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MIPS: Inline inequality compares of strings into CompareICStub

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Port r10988 (c6c9ebb5).

Original commit message:

Inline inequality compares of strings into CompareICStub instead of jumping into the CompareStub that handles the generic case.

BUG=
TEST=

Review URL: https://chromiumcodereview.appspot.com/9669026
Patch from Daniel Kalmar <kalmard@homejinni.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11002 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This commit is contained in:
yangguo@chromium.org 2012-03-12 08:24:10 +00:00
parent 9de66b9f3a
commit 165e42c291
1 changed files with 30 additions and 17 deletions
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47
src/mips/code-stubs-mips.cc
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@ -6895,6 +6895,8 @@ void ICCompareStub::GenerateStrings(MacroAssembler* masm) {
ASSERT(state_ == CompareIC::STRINGS);
Label miss;
bool equality = Token::IsEqualityOp(op_);
// Registers containing left and right operands respectively.
Register left = a1;
Register right = a0;
@ -6931,32 +6933,43 @@ void ICCompareStub::GenerateStrings(MacroAssembler* masm) {
// Check that both strings are symbols. If they are, we're done
// because we already know they are not identical.
ASSERT(GetCondition() == eq);
STATIC_ASSERT(kSymbolTag != 0);
__ And(tmp3, tmp1, Operand(tmp2));
__ And(tmp5, tmp3, Operand(kIsSymbolMask));
Label is_symbol;
__ Branch(&is_symbol, eq, tmp5, Operand(zero_reg), USE_DELAY_SLOT);
__ mov(v0, a0); // In the delay slot.
// Make sure a0 is non-zero. At this point input operands are
// guaranteed to be non-zero.
ASSERT(right.is(a0));
__ Ret();
__ bind(&is_symbol);
if (equality) {
ASSERT(GetCondition() == eq);
STATIC_ASSERT(kSymbolTag != 0);
__ And(tmp3, tmp1, Operand(tmp2));
__ And(tmp5, tmp3, Operand(kIsSymbolMask));
Label is_symbol;
__ Branch(&is_symbol, eq, tmp5, Operand(zero_reg), USE_DELAY_SLOT);
__ mov(v0, a0); // In the delay slot.
// Make sure a0 is non-zero. At this point input operands are
// guaranteed to be non-zero.
ASSERT(right.is(a0));
__ Ret();
__ bind(&is_symbol);
}
// Check that both strings are sequential ASCII.
Label runtime;
__ JumpIfBothInstanceTypesAreNotSequentialAscii(tmp1, tmp2, tmp3, tmp4,
&runtime);
__ JumpIfBothInstanceTypesAreNotSequentialAscii(
tmp1, tmp2, tmp3, tmp4, &runtime);
// Compare flat ASCII strings. Returns when done.
StringCompareStub::GenerateFlatAsciiStringEquals(
masm, left, right, tmp1, tmp2, tmp3);
if (equality) {
StringCompareStub::GenerateFlatAsciiStringEquals(
masm, left, right, tmp1, tmp2, tmp3);
} else {
StringCompareStub::GenerateCompareFlatAsciiStrings(
masm, left, right, tmp1, tmp2, tmp3, tmp4);
}
// Handle more complex cases in runtime.
__ bind(&runtime);
__ Push(left, right);
__ TailCallRuntime(Runtime::kStringEquals, 2, 1);
if (equality) {
__ TailCallRuntime(Runtime::kStringEquals, 2, 1);
} else {
__ TailCallRuntime(Runtime::kStringCompare, 2, 1);
}
__ bind(&miss);
GenerateMiss(masm);