From: jakub <jakub@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Mon, 30 Sep 2013 20:15:20 +0000 (+0000)
Subject: 	PR middle-end/58564
X-Git-Tag: upstream/4.9.2~3991
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=c60fcb502eb64f4d8888d13f236d4c6da5d79e2a;p=platform%2Fupstream%2Flinaro-gcc.git

	PR middle-end/58564
	* fold-const.c (fold_ternary_loc): For A < 0 : <sign bit of A> : 0
	optimization, punt if sign_bit_p looked through any zero extension.

	* gcc.c-torture/execute/pr58564.c: New test.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@203042 138bc75d-0d04-0410-961f-82ee72b054a4
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ee3e01e..29c8d6b 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2013-09-30  Jakub Jelinek  <jakub@redhat.com>
+
+	PR middle-end/58564
+	* fold-const.c (fold_ternary_loc): For A < 0 : <sign bit of A> : 0
+	optimization, punt if sign_bit_p looked through any zero extension.
+
 2013-09-30  Teresa Johnson  <tejohnson@google.com>
 
 	* tree-ssa-threadupdate.c (ssa_fix_duplicate_block_edges):
diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 72a43e0..f68fd8b 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -14196,14 +14196,29 @@ fold_ternary_loc (location_t loc, enum tree_code code, tree type,
 	  && integer_zerop (op2)
 	  && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
 	{
+	  /* sign_bit_p looks through both zero and sign extensions,
+	     but for this optimization only sign extensions are
+	     usable.  */
+	  tree tem2 = TREE_OPERAND (arg0, 0);
+	  while (tem != tem2)
+	    {
+	      if (TREE_CODE (tem2) != NOP_EXPR
+		  || TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (tem2, 0))))
+		{
+		  tem = NULL_TREE;
+		  break;
+		}
+	      tem2 = TREE_OPERAND (tem2, 0);
+	    }
 	  /* sign_bit_p only checks ARG1 bits within A's precision.
 	     If <sign bit of A> has wider type than A, bits outside
 	     of A's precision in <sign bit of A> need to be checked.
 	     If they are all 0, this optimization needs to be done
 	     in unsigned A's type, if they are all 1 in signed A's type,
 	     otherwise this can't be done.  */
-	  if (TYPE_PRECISION (TREE_TYPE (tem))
-	      < TYPE_PRECISION (TREE_TYPE (arg1))
+	  if (tem
+	      && TYPE_PRECISION (TREE_TYPE (tem))
+		 < TYPE_PRECISION (TREE_TYPE (arg1))
 	      && TYPE_PRECISION (TREE_TYPE (tem))
 		 < TYPE_PRECISION (type))
 	    {
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 9814774..3b22081 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,9 +1,13 @@
+2013-09-30  Jakub Jelinek  <jakub@redhat.com>
+
+	PR middle-end/58564
+	* gcc.c-torture/execute/pr58564.c: New test.
+
 2013-09-30  Teresa Johnson  <tejohnson@google.com>
 
 	* testsuite/gcc.dg/tree-ssa/ssa-dom-thread-3.c (expand_one_var):
 	Update for additional dump message.
 
-
 2013-09-30  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/58554
diff --git a/gcc/testsuite/gcc.c-torture/execute/pr58564.c b/gcc/testsuite/gcc.c-torture/execute/pr58564.c
new file mode 100644
index 0000000..967ee95
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr58564.c
@@ -0,0 +1,14 @@
+/* PR middle-end/58564 */
+
+extern void abort (void);
+int a, b;
+short *c, **d = &c;
+
+int
+main ()
+{
+  b = (0, 0 > ((&c == d) & (1 && (a ^ 1)))) | 0U;
+  if (b != 0)
+    abort ();
+  return 0;
+}