mmx: Use MMX2 intrinsics from xmmintrin.h directly.

We had lots of hacks to handle the inability to include xmmintrin.h
without compiling with -msse (lest SSE instructions be used in
pixman-mmx.c). Some recent version of gcc relaxed this restriction.

Change configure.ac to test that xmmintrin.h can be included and that we
can use some intrinsics from it, and remove the work-around code from
pixman-mmx.c.

Evidently allows gcc 4.9.3 to optimize better as well:

   text	   data	    bss	    dec	    hex	filename
 657078	  30848	    680	 688606	  a81de	libpixman-1.so.0.33.3 before
 656710	  30848	    680	 688238	  a806e	libpixman-1.so.0.33.3 after

Reviewed-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>
Tested-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Signed-off-by: Matt Turner <mattst88@gmail.com>
2 files changed