On Sun, Nov 8, 2015 at 9:58 PM, Segher Boessenkool <seg...@kernel.crashing.org> wrote: > On Fri, Nov 06, 2015 at 04:00:08PM -0600, Segher Boessenkool wrote: >> This patch stops combine from generating widening muls of anything else >> but registers (immediates, memory, ...). This probably is a reasonable >> tradeoff for all targets, even those (if any) that have such insns. >> >> > >I'll let you put it through it's paces on your setup :) >> >> > I'll let Segher give the final yes/no on this, but it generally looks >> > good to me. >> >> It looks okay to me too. Testing now, combine patches have the tendency >> to do unforeseen things on other targets ;-) > > Testing shows it makes a difference only very rarely. For many targets > it makes no difference, for a few it is a small win. For 32-bit x86 it > creates slightly bigger code. > > I think it looks good, but let's wait to hear Uros' opinion.
>From the original patch submission, it looks that this patch would also benefit x86_32. Regarding the above code size increase - do you perhaps have a testcase, to see what causes the difference? It isn't necessary due to the patch, but perhaps some loads are moved to the insn and aren't CSE'd anymore. Uros.
