Fix PR43306: correct evolution_function_right_is_integer_cst.

2010-03-09  Sebastian Pop  <sebastian.pop@amd.com>

	PR middle-end/43306
	* tree-chrec.c (evolution_function_right_is_integer_cst): CHREC_RIGHT
	should be an INTEGER_CST.  Also handle CASE_CONVERT.
	* gcc.dg/graphite/pr43306.c: New.

From-SVN: r157434

gcc/ChangeLog.graphite

 2010-03-09  Sebastian Pop  <sebastian.pop@amd.com>
 
+	PR middle-end/43306
+	* tree-chrec.c (evolution_function_right_is_integer_cst): CHREC_RIGHT
+	should be an INTEGER_CST.  Also handle CASE_CONVERT.
+	* gcc.dg/graphite/pr43306.c: New.
+
+2010-03-09  Sebastian Pop  <sebastian.pop@amd.com>
+
 	* graphite.c (graphite_initialize): To bound the number of bbs per
 	function, use PARAM_GRAPHITE_MAX_BBS_PER_FUNCTION.
 	* params.def (PARAM_GRAPHITE_MAX_BBS_PER_FUNCTION): Declared.

gcc/testsuite/gcc.dg/graphite/pr43306.c

+/* { dg-options "-O1 -fstrict-overflow -fgraphite-identity" } */
+
+void foo(int x[])
+{
+  int i, j;
+  for (i = 0; i < 2; i++)
+    for (j = 0; j < 2; j++)
+      x[i] = x[i*j];
+}

gcc/tree-chrec.c

@@ -1529,14 +1529,12 @@ evolution_function_right_is_integer_cst (const_tree chrec)
       return true;
 
     case POLYNOMIAL_CHREC:
-      if (!evolution_function_right_is_integer_cst (CHREC_RIGHT (chrec)))
-	return false;
-
-      if (TREE_CODE (CHREC_LEFT (chrec)) == POLYNOMIAL_CHREC
-	&& !evolution_function_right_is_integer_cst (CHREC_LEFT (chrec)))
-	return false;
+      return TREE_CODE (CHREC_RIGHT (chrec)) == INTEGER_CST
+	&& (TREE_CODE (CHREC_LEFT (chrec)) != POLYNOMIAL_CHREC
+	    || evolution_function_right_is_integer_cst (CHREC_LEFT (chrec)));
 
-      return true;
+    CASE_CONVERT:
+      return evolution_function_right_is_integer_cst (TREE_OPERAND (chrec, 0));
 
     default:
       return false;