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 e945a28d26f8d3740f7e8b8a59731af9ec2639a9..1d5434c3bb9127e2725a450fa8d53b25a3c63993 100644 (file)
--- 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 8bc934129987b18a0076fdb0b8615b852484d33a..9bace80590df9647bb4fb6c7e2f0cfa1cb32ae1b 100644 (file)
--- 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 (file)
index 0000000..b544940
--- /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 795b02728aeac7c5709295a9310c1d86b047f81c..d96268314c4177c6adc35d6c51e97432db66a3f2 100644 (file)
--- 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);
            }