https://gcc.gnu.org/g:e2959d86a35136b1c20031d5d8b0b331d5540a4f
commit e2959d86a35136b1c20031d5d8b0b331d5540a4f Author: Jeff Law <[email protected]> Date: Mon Nov 17 10:40:46 2025 -0700 [PR rtl-optimization/122575] Fix mode on optimized IOR comparison As Andrew P recognized, we were using the wrong mode when simplifying certain equality tests like (eq (ior (ne x 0 (y)). Sam took Andrew's suggestion and verified it fixed the problem he was stumbling over. So even though I haven't recreated the problem, I'm reasonably confident we've got the right fix. I've bootstrapped and regression tested on x86. PR rtl-optimization/122575 gcc/ * simplify-rtx.cc (simplify_context::simplify_relational_operation_1): Use correct mode for simplified IOR expression inside equality conditional. (cherry picked from commit 2e1d74b27283b5c20b0e1611c358dbf4e62db54f) Diff: --- gcc/simplify-rtx.cc | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/gcc/simplify-rtx.cc b/gcc/simplify-rtx.cc index 2f9a1d369dad..c5cd07aef156 100644 --- a/gcc/simplify-rtx.cc +++ b/gcc/simplify-rtx.cc @@ -6380,10 +6380,10 @@ simplify_context::simplify_relational_operation_1 (rtx_code code, /* only enters if op1 is 0 */ /* Verify IOR operand is NE */ && GET_CODE (XEXP (op0, 0)) == NE - /* Verfiy second NE operand is 0 */ + /* Verify second NE operand is 0 */ && XEXP (XEXP (op0, 0), 1) == CONST0_RTX (mode)) { - rtx t = gen_rtx_IOR (mode, XEXP (XEXP (op0, 0), 0), XEXP (op0, 1)); + rtx t = gen_rtx_IOR (cmp_mode, XEXP (XEXP (op0, 0), 0), XEXP (op0, 1)); t = gen_rtx_fmt_ee (code, mode, t, CONST0_RTX (mode)); return t; }
