Active smi-only optimizations for large array literals.

Activate smi-only optimizations for large array literals.

BUG=none
TEST=none

Committed: http://code.google.com/p/v8/source/detail?r=9553

[danno, 2011-10-07 14:11:45]

PTAL.

Guidance:

- I removed most of the flag gates around smi-only array code, only leaving them
around the central bottleneck that makes Arrays and Objects have
FAST_SMI_ONLY_ELEMENTS. 

- I added a special map tweak in the ArrayLiteral boilerplate code that is tuned
specifically to activate FAST_SMI_ONLY_ELEMENTS on the cases that are in the
Kraken benchmark.

- A implemented a few micro optimizations for regressions that showed up in
other benchmarks

[Jakob Kummerow, 2011-10-07 17:58:13]

LGTM

http://codereview.chromium.org/8177005/diff/1/src/builtins.cc
File src/builtins.cc (right):

http://codereview.chromium.org/8177005/diff/1/src/builtins.cc#newcode413
src/builtins.cc:413: MaybeObject* maybe_writable_result = 
array->EnsureWritableFastElements();
nit: excess space after =

http://codereview.chromium.org/8177005/diff/1/src/builtins.cc#newcode414
src/builtins.cc:414: if (maybe_writable_result->IsFailure()) return
maybe_writable_result;
You don't need this line (it's included in the next condition anyway).

http://codereview.chromium.org/8177005/diff/1/src/objects-inl.h
File src/objects-inl.h (right):

http://codereview.chromium.org/8177005/diff/1/src/objects-inl.h#newcode1658
src/objects-inl.h:1658: static int foo = 0;
debugging leftover?

[danno, 2011-10-10 11:26:33]

addressed feedback and landed

http://codereview.chromium.org/8177005/diff/1/src/builtins.cc
File src/builtins.cc (right):

http://codereview.chromium.org/8177005/diff/1/src/builtins.cc#newcode413
src/builtins.cc:413: MaybeObject* maybe_writable_result = 
array->EnsureWritableFastElements();
On 2011/10/07 17:58:13, Jakob wrote:
> nit: excess space after =

Done.

http://codereview.chromium.org/8177005/diff/1/src/builtins.cc#newcode414
src/builtins.cc:414: if (maybe_writable_result->IsFailure()) return
maybe_writable_result;
On 2011/10/07 17:58:13, Jakob wrote:
> You don't need this line (it's included in the next condition anyway).

Done.

http://codereview.chromium.org/8177005/diff/1/src/objects-inl.h
File src/objects-inl.h (right):

http://codereview.chromium.org/8177005/diff/1/src/objects-inl.h#newcode1658
src/objects-inl.h:1658: static int foo = 0;
On 2011/10/07 17:58:13, Jakob wrote:
> debugging leftover?

Done.