Dominik Vogt wrote: > So, we could add a special case for const0_rtx that generates the > LT pattern and does not rely on Combine, and get rid of the > peephole. I'm not sure this is worthwhile thoug, because the > peephole has other beneficial effects (as discussed), and until > we've solved the problems preventing Combine from merging L+LTR in > some cases, this is the best we have. What do you think?
If we removed the peephole (for now), the patch now only touches parts of the backend used to emit atomic instructions, so code generation for any code that doesn't use those is guaranteed to be unchanged. Given that we're quite late in the cycle, this might be a good idea at this point ... But I don't see anything actually incorrect in the peephole, and it might indeed be a good thing in general -- just maybe more appropriate for the next stage1. Andreas, do you have an opinion on this? Bye, Ulrich -- Dr. Ulrich Weigand GNU/Linux compilers and toolchain ulrich.weig...@de.ibm.com