https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111699
--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The trunk branch has been updated by Andrew Pinski <pins...@gcc.gnu.org>: https://gcc.gnu.org/g:e77428a9a336f57e3efe3eff95f2b491d7e9be14 commit r14-4432-ge77428a9a336f57e3efe3eff95f2b491d7e9be14 Author: Andrew Pinski <pins...@gmail.com> Date: Thu Oct 5 12:21:19 2023 -0700 MATCH: Fix infinite loop between `vec_cond(vec_cond(a,b,0), c, d)` and `a & b` Match has a pattern which converts `vec_cond(vec_cond(a,b,0), c, d)` into `vec_cond(a & b, c, d)` but since in this case a is a comparison fold will change `a & b` back into `vec_cond(a,b,0)` which causes an infinite loop. The best way to fix this is to enable the patterns for vec_cond(*,vec_cond,*) only for GIMPLE so we don't get an infinite loop for fold any more. Note this is a latent bug since these patterns were added in r11-2577-g229752afe3156a and was exposed by r14-3350-g47b833a9abe1 where now able to remove a VIEW_CONVERT_EXPR. OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions. PR middle-end/111699 gcc/ChangeLog: * match.pd ((c ? a : b) op d, (c ? a : b) op (c ? d : e), (v ? w : 0) ? a : b, c1 ? c2 ? a : b : b): Enable only for GIMPLE. gcc/testsuite/ChangeLog: * gcc.c-torture/compile/pr111699-1.c: New test.