Reviewers: Yang, danno, Paul Lind,
Description:
MIPS: Simplify StringCharCodeAt in non-crankshaft codegen.
Port r9936 (61034d).
BUG=
TEST=
Please review this at http://codereview.chromium.org/8506024/
Affected files:
M src/mips/code-stubs-mips.cc
M src/mips/full-codegen-mips.cc
M src/mips/ic-mips.cc
M src/mips/lithium-codegen-mips.cc
M src/mips/stub-cache-mips.cc
Index: src/mips/code-stubs-mips.cc
diff --git a/src/mips/code-stubs-mips.cc b/src/mips/code-stubs-mips.cc
index
5e0e238df17c4dac6e5fea2c2eaa5412180be075..e0f5b2768c2de277af00728f22f6697207976eae
100644
--- a/src/mips/code-stubs-mips.cc
+++ b/src/mips/code-stubs-mips.cc
@@ -5243,7 +5243,6 @@ void
StringCharCodeAtGenerator::GenerateFast(MacroAssembler* masm) {
Label got_char_code;
Label sliced_string;
- ASSERT(!t0.is(scratch_));
ASSERT(!t0.is(index_));
ASSERT(!t0.is(result_));
ASSERT(!t0.is(object_));
@@ -5261,13 +5260,11 @@ void
StringCharCodeAtGenerator::GenerateFast(MacroAssembler* masm) {
// If the index is non-smi trigger the non-smi case.
__ JumpIfNotSmi(index_, &index_not_smi_);
- // Put smi-tagged index into scratch register.
- __ mov(scratch_, index_);
__ bind(&got_smi_index_);
// Check for index out of range.
__ lw(t0, FieldMemOperand(object_, String::kLengthOffset));
- __ Branch(index_out_of_range_, ls, t0, Operand(scratch_));
+ __ Branch(index_out_of_range_, ls, t0, Operand(index_));
// We need special handling for non-flat strings.
STATIC_ASSERT(kSeqStringTag == 0);
@@ -5291,28 +5288,28 @@ void
StringCharCodeAtGenerator::GenerateFast(MacroAssembler* masm) {
__ LoadRoot(t0, Heap::kEmptyStringRootIndex);
__ Branch(&call_runtime_, ne, result_, Operand(t0));
- // Get the first of the two strings and load its instance type.
- __ lw(result_, FieldMemOperand(object_, ConsString::kFirstOffset));
+ // Get the first of the two parts.
+ __ lw(object_, FieldMemOperand(object_, ConsString::kFirstOffset));
__ jmp(&assure_seq_string);
// SlicedString, unpack and add offset.
__ bind(&sliced_string);
__ lw(result_, FieldMemOperand(object_, SlicedString::kOffsetOffset));
- __ addu(scratch_, scratch_, result_);
- __ lw(result_, FieldMemOperand(object_, SlicedString::kParentOffset));
+ __ Addu(index_, index_, result_);
+ __ lw(object_, FieldMemOperand(object_, SlicedString::kParentOffset));
// Assure that we are dealing with a sequential string. Go to runtime if
not.
__ bind(&assure_seq_string);
- __ lw(result_, FieldMemOperand(result_, HeapObject::kMapOffset));
+ __ lw(result_, FieldMemOperand(object_, HeapObject::kMapOffset));
__ lbu(result_, FieldMemOperand(result_, Map::kInstanceTypeOffset));
// Check that parent is not an external string. Go to runtime otherwise.
+ // Note that if the original string is a cons or slice with an external
+ // string as underlying string, we pass that unpacked underlying string
with
+ // the updated index to the runtime function.
STATIC_ASSERT(kSeqStringTag == 0);
__ And(t0, result_, Operand(kStringRepresentationMask));
__ Branch(&call_runtime_, ne, t0, Operand(zero_reg));
- // Actually fetch the parent string if it is confirmed to be sequential.
- STATIC_ASSERT(SlicedString::kParentOffset == ConsString::kFirstOffset);
- __ lw(object_, FieldMemOperand(object_, SlicedString::kParentOffset));
// Check for 1-byte or 2-byte string.
__ bind(&flat_string);
@@ -5326,18 +5323,18 @@ void
StringCharCodeAtGenerator::GenerateFast(MacroAssembler* masm) {
// add without shifting since the smi tag size is the log2 of the
// number of bytes in a two-byte character.
STATIC_ASSERT(kSmiTag == 0 && kSmiTagSize == 1 && kSmiShiftSize == 0);
- __ Addu(scratch_, object_, Operand(scratch_));
- __ lhu(result_, FieldMemOperand(scratch_,
SeqTwoByteString::kHeaderSize));
+ __ Addu(index_, object_, Operand(index_));
+ __ lhu(result_, FieldMemOperand(index_, SeqTwoByteString::kHeaderSize));
__ Branch(&got_char_code);
// ASCII string.
// Load the byte into the result register.
__ bind(&ascii_string);
- __ srl(t0, scratch_, kSmiTagSize);
- __ Addu(scratch_, object_, t0);
+ __ srl(t0, index_, kSmiTagSize);
+ __ Addu(index_, object_, t0);
- __ lbu(result_, FieldMemOperand(scratch_, SeqAsciiString::kHeaderSize));
+ __ lbu(result_, FieldMemOperand(index_, SeqAsciiString::kHeaderSize));
__ bind(&got_char_code);
__ sll(result_, result_, kSmiTagSize);
@@ -5354,13 +5351,13 @@ void StringCharCodeAtGenerator::GenerateSlow(
__ bind(&index_not_smi_);
// If index is a heap number, try converting it to an integer.
__ CheckMap(index_,
- scratch_,
+ result_,
Heap::kHeapNumberMapRootIndex,
index_not_number_,
DONT_DO_SMI_CHECK);
call_helper.BeforeCall(masm);
// Consumed by runtime conversion function:
- __ Push(object_, index_, index_);
+ __ Push(object_, index_);
if (index_flags_ == STRING_INDEX_IS_NUMBER) {
__ CallRuntime(Runtime::kNumberToIntegerMapMinusZero, 1);
} else {
@@ -5372,16 +5369,14 @@ void StringCharCodeAtGenerator::GenerateSlow(
// Save the conversion result before the pop instructions below
// have a chance to overwrite it.
- __ Move(scratch_, v0);
-
- __ pop(index_);
+ __ Move(index_, v0);
__ pop(object_);
// Reload the instance type.
__ lw(result_, FieldMemOperand(object_, HeapObject::kMapOffset));
__ lbu(result_, FieldMemOperand(result_, Map::kInstanceTypeOffset));
call_helper.AfterCall(masm);
// If index is still not a smi, it must be out of range.
- __ JumpIfNotSmi(scratch_, index_out_of_range_);
+ __ JumpIfNotSmi(index_, index_out_of_range_);
// Otherwise, return to the fast path.
__ Branch(&got_smi_index_);
Index: src/mips/full-codegen-mips.cc
diff --git a/src/mips/full-codegen-mips.cc b/src/mips/full-codegen-mips.cc
index
2c82bfaf40a45945247fd20dba1b75c1c5c79c3f..555cad9899410bc83d7923ea798d80817362dd60
100644
--- a/src/mips/full-codegen-mips.cc
+++ b/src/mips/full-codegen-mips.cc
@@ -3058,7 +3058,6 @@ void
FullCodeGenerator::EmitStringCharCodeAt(CallRuntime* expr) {
Register object = a1;
Register index = a0;
- Register scratch = a2;
Register result = v0;
__ pop(object);
@@ -3068,7 +3067,6 @@ void
FullCodeGenerator::EmitStringCharCodeAt(CallRuntime* expr) {
Label done;
StringCharCodeAtGenerator generator(object,
index,
- scratch,
result,
&need_conversion,
&need_conversion,
@@ -3107,8 +3105,7 @@ void FullCodeGenerator::EmitStringCharAt(CallRuntime*
expr) {
Register object = a1;
Register index = a0;
- Register scratch1 = a2;
- Register scratch2 = a3;
+ Register scratch = a3;
Register result = v0;
__ pop(object);
@@ -3118,8 +3115,7 @@ void FullCodeGenerator::EmitStringCharAt(CallRuntime*
expr) {
Label done;
StringCharAtGenerator generator(object,
index,
- scratch1,
- scratch2,
+ scratch,
result,
&need_conversion,
&need_conversion,
Index: src/mips/ic-mips.cc
diff --git a/src/mips/ic-mips.cc b/src/mips/ic-mips.cc
index
a8b3fa37369d92a08a7a9e26131699b19f36fbed..b057695f0105b9b19ea9e6a10398399c2e047b21
100644
--- a/src/mips/ic-mips.cc
+++ b/src/mips/ic-mips.cc
@@ -1120,14 +1120,12 @@ void KeyedLoadIC::GenerateString(MacroAssembler*
masm) {
Register receiver = a1;
Register index = a0;
- Register scratch1 = a2;
- Register scratch2 = a3;
+ Register scratch = a3;
Register result = v0;
StringCharAtGenerator char_at_generator(receiver,
index,
- scratch1,
- scratch2,
+ scratch,
result,
&miss, // When not a string.
&miss, // When not a number.
Index: src/mips/lithium-codegen-mips.cc
diff --git a/src/mips/lithium-codegen-mips.cc
b/src/mips/lithium-codegen-mips.cc
index
fee9dadc2135b450f6697b8fc1de462dd3ab7bc1..5d9e7fccbf03365ab5b53b6ddd4b17b0bf1c6fad
100644
--- a/src/mips/lithium-codegen-mips.cc
+++ b/src/mips/lithium-codegen-mips.cc
@@ -3569,6 +3569,9 @@ void LCodeGen::DoStringCharCodeAt(LStringCharCodeAt*
instr) {
// Check whether the string is sequential. The only non-sequential
// shapes we support have just been unwrapped above.
+ // Note that if the original string is a cons or slice with an external
+ // string as underlying string, we pass that unpacked underlying string
with
+ // the updated index to the runtime function.
__ bind(&check_sequential);
STATIC_ASSERT(kSeqStringTag == 0);
__ And(temp, result, Operand(kStringRepresentationMask));
Index: src/mips/stub-cache-mips.cc
diff --git a/src/mips/stub-cache-mips.cc b/src/mips/stub-cache-mips.cc
index
2d6069369748fd981d34d7562a1ef4bf11c09af7..1cc8a97b6614deaedc2529d8c26ecc81b27a15c9
100644
--- a/src/mips/stub-cache-mips.cc
+++ b/src/mips/stub-cache-mips.cc
@@ -1751,7 +1751,6 @@ Handle<Code>
CallStubCompiler::CompileStringCharCodeAtCall(
Register receiver = a1;
Register index = t1;
- Register scratch = a3;
Register result = v0;
__ lw(receiver, MemOperand(sp, argc * kPointerSize));
if (argc > 0) {
@@ -1762,7 +1761,6 @@ Handle<Code>
CallStubCompiler::CompileStringCharCodeAtCall(
StringCharCodeAtGenerator generator(receiver,
index,
- scratch,
result,
&miss, // When not a string.
&miss, // When not a number.
@@ -1833,8 +1831,7 @@ Handle<Code>
CallStubCompiler::CompileStringCharAtCall(
Register receiver = v0;
Register index = t1;
- Register scratch1 = a1;
- Register scratch2 = a3;
+ Register scratch = a3;
Register result = v0;
__ lw(receiver, MemOperand(sp, argc * kPointerSize));
if (argc > 0) {
@@ -1845,8 +1842,7 @@ Handle<Code>
CallStubCompiler::CompileStringCharAtCall(
StringCharAtGenerator generator(receiver,
index,
- scratch1,
- scratch2,
+ scratch,
result,
&miss, // When not a string.
&miss, // When not a number.
--
v8-dev mailing list
[email protected]
http://groups.google.com/group/v8-dev
