https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104307
--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-11 branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:c81d1a061e5cfab6bd276c5be4cd6161b11e6d44 commit r11-9596-gc81d1a061e5cfab6bd276c5be4cd6161b11e6d44 Author: Jakub Jelinek <ja...@redhat.com> Date: Tue Feb 1 16:02:54 2022 +0100 veclower: Fix up -fcompare-debug issue in expand_vector_comparison [PR104307] The following testcase fails -fcompare-debug, because expand_vector_comparison since r11-1786-g1ac9258cca8030745d3c0b8f63186f0adf0ebc27 sets vec_cond_expr_only when it sees some use other than VEC_COND_EXPR that uses the lhs in its condition. Obviously we should ignore debug stmts when doing so, e.g. by not pushing them to uses. That would be a 2 liner change, but while looking at it, I'm also worried about VEC_COND_EXPRs that would use the lhs in more than one operand, like VEC_COND_EXPR <lhs, lhs, something> or VEC_COND_EXPR <lhs, something, lhs> (sure, they ought to be folded, but what if they weren't). Because if something like that happens, then FOR_EACH_IMM_USE_FAST would push the same stmt multiple times and expand_vector_condition can return true even when it modifies it (for vector bool masking). And lastly, it seems quite wasteful to safe_push statements that will just cause vec_cond_expr_only = false; and break; in the second loop, both for cases like 1000 immediate non-VEC_COND_EXPR uses and for cases like 999 VEC_COND_EXPRs with lhs in cond followed by a single non-VEC_COND_EXPR use. So this patch only pushes VEC_COND_EXPRs there. 2022-02-01 Jakub Jelinek <ja...@redhat.com> PR middle-end/104307 * tree-vect-generic.c (expand_vector_comparison): Don't push debug stmts to uses vector, just set vec_cond_expr_only to false for non-VEC_COND_EXPRs instead of pushing them into uses. Treat VEC_COND_EXPRs that use lhs not just in rhs1, but rhs2 or rhs3 too like non-VEC_COND_EXPRs. * gcc.target/i386/pr104307.c: New test. (cherry picked from commit e9bf6d6b0e1d67df6dcee042fbe37ab72c3a38d7)
