[Pixman] [PATCH] SIMD: Try without any CFLAGS before forcing -mcpu=
lool at dooz.org
Sun Mar 14 10:25:10 PDT 2010
On Wed, Mar 10, 2010, Siarhei Siamashka wrote:
> I would prefer a bit more descriptive comment (with the details copied
> from that launchpad page).
I see you pushed this now; thanks! Yeah, it's not obvious why one
needs to try with the toolchain defaults first. I'm attaching a patch
to update the comments.
> Patch looks mostly OK to me and improves arm simd support a bit. It still
> fails with CFLAGS="-O2 -mthumb" (and toolchain configured to compile for armv4
> by default)
This is unfortunate, but even if I could change the configure test to
succeed here, the actual build would place CFLAGS last
(user-overrides); it's perhaps best if the build fails at this point.
The other option would be to munge the user-specific CFLAGS in
configure, but I'm not sure I'm confortable with that, plus these can
be overriden during the build as well.
So I guess people forcing Thumb in CFLAGS with a default of an old CPU
will have a bit more pain here. I think it also fails if you force
-mcpu=oldcpu in CFLAGS.
> But that was also happening earlier, so it is not a regression.
> In my opinion the best solution overall would be to move all the assembly
> optimizations into separate .S files also for legacy ARM processors and
> get rid of these compiler option hacks. I think that bringing support for
> legacy ARM processors into a better shape is quite realistic even for 0.18.0
> stable release, which is due to be released this month. But it can only happen
> if enough people are interested in this, and more importantly, are ready to
> actively participate in testing.
I think this should be kept as an open bug against pixman that the
inline asm()s would better be written as separate .S files (thanks for
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