X64: implement DoHasCachedArrayIndex in lithium compiler.

X64: implement DoHasCachedArrayIndex in lithium compiler.


Committed: http://code.google.com/p/v8/source/detail?r=7015

[Lasse Reichstein, 2011-03-02 09:59:07]

LGTM

http://codereview.chromium.org/6596104/diff/1/src/x64/lithium-codegen-x64.cc
File src/x64/lithium-codegen-x64.cc (right):

http://codereview.chromium.org/6596104/diff/1/src/x64/lithium-codegen-x64.cc#...
src/x64/lithium-codegen-x64.cc:1641:
Immediate(String::kContainsCachedArrayIndexMask));
Indentation.

http://codereview.chromium.org/6596104/diff/1/src/x64/lithium-codegen-x64.cc#...
src/x64/lithium-codegen-x64.cc:1644: __ LoadRoot(result,
Heap::kFalseValueRootIndex);
Could we do just one computed load from the root array here?
E.g.
  ASSERT(Heap::kTrueValueRootIndex + 1 == Heap::kFalseValueRootIndex);
  __ setcc(zero, result);
  __ movzxbl(result, result);
  __ LoadRoot(result, result, Heap::kTrueValueRootIndex);

(adding a 
  void LoadRoot(Register dst, Register dynIdx, int idx) {
    __ movq(dst, Operand(kRootRegister, dynIdx, times_pointer_size, idx *
kPointerSize);
  }
if it's not there already).

I think we use similar code elsewhere.

[Rico, 2011-03-02 10:12:15]

http://codereview.chromium.org/6596104/diff/1/src/x64/lithium-codegen-x64.cc
File src/x64/lithium-codegen-x64.cc (right):

http://codereview.chromium.org/6596104/diff/1/src/x64/lithium-codegen-x64.cc#...
src/x64/lithium-codegen-x64.cc:1641:
Immediate(String::kContainsCachedArrayIndexMask));
On 2011/03/02 09:59:07, Lasse Reichstein wrote:
> Indentation.

Done.

http://codereview.chromium.org/6596104/diff/1/src/x64/lithium-codegen-x64.cc#...
src/x64/lithium-codegen-x64.cc:1644: __ LoadRoot(result,
Heap::kFalseValueRootIndex);
On 2011/03/02 09:59:07, Lasse Reichstein wrote:
> Could we do just one computed load from the root array here?
> E.g.
>   ASSERT(Heap::kTrueValueRootIndex + 1 == Heap::kFalseValueRootIndex);
>   __ setcc(zero, result);
>   __ movzxbl(result, result);
>   __ LoadRoot(result, result, Heap::kTrueValueRootIndex);
> 
> (adding a 
>   void LoadRoot(Register dst, Register dynIdx, int idx) {
>     __ movq(dst, Operand(kRootRegister, dynIdx, times_pointer_size, idx *
> kPointerSize);
>   }
> if it's not there already).
> 
> I think we use similar code elsewhere.

As discussed offline this will not really have any effect here, leaving it as is
to be consistent with the remainder of the lithium instructions.