re PR tree-optimization/21088 (VRP passes fold the type of operands of a comparison)

	PR tree-optimization/21088
	* fold-const.c (fold_unary, fold_binary, fold_ternary):
	Export.
	* tree-vrp.c (compare_values): Use fold_binary to compare
	pointers.  Use boolean_type_node as the type of a comparison
	expression being folded.
	* tree.h: Add prototypes for fold_unary, fold_binary,
	fold_ternary.

From-SVN: r98600

gcc/ChangeLog

+2005-04-23  Kazu Hirata  <kazu@cs.umass.edu>
+
+	PR tree-optimization/21088
+	* fold-const.c (fold_unary, fold_binary, fold_ternary):
+	Export.
+	* tree-vrp.c (compare_values): Use fold_binary to compare
+	pointers.  Use boolean_type_node as the type of a comparison
+	expression being folded.
+	* tree.h: Add prototypes for fold_unary, fold_binary,
+	fold_ternary.
+
 2005-04-22  Diego Novillo  <dnovillo@redhat.com>
 
 	* Makefile.in (tree-into-ssa.o): Add dependency on PARAMS_H.

gcc/fold-const.c

@@ -6678,7 +6678,7 @@ fold_complex_div (tree type, tree ac, tree bc, enum tree_code code)
    OP0.  Return the folded expression if folding is successful.
    Otherwise, return NULL_TREE.  */
 
-static tree
+tree
 fold_unary (enum tree_code code, tree type, tree op0)
 {
   tree tem;
@@ -7113,7 +7113,7 @@ fold_unary (enum tree_code code, tree type, tree op0)
    OP0 and OP1.  Return the folded expression if folding is
    successful.  Otherwise, return NULL_TREE.  */
 
-static tree
+tree
 fold_binary (enum tree_code code, tree type, tree op0, tree op1)
 {
   tree t1 = NULL_TREE;
@@ -9852,7 +9852,7 @@ fold_binary (enum tree_code code, tree type, tree op0, tree op1)
    OP0, OP1, and OP2.  Return the folded expression if folding is
    successful.  Otherwise, return NULL_TREE.  */
 
-static tree
+tree
 fold_ternary (enum tree_code code, tree type, tree op0, tree op1, tree op2)
 {
   tree tem;

gcc/tree-vrp.c

@@ -416,17 +416,17 @@ compare_values (tree val1, tree val2)
 	return 0;
       
       /* If VAL1 is a lower address than VAL2, return -1.  */
-      t = fold (build2 (LT_EXPR, TREE_TYPE (val1), val1, val2));
+      t = fold_binary (LT_EXPR, boolean_type_node, val1, val2);
       if (t == boolean_true_node)
 	return -1;
 
       /* If VAL1 is a higher address than VAL2, return +1.  */
-      t = fold (build2 (GT_EXPR, TREE_TYPE (val1), val1, val2));
+      t = fold_binary (GT_EXPR, boolean_type_node, val1, val2);
       if (t == boolean_true_node)
 	return 1;
 
       /* If VAL1 is different than VAL2, return +2.  */
-      t = fold (build2 (NE_EXPR, TREE_TYPE (val1), val1, val2));
+      t = fold_binary (NE_EXPR, boolean_type_node, val1, val2);
       if (t == boolean_true_node)
 	return 2;
 

gcc/tree.h

@@ -3511,6 +3511,9 @@ extern void using_eh_for_cleanups (void);
    subexpressions are not changed.  */
 
 extern tree fold (tree);
+extern tree fold_unary (enum tree_code, tree, tree);
+extern tree fold_binary (enum tree_code, tree, tree, tree);
+extern tree fold_ternary (enum tree_code, tree, tree, tree, tree);
 extern tree fold_build1 (enum tree_code, tree, tree);
 extern tree fold_build2 (enum tree_code, tree, tree, tree);
 extern tree fold_build3 (enum tree_code, tree, tree, tree, tree);