http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36503
--- Comment #9 from Uros Bizjak <ubizjak at gmail dot com> 2010-10-22 07:37:22 UTC --- (In reply to comment #8) > I built ffmpeg for x86-64 with --disable-asm with the attached patch and the > regression tests failed. Reverting the patch fixes them. I saved the binaries > but haven't investigated yet. The problem is that new insn pattern clobbers %ecx. Currently, this is not modeled correctly - if this is fixed, then the combine doesn't recognize combined pattern. So, either combine should be fixed to allow correct (match_dup X) in the combined pattern or this transformation should be implemented in generic part of the compiler.
