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Porting r10221 to x64 (avoid bailing out to runtime for short substrings).

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Review URL: http://codereview.chromium.org/8894001

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10251 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This commit is contained in:
yangguo@chromium.org 2011-12-14 10:26:24 +00:00
parent 33a9e76808
commit 03696ca765
2 changed files with 110 additions and 95 deletions
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5
src/ia32/code-stubs-ia32.cc
View File

@ -6181,7 +6181,7 @@ void SubStringStub::Generate(MacroAssembler* masm) {
if (FLAG_string_slices) {
Label copy_routine;
// edi: underlying subject string
// ebx: instance type of original subject string
// ebx: instance type of underlying subject string
// edx: adjusted start index (smi)
// ecx: length (smi)
__ cmp(ecx, Immediate(Smi::FromInt(SlicedString::kMinLength)));
@ -6214,7 +6214,7 @@ void SubStringStub::Generate(MacroAssembler* masm) {
}
// edi: underlying subject string
// ebx: instance type of original subject string
// ebx: instance type of underlying subject string
// edx: adjusted start index (smi)
// ecx: length (smi)
// The subject string can only be external or sequential string of either
@ -6226,7 +6226,6 @@ void SubStringStub::Generate(MacroAssembler* masm) {
__ j(zero, &sequential_string);
// Handle external string.
Label ascii_external, done;
// Rule out short external strings.
STATIC_CHECK(kShortExternalStringTag != 0);
__ test_b(ebx, kShortExternalStringMask);

200
src/x64/code-stubs-x64.cc
View File

@ -5040,8 +5040,12 @@ void SubStringStub::Generate(MacroAssembler* masm) {
__ SmiSub(rcx, rcx, rdx); // Overflow doesn't happen.
__ cmpq(FieldOperand(rax, String::kLengthOffset), rcx);
Label return_rax;
__ j(equal, &return_rax);
Label not_original_string;
__ j(not_equal, &not_original_string, Label::kNear);
Counters* counters = masm->isolate()->counters();
__ IncrementCounter(counters->sub_string_native(), 1);
__ ret(kArgumentsSize);
__ bind(&not_original_string);
// Special handling of sub-strings of length 1 and 2. One character strings
// are handled in the runtime system (looked up in the single character
// cache). Two character strings are looked for in the symbol cache.
@ -5060,68 +5064,77 @@ void SubStringStub::Generate(MacroAssembler* masm) {
// Get the two characters forming the sub string.
__ SmiToInteger32(rdx, rdx); // From index is no longer smi.
__ movzxbq(rbx, FieldOperand(rax, rdx, times_1, SeqAsciiString::kHeaderSize));
__ movzxbq(rcx,
__ movzxbq(rdi,
FieldOperand(rax, rdx, times_1, SeqAsciiString::kHeaderSize + 1));
// Try to lookup two character string in symbol table.
Label make_two_character_string;
StringHelper::GenerateTwoCharacterSymbolTableProbe(
masm, rbx, rcx, rax, rdx, rdi, r14, &make_two_character_string);
masm, rbx, rdi, r9, r11, r14, r15, &make_two_character_string);
__ IncrementCounter(counters->sub_string_native(), 1);
__ ret(3 * kPointerSize);
__ bind(&make_two_character_string);
// Setup registers for allocating the two character string.
__ movq(rax, Operand(rsp, kStringOffset));
__ movq(rbx, FieldOperand(rax, HeapObject::kMapOffset));
__ movzxwq(rbx, FieldOperand(rax, rdx, times_1, SeqAsciiString::kHeaderSize));
__ AllocateAsciiString(rax, rcx, r11, r14, r15, &runtime);
__ movw(FieldOperand(rax, SeqAsciiString::kHeaderSize), rbx);
__ IncrementCounter(counters->sub_string_native(), 1);
__ ret(3 * kPointerSize);
__ bind(&result_longer_than_two);
// rax: string
// rbx: instance type
// rcx: sub string length
// rdx: from index (smi)
// Deal with different string types: update the index if necessary
// and put the underlying string into edi.
Label underlying_unpacked, sliced_string, seq_or_external_string;
// If the string is not indirect, it can only be sequential or external.
STATIC_ASSERT(kIsIndirectStringMask == (kSlicedStringTag & kConsStringTag));
STATIC_ASSERT(kIsIndirectStringMask != 0);
__ testb(rbx, Immediate(kIsIndirectStringMask));
__ j(zero, &seq_or_external_string, Label::kNear);
__ testb(rbx, Immediate(kSlicedNotConsMask));
__ j(not_zero, &sliced_string, Label::kNear);
// Cons string. Check whether it is flat, then fetch first part.
// Flat cons strings have an empty second part.
__ CompareRoot(FieldOperand(rax, ConsString::kSecondOffset),
Heap::kEmptyStringRootIndex);
__ j(not_equal, &runtime);
__ movq(rdi, FieldOperand(rax, ConsString::kFirstOffset));
// Update instance type.
__ movq(rbx, FieldOperand(rdi, HeapObject::kMapOffset));
__ movzxbl(rbx, FieldOperand(rbx, Map::kInstanceTypeOffset));
__ Set(rcx, 2);
__ jmp(&underlying_unpacked, Label::kNear);
__ bind(&sliced_string);
// Sliced string. Fetch parent and correct start index by offset.
__ addq(rdx, FieldOperand(rax, SlicedString::kOffsetOffset));
__ movq(rdi, FieldOperand(rax, SlicedString::kParentOffset));
// Update instance type.
__ movq(rbx, FieldOperand(rdi, HeapObject::kMapOffset));
__ movzxbl(rbx, FieldOperand(rbx, Map::kInstanceTypeOffset));
__ jmp(&underlying_unpacked, Label::kNear);
__ bind(&seq_or_external_string);
// Sequential or external string. Just move string to the correct register.
__ movq(rdi, rax);
__ bind(&underlying_unpacked);
if (FLAG_string_slices) {
Label copy_routine;
// rdi: underlying subject string
// rbx: instance type of underlying subject string
// rdx: adjusted start index (smi)
// rcx: length
// If coming from the make_two_character_string path, the string
// is too short to be sliced anyways.
STATIC_ASSERT(2 < SlicedString::kMinLength);
__ jmp(&copy_routine);
__ bind(&result_longer_than_two);
// rax: string
// rbx: instance type
// rcx: sub string length
// rdx: from index (smi)
Label allocate_slice, sliced_string, seq_or_external_string;
__ cmpq(rcx, Immediate(SlicedString::kMinLength));
// Short slice. Copy instead of slicing.
__ j(less, &copy_routine);
// If the string is not indirect, it can only be sequential or external.
STATIC_ASSERT(kIsIndirectStringMask == (kSlicedStringTag & kConsStringTag));
STATIC_ASSERT(kIsIndirectStringMask != 0);
__ testb(rbx, Immediate(kIsIndirectStringMask));
__ j(zero, &seq_or_external_string, Label::kNear);
__ testb(rbx, Immediate(kSlicedNotConsMask));
__ j(not_zero, &sliced_string, Label::kNear);
// Cons string. Check whether it is flat, then fetch first part.
__ CompareRoot(FieldOperand(rax, ConsString::kSecondOffset),
Heap::kEmptyStringRootIndex);
__ j(not_equal, &runtime);
__ movq(rdi, FieldOperand(rax, ConsString::kFirstOffset));
__ jmp(&allocate_slice, Label::kNear);
__ bind(&sliced_string);
// Sliced string. Fetch parent and correct start index by offset.
__ addq(rdx, FieldOperand(rax, SlicedString::kOffsetOffset));
__ movq(rdi, FieldOperand(rax, SlicedString::kParentOffset));
__ jmp(&allocate_slice, Label::kNear);
__ bind(&seq_or_external_string);
// Sequential or external string. Just move string to the correct register.
__ movq(rdi, rax);
__ bind(&allocate_slice);
// edi: underlying subject string
// ebx: instance type of original subject string
// edx: offset
// ecx: length
// Allocate new sliced string. At this point we do not reload the instance
// type including the string encoding because we simply rely on the info
// provided by the original string. It does not matter if the original
@ -5132,10 +5145,10 @@ void SubStringStub::Generate(MacroAssembler* masm) {
STATIC_ASSERT((kStringEncodingMask & kTwoByteStringTag) == 0);
__ testb(rbx, Immediate(kStringEncodingMask));
__ j(zero, &two_byte_slice, Label::kNear);
__ AllocateAsciiSlicedString(rax, rbx, no_reg, &runtime);
__ AllocateAsciiSlicedString(rax, rbx, r14, &runtime);
__ jmp(&set_slice_header, Label::kNear);
__ bind(&two_byte_slice);
__ AllocateTwoByteSlicedString(rax, rbx, no_reg, &runtime);
__ AllocateTwoByteSlicedString(rax, rbx, r14, &runtime);
__ bind(&set_slice_header);
__ movq(FieldOperand(rax, SlicedString::kOffsetOffset), rdx);
__ Integer32ToSmi(rcx, rcx);
@ -5143,82 +5156,85 @@ void SubStringStub::Generate(MacroAssembler* masm) {
__ movq(FieldOperand(rax, SlicedString::kParentOffset), rdi);
__ movq(FieldOperand(rax, SlicedString::kHashFieldOffset),
Immediate(String::kEmptyHashField));
__ jmp(&return_rax);
__ IncrementCounter(counters->sub_string_native(), 1);
__ ret(kArgumentsSize);
__ bind(&copy_routine);
} else {
__ bind(&result_longer_than_two);
}
// rax: string
// rbx: instance type
// rcx: result string length
// Check for flat ascii string
Label non_ascii_flat;
__ JumpIfInstanceTypeIsNotSequentialAscii(rbx, rbx, &non_ascii_flat);
// rdi: underlying subject string
// rbx: instance type of underlying subject string
// rdx: adjusted start index (smi)
// rcx: length
// The subject string can only be external or sequential string of either
// encoding at this point.
Label two_byte_sequential, sequential_string;
STATIC_ASSERT(kExternalStringTag != 0);
STATIC_ASSERT(kSeqStringTag == 0);
__ testb(rbx, Immediate(kExternalStringTag));
__ j(zero, &sequential_string);
// Handle external string.
// Rule out short external strings.
STATIC_CHECK(kShortExternalStringTag != 0);
__ testb(rbx, Immediate(kShortExternalStringMask));
__ j(not_zero, &runtime);
__ movq(rdi, FieldOperand(rdi, ExternalString::kResourceDataOffset));
// Move the pointer so that offset-wise, it looks like a sequential string.
STATIC_ASSERT(SeqTwoByteString::kHeaderSize == SeqAsciiString::kHeaderSize);
__ subq(rdi, Immediate(SeqTwoByteString::kHeaderSize - kHeapObjectTag));
__ bind(&sequential_string);
STATIC_ASSERT((kAsciiStringTag & kStringEncodingMask) != 0);
__ testb(rbx, Immediate(kStringEncodingMask));
__ j(zero, &two_byte_sequential);
// Allocate the result.
__ AllocateAsciiString(rax, rcx, rbx, rdx, rdi, &runtime);
__ AllocateAsciiString(rax, rcx, r11, r14, r15, &runtime);
// rax: result string
// rcx: result string length
__ movq(rdx, rsi); // esi used by following code.
// Locate first character of result.
__ lea(rdi, FieldOperand(rax, SeqAsciiString::kHeaderSize));
// Load string argument and locate character of sub string start.
__ movq(rsi, Operand(rsp, kStringOffset));
__ movq(rbx, Operand(rsp, kFromOffset));
{
SmiIndex smi_as_index = masm->SmiToIndex(rbx, rbx, times_1);
__ lea(rsi, Operand(rsi, smi_as_index.reg, smi_as_index.scale,
__ movq(r14, rsi); // esi used by following code.
{ // Locate character of sub string start.
SmiIndex smi_as_index = masm->SmiToIndex(rdx, rdx, times_1);
__ lea(rsi, Operand(rdi, smi_as_index.reg, smi_as_index.scale,
SeqAsciiString::kHeaderSize - kHeapObjectTag));
}
// Locate first character of result.
__ lea(rdi, FieldOperand(rax, SeqAsciiString::kHeaderSize));
// rax: result string
// rcx: result length
// rdx: original value of rsi
// rdi: first character of result
// rsi: character of sub string start
// r14: original value of rsi
StringHelper::GenerateCopyCharactersREP(masm, rdi, rsi, rcx, true);
__ movq(rsi, rdx); // Restore rsi.
Counters* counters = masm->isolate()->counters();
__ movq(rsi, r14); // Restore rsi.
__ IncrementCounter(counters->sub_string_native(), 1);
__ ret(kArgumentsSize);
__ bind(&non_ascii_flat);
// rax: string
// rbx: instance type & kStringRepresentationMask | kStringEncodingMask
// rcx: result string length
// Check for sequential two byte string
__ cmpb(rbx, Immediate(kSeqStringTag | kTwoByteStringTag));
__ j(not_equal, &runtime);
__ bind(&two_byte_sequential);
// Allocate the result.
__ AllocateTwoByteString(rax, rcx, rbx, rdx, rdi, &runtime);
__ AllocateTwoByteString(rax, rcx, r11, r14, r15, &runtime);
// rax: result string
// rcx: result string length
__ movq(rdx, rsi); // esi used by following code.
// Locate first character of result.
__ lea(rdi, FieldOperand(rax, SeqTwoByteString::kHeaderSize));
// Load string argument and locate character of sub string start.
__ movq(rsi, Operand(rsp, kStringOffset));
__ movq(rbx, Operand(rsp, kFromOffset));
{
SmiIndex smi_as_index = masm->SmiToIndex(rbx, rbx, times_2);
__ lea(rsi, Operand(rsi, smi_as_index.reg, smi_as_index.scale,
__ movq(r14, rsi); // esi used by following code.
{ // Locate character of sub string start.
SmiIndex smi_as_index = masm->SmiToIndex(rdx, rdx, times_2);
__ lea(rsi, Operand(rdi, smi_as_index.reg, smi_as_index.scale,
SeqAsciiString::kHeaderSize - kHeapObjectTag));
}
// Locate first character of result.
__ lea(rdi, FieldOperand(rax, SeqTwoByteString::kHeaderSize));
// rax: result string
// rcx: result length
// rdx: original value of rsi
// rdi: first character of result
// rsi: character of sub string start
// r14: original value of rsi
StringHelper::GenerateCopyCharactersREP(masm, rdi, rsi, rcx, false);
__ movq(rsi, rdx); // Restore esi.
__ bind(&return_rax);
__ movq(rsi, r14); // Restore esi.
__ IncrementCounter(counters->sub_string_native(), 1);
__ ret(kArgumentsSize);