[committed]

[James Morrison]

 Hi,

  I bootstrapped and regtested again this patch that.  Diego approved 
this patch a while ago for 4.2.  It is now commited to mainline as r107243.

Jim

2005-08-02  James A. Morrison  <phython@gcc.gnu.org>

	* tree-vrp.c (compare_ranges): Return false for EQ_EXPR if VR0 is less
	than VR1 or vice-versa.

Index: tree-vrp.c
===================================================================
RCS file: /cvsroot/gcc/gcc/gcc/tree-vrp.c,v
retrieving revision 2.47
diff -u -p -r2.47 tree-vrp.c
--- tree-vrp.c	29 Jul 2005 15:21:54 -0000	2.47
+++ tree-vrp.c	30 Jul 2005 18:10:26 -0000
@@ -1677,6 +1710,10 @@ compare_ranges (enum tree_code comp, val
 	  else if (cmp_min != -2 && cmp_max != -2)
 	    return boolean_false_node;
 	}
+      /* If [V0_MIN, V1_MAX] < [V1_MIN, V1_MAX] then V0 != V1.  */
+      else if (compare_values (vr0->min, vr1->max) == 1
+	       || compare_values (vr1->min, vr0->max) == 1)
+	return boolean_false_node;
 
       return NULL_TREE;
     }