(optimize_bit_field): Don't remove a SUBREG that changes mode class.

From-SVN: r8744

diff --git a/gcc/function.c b/gcc/function.c
index 884cca70ff209bf5eb7116571a61fd7e4f82ab20..73f59dab4e78c3556ec86f1534105e16f5c9312f 100644 (file)
--- a/gcc/function.c
+++ b/gcc/function.c
@@ -1,5 +1,5 @@
 /* Expands front end tree to back end RTL for GNU C-Compiler
-   Copyright (C) 1987, 88, 89, 91, 92, 93, 1994 Free Software Foundation, Inc.
+   Copyright (C) 1987, 88, 89, 91-94, 1995 Free Software Foundation, Inc.
 
 This file is part of GNU CC.
 
@@ -2318,7 +2318,9 @@ optimize_bit_field (body, insn, equiv_mem)
              rtx dest = SET_DEST (body);
 
              while (GET_CODE (dest) == SUBREG
-                    && SUBREG_WORD (dest) == 0)
+                    && SUBREG_WORD (dest) == 0
+                    && (GET_MODE_CLASS (GET_MODE (dest))
+                        == GET_MODE_CLASS (GET_MODE (SUBREG_REG (dest)))))
                dest = SUBREG_REG (dest);
 
              validate_change (insn, &SET_DEST (body), dest, 1);