Remove spilled code from special cases of comparison.

Remove spilled code from special cases of comparison.

Committed: http://code.google.com/p/v8/source/detail?r=1108

[Mads Ager (chromium), 2009-01-20 09:20:14]

LGTM

[Kevin Millikin (Chromium), 2009-01-20 10:27:21]

First round of comments.

http://codereview.chromium.org/18402/diff/1/2
File src/codegen-ia32.cc (right):

http://codereview.chromium.org/18402/diff/1/2#newcode4157
Line 4157: frame_->Spill(answer.reg());
You should spill answer.reg() more lazily: only on paths where overwriting it is
inevitable.

http://codereview.chromium.org/18402/diff/1/2#newcode4165
Line 4165: answer.Unuse();
Unuse answer before the branch.

http://codereview.chromium.org/18402/diff/1/2#newcode4185
Line 4185: temp.Unuse();
Unuse temp and answer before the branch.

http://codereview.chromium.org/18402/diff/1/2#newcode4194
Line 4194: answer.Unuse();
Same.

http://codereview.chromium.org/18402/diff/1/2#newcode4228
Line 4228: __ mov(map.reg(), FieldOperand(answer.reg(),
HeapObject::kMapOffset));
Can we move the lookup of the map after the following branch?  Then if the
branch is taken we avoid the read and potentially having to spill to allocate a
register.

http://codereview.chromium.org/18402/diff/1/2#newcode4290
Line 4290: answer.Unuse();
Unuse answer before branching.

[William Hesse, 2009-01-20 12:02:50]

Updated file uploaded.

http://codereview.chromium.org/18402/diff/1/2
File src/codegen-ia32.cc (right):

http://codereview.chromium.org/18402/diff/1/2#newcode4157
Line 4157: frame_->Spill(answer.reg());
On 2009/01/20 10:27:22, Kevin Millikin wrote:
> You should spill answer.reg() more lazily: only on paths where overwriting it
is
> inevitable.

Done.

http://codereview.chromium.org/18402/diff/1/2#newcode4165
Line 4165: answer.Unuse();
On 2009/01/20 10:27:22, Kevin Millikin wrote:
> Unuse answer before the branch.

Done.

http://codereview.chromium.org/18402/diff/1/2#newcode4185
Line 4185: temp.Unuse();
On 2009/01/20 10:27:22, Kevin Millikin wrote:
> Unuse temp and answer before the branch.

Done.

http://codereview.chromium.org/18402/diff/1/2#newcode4194
Line 4194: answer.Unuse();
On 2009/01/20 10:27:22, Kevin Millikin wrote:
> Same.

Done.

http://codereview.chromium.org/18402/diff/1/2#newcode4228
Line 4228: __ mov(map.reg(), FieldOperand(answer.reg(),
HeapObject::kMapOffset));
On 2009/01/20 10:27:22, Kevin Millikin wrote:
> Can we move the lookup of the map after the following branch?  Then if the
> branch is taken we avoid the read and potentially having to spill to allocate
a
> register.

Done.

http://codereview.chromium.org/18402/diff/1/2#newcode4290
Line 4290: answer.Unuse();
On 2009/01/20 10:27:22, Kevin Millikin wrote:
> Unuse answer before branching.

Done.

[Kevin Millikin (Chromium), 2009-01-20 12:11:25]

LGTM.