From: Richard Biener <rguenther@suse.de>
Date: Tue, 2 Dec 2014 09:03:44 +0000 (+0000)
Subject: match.pd: Restrict division combining to trunc_div and exact_div.
X-Git-Tag: releases/gcc-5.1.0~2678
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=280931058a2f5beb7cebef0d5a0a6491c182cfb4;p=thirdparty%2Fgcc.git

match.pd: Restrict division combining to trunc_div and exact_div.

2014-12-02  Richard Biener  <rguenther@suse.de>

	* match.pd: Restrict division combining to trunc_div and
	exact_div.

From-SVN: r218260
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 8924c7aa95ee..aed08f432991 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2014-12-02  Richard Biener  <rguenther@suse.de>
+
+	* match.pd: Restrict division combining to trunc_div and
+	exact_div.
+
 2014-12-02  Jakub Jelinek  <jakub@redhat.com>
 
 	* config/sparc/sparc.c (sparc_atomic_assign_expand_fenv):
diff --git a/gcc/match.pd b/gcc/match.pd
index ee9bbc65fafe..b36aa2fe76a3 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -129,8 +129,9 @@ along with GCC; see the file COPYING3.  If not see
       && TYPE_UNSIGNED (type))
   (trunc_div @0 @1)))
 
-/* Combine two successive divisions.  */
-(for div (trunc_div ceil_div floor_div round_div exact_div)
+/* Combine two successive divisions.  Note that combining ceil_div
+   and floor_div is trickier and combining round_div even more so.  */
+(for div (trunc_div exact_div)
  (simplify
   (div (div @0 INTEGER_CST@1) INTEGER_CST@2)
   (with {