From: rguenth <rguenth@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Thu, 16 Jul 2015 11:27:34 +0000 (+0000)
Subject: 2015-07-16  Richard Biener  <rguenther@suse.de>
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=e321bcecb143e2db91805771b79447991da5e7b8;p=thirdparty%2Fgcc.git

2015-07-16  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/66894
	* tree-vrp.c (register_edge_assert_for_2): Fix bad assumption
	about deriving NE_EXPR from truncated values.

	* gcc.dg/torture/pr66894.c: New testcase.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@225870 138bc75d-0d04-0410-961f-82ee72b054a4
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index e945a28d26f8..1d5434c3bb91 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2015-07-16  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/66894
+	* tree-vrp.c (register_edge_assert_for_2): Fix bad assumption
+	about deriving NE_EXPR from truncated values.
+
 2015-07-16  Martin Liska  <mliska@suse.cz>
 
 	* alloc-pool.h
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 8bc934129987..9bace80590df 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2015-07-16  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/66894
+	* gcc.dg/torture/pr66894.c: New testcase.
+
 2015-07-16  Richard Biener  <rguenther@suse.de>
 
 	* gcc.dg/tree-ssa/pr21031.c: Adjust.
diff --git a/gcc/testsuite/gcc.dg/torture/pr66894.c b/gcc/testsuite/gcc.dg/torture/pr66894.c
new file mode 100644
index 000000000000..b54494002b64
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr66894.c
@@ -0,0 +1,21 @@
+/* { dg-do run } */
+
+short a, b;
+
+int
+main ()
+{
+  for (; a != 1; a += 3)
+    {
+      int c = 0;
+      for (; c < 2; c++)
+	if (a)
+	  {
+	    char d = a;
+	    b = d ? 1 / d : 0; 
+	  }
+	else
+	  break;
+    }
+  return 0;
+}
diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index 795b02728aea..d96268314c41 100644
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -5382,13 +5382,11 @@ register_edge_assert_for_2 (tree name, edge e, gimple_stmt_iterator bsi,
 	    }
 	  else if (CONVERT_EXPR_CODE_P (code))
 	    {
-	      /* For truncating conversions require that the constant
-	         fits in the truncated type if we are going to record
+	      /* For truncating conversions we cannot record
 		 an inequality.  */
 	      if (comp_code == NE_EXPR
 		  && (TYPE_PRECISION (TREE_TYPE (name2))
-		      < TYPE_PRECISION (TREE_TYPE (name)))
-		  && ! int_fits_type_p (val, TREE_TYPE (name2)))
+		      < TYPE_PRECISION (TREE_TYPE (name))))
 		continue;
 	      cst = fold_convert (TREE_TYPE (name2), val);
 	    }