From: amker <amker@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Thu, 21 Apr 2016 11:28:58 +0000 (+0000)
Subject: 	PR tree-optimization/70715
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=7434c6fb45d300df145187c78ca4271fccfb9c0b;p=thirdparty%2Fgcc.git

	PR tree-optimization/70715
	* tree-ssa-loop-niter.c (loop_exits_before_overflow): Check equality
	after expanding BASE using expand_simple_operations.

	gcc/testsuite/ChangeLog
	PR tree-optimization/70715
	* gcc.dg/tree-ssa/scev-13.c: New test.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@235333 138bc75d-0d04-0410-961f-82ee72b054a4
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 86bee074b69f..a3412c900298 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2016-04-21  Bin Cheng  <bin.cheng@arm.com>
+
+	PR tree-optimization/70715
+	* tree-ssa-loop-niter.c (loop_exits_before_overflow): Check equality
+	after expanding BASE using expand_simple_operations.
+
 2016-04-21  Marc Glisse  <marc.glisse@inria.fr>
 
 	* match.pd (min(-x, -y), max(-x, -y), min(~x, ~y), max(~x, ~y)):
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 08f70405c52e..7a17aa2ebb63 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2016-04-21  Bin Cheng  <bin.cheng@arm.com>
+
+	PR tree-optimization/70715
+	* gcc.dg/tree-ssa/scev-13.c: New test.
+
 2016-04-21  Marc Glisse  <marc.glisse@inria.fr>
 
 	* gcc.dg/tree-ssa/minmax-2.c: New testcase.
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/scev-13.c b/gcc/testsuite/gcc.dg/tree-ssa/scev-13.c
new file mode 100644
index 000000000000..b9223c80e7b8
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/scev-13.c
@@ -0,0 +1,15 @@
+/* { dg-do compile } */
+/* { dg-options "-O3 -fdump-tree-ldist" } */
+
+int
+foo (char *p, unsigned n)
+{
+  while(n--)
+    {
+      p[n]='A';
+    }
+  return 0;
+}
+
+/* Loop can be transformed into builtin memset since &p[n] is SCEV.  */
+/* { dg-final { scan-tree-dump "builtin_memset" "ldist" } } */
diff --git a/gcc/tree-ssa-loop-niter.c b/gcc/tree-ssa-loop-niter.c
index 81689fc1aa43..c61083e7fd3e 100644
--- a/gcc/tree-ssa-loop-niter.c
+++ b/gcc/tree-ssa-loop-niter.c
@@ -4141,7 +4141,11 @@ loop_exits_before_overflow (tree base, tree step,
 	    continue;
 
 	  /* Done proving if this is a no-overflow control IV.  */
-	  if (operand_equal_p (base, civ->base, 0))
+	  if (operand_equal_p (base, civ->base, 0)
+	      /* Control IV is recorded after expanding simple operations,
+		 Here we compare it against expanded base too.  */
+	      || operand_equal_p (expand_simple_operations (base),
+				  civ->base, 0))
 	    return true;
 
 	  /* If this is a before stepping control IV, in other words, we have