Revision: 10012
Author: [email protected]
Date: Thu Nov 17 00:40:40 2011
Log: Change generated code for substring not to bail out to runtime
system.
There is no need to bail out to runtime system when creating sliced strings
of external strings since the string content is unimportant.
Review URL: http://codereview.chromium.org/8513016
http://code.google.com/p/v8/source/detail?r=10012
Modified:
/branches/bleeding_edge/src/arm/code-stubs-arm.cc
/branches/bleeding_edge/src/ia32/code-stubs-ia32.cc
/branches/bleeding_edge/src/x64/code-stubs-x64.cc
=======================================
--- /branches/bleeding_edge/src/arm/code-stubs-arm.cc Fri Nov 11 06:49:16
2011
+++ /branches/bleeding_edge/src/arm/code-stubs-arm.cc Thu Nov 17 00:40:40
2011
@@ -5815,15 +5815,12 @@
// r3: from index (untagged smi)
// r6 (a.k.a. to): to (smi)
// r7 (a.k.a. from): from offset (smi)
- Label allocate_slice, sliced_string, seq_string;
- STATIC_ASSERT(kSeqStringTag == 0);
- __ tst(r1, Operand(kStringRepresentationMask));
- __ b(eq, &seq_string);
+ Label allocate_slice, 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);
__ tst(r1, Operand(kIsIndirectStringMask));
- // External string. Jump to runtime.
- __ b(eq, &runtime);
+ __ b(eq, &seq_or_external_string);
__ tst(r1, Operand(kSlicedNotConsMask));
__ b(ne, &sliced_string);
@@ -5842,8 +5839,8 @@
__ ldr(r5, FieldMemOperand(r0, SlicedString::kParentOffset));
__ jmp(&allocate_slice);
- __ bind(&seq_string);
- // Sequential string. Just move string to the right register.
+ __ bind(&seq_or_external_string);
+ // Sequential or external string. Just move string to the correct
register.
__ mov(r5, r0);
__ bind(&allocate_slice);
=======================================
--- /branches/bleeding_edge/src/ia32/code-stubs-ia32.cc Fri Nov 11 06:49:16
2011
+++ /branches/bleeding_edge/src/ia32/code-stubs-ia32.cc Thu Nov 17 00:40:40
2011
@@ -5973,18 +5973,15 @@
// ebx: instance type
// ecx: sub string length
// edx: from index (smi)
- Label allocate_slice, sliced_string, seq_string;
+ Label allocate_slice, sliced_string, seq_or_external_string;
__ cmp(ecx, SlicedString::kMinLength);
// Short slice. Copy instead of slicing.
__ j(less, ©_routine);
- STATIC_ASSERT(kSeqStringTag == 0);
- __ test(ebx, Immediate(kStringRepresentationMask));
- __ j(zero, &seq_string, Label::kNear);
+ // If the string is not indirect, it can only be sequential or
external.
STATIC_ASSERT(kIsIndirectStringMask == (kSlicedStringTag &
kConsStringTag));
STATIC_ASSERT(kIsIndirectStringMask != 0);
__ test(ebx, Immediate(kIsIndirectStringMask));
- // External string. Jump to runtime.
- __ j(zero, &runtime);
+ __ j(zero, &seq_or_external_string, Label::kNear);
Factory* factory = masm->isolate()->factory();
__ test(ebx, Immediate(kSlicedNotConsMask));
@@ -6002,8 +5999,8 @@
__ mov(edi, FieldOperand(eax, SlicedString::kParentOffset));
__ jmp(&allocate_slice, Label::kNear);
- __ bind(&seq_string);
- // Sequential string. Just move string to the right register.
+ __ bind(&seq_or_external_string);
+ // Sequential or external string. Just move string to the correct
register.
__ mov(edi, eax);
__ bind(&allocate_slice);
=======================================
--- /branches/bleeding_edge/src/x64/code-stubs-x64.cc Fri Nov 11 06:49:16
2011
+++ /branches/bleeding_edge/src/x64/code-stubs-x64.cc Thu Nov 17 00:40:40
2011
@@ -4912,18 +4912,15 @@
// rbx: instance type
// rcx: sub string length
// rdx: from index (smi)
- Label allocate_slice, sliced_string, seq_string;
+ Label allocate_slice, sliced_string, seq_or_external_string;
__ cmpq(rcx, Immediate(SlicedString::kMinLength));
// Short slice. Copy instead of slicing.
__ j(less, ©_routine);
- STATIC_ASSERT(kSeqStringTag == 0);
- __ testb(rbx, Immediate(kStringRepresentationMask));
- __ j(zero, &seq_string, Label::kNear);
+ // 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));
- // External string. Jump to runtime.
- __ j(zero, &runtime);
+ __ j(zero, &seq_or_external_string, Label::kNear);
__ testb(rbx, Immediate(kSlicedNotConsMask));
__ j(not_zero, &sliced_string, Label::kNear);
@@ -4940,8 +4937,8 @@
__ movq(rdi, FieldOperand(rax, SlicedString::kParentOffset));
__ jmp(&allocate_slice, Label::kNear);
- __ bind(&seq_string);
- // Sequential string. Just move string to the right register.
+ __ bind(&seq_or_external_string);
+ // Sequential or external string. Just move string to the correct
register.
__ movq(rdi, rax);
__ bind(&allocate_slice);
--
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