>accepting -march=iwmmxt on x86 is a bug in GCC "-march" just tells gcc for what processor it has to generate the code. It does not matter what processor the computer actually has. I mean, it's ok to compile code for ARM on x86 computer, or the other way around. <div class="gmail_quote">On Thu, Oct 6, 2011 at 2:15 PM, Søren Sandmann <<a href="mailto:sandmann@cs.au.dk" target="_blank">sandmann@cs.au.dk</a>> wrote: <blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"> <div>Matt Turner <<a href="mailto:mattst88@gmail.com" target="_blank">mattst88@gmail.com</a>> writes: > I'm not able to reproduce it, but I have two reports that iwMMXt is > incorrectly detected on x86 and amd64. This happens because it uses the > standard _mm_* intrinsic functions. It should fail on x86 and amd64 > because configure will use -march=iwmmxt to compile the test, which > isn't a valid option on these platforms. > > So, just #error out in the test if the __arm__ preprocessor directive > isn't defined. </div>Looks good to me, though presumably accepting -march=iwmmxt on x86 is a bug in GCC. Also, looking at this again, isn't there a typo in the compiler check: <div> #if defined(__GNUC__) && (__GNUC__ < 4 || (__GNUC__ == 3 && __GNUC_MINOR__ < 6)) #error "Need GCC >= 4.6 for IWMMXT intrinsics" #endif </div>where __GNUC__ == 3 should be __GNUC__ == 4? Soren <div> > Fixes <a href="https://bugs.gentoo.org/show_bug.cgi?id=385179" target="_blank">https://bugs.gentoo.org/show_bug.cgi?id=385179</a> > > Signed-off-by: Matt Turner <<a href="mailto:mattst88@gmail.com" target="_blank">mattst88@gmail.com</a>> > --- > <a href="http://configure.ac" target="_blank">configure.ac</a> | 3 +++ > 1 files changed, 3 insertions(+), 0 deletions(-) > > diff --git a/<a href="http://configure.ac" target="_blank">configure.ac</a> b/<a href="http://configure.ac" target="_blank">configure.ac</a> > index 481d0bb..471a127 100644 > --- a/<a href="http://configure.ac" target="_blank">configure.ac</a> > +++ b/<a href="http://configure.ac" target="_blank">configure.ac</a> > @@ -552,6 +552,9 @@ AC_MSG_CHECKING(whether to use ARM IWMMXT intrinsics) > xserver_save_CFLAGS=$CFLAGS > CFLAGS="$IWMMXT_CFLAGS $CFLAGS" > AC_COMPILE_IFELSE([ > +#ifndef __arm__ > +#error "IWMMXT is only available on ARM" > +#endif > #if defined(__GNUC__) && (__GNUC__ < 4 || (__GNUC__ == 3 && __GNUC_MINOR__ < 6)) > #error "Need GCC >= 4.6 for IWMMXT intrinsics" > #endif </div>_______________________________________________ Pixman mailing list <a href="mailto:Pixman@lists.freedesktop.org" target="_blank">Pixman@lists.freedesktop.org</a> <a href="http://lists.freedesktop.org/mailman/listinfo/pixman" target="_blank">http://lists.freedesktop.org/mailman/listinfo/pixman</a> </blockquote></div>