regmove.c (regmove_optimize): Use lowpart_subreg instead of gen_rtx_SUBREG with…

regmove.c (regmove_optimize): Use lowpart_subreg instead of gen_rtx_SUBREG with incorrect offset to compute...

	* regmove.c (regmove_optimize): Use lowpart_subreg instead of
	gen_rtx_SUBREG with incorrect offset to compute SRC_SUBREG.

From-SVN: r90762

gcc/ChangeLog

+2004-11-16  Ulrich Weigand  <uweigand@de.ibm.com>
+
+	* regmove.c (regmove_optimize): Use lowpart_subreg instead of
+	gen_rtx_SUBREG with incorrect offset to compute SRC_SUBREG.
+
 2004-11-16  Devang Patel  <dpatel@apple.com>
 
 	* tree-if-conv.c (clean_predicate_lists): Update gcc_assert check.

gcc/regmove.c

@@ -1150,10 +1150,11 @@ regmove_optimize (rtx f, int nregs, FILE *regmove_dump_file)
 		  && GET_MODE_SIZE (GET_MODE (dst))
 		     >= GET_MODE_SIZE (GET_MODE (SUBREG_REG (dst))))
 		{
-		  src_subreg
-		    = gen_rtx_SUBREG (GET_MODE (SUBREG_REG (dst)),
-				      src, SUBREG_BYTE (dst));
 		  dst = SUBREG_REG (dst);
+		  src_subreg = lowpart_subreg (GET_MODE (dst),
+					       src, GET_MODE (src));
+		  if (!src_subreg)
+		    continue;
 		}
 	      if (!REG_P (dst)
 		  || REGNO (dst) < FIRST_PSEUDO_REGISTER)