From: Doug Evans <dje@gnu.org>
Date: Thu, 3 Feb 1994 22:14:46 +0000 (+0000)
Subject: (store_bit_field, insv case): Don't use PUT_MODE on
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=bac7cdfd7d0dfa7d9bb7065faf11882cc1922821;p=gcc.git

(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 09e51adf23d..ccf130e5672 100644
--- 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);