Index: src/x64/code-stubs-x64.cc |
diff --git a/src/x64/code-stubs-x64.cc b/src/x64/code-stubs-x64.cc |
index 1a6efcbd61acc781addb3f175e7c5e7f6cd1dd6b..094e158f9a53c7890582b11ad15b388a2020ad04 100644 |
--- a/src/x64/code-stubs-x64.cc |
+++ b/src/x64/code-stubs-x64.cc |
@@ -3780,6 +3780,7 @@ void StringCharCodeAtGenerator::GenerateFast(MacroAssembler* masm) { |
Label flat_string; |
Label ascii_string; |
Label got_char_code; |
+ Label sliced_string; |
// If the receiver is a smi trigger the non-string case. |
__ JumpIfSmi(object_, receiver_not_string_); |
@@ -3808,8 +3809,11 @@ void StringCharCodeAtGenerator::GenerateFast(MacroAssembler* masm) { |
__ j(zero, &flat_string); |
// Handle non-flat strings. |
- __ testb(result_, Immediate(kIsConsStringMask)); |
- __ j(zero, &call_runtime_); |
+ __ and_(result_, Immediate(kStringRepresentationMask)); |
+ __ cmpb(result_, Immediate(kSlicedStringTag)); |
+ __ j(equal, &sliced_string); |
+ __ cmpb(result_, Immediate(kExternalStringTag)); |
+ __ j(equal, &call_runtime_); |
// ConsString. |
// Check whether the right hand side is the empty string (i.e. if |
@@ -3827,6 +3831,14 @@ void StringCharCodeAtGenerator::GenerateFast(MacroAssembler* masm) { |
STATIC_ASSERT(kSeqStringTag == 0); |
__ testb(result_, Immediate(kStringRepresentationMask)); |
__ j(not_zero, &call_runtime_); |
+ __ jmp(&flat_string); |
+ |
+ // SlicedString, unpack and add offset. |
+ __ bind(&sliced_string); |
+ __ addq(scratch_, FieldOperand(object_, SlicedString::kOffsetOffset)); |
+ __ movq(object_, FieldOperand(object_, SlicedString::kParentOffset)); |
+ __ movq(result_, FieldOperand(object_, HeapObject::kMapOffset)); |
+ __ movzxbl(result_, FieldOperand(result_, Map::kInstanceTypeOffset)); |
// Check for 1-byte or 2-byte string. |
__ bind(&flat_string); |
@@ -4137,6 +4149,8 @@ void StringAddStub::Generate(MacroAssembler* masm) { |
__ and_(rcx, Immediate(kStringRepresentationMask)); |
__ cmpl(rcx, Immediate(kExternalStringTag)); |
__ j(equal, &string_add_runtime); |
+ // We cannot encounter sliced strings here since: |
+ STATIC_ASSERT(SlicedString::kMinLength >= String::kMinNonFlatLength); |
// Now check if both strings are ascii strings. |
// rax: first string |
// rbx: length of resulting flat string |
@@ -4529,6 +4543,9 @@ void StringHelper::GenerateHashGetHash(MacroAssembler* masm, |
void SubStringStub::Generate(MacroAssembler* masm) { |
Label runtime; |
Yang
2011/07/27 11:51:58
Do not create string slice unless experimental fla
|
+ if (FLAG_string_slices) { |
+ __ jmp(&runtime); |
+ } |
// Stack frame on entry. |
// rsp[0]: return address |
// rsp[8]: to |