https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95433
--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Marc Glisse <gli...@gcc.gnu.org>: https://gcc.gnu.org/g:287522613d661b4c5ba8403b051eb470c1674cba commit r11-2629-g287522613d661b4c5ba8403b051eb470c1674cba Author: Marc Glisse <marc.gli...@inria.fr> Date: Mon Aug 10 12:50:42 2020 +0200 Simplify X * C1 == C2 with wrapping overflow Odd numbers are invertible in Z / 2^n Z, so X * C1 == C2 can be rewritten as X == C2 * inv(C1) when overflow wraps. mod_inv should probably be updated to better match the other wide_int functions, but that's a separate issue. 2020-08-10 Marc Glisse <marc.gli...@inria.fr> PR tree-optimization/95433 * match.pd (X * C1 == C2): Handle wrapping overflow. * expr.c (maybe_optimize_mod_cmp): Qualify call to mod_inv. (mod_inv): Move... * wide-int.cc (mod_inv): ... here. * wide-int.h (mod_inv): Declare it. * gcc.dg/tree-ssa/pr95433-2.c: New file.
