On Fri, Apr 4, 2014 at 7:51 PM, Jeff Law <l...@redhat.com> wrote: > On 04/04/14 10:18, Andreas Krebbel wrote: >> >> Hi, >> >> the attached patch modifies the builtin-bswap-6/7 testcases in order >> to prevent GCC from using math instead of a compare. Only with a >> compare the folding in combine actually takes place. >> >> Whether the return value is produce with a compare or not depends >> again on the value of branch cost. >> >> Ideally we would be able to do the folding also with the math trick >> but it is probably not that easy since we have already lost the >> information that in the end all we need is a 0 or a 1. >> >> Ok? >> >> Bye, >> >> -Andreas- >> >> 2014-04-04 Andreas Krebbel <andreas.kreb...@de.ibm.com> >> >> * gcc.dg/builtin-bswap-6.c: Adjust return value to disable GCC >> optimization. >> * gcc.dg/builtin-bswap-7.c: Likewise. > > OK.
The adjusted testcases now fail on x86_64/i?86 at least. See PR60776. Richard. > Jeff >
