audio use xmmintrin for sse to reduce requirement from sse2 to sse...

audio use xmmintrin for sse to reduce requirement from sse2 to sse
BUG=44643
TEST=build with compiler options that enable sse but disable sse2 and chrome should still build and run on Pentium3.


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=48515

[fbarchard, 2010-05-28 17:22:00]

downgrading requirement from sse2 to sse by using xmmintrin.h

sse (float) on pentium3 uses xmmintrin.h
emmintrin.h is for 'williamette new instructions', which is pentium4 sse2, which
is mostly mmx instructions on sse registers (int).
For codecs and graphics, mmx and sse2 are used extensively, but sse is fairly
rare.  We may use it more for audio in the future.

[scherkus (not reviewing), 2010-05-28 19:00:13]

LGTM

are there any gyp changes needed?

[fbarchard, 2010-05-28 19:39:22]

On 2010/05/28 19:00:13, scherkus wrote:
> LGTM
> 
> are there any gyp changes needed?

no gyp changes needed.