https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116486
--- Comment #5 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:25d51fb7d098a9ac8880ccb2121d889815680177 commit r15-3364-g25d51fb7d098a9ac8880ccb2121d889815680177 Author: Jakub Jelinek <ja...@redhat.com> Date: Mon Sep 2 09:44:09 2024 +0200 ranger: Fix up range computation for CLZ [PR116486] The initial CLZ gimple-range-op.cc implementation handled just the case where second argument to .CLZ is equal to prec, but in r15-1014 I've added also handling of the -1 case. As the following testcase shows, incorrectly though for the case where the first argument has [0,0] range. If the second argument is prec, then the result should be [prec,prec] and that was handled correctly, but when the second argument is -1, the result should be [-1,-1] but instead it was incorrectly computed as [prec-1,prec-1] (when second argument is prec, mini is 0 and maxi is prec, while when second argument is -1, mini is -1 and maxi is prec-1). Fixed thusly (the actual handling is then similar to the CTZ [0,0] case). 2024-09-02 Jakub Jelinek <ja...@redhat.com> PR middle-end/116486 * gimple-range-op.cc (cfn_clz::fold_range): If lh is [0,0] and mini is -1, return [-1,-1] range rather than [prec-1,prec-1]. * gcc.dg/bitint-109.c: New test.
