re PR tree-optimization/55052 (vect-widening tests are failing and giving wrong results)

gcc/
	PR rtl-optimization/55052
	* simplify-rtx.c (simplify_subreg): Restore SCALAR_INT_MODE_P check.

From-SVN: r193909

gcc/ChangeLog

+2012-11-28  Richard Sandiford  <rdsandiford@googlemail.com>
+
+	PR rtl-optimization/55052
+	* simplify-rtx.c (simplify_subreg): Restore SCALAR_INT_MODE_P check.
+
 2012-11-28  David Edelsohn  <dje.gcc@gmail.com>
 
 	* target.def (use_blocks_for_decl_p): New hook.

gcc/simplify-rtx.c

@@ -5875,7 +5875,7 @@ simplify_subreg (enum machine_mode outermode, rtx op,
 
   /* A SUBREG resulting from a zero extension may fold to zero if
      it extracts higher bits that the ZERO_EXTEND's source bits.  */
-  if (GET_CODE (op) == ZERO_EXTEND)
+  if (GET_CODE (op) == ZERO_EXTEND && SCALAR_INT_MODE_P (innermode))
     {
       unsigned int bitpos = subreg_lsb_1 (outermode, innermode, byte);
       if (bitpos >= GET_MODE_PRECISION (GET_MODE (XEXP (op, 0))))