re PR middle-end/23522 (fold_widened_comparison bug)

	PR middle-end/23522
	* fold-const.c (fold_widened_comparison): Do not allow range based
	constant folding when right operand cannot be unwidened.

Co-Authored-By: Ian Lance Taylor <ian@airs.com>

From-SVN: r105536

gcc/ChangeLog

+2005-10-17  Alexey Starovoytov  <alexey.starovoytov@sun.com>
+            Ian Lance Taylor <ian@airs.com>
+
+	PR middle-end/23522
+	* fold-const.c (fold_widened_comparison): Do not allow range based
+	constant folding when right operand cannot be unwidened.
+
 2005-10-17  Richard Henderson  <rth@redhat.com>
 
 	* builtins.c (expand_builtin_synchronize): Build a new-style asm

gcc/fold-const.c

@@ -6250,8 +6250,6 @@ fold_widened_comparison (enum tree_code code, tree type, tree arg0, tree arg1)
     return NULL_TREE;
 
   arg1_unw = get_unwidened (arg1, shorter_type);
-  if (!arg1_unw)
-    return NULL_TREE;
 
   /* If possible, express the comparison in the shorter mode.  */
   if ((code == EQ_EXPR || code == NE_EXPR
@@ -6264,7 +6262,9 @@ fold_widened_comparison (enum tree_code code, tree type, tree arg0, tree arg1)
     return fold_build2 (code, type, arg0_unw,
 		       fold_convert (shorter_type, arg1_unw));
 
-  if (TREE_CODE (arg1_unw) != INTEGER_CST)
+  if (TREE_CODE (arg1_unw) != INTEGER_CST
+      || TREE_CODE (shorter_type) != INTEGER_TYPE
+      || !int_fits_type_p (arg1_unw, shorter_type))
     return NULL_TREE;
 
   /* If we are comparing with the integer that does not fit into the range