combine.c (combine_simplify_rtx): Generate a new shift operation when…

combine.c (combine_simplify_rtx): Generate a new shift operation when simplifying the first operand of a (neg...


	* combine.c (combine_simplify_rtx): Generate a new shift operation
	when simplifying the first operand of a (neg (ashift)) expression.

From-SVN: r44202

gcc/ChangeLog

+2001-07-20  Diego Novillo  <dnovillo@redhat.com>
+
+	* combine.c (combine_simplify_rtx): Generate a new shift operation
+	when simplifying the first operand of a (neg (ashift)) expression.
+
 2001-07-20  Roman Lechtchinsky  <rl@cs.tu-berlin.de>
 
 	* regclass.c (N_REG_INTS): Use only 32 bits per element.

gcc/combine.c

@@ -3921,10 +3921,7 @@ combine_simplify_rtx (x, op0_mode, last, in_dest)
 	  temp = simplify_unary_operation (NEG, mode,
 					   XEXP (XEXP (x, 0), 0), mode);
 	  if (temp)
-	    {
-	      SUBST (XEXP (XEXP (x, 0), 0), temp);
-	      return XEXP (x, 0);
-	    }
+	    return gen_binary (ASHIFT, mode, temp, XEXP (XEXP (x, 0), 1));
 	}
 
       temp = expand_compound_operation (XEXP (x, 0));