Reviewers: Jakob,
Message:
PTAL.
http://codereview.chromium.org/8889047/diff/1/src/arm/code-stubs-arm.cc
File src/arm/code-stubs-arm.cc (left):
http://codereview.chromium.org/8889047/diff/1/src/arm/code-stubs-arm.cc#oldcode3524
src/arm/code-stubs-arm.cc:3524: __ vmov(exponent, single_scratch, eq);
We try to detect integer values saved in the double register
double_exponent by converting it to integer and back to double, then
comparing. Unlike on intel architectures, single_scratch saving the
intermediate integer is clobbered during the second conversion.
http://codereview.chromium.org/8889047/diff/1/src/arm/code-stubs-arm.cc
File src/arm/code-stubs-arm.cc (right):
http://codereview.chromium.org/8889047/diff/1/src/arm/code-stubs-arm.cc#newcode3636
src/arm/code-stubs-arm.cc:3636: __ Ret(2);
On ARM we don't multiply with kPointerSize.
Description:
Fixing bug introduced in r10210 that crashes v8 raytrace benchmark.
BUG=
TEST=
Please review this at http://codereview.chromium.org/8889047/
SVN Base: https://v8.googlecode.com/svn/branches/bleeding_edge
Affected files:
M src/arm/code-stubs-arm.cc
M test/mjsunit/math-pow.js
Index: src/arm/code-stubs-arm.cc
diff --git a/src/arm/code-stubs-arm.cc b/src/arm/code-stubs-arm.cc
index
a9d9676b3f4e741e913f71598e8eb4f57d1203f8..282df1565471a031b02ee8afe01397aa8253a053
100644
--- a/src/arm/code-stubs-arm.cc
+++ b/src/arm/code-stubs-arm.cc
@@ -3515,14 +3515,14 @@ void MathPowStub::Generate(MacroAssembler* masm) {
}
if (exponent_type_ != INTEGER) {
+ Label int_exponent_convert;
// Detect integer exponents stored as double.
__ vcvt_u32_f64(single_scratch, double_exponent);
// We do not check for NaN or Infinity here because comparing numbers
on
// ARM correctly distinguishes NaNs. We end up calling the built-in.
__ vcvt_f64_u32(double_scratch, single_scratch);
__ VFPCompareAndSetFlags(double_scratch, double_exponent);
- __ vmov(exponent, single_scratch, eq);
- __ b(eq, &int_exponent);
+ __ b(eq, &int_exponent_convert);
if (exponent_type_ == ON_STACK) {
// Detect square root case. Crankshaft detects constant +/-0.5 at
@@ -3579,6 +3579,10 @@ void MathPowStub::Generate(MacroAssembler* masm) {
__ pop(lr);
__ GetCFunctionDoubleResult(double_result);
__ jmp(&done);
+
+ __ bind(&int_exponent_convert);
+ __ vcvt_u32_f64(single_scratch, double_exponent);
+ __ vmov(exponent, single_scratch);
}
// Calculate power with integer exponent.
@@ -3629,7 +3633,7 @@ void MathPowStub::Generate(MacroAssembler* masm) {
FieldMemOperand(heapnumber, HeapNumber::kValueOffset));
ASSERT(heapnumber.is(r0));
__ IncrementCounter(counters->math_pow(), 1, scratch, scratch2);
- __ Ret(2 * kPointerSize);
+ __ Ret(2);
} else {
__ push(lr);
{
Index: test/mjsunit/math-pow.js
diff --git a/test/mjsunit/math-pow.js b/test/mjsunit/math-pow.js
index
535588dbd1f3d5c5cad090576c304bde42243e79..174065a70c560dc1bb50898667a5657038517049
100644
--- a/test/mjsunit/math-pow.js
+++ b/test/mjsunit/math-pow.js
@@ -140,6 +140,9 @@ function test() {
assertEquals(NaN, Math.pow(-16, 0.5));
assertEquals(0.25, Math.pow(16, -0.5));
assertEquals(NaN, Math.pow(-16, -0.5));
+
+ // Test detecting and converting integer value as double.
+ assertEquals(8, Math.pow(2, Math.sqrt(9)));
// Tests from Mozilla 15.8.2.13.
assertEquals(2, Math.pow.length);
--
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