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[PATCH] Fix PR66894
- From: Richard Biener <rguenther at suse dot de>
- To: gcc-patches at gcc dot gnu dot org
- Date: Thu, 16 Jul 2015 13:25:24 +0200 (CEST)
- Subject: [PATCH] Fix PR66894
- Authentication-results: sourceware.org; auth=none
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied.
Richard.
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.
Index: gcc/tree-vrp.c
===================================================================
--- gcc/tree-vrp.c (revision 225860)
+++ gcc/tree-vrp.c (working copy)
@@ -5382,13 +5382,11 @@ register_edge_assert_for_2 (tree name, e
}
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);
}
Index: gcc/testsuite/gcc.dg/torture/pr66894.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/pr66894.c (revision 0)
+++ gcc/testsuite/gcc.dg/torture/pr66894.c (working copy)
@@ -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;
+}