[PATCH] Fix PR28045

[Richard Guenther]

This fixes PR28045, a bug in operand_equal_p that thinks that
(long)a.val == a.val, which in turn causes fold_range_test to emit
wrong code.

Bootstrapped and tested on x86_64-unknown-linux-gnu.

Ok for mainline and branches?

Thanks,
Richard.

:ADDPATCH middle-end:

2006-06-18  Richard Guenther  <rguenther@suse.de>

	PR middle-end/28045
	* fold-const.c (operand_equal_p): Check if the argument types
	have the same precision before stripping NOPs.

	* gcc.dg/torture/pr28045.c: New testcase.

Index: fold-const.c
===================================================================
*** fold-const.c	(revision 114755)
--- fold-const.c	(working copy)
*************** operand_equal_p (tree arg0, tree arg1, u
*** 2497,2502 ****
--- 2497,2507 ----
    if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1)))
      return 0;
  
+   /* If both types don't have the same precision, then it is not safe
+      to strip NOPs.  */
+   if (TYPE_PRECISION (TREE_TYPE (arg0)) != TYPE_PRECISION (TREE_TYPE (arg1)))
+     return 0;
+ 
    STRIP_NOPS (arg0);
    STRIP_NOPS (arg1);
  


/* { dg-do run } */

extern void abort(void);
struct a
{
   unsigned int bits : 1;
   signed long val : ((sizeof(long) * 8) - 1);
};
int Fnegate (struct a b)
{
  if ((-((long)b.val)) <= ((long) ((1UL << ((sizeof(long) * 8) - 2)) -1UL))
      && (-((long)b.val)) >= (-(((long) ((1UL << ((sizeof(long) * 8) - 2)) -1UL))) - 1))
     return 0 ;
  abort ();
}
int main ()
{
  struct a b = {1, 1};
  Fnegate (b);
  return 0;
}