https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110271
--- Comment #5 from CVS 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:5b67116a85298bbe358b036d34ad23119cebbdac commit r14-1895-g5b67116a85298bbe358b036d34ad23119cebbdac Author: Jakub Jelinek <ja...@redhat.com> Date: Fri Jun 16 19:46:36 2023 +0200 tree-ssa-math-opts: Fix up uaddc/usubc pattern matching [PR110271] The following testcase ICEs, because I misremembered what the return value from match_arith_overflow is. It isn't true if __builtin_*_overflow was matched, but it is true only in the BIT_NOT_EXPR case if stmt was removed. So, if match_arith_overflow matches something, gsi_stmt (gsi) will not be stmt and match_uaddc_usubc will be confused and can ICE. The following patch fixes it by checking if gsi_stmt (gsi) == stmt, in that case we know it is still a PLUS_EXPR/MINUS_EXPR and we can try to pattern match it further as UADDC/USUBC. 2023-06-16 Jakub Jelinek <ja...@redhat.com> PR tree-optimization/110271 * tree-ssa-math-opts.cc (math_opts_dom_walker::after_dom_children) <case PLUS_EXPR>: Ignore return value from match_arith_overflow, instead call match_uaddc_usubc only if gsi_stmt (gsi) is still stmt. * gcc.c-torture/compile/pr110271.c: New test.
