re PR tree-optimization/37207 (ice at tree-ssa-ifcombine.c:222 for -Os)

2008-08-29  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/37207
	* tree-vrp.c (extract_range_from_binary_expr): Also try
	to constant fold if only one of the operands is a constant.

	* gcc.dg/tree-ssa/vrp46.c: New testcase.

From-SVN: r139754

gcc/ChangeLog

+2008-08-29  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/37207
+	* tree-vrp.c (extract_range_from_binary_expr): Also try
+	to constant fold if only one of the operands is a constant.
+
 2008-08-29  Nick Clifton  <nickc@redhat.com>
 
 	* config/m32r/m32r.h (LEGITIMATE_CONSTANT_P): Treat LABEL_REFs in

gcc/testsuite/ChangeLog

+2008-08-29  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/37207
+	* gcc.dg/tree-ssa/vrp46.c: New testcase.
+
 2008-08-28  Adam Nemet  <anemet@caviumnetworks.com>
 
 	* gcc.target/mips/octeon-bbit-1.c: New test.

gcc/testsuite/gcc.dg/tree-ssa/vrp46.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-vrp1" } */
+
+void
+func_18 ( int t )
+{
+  unsigned l_889;
+  int l_895 = 1;
+  for (0; 1; ++l_889)
+    {
+      int t1 = 0;
+      if (func_81 (1))
+	{
+	  int rhs = l_895;
+	  if (rhs == 0)
+	    rhs = 1;
+	  if (1 & (t % rhs))
+	    t1 = 1;
+	}
+      func_98 (t1);
+      l_895 = 0;
+    }
+}
+
+/* There should be a single if left.  */
+
+/* { dg-final { scan-tree-dump-times "if" 1 "vrp1" } } */
+/* { dg-final { cleanup-tree-dump "vrp1" } } */

gcc/tree-vrp.c

@@ -2058,10 +2058,13 @@ extract_range_from_binary_expr (value_range_t *vr,
       && code != TRUTH_OR_EXPR)
     {
       /* We can still do constant propagation here.  */
-      if ((op0 = op_with_constant_singleton_value_range (op0)) != NULL_TREE
-	  && (op1 = op_with_constant_singleton_value_range (op1)) != NULL_TREE)
+      tree const_op0 = op_with_constant_singleton_value_range (op0);
+      tree const_op1 = op_with_constant_singleton_value_range (op1);
+      if (const_op0 || const_op1)
 	{
-	  tree tem = fold_binary (code, expr_type, op0, op1);
+	  tree tem = fold_binary (code, expr_type,
+				  const_op0 ? const_op0 : op0,
+				  const_op1 ? const_op1 : op1);
 	  if (tem
 	      && is_gimple_min_invariant (tem)
 	      && !is_overflow_infinity (tem))