On Sep 29, 2020, Alexandre Oliva <ol...@adacore.com> wrote: > Yeah, ifcombine's bb_no_side_effects_p gives up on any gimple_vuse in > the inner block. that won't do when the whole point is to merge loads > from memory.
> That seems excessive. Since we rule out any memory-changing side > effects, I suppose we could get away with checking for volatile operands > there. Then, adding just a little SSA_DEF chasing, I believe I could > bring all of the fold_truth_andor_1 logic I've worked on into ifcombine > without much difficulty, and then we could do away with at least that > part of fold_truth_andor. Confirmed, a very ugly prototype seems to work! -- Alexandre Oliva, happy hacker https://FSFLA.org/blogs/lxo/ Free Software Activist GNU Toolchain Engineer
