ARM: Merge redundant entries in literal pool.

ARM: Merge redundant entries in literal pool.

This patch also clean up 64-bits literals handling.

R=bmeurer@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=17789

[Benedikt Meurer, 2013-11-15 07:37:30]

Did you measure the impact on real-world websites?

[Benedikt Meurer, 2013-11-15 08:47:01]

First round of comments.

https://codereview.chromium.org/61763025/diff/1/src/arm/assembler-arm.cc
File src/arm/assembler-arm.cc (right):

https://codereview.chromium.org/61763025/diff/1/src/arm/assembler-arm.cc#newc...
src/arm/assembler-arm.cc:3322: require_64_bit_align = (((uintptr_t)pc_ +
size_up_to_marker) & 0x3);
Checking for 64 bit alignment should use & 0x7.

https://codereview.chromium.org/61763025/diff/1/src/arm/assembler-arm.cc#newc...
src/arm/assembler-arm.cc:3420: memcpy(&uint_data, &double_data,
sizeof(double_data));
How about using BitCast here?

https://codereview.chromium.org/61763025/diff/1/src/assembler.h
File src/assembler.h (right):

https://codereview.chromium.org/61763025/diff/1/src/assembler.h#newcode377
src/assembler.h:377: memcpy(&tmp, &data64_, sizeof(tmp));
Same as above.

[Rodolph Perfetta, 2013-11-15 11:04:26]

Performance wise we also looked at Kraken, no visible impact.

https://codereview.chromium.org/61763025/diff/1/src/arm/assembler-arm.cc
File src/arm/assembler-arm.cc (right):

https://codereview.chromium.org/61763025/diff/1/src/arm/assembler-arm.cc#newc...
src/arm/assembler-arm.cc:3322: require_64_bit_align = (((uintptr_t)pc_ +
size_up_to_marker) & 0x3);
On 2013/11/15 08:47:01, Benedikt Meurer wrote:
> Checking for 64 bit alignment should use & 0x7.

Done.

https://codereview.chromium.org/61763025/diff/1/src/arm/assembler-arm.cc#newc...
src/arm/assembler-arm.cc:3420: memcpy(&uint_data, &double_data,
sizeof(double_data));
We don't even need Bitcast, raw_data64 already does it. Updated.

On 2013/11/15 08:47:01, Benedikt Meurer wrote:
> How about using BitCast here?

https://codereview.chromium.org/61763025/diff/1/src/assembler.h
File src/assembler.h (right):

https://codereview.chromium.org/61763025/diff/1/src/assembler.h#newcode377
src/assembler.h:377: memcpy(&tmp, &data64_, sizeof(tmp));
On 2013/11/15 08:47:01, Benedikt Meurer wrote:
> Same as above.

Done.

[Benedikt Meurer, 2013-11-15 12:23:34]

LGTM, will land.

[Benedikt Meurer, 2013-11-15 12:24:17]

Committed patchset #2 manually as r17789 (presubmit successful).