https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110386
--- Comment #10 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-13 branch has been updated by Andrew Pinski <pins...@gcc.gnu.org>: https://gcc.gnu.org/g:b5fa95a3569f6ee66697876a3a380fef1b333f3d commit r13-7927-gb5fa95a3569f6ee66697876a3a380fef1b333f3d Author: Andrew Pinski <apin...@marvell.com> Date: Sat Sep 23 21:53:09 2023 -0700 Fix PR 110386: backprop vs ABSU_EXPR The issue here is that when backprop tries to go and strip sign ops, it skips over ABSU_EXPR but ABSU_EXPR not only does an ABS, it also changes the type to unsigned. Since strip_sign_op_1 is only supposed to strip off sign changing operands and not ones that change types, removing ABSU_EXPR here is correct. We don't handle nop conversions so this does cause any missed optimizations either. Committed to the GCC 13 branch after bootstrapped and tested on x86_64-linux-gnu with no regressions. PR tree-optimization/110386 gcc/ChangeLog: * gimple-ssa-backprop.cc (strip_sign_op_1): Remove ABSU_EXPR. gcc/testsuite/ChangeLog: * gcc.c-torture/compile/pr110386-1.c: New test. * gcc.c-torture/compile/pr110386-2.c: New test. (cherry picked from commit 2bbac12ea7bd8a3eef5382e1b13f6019df4ec03f)