First implementation of fast path for instantiation of array literals composed of doubles.

First implementation of fast path for instantiation of array literals composed of doubles.

Committed: https://code.google.com/p/v8/source/detail?r=11114

[Jakob Kummerow, 2012-03-21 10:36:46]

LGTM if comments are addressed.

http://codereview.chromium.org/9814006/diff/1/src/ia32/lithium-codegen-ia32.cc
File src/ia32/lithium-codegen-ia32.cc (right):

http://codereview.chromium.org/9814006/diff/1/src/ia32/lithium-codegen-ia32.c...
src/ia32/lithium-codegen-ia32.cc:4467: for (int i = 0; i <
FixedArray::kHeaderSize; i += kPointerSize) {
This should be FixedArrayBase::kHeaderSize (doesn't make a difference in
practice because FixedArray inherits kHeaderSize from FixedArrayBase, but let's
be correct here nevertheless).

http://codereview.chromium.org/9814006/diff/1/src/ia32/lithium-codegen-ia32.c...
src/ia32/lithium-codegen-ia32.cc:4478: int64_t i_value;
Remove the "i_". Just "value".
The same applies to i_value_low and i_value_high below.

[Sven Panne, 2012-03-21 11:04:12]

http://codereview.chromium.org/9814006/diff/1/src/ia32/lithium-codegen-ia32.cc
File src/ia32/lithium-codegen-ia32.cc (right):

http://codereview.chromium.org/9814006/diff/1/src/ia32/lithium-codegen-ia32.c...
src/ia32/lithium-codegen-ia32.cc:4478: int64_t i_value;
To reduce copy-n-paste, adding a method to FixedDoubleArray for getting an
int64_t from an element for a given index would be nicer IMHO. This method can
be re-used on all architectures. Not a big saving, but anyway: Redundancy is the
root of all evil. :-)

[Sven Panne, 2012-03-23 09:48:30]

LGTM (again) with a tiny nit

http://codereview.chromium.org/9814006/diff/4001/src/objects-inl.h
File src/objects-inl.h (right):

http://codereview.chromium.org/9814006/diff/4001/src/objects-inl.h#newcode1714
src/objects-inl.h:1714: int64_t result = READ_INT64_FIELD(this, kHeaderSize +
index * kDoubleSize);
No need to name this explicitly...