From: Richard Biener <rguenther@suse.de>
Date: Thu, 11 Feb 2016 08:11:52 +0000 (+0000)
Subject: re PR rtl-optimization/69291 (wrong code at -O1 for ruby-2.3.0/regcomp.c:985:compile_... 
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=f167cf54a1a6a7deb5d834cf4703a8a7f221f4e0;p=gcc.git

re PR rtl-optimization/69291 (wrong code at -O1 for ruby-2.3.0/regcomp.c:985:compile_length_quantifier_node())

2016-02-11  Richard Biener  <rguenther@suse.de>

	PR rtl-optimization/69291
	* ifcvt.c (noce_try_store_flag_constants): Do not allow
	subexpressions affected by changing the result.

From-SVN: r233316
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index b4495d868c2..6037782465c 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2016-02-11  Richard Biener  <rguenther@suse.de>
+
+	PR rtl-optimization/69291
+	* ifcvt.c (noce_try_store_flag_constants): Do not allow
+	subexpressions affected by changing the result.
+
 2016-02-10  Vladimir Makarov  <vmakarov@redhat.com>
 
 	PR target/69148
diff --git a/gcc/ifcvt.c b/gcc/ifcvt.c
index a50e33dc66c..205590938a5 100644
--- a/gcc/ifcvt.c
+++ b/gcc/ifcvt.c
@@ -1274,7 +1274,10 @@ noce_try_store_flag_constants (struct noce_if_info *if_info)
       && CONST_INT_P (XEXP (a, 1))
       && CONST_INT_P (XEXP (b, 1))
       && rtx_equal_p (XEXP (a, 0), XEXP (b, 0))
-      && noce_operand_ok (XEXP (a, 0))
+      /* Allow expressions that are not using the result or plain
+         registers where we handle overlap below.  */
+      && (REG_P (XEXP (a, 0))
+	  || ! reg_overlap_mentioned_p (if_info->x, XEXP (a, 0)))
       && if_info->branch_cost >= 2)
     {
       common = XEXP (a, 0);