[cairo] [cairo-announce] [ANNOUNCE] Stable pixman release 0.16.0 now available

Siarhei Siamashka siarhei.siamashka at gmail.com
Tue Sep 1 15:49:00 PDT 2009

On Monday 31 August 2009, Koen Kooi wrote:

> And I still hate that pixman puts in it's own -march and -mcpu, but
> that's a discussion for another day.

Pixman puts -mcpu only into the flags for compiling some selected files,
*after* configure script has already verified that gcc can accept this set of
flags. If gcc would reject this combination of flags, it would not try to
compile these sources at all. Still a missing part here is -mfloat-abi=softfp
option for the source file with NEON optimizations.

This behavior is consistent with the rest of pixman, except that gcc behaves a
lot more ugly on ARM than on other platforms.

The whole point is that gcc is doing sanity checks (generally a good thing),
but is overly paranoid. So it needs to be convinced to accept the code with
some ugly tweaks. This solution has no other drawbacks except that it is
estatically displeasing. If you know about any other problems, please share
this information.

There is also another extreme - implementation of all the NEON optimizations
in a separate *.S assembly file. This will make gcc shut up completely and
link whatever blob you provide to it (linker would do some basic validation
though). But ABI conformance and other important things are mostly up to the
developer in this case.

Best regards,
Siarhei Siamashka

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