https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118902
--- Comment #5 from GCC 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:16082bdc6beef1ca1485ed5ccdc0c52aabbe0f4c commit r16-24-g16082bdc6beef1ca1485ed5ccdc0c52aabbe0f4c Author: Andrew Pinski <quic_apin...@quicinc.com> Date: Thu Feb 13 20:23:48 2025 -0800 gimple: Canonical order for invariants [PR118902] So unlike constants, address invariants are currently put first if used with a SSA NAME. It would be better if address invariants are consistent with constants and this patch changes that. gcc.dg/tree-ssa/pr118902-1.c is an example where this canonicalization can help. In it if `p` variable was a global variable, FRE (VN) would have figured it out that `a` could never be equal to `&p` inside the loop. But without the canonicalization we end up with `&p == a.0_1` which VN does try to handle for conditional VN. Bootstrapped and tested on x86_64. PR tree-optimization/118902 gcc/ChangeLog: * fold-const.cc (tree_swap_operands_p): Place invariants in the first operand if not used with constants. gcc/testsuite/ChangeLog: * gcc.dg/tree-ssa/pr118902-1.c: New test. Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>
