re PR tree-optimization/24653 (EON regressed seriously on x86-64)

	PR tree-optimization/24653
	* tree-ssa-ccp.c (ccp_fold): Strip down useless conversions.

From-SVN: r107304

gcc/ChangeLog

+2005-11-21  Jan Hubicka  <jh@suse.cz>
+
+	PR tree-optimization/24653
+	* tree-ssa-ccp.c (ccp_fold): Strip down useless conversions.
+
 2005-11-21  Uros Bizjak  <uros@kss-loka.si>
 
 	* config/i386/predicates.md (ax_reg_operand): New predicate.

gcc/tree-ssa-ccp.c

@@ -879,6 +879,10 @@ ccp_fold (tree stmt)
 	    op0 = get_value (op0, true)->value;
 	}
 
+      if ((code == NOP_EXPR || code == CONVERT_EXPR)
+	  && tree_ssa_useless_type_conversion_1 (TREE_TYPE (rhs),
+		  				 TREE_TYPE (op0)))
+	return op0;
       return fold_unary (code, TREE_TYPE (rhs), op0);
     }