From: Jeff Law <jlaw@ventanamicro.com>
Date: Mon, 17 Nov 2025 17:40:46 +0000 (-0700)
Subject: [PR rtl-optimization/122575] Fix mode on optimized IOR comparison
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=2e1d74b27283b5c20b0e1611c358dbf4e62db54f;p=thirdparty%2Fgcc.git

[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.
---

diff --git a/gcc/simplify-rtx.cc b/gcc/simplify-rtx.cc
index 2f7ad2de1d1..86baeb06ad4 100644
--- a/gcc/simplify-rtx.cc
+++ b/gcc/simplify-rtx.cc
@@ -6500,10 +6500,10 @@ 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;
 	}