simplify-rtx.c (simplify_subreg): Use the correct mode when determining whether…

simplify-rtx.c (simplify_subreg): Use the correct mode when determining whether a SUBREG of a CONCAT refers to...


	* simplify-rtx.c (simplify_subreg): Use the correct mode when
	determining whether a SUBREG of a CONCAT refers to the first or
	second component.

From-SVN: r120101

gcc/ChangeLog

+2006-12-20  Roger Sayle  <roger@eyesopen.com>
+
+	* simplify-rtx.c (simplify_subreg): Use the correct mode when
+	determining whether a SUBREG of a CONCAT refers to the first or
+	second component.
+
 2006-12-21  Ben Elliston  <bje@au.ibm.com>
 
 	* config/spu/spu.c (spu_builtin_mul_widen_even): Remove unused

gcc/simplify-rtx.c

@@ -4648,13 +4648,22 @@ simplify_subreg (enum machine_mode outermode, rtx op,
      of real and imaginary part.  */
   if (GET_CODE (op) == CONCAT)
     {
-      unsigned int inner_size, final_offset;
+      unsigned int part_size, final_offset;
       rtx part, res;
 
-      inner_size = GET_MODE_UNIT_SIZE (innermode);
-      part = byte < inner_size ? XEXP (op, 0) : XEXP (op, 1);
-      final_offset = byte % inner_size;
-      if (final_offset + GET_MODE_SIZE (outermode) > inner_size)
+      part_size = GET_MODE_UNIT_SIZE (GET_MODE (XEXP (op, 0)));
+      if (byte < part_size)
+	{
+	  part = XEXP (op, 0);
+	  final_offset = byte;
+	}
+      else
+	{
+	  part = XEXP (op, 1);
+	  final_offset = byte - part_size;
+	}
+
+      if (final_offset + GET_MODE_SIZE (outermode) > part_size)
 	return NULL_RTX;
 
       res = simplify_subreg (outermode, part, GET_MODE (part), final_offset);