = NO_MARKING_PARITY;
} else {
sequence++; // Skip the kCallOpcode byte
Address target_address = sequence + *reinterpret_cast<int*>(sequence) +
Assembler::kCallTargetAddressOffset;
Code* stub = GetCodeFromTargetAddress(target_address);
GetCodeAgeAndParity(stub, age, parity);
}
}
void Code::PatchPlatformCodeAge(Isolate* isolate,
byte* sequence,
Code::Age age,
MarkingParity parity) {
uint32_t young_length = isolate->code_aging_helper()->young_sequence_length();
if (age == kNoAgeCodeAge) {
isolate->code_aging_helper()->CopyYoungSequenceTo(sequence);
CpuFeatures::FlushICache(sequence, young_length);
} else {
Code* stub = GetCodeAgeStub(isolate, age, parity);
CodePatcher patcher(sequence, young_length);
patcher.masm()->call(stub->instruction_start(), RelocInfo::NONE32);
}
}
} } // namespace v8::internal
#endif // V8_TARGET_ARCH_X87