Prefill pre-allocated memory of folded allocation with one pointer fillers when heap verifier is on.

Prefill pre-allocated memory of folded allocation with one pointer fillers when heap verifier is on.

BUG=
R=mstarzinger@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=15798

[Michael Starzinger, 2013-07-22 09:04:31]

LGTM (with two comments to address).

https://codereview.chromium.org/19723004/diff/2001/src/hydrogen-instructions.cc
File src/hydrogen-instructions.cc (right):

https://codereview.chromium.org/19723004/diff/2001/src/hydrogen-instructions....
src/hydrogen-instructions.cc:3241:
dominator_allocate_instr->SetFlags(HAllocate::PREFILL_WITH_FILLER);
I like this! Now the hydrogen graph stays the same, no matter whether the heap
verifier is running or not.

https://codereview.chromium.org/19723004/diff/2001/src/ia32/lithium-codegen-i...
File src/ia32/lithium-codegen-ia32.cc (right):

https://codereview.chromium.org/19723004/diff/2001/src/ia32/lithium-codegen-i...
src/ia32/lithium-codegen-ia32.cc:6066: __ mov(MemOperand(result, temp,
times_pointer_size, -1),
Better use FieldOperand here instead of the MemOperand with a magic -1 value.

https://codereview.chromium.org/19723004/diff/2001/src/x64/lithium-codegen-x6...
File src/x64/lithium-codegen-x64.cc (right):

https://codereview.chromium.org/19723004/diff/2001/src/x64/lithium-codegen-x6...
src/x64/lithium-codegen-x64.cc:5095: __ Move(MemOperand(result, temp,
times_pointer_size, -1),
Better use FieldOperand here instead of the MemOperand with a magic -1 value.

[Hannes Payer (out of office), 2013-07-22 11:05:41]

https://codereview.chromium.org/19723004/diff/2001/src/ia32/lithium-codegen-i...
File src/ia32/lithium-codegen-ia32.cc (right):

https://codereview.chromium.org/19723004/diff/2001/src/ia32/lithium-codegen-i...
src/ia32/lithium-codegen-ia32.cc:6066: __ mov(MemOperand(result, temp,
times_pointer_size, -1),
On 2013/07/22 09:04:31, Michael Starzinger wrote:
> Better use FieldOperand here instead of the MemOperand with a magic -1 value.

Done.

https://codereview.chromium.org/19723004/diff/2001/src/x64/lithium-codegen-x6...
File src/x64/lithium-codegen-x64.cc (right):

https://codereview.chromium.org/19723004/diff/2001/src/x64/lithium-codegen-x6...
src/x64/lithium-codegen-x64.cc:5095: __ Move(MemOperand(result, temp,
times_pointer_size, -1),
On 2013/07/22 09:04:31, Michael Starzinger wrote:
> Better use FieldOperand here instead of the MemOperand with a magic -1 value.

Done.

[Hannes Payer (out of office), 2013-07-22 11:07:53]

Committed patchset #3 manually as r15798 (presubmit successful).