On Sat, 2014-09-27 at 11:10 -0700, Andi Kleen wrote: > From: Andi Kleen <a...@linux.intel.com> > > In my tests the optimized glibc out of line strcmp is always faster than > using inline rep ; cmpsb, even for small strings. The Intel optimization > manual > also recommends to not use it. So remove the cmpstrnsi instruction. > > Tested on Sandy Bridge, Westmere Intel CPUs. > > gcc/: > > 2014-09-27 Andi Kleen <a...@linux.intel.com> > > * config/i386/i386.md (cmpstrnsi, cmpintqi): Remove expanders.
This has been mentioned a while ago, e.g. https://gcc.gnu.org/ml/gcc/2002-10/msg01616.html https://gcc.gnu.org/ml/gcc/2003-04/msg00166.html Instead of just completely removing it, how about disabling it for newer CPU types if not optimizing for size? Cheers, Oleg
