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Revert of [x64] Use xorl to materialize smi zero. (patchset #1 id:1 of https://codereview.chromium.org/1085153002/)

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Reason for revert:
Seems to cause performance regressions.

Original issue's description:
> [x64] Use xorl to materialize smi zero.
>
> Before we always loaded smi zero via a movabs with a 64-bit immediate,
> which is pretty expensive compared to the xorl.
>
> R=jarin@chromium.org
>
> Committed: https://crrev.com/f236777bfe6e080ff1ead6baf847cc9b6bb4f9cb
> Cr-Commit-Position: refs/heads/master@{#27829}

TBR=jarin@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:477592
LOG=n

Review URL: https://codereview.chromium.org/1059543004

Cr-Commit-Position: refs/heads/master@{#27867}
This commit is contained in:
bmeurer 2015-04-16 01:31:26 -07:00 committed by Commit bot
parent f89bea1e17
commit c66a2f7b46
1 changed files with 1 additions and 8 deletions
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9
src/x64/macro-assembler-x64.cc
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@ -915,7 +915,6 @@ void MacroAssembler::SafePush(Smi* src) {
Register MacroAssembler::GetSmiConstant(Smi* source) {
STATIC_ASSERT(kSmiTag == 0);
int value = source->value();
if (value == 0) {
xorl(kScratchRegister, kScratchRegister);
@ -927,13 +926,7 @@ Register MacroAssembler::GetSmiConstant(Smi* source) {
void MacroAssembler::LoadSmiConstant(Register dst, Smi* source) {
STATIC_ASSERT(kSmiTag == 0);
int value = source->value();
if (value == 0) {
xorl(dst, dst);
} else {
Move(dst, source, Assembler::RelocInfoNone());
}
Move(dst, source, Assembler::RelocInfoNone());
}