From: Sam James <sam@gentoo.org>
Date: Mon, 23 Jun 2025 22:28:01 +0000 (+0100)
Subject: Fixup dropping REG_EQUAL note in ext-dce
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cdd678544fefc313cb1c9da0327158d3ed355f62;p=thirdparty%2Fgcc.git

Fixup dropping REG_EQUAL note in ext-dce

Followup to r16-1613-g34e1e5e33ec3eb. remove_reg_equal_equiv_notes's
2nd argument is 'no_rescan' which we accidentally had on, tripping
an assert in combine or ira because we hadn't left things in a consistent
state.

Fix the thinko by enabling rescanning.

gcc/ChangeLog:
	PR rtl-optimization/120795

	* ext-dce.cc (ext_dce_try_optimize_insn): Enable rescan in
	remove_reg_equal_equiv_notes call.

Co-authored-by: Jeff Law <jlaw@ventanamicro.com>
---

diff --git a/gcc/ext-dce.cc b/gcc/ext-dce.cc
index b1d5ee4b36c..df17b018bf1 100644
--- a/gcc/ext-dce.cc
+++ b/gcc/ext-dce.cc
@@ -446,7 +446,7 @@ ext_dce_try_optimize_insn (rtx_insn *insn, rtx set)
       /* INSN may have a REG_EQUAL note indicating that the value was
 	 sign or zero extended.  That note is no longer valid since we've
 	 just removed the extension.  Just wipe the notes.  */
-      remove_reg_equal_equiv_notes (insn, true);
+      remove_reg_equal_equiv_notes (insn, false);
     }
   else
     {