AuroraMiddleware/v8
1
0
Fork 0
Code Issues 2 Pull Requests Releases Wiki Activity

Avoid redundant smi check for Math.abs

Browse Source 
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/21180004

Patch from Weiliang Lin <weiliang.lin2@gmail.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16021 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This commit is contained in:
jkummerow@chromium.org 2013-08-02 08:59:02 +00:00
parent 15c1d23fbc
commit a47705644e
5 changed files with 27 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
src/arm/lithium-codegen-arm.cc
View File

@ -3765,7 +3765,7 @@ void LCodeGen::DoMathAbs(LMathAbs* instr) {
DwVfpRegister input = ToDoubleRegister(instr->value());
DwVfpRegister result = ToDoubleRegister(instr->result());
__ vabs(result, input);
} else if (r.IsInteger32()) {
} else if (r.IsSmiOrInteger32()) {
EmitIntegerMathAbs(instr);
} else {
// Representation is tagged.

2
src/ia32/lithium-codegen-ia32.cc
View File

@ -3821,7 +3821,7 @@ void LCodeGen::DoMathAbs(LMathAbs* instr) {
__ xorps(scratch, scratch);
__ subsd(scratch, input_reg);
__ pand(input_reg, scratch);
} else if (r.IsInteger32()) {
} else if (r.IsSmiOrInteger32()) {
EmitIntegerMathAbs(instr);
} else { // Tagged case.
DeferredMathAbsTaggedHeapNumber* deferred =

13
src/x64/lithium-codegen-x64.cc
View File

@ -3426,6 +3426,17 @@ void LCodeGen::EmitIntegerMathAbs(LMathAbs* instr) {
}
void LCodeGen::EmitInteger64MathAbs(LMathAbs* instr) {
Register input_reg = ToRegister(instr->value());
__ testq(input_reg, input_reg);
Label is_positive;
__ j(not_sign, &is_positive, Label::kNear);
__ neg(input_reg); // Sets flags.
DeoptimizeIf(negative, instr->environment());
__ bind(&is_positive);
}
void LCodeGen::DoMathAbs(LMathAbs* instr) {
// Class for deferred case.
class DeferredMathAbsTaggedHeapNumber: public LDeferredCode {
@ -3451,6 +3462,8 @@ void LCodeGen::DoMathAbs(LMathAbs* instr) {
__ andpd(input_reg, scratch);
} else if (r.IsInteger32()) {
EmitIntegerMathAbs(instr);
} else if (r.IsSmi()) {
EmitInteger64MathAbs(instr);
} else { // Tagged case.
DeferredMathAbsTaggedHeapNumber* deferred =
new(zone()) DeferredMathAbsTaggedHeapNumber(this, instr);

1
src/x64/lithium-codegen-x64.h
View File

@ -268,6 +268,7 @@ class LCodeGen BASE_EMBEDDED {
uint32_t additional_index = 0);
void EmitIntegerMathAbs(LMathAbs* instr);
void EmitInteger64MathAbs(LMathAbs* instr);
// Support for recording safepoint and position information.
void RecordSafepoint(LPointerMap* pointers,

11
test/mjsunit/math-abs.js
View File

@ -109,3 +109,14 @@ for(var i = 0; i < 1000; i++) {
assertEquals(42, foo(-42));
%OptimizeFunctionOnNextCall(foo)
assertEquals(42, foo(-42));
// Regression test for SMI input of Math.abs on X64, see:
// https://codereview.chromium.org/21180004/
var a = [-1, -2];
function foo2() {
return Math.abs(a[0]);
}
assertEquals(1, foo2());
assertEquals(1, foo2());
%OptimizeFunctionOnNextCall(foo2);
assertEquals(1, foo2());