(store_bit_field, insv case): Don't use PUT_MODE on

xop0 when it is a SUBREG, generate a new SUBREG.

From-SVN: r6478

diff --git a/gcc/expmed.c b/gcc/expmed.c
index 09e51adf23d9bc178b23133e521398188b70411c..ccf130e5672ef48d3f869d8d49ed450a48e9d2bb 100644 (file)
--- a/gcc/expmed.c
+++ b/gcc/expmed.c
@@ -421,7 +421,9 @@ store_bit_field (str_rtx, bitsize, bitnum, fieldmode, value, align, total_size)
       /* If xop0 is a register, we need it in MAXMODE
         to make it acceptable to the format of insv.  */
       if (GET_CODE (xop0) == SUBREG)
-       PUT_MODE (xop0, maxmode);
+       /* We can't just change the mode, because this might clobber op0,
+          and we will need the original value of op0 if insv fails.  */
+       xop0 = gen_rtx (SUBREG, maxmode, SUBREG_REG (xop0), SUBREG_WORD (xop0));
       if (GET_CODE (xop0) == REG && GET_MODE (xop0) != maxmode)
        xop0 = gen_rtx (SUBREG, maxmode, xop0, 0);