[Pixman] ARM iwmmxt patches

Soeren Sandmann sandmann at cs.au.dk
Wed Aug 31 16:37:54 PDT 2011

Matt Turner <mattst88 at gmail.com> writes:

>>> Never does using inline assembly seem to make any sort of meaningful
>>> difference over simply compiling pixman-mmx.c for ARM/iwmmxt. I tried
>>> checking the alignment in the 'wip' commit in the blt function to
>>> avoid a lot of unnecessary walign instructions, but as you can see
>>> from the benchmark results, it doesn't help anything.
>> The cairo-trace tests are better benchmarks to use in general because
>> they reflect real-world use. lowlevel-blt-bench really should only be
>> used for the case where you are optimizing a specific compositing
>> routine.
> OK, I'll run cairo-trace to determine the effect of the inline
> assembly. I think the addition of inline assembly could go in as
> follow-on patches though, right?

Right, as long as they are not required to avoid regressions on either
x86 or ARM.

There are still some problems with the rest of the patch set
though. Several of the comments from Siarhei and me have not been
addressed, and compiling your iwmmxt-optimizations2 branch on x86
results in

../pixman/.libs/libpixman-1.so: undefined reference to `_mm_align_si64'


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