// 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/ia32/codegen-ia32.h"
#if V8_TARGET_ARCH_IA32
#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.
UnaryMathFunctionWithIsolate CreateSqrtFunction(Isolate* isolate) {
size_t actual_size;
// Allocate buffer in executable space.
byte* buffer =
static_cast<byte*>(base::OS::Allocate(1 * KB, &actual_size, true));
if (buffer == nullptr) return nullptr;
MacroAssembler masm(isolate, buffer, static_cast<int>(actual_size),
CodeObjectRequired::kNo);
// esp[1 * kPointerSize]: raw double input
// esp[0 * kPointerSize]: return address
// Move double input into registers.
{
__ movsd(xmm0, Operand(esp, 1 * kPointerSize));
__ sqrtsd(xmm0, xmm0);
__ movsd(Operand(esp, 1 * kPointerSize), xmm0);
// Load result into floating point register as return value.
__ fld_d(Operand(esp, 1 * kPointerSize));
__ Ret();
}
CodeDesc desc;
masm.GetCode(&desc);
DCHECK(!RelocInfo::RequiresRelocation(desc));
Assembler::FlushICache(isolate, buffer, actual_size);
base::OS::ProtectCode(buffer, actual_size);
return FUNCTION_CAST<UnaryMathFunctionWithIsolate>(buffer);
}
// Helper functions for CreateMemMoveFunction.
#undef __
#define __ ACCESS_MASM(masm)
enum Direction { FORWARD, BACKWARD };
enum Alignment { MOVE_ALIGNED, MOVE_UNALIGNED };
// Expects registers:
// esi - source, aligned if alignment == ALIGNED
// edi - destination, always aligned
// ecx - count (copy size in bytes)
// edx - loop count (number of 64 byte chunks)
void MemMoveEmitMainLoop(MacroAssembler* masm,
Label* move_last_15,
Direction direction,
Alignment alignment) {
Register src = esi;
Register dst = edi;
Register count = ecx;
Register loop_count = edx;
Label loop, move_last_31, move_last_63;
__ cmp(loop_count, 0);
__ j(equal, &move_last_63);
__ bind(&loop);
// Main loop. Copy in 64 byte chunks.
if (direction == BACKWARD) __ sub(src, Immediate(0x40));
__ movdq(alignment == MOVE_ALIGNED, xmm0, Operand(src, 0x00));
__ movdq(alignment == MOVE_ALIGNED, xmm1, Operand(src, 0x10));
__ movdq(alignment == MOVE_ALIGNED, xmm2, Operand(src, 0x20));
__ movdq(alignment == MOVE_ALIGNED, xmm3, Operand(src, 0x30));
if (direction == FORWARD) __ add(src, Immediate(0x40));
if (direction == BACKWARD) __ sub(dst, Immediate(0x40));
__ movdqa(Operand(dst, 0x00), xmm0);
__ movdqa(Operand(dst, 0x10), xmm1);
__ movdqa(Operand(dst, 0x20), xmm2);
__ movdqa(Operand(dst, 0x30), xmm3);
if (direction == FORWARD) __ add(dst, Immediate(0x40));
__ dec(loop_count);
__ j(not_zero, &loop);
// At most 63 bytes left to copy.
__ bind(&move_last_63);
__ test(count, Immediate(0x20));
__ j(zero, &move_last_31);
if (direction == BACKWARD) __ sub(src, Immediate(0x20));
__ movdq(alignment == MOVE_ALIGNED, xmm0, Operand(src, 0x00));
__ movdq(alignment == MOVE_ALIGNED, xmm1, Operand(src, 0x10));
if (direction == FORWARD) __ add(src, Immediate(0x20));
if (direction == BACKWARD) __ sub(dst, Immediate(0x20));
__ movdqa(Operand(dst, 0x00), xmm0);
__ movdqa(Operand(dst, 0x10), xmm1);
if (direction == FORWARD) __ add(dst, Immediate(0x20));
// At most 31 bytes left to copy.
__ bind(&move_last_31);
__ test(count, Immediate(0x10));
__ j(zero, move_last_15);
if (direction == BACKWARD) __ sub(src, Immediate(0x10));
__ movdq(alignment == MOVE_ALIGNED, xmm0, Operand(src, 0));
if (direction == FORWARD) __ add(src, Immediate(0x10));
if (direction == BACKWARD) __ sub(dst, Immediate(0x10));
__ movdqa(Operand(dst, 0), xmm0);
if (direction == FORWARD) __ add(dst, Immediate(0x10));
}
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(Isolate* isolate) {
size_t actual_size;
// Allocate buffer in executable space.
byte* buffer =
static_cast<byte*>(base::OS::Allocate(1 * KB, &actual_size, true));
if (buffer == nullptr) return nullptr;
MacroAssembler masm(isolate, buffer, static_cast<int>(actual_size),
CodeObjectRequired::kNo);
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;
// When copying up to this many bytes, use special "small" handlers.
const size_t kSmallCopySize = 8;
// When copying up to this many bytes, use special "medium" handlers.
const size_t kMediumCopySize = 63;
// When non-overlapping region of src and dst is less than this,
// use a more careful implementation (slightly slower).
const size_t kMinMoveDistance = 16;
// Note that these values are dictated by the implementation below,
// do not just change them and hope things will work!
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;
Register loop_count = edx;
__ 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);
__ prefetch(Operand(src, 0), 1);
__ cmp(count, kSmallCopySize);
__ j(below_equal, &small_size);
__ cmp(count, kMediumCopySize);
__ j(below_equal, &medium_size);
__ cmp(dst, src);
__ j(above, &backward);
{
// |dst| is a lower address than |src|. Copy front-to-back.
Label unaligned_source, move_last_15, skip_last_move;
__ mov(eax, src);
__ sub(eax, dst);
__ cmp(eax, kMinMoveDistance);
__ j(below, &forward_much_overlap);
// Copy first 16 bytes.
__ movdqu(xmm0, Operand(src, 0));
__ movdqu(Operand(dst, 0), xmm0);
// Determine distance to alignment: 16 - (dst & 0xF).
__ mov(edx, dst);
__ and_(edx, 0xF);
__ neg(edx);
__ add(edx, Immediate(16));
__ add(dst, edx);
__ add(src, edx);
__ sub(count, edx);
// dst is now aligned. Main copy loop.
__ mov(loop_count, count);
__ shr(loop_count, 6);
// Check if src is also aligned.
__ test(src, Immediate(0xF));
__ j(not_zero, &unaligned_source);
// Copy loop for aligned source and destination.
MemMoveEmitMainLoop(&masm, &move_last_15, FORWARD, MOVE_ALIGNED);
// At most 15 bytes to copy. Copy 16 bytes at end of string.
__ bind(&move_last_15);
__ and_(count, 0xF);
__ j(zero, &skip_last_move, Label::kNear);
__ movdqu(xmm0, Operand(src, count, times_1, -0x10));
__ movdqu(Operand(dst, count, times_1, -0x10), xmm0);
__ bind(&skip_last_move);
MemMoveEmitPopAndReturn(&masm);
// Copy loop for unaligned source and aligned destination.
__ bind(&unaligned_source);
MemMoveEmitMainLoop(&masm, &move_last_15, FORWARD, MOVE_UNALIGNED);
__ jmp(&move_last_15);
// Less than kMinMoveDistance offset between dst and src.
Label loop_until_aligned, last_15_much_overlap;
__ bind(&loop_until_aligned);
__ mov_b(eax, Operand(src, 0));
__ inc(src);
__ mov_b(Operand(dst, 0), eax);
__ inc(dst);
__ dec(count);
__ bind(&forward_much_overlap); // Entry point into this block.
__ test(dst, Immediate(0xF));
__ j(not_zero, &loop_until_aligned);
// dst is now aligned, src can't be. Main copy loop.
__ mov(loop_count, count);
__ shr(loop_count, 6);
MemMoveEmitMainLoop(&masm, &last_15_much_overlap,
FORWARD, MOVE_UNALIGNED);
__ bind(&last_15_much_overlap);
__ and_(count, 0xF);
__ j(zero, &pop_and_return);
__ cmp(count, kSmallCopySize);
__ j(below_equal, &small_size);
__ jmp(&medium_size);
}
{
// |dst| is a higher address than |src|. Copy backwards.
Label unaligned_source, move_first_15, skip_last_move;
__ bind(&backward);
// |dst| and |src| always point to the end of what's left to copy.
__ add(dst, count);
__ add(src, count);
__ mov(eax, dst);
__ sub(eax, src);
__ cmp(eax, kMinMoveDistance);
__ j(below, &backward_much_overlap);
// Copy last 16 bytes.
__ movdqu(xmm0, Operand(src, -0x10));
__ movdqu(Operand(dst, -0x10), xmm0);
// Find distance to alignment: dst & 0xF
__ mov(edx, dst);
__ and_(edx, 0xF);
__ sub(dst, edx);
__ sub(src, edx);
__ sub(count, edx);
// dst is now aligned. Main copy loop.
__ mov(loop_count, count);
__ shr(loop_count, 6);
// Check if src is also aligned.
__ test(src, Immediate(0xF));
__ j(not_zero, &unaligned_source);
// Copy loop for aligned source and destination.
MemMoveEmitMainLoop(&masm, &move_first_15, BACKWARD, MOVE_ALIGNED);
// At most 15 bytes to copy. Copy 16 bytes at beginning of string.
__ bind(&move_first_15);
__ and_(count, 0xF);
__ j(zero, &skip_last_move, Label::kNear);
__ sub(src, count);
__ sub(dst, count);
__ movdqu(xmm0, Operand(src, 0));
__ movdqu(Operand(dst, 0), xmm0);
__ bind(&skip_last_move);
MemMoveEmitPopAndReturn(&masm);
// Copy loop for unaligned source and aligned destination.
__ bind(&unaligned_source);
MemMoveEmitMainLoop(&masm, &move_first_15, BACKWARD, MOVE_UNALIGNED);
__ jmp(&move_first_15);
// Less than kMinMoveDistance offset between dst and src.
Label loop_until_aligned, first_15_much_overlap;
__ bind(&loop_until_aligned);
__ dec(src);
__ dec(dst);
__ mov_b(eax, Operand(src, 0));
__ mov_b(Operand(dst, 0), eax);
__ dec(count);
__ bind(&backward_much_overlap); // Entry point into this block.
__ test(dst, Immediate(0xF));
__ j(not_zero, &loop_until_aligned);
// dst is now aligned, src can't be. Main copy loop.
__ mov(loop_count, count);
__ shr(loop_count, 6);
MemMoveEmitMainLoop(&masm, &first_15_much_overlap,
BACKWARD, MOVE_UNALIGNED);
__ bind(&first_15_much_overlap);
__ and_(count, 0xF);
__ j(zero, &pop_and_return);
// Small/medium handlers expect dst/src to point to the beginning.
__ sub(dst, count);
__ sub(src, count);
__ cmp(count, kSmallCopySize);
__ j(below_equal, &small_size);
__ jmp(&medium_size);
}
{
// Special handlers for 9 <= copy_size < 64. No assumptions about
// alignment or move distance, so all reads must be unaligned and
// must happen before any writes.
Label medium_handlers, f9_16, f17_32, f33_48, f49_63;
__ bind(&f9_16);
__ movsd(xmm0, Operand(src, 0));
__ movsd(xmm1, Operand(src, count, times_1, -8));
__ movsd(Operand(dst, 0), xmm0);
__ movsd(Operand(dst, count, times_1, -8), xmm1);
MemMoveEmitPopAndReturn(&masm);
__ bind(&f17_32);
__ movdqu(xmm0, Operand(src, 0));
__ movdqu(xmm1, Operand(src, count, times_1, -0x10));
__ movdqu(Operand(dst, 0x00), xmm0);
__ movdqu(Operand(dst, count, times_1, -0x10), xmm1);
MemMoveEmitPopAndReturn(&masm);
__ bind(&f33_48);
__ movdqu(xmm0, Operand(src, 0x00));
__ movdqu(xmm1, Operand(src, 0x10));
__ movdqu(xmm2, Operand(src, count, times_1, -0x10));
__ movdqu(Operand(dst, 0x00), xmm0);
__ movdqu(Operand(dst, 0x10), xmm1);
__ movdqu(Operand(dst, count, times_1, -0x10), xmm2);
MemMoveEmitPopAndReturn(&masm);
__ bind(&f49_63);
__ movdqu(xmm0, Operand(src, 0x00));
__ movdqu(xmm1, Operand(src, 0x10));
__ movdqu(xmm2, Operand(src, 0x20));
__ movdqu(xmm3, Operand(src, count, times_1, -0x10));
__ movdqu(Operand(dst, 0x00), xmm0);
__ movdqu(Operand(dst, 0x10), xmm1);
__ movdqu(Operand(dst, 0x20), xmm2);
__ movdqu(Operand(dst, count, times_1, -0x10), xmm3);
MemMoveEmitPopAndReturn(&masm);
__ bind(&medium_handlers);
__ dd(conv.address(&f9_16));
__ dd(conv.address(&f17_32));
__ dd(conv.address(&f33_48));
__ dd(conv.address(&f49_63));
__ bind(&medium_size); // Entry point into this block.
__ mov(eax, count);
__ dec(eax);
__ shr(eax, 4);
if (FLAG_debug_code) {
Label ok;
__ cmp(eax, 3);
__ j(below_equal, &ok);
__ int3();
__ bind(&ok);
}
__ mov(eax, Operand(eax, times_4, conv.address(&medium_handlers)));
__ jmp(eax);
}
{
// Specialized copiers for copy_size <= 8 bytes.
Label small_handlers, f0, f1, f2, f3, f4, f5_8;
__ bind(&f0);
MemMoveEmitPopAndReturn(&masm);
__ bind(&f1);
__ mov_b(eax, Operand(src, 0));
__ mov_b(Operand(dst, 0), eax);
MemMoveEmitPopAndReturn(&masm);
__ bind(&f2);
__ mov_w(eax, Operand(src, 0));
__ mov_w(Operand(dst, 0), eax);
MemMoveEmitPopAndReturn(&masm);
__ bind(&f3);
__ mov_w(eax, Operand(src, 0));
__ mov_b(edx, Operand(src, 2));
__ mov_w(Operand(dst, 0), eax);
__ mov_b(Operand(dst, 2), edx);
MemMoveEmitPopAndReturn(&masm);
__ bind(&f4);
__ mov(eax, Operand(src, 0));
__ mov(Operand(dst, 0), eax);
MemMoveEmitPopAndReturn(&masm);
__ bind(&f5_8);
__ mov(eax, Operand(src, 0));
__ mov(edx, Operand(src, count, times_1, -4));
__ mov(Operand(dst, 0), eax);
__ mov(Operand(dst, count, times_1, -4), edx);
MemMoveEmitPopAndReturn(&masm);
__ bind(&small_handlers);
__ dd(conv.address(&f0));
__ dd(conv.address(&f1));
__ dd(conv.address(&f2));
__ dd(conv.address(&f3));
__ dd(conv.address(&f4));
__ dd(conv.address(&f5_8));
__ dd(conv.address(&f5_8));
__ dd(conv.address(&f5_8));
__ dd(conv.address(&f5_8));
__ bind(&small_size); // Entry point into this block.
if (FLAG_debug_code) {
Label ok;
__ cmp(count, 8);
__ j(below_equal, &ok);
__ int3();
__ bind(&ok);
}
__ mov(eax, Operand(count, times_4, conv.address(&small_handlers)));
__ jmp(eax);
}
__ bind(&pop_and_return);
MemMoveEmitPopAndReturn(&masm);
CodeDesc desc;
masm.GetCode(&desc);
DCHECK(!RelocInfo::RequiresRelocation(desc));
Assembler::FlushICache(isolate, 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 StringCharLoadGenerator::Generate(MacroAssembler* masm,
Factory* factory,
Register string,
Register index,
Register result,
Label* call_runtime) {
Label indirect_string_loaded;
__ bind(&indirect_string_loaded);
// 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, thin_string;
__ and_(result, Immediate(kStringRepresentationMask));
__ cmp(result, Immediate(kConsStringTag));
__ j(equal, &cons_string, Label::kNear);
__ cmp(result, Immediate(kThinStringTag));
__ j(equal, &thin_string, Label::kNear);
// Handle slices.
__ mov(result, FieldOperand(string, SlicedString::kOffsetOffset));
__ SmiUntag(result);
__ add(index, result);
__ mov(string, FieldOperand(string, SlicedString::kParentOffset));
__ jmp(&indirect_string_loaded);
// Handle thin strings.
__ bind(&thin_string);
__ mov(string, FieldOperand(string, ThinString::kActualOffset));
__ jmp(&indirect_string_loaded);
// 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));
__ jmp(&indirect_string_loaded);
// 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 one_byte_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, Immediate(kShortExternalStringMask));
__ j(not_zero, call_runtime);
// Check encoding.
STATIC_ASSERT(kTwoByteStringTag == 0);
__ test_b(result, Immediate(kStringEncodingMask));
__ mov(result, FieldOperand(string, ExternalString::kResourceDataOffset));
__ j(not_equal, &one_byte_external, Label::kNear);
// Two-byte string.
__ movzx_w(result, Operand(result, index, times_2, 0));
__ jmp(&done, Label::kNear);
__ bind(&one_byte_external);
// One-byte string.
__ movzx_b(result, Operand(result, index, times_1, 0));
__ jmp(&done, Label::kNear);
// Dispatch on the encoding: one-byte or two-byte.
Label one_byte;
__ bind(&seq_string);
STATIC_ASSERT((kStringEncodingMask & kOneByteStringTag) != 0);
STATIC_ASSERT((kStringEncodingMask & kTwoByteStringTag) == 0);
__ test(result, Immediate(kStringEncodingMask));
__ j(not_zero, &one_byte, 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);
// One-byte string.
// Load the byte into the result register.
__ bind(&one_byte);
__ movzx_b(result, FieldOperand(string,
index,
times_1,
SeqOneByteString::kHeaderSize));
__ bind(&done);
}
#undef __
CodeAgingHelper::CodeAgingHelper(Isolate* isolate) {
USE(isolate);
DCHECK(young_sequence_.length() == kNoCodeAgeSequenceLength);
CodePatcher patcher(isolate, 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;
}
Code::Age Code::GetCodeAge(Isolate* isolate, byte* sequence) {
if (IsYoungSequence(isolate, sequence)) return kNoAgeCodeAge;
sequence++; // Skip the kCallOpcode byte
Address target_address = sequence + *reinterpret_cast<int*>(sequence) +
Assembler::kCallTargetAddressOffset;
Code* stub = GetCodeFromTargetAddress(target_address);
return GetAgeOfCodeAgeStub(stub);
}
void Code::PatchPlatformCodeAge(Isolate* isolate, byte* sequence,
Code::Age age) {
uint32_t young_length = isolate->code_aging_helper()->young_sequence_length();
if (age == kNoAgeCodeAge) {
isolate->code_aging_helper()->CopyYoungSequenceTo(sequence);
Assembler::FlushICache(isolate, sequence, young_length);
} else {
Code* stub = GetCodeAgeStub(isolate, age);
CodePatcher patcher(isolate, sequence, young_length);
patcher.masm()->call(stub->instruction_start(), RelocInfo::NONE32);
}
}
} // namespace internal
} // namespace v8
#endif // V8_TARGET_ARCH_IA32