Reviewers: ulan,
Description:
Handle flooring division in LCodeGen::DoDivByConstI on ARM, too.
We should really split up the Lithium instruction, but this will be
done in some future cleanup CL.
Removed some "const"s for local variables on the way, they don't really
help us much and just clutter up the code.
Please review this at https://codereview.chromium.org/196603004/
SVN Base: https://v8.googlecode.com/svn/branches/bleeding_edge
Affected files (+21, -20 lines):
M src/arm/lithium-codegen-arm.cc
Index: src/arm/lithium-codegen-arm.cc
diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index
140493e1b83a72b16dab9e92c77a2d9c77f0c41f..b410cb9ab9b6df63bc96a2f316820ee201bda921
100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -1358,9 +1358,9 @@ void LCodeGen::DoDivByConstI(LDivByConstI* instr) {
void LCodeGen::DoDivI(LDivI* instr) {
HBinaryOperation* hdiv = instr->hydrogen();
- const Register left = ToRegister(instr->left());
- const Register right = ToRegister(instr->right());
- const Register result = ToRegister(instr->result());
+ Register left = ToRegister(instr->left());
+ Register right = ToRegister(instr->right());
+ Register result = ToRegister(instr->result());
// Check for x / 0.
if (hdiv->CheckFlag(HValue::kCanBeDivByZero)) {
@@ -1395,17 +1395,9 @@ void LCodeGen::DoDivI(LDivI* instr) {
if (CpuFeatures::IsSupported(SUDIV)) {
CpuFeatureScope scope(masm(), SUDIV);
__ sdiv(result, left, right);
-
- if (!hdiv->CheckFlag(HValue::kAllUsesTruncatingToInt32)) {
- // Compute remainder and deopt if it's not zero.
- const Register remainder = scratch0();
- __ mls(remainder, result, right, left);
- __ cmp(remainder, Operand::Zero());
- DeoptimizeIf(ne, instr->environment());
- }
} else {
- const DoubleRegister vleft = ToDoubleRegister(instr->temp());
- const DoubleRegister vright = double_scratch0();
+ DoubleRegister vleft = ToDoubleRegister(instr->temp());
+ DoubleRegister vright = double_scratch0();
__ vmov(double_scratch0().low(), left);
__ vcvt_f64_s32(vleft, double_scratch0().low());
__ vmov(double_scratch0().low(), right);
@@ -1413,14 +1405,23 @@ void LCodeGen::DoDivI(LDivI* instr) {
__ vdiv(vleft, vleft, vright); // vleft now contains the result.
__ vcvt_s32_f64(double_scratch0().low(), vleft);
__ vmov(result, double_scratch0().low());
+ }
- if (!hdiv->CheckFlag(HValue::kAllUsesTruncatingToInt32)) {
- // Deopt if exact conversion to integer was not possible.
- // Use vright as scratch register.
- __ vcvt_f64_s32(double_scratch0(), double_scratch0().low());
- __ VFPCompareAndSetFlags(vleft, double_scratch0());
- DeoptimizeIf(ne, instr->environment());
- }
+ if (hdiv->IsMathFloorOfDiv()) {
+ Label done;
+ Register remainder = scratch0();
+ __ mls(remainder, result, right, left);
+ __ cmp(remainder, Operand::Zero());
+ __ b(eq, &done);
+ __ eor(remainder, remainder, Operand(right));
+ __ add(result, result, Operand(remainder, ASR, 31));
+ __ bind(&done);
+ } else if (!hdiv->CheckFlag(HValue::kAllUsesTruncatingToInt32)) {
+ // Compute remainder and deopt if it's not zero.
+ Register remainder = scratch0();
+ __ mls(remainder, result, right, left);
+ __ cmp(remainder, Operand::Zero());
+ DeoptimizeIf(ne, instr->environment());
}
}
--
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