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MIPS: Fix r21780 - “Fixed flooring division by a power of 2, once again...”

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Initialize scratch register for all possible code paths.

TEST=mjsunit/compiler/division-by-constant.js
BUG=
R=plind44@gmail.com

Review URL: https://codereview.chromium.org/333713002

Patch from Balazs Kilvady <kilvadyb@homejinni.com>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21822 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This commit is contained in:
plind44@gmail.com 2014-06-12 20:25:47 +00:00
parent ed61b85c78
commit d773d05ba6
1 changed files with 7 additions and 7 deletions
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14
src/mips/lithium-codegen-mips.cc
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@ -1327,18 +1327,18 @@ void LCodeGen::DoFlooringDivByPowerOf2I(LFlooringDivByPowerOf2I* instr) {
}
// If the divisor is negative, we have to negate and handle edge cases.
if (instr->hydrogen()->CheckFlag(HValue::kLeftCanBeMinInt)) {
// divident can be the same register as result so save the value of it
// for checking overflow.
__ Move(scratch, dividend);
}
// dividend can be the same register as result so save the value of it
// for checking overflow.
__ Move(scratch, dividend);
__ Subu(result, zero_reg, dividend);
if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
DeoptimizeIf(eq, instr->environment(), result, Operand(zero_reg));
}
// Dividing by -1 is basically negation, unless we overflow.
__ Xor(at, scratch, result);
__ Xor(scratch, scratch, result);
if (divisor == -1) {
if (instr->hydrogen()->CheckFlag(HValue::kLeftCanBeMinInt)) {
DeoptimizeIf(ge, instr->environment(), at, Operand(zero_reg));
@ -1353,7 +1353,7 @@ void LCodeGen::DoFlooringDivByPowerOf2I(LFlooringDivByPowerOf2I* instr) {
}
Label no_overflow, done;
__ Branch(&no_overflow, lt, at, Operand(zero_reg));
__ Branch(&no_overflow, lt, scratch, Operand(zero_reg));
__ li(result, Operand(kMinInt / divisor));
__ Branch(&done);
__ bind(&no_overflow);