re PR middle-end/36817 (internal compiler error: in compare_values_warnv)

2008-08-21  Richard Guenther  <rguenther@suse.de>

	PR middle-end/36817
	* tree-chrec.c (chrec_apply): Always call chrec_fold_plus which
	makes sure to produce a result of the correct type.

	* gcc.c-torture/compile/pr36817.c: New testcase.

From-SVN: r139385

gcc/ChangeLog

+2008-08-21  Richard Guenther  <rguenther@suse.de>
+
+	PR middle-end/36817
+	* tree-chrec.c (chrec_apply): Always call chrec_fold_plus which
+	makes sure to produce a result of the correct type.
+
 2008-08-21  Jan Hubicka  <jh@suse.cz>
 	Backport from LTO branch:
 

gcc/testsuite/ChangeLog

 2008-08-21  Richard Guenther  <rguenther@suse.de>
 
+	PR middle-end/36817
+	* gcc.c-torture/compile/pr36817.c: New testcase.
+
+2008-08-21  Richard Guenther  <rguenther@suse.de>
+
 	* gcc.dg/tree-ssa/ssa-fre-13.c: Remove XFAIL.
 	* gcc.dg/tree-ssa/ssa-fre-14.c: Likewise.
 	* gcc.dg/tree-ssa/ssa-fre-17.c: Likewise.

gcc/testsuite/gcc.c-torture/compile/pr36817.c

+void xxx()
+{
+  unsigned i;
+  unsigned *p=0;
+  for(i=0; i<4; ++i)
+    *p++=0;
+  for(i=0; i<4; ++i)
+    *p++=0;
+}
+

gcc/tree-chrec.c

@@ -579,7 +579,6 @@ chrec_apply (unsigned var,
       /* "{a, +, b} (x)"  ->  "a + b*x".  */
       x = chrec_convert_rhs (type, x, NULL);
       res = chrec_fold_multiply (TREE_TYPE (x), CHREC_RIGHT (chrec), x);
-      if (!integer_zerop (CHREC_LEFT (chrec)))
       res = chrec_fold_plus (type, CHREC_LEFT (chrec), res);
     }