Date: Tue, 4 Jun 2002 11:16:44 +1000 (EST) From: Bruce Evans <bde@zeta.org.au> To: current@FreeBSD.ORG Cc: obrien@FreeBSD.ORG Subject: Re: memset() broken in gcc-3.1 on i386's Message-ID: <20020604110707.H1982-100000@gamplex.bde.org> In-Reply-To: <20020604084202.Q939-100000@gamplex.bde.org>
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On Tue, 4 Jun 2002, I wrote:
> gcc now generates inline code for memset in some cases. Broken code.
Actually, it only generates inline code for memset in a few more cases,
and the case of a non-constant length is broken (and some cases of
constant lengths are pessimized (e.g., length 7)).
> ...
> This broke newfs (newfs left some garbage in a bitmap).
Actually, it broke fsck_ffs.
Workaround to avoid the known broken case:
%%%
Index: builtins.c
===================================================================
RCS file: /home/ncvs/src/contrib/gcc/builtins.c,v
retrieving revision 1.1.1.3
diff -u -2 -r1.1.1.3 builtins.c
--- builtins.c 13 May 2002 03:35:47 -0000 1.1.1.3
+++ builtins.c 4 Jun 2002 00:53:22 -0000
@@ -2195,4 +2195,9 @@
len_rtx = expand_expr (len, NULL_RTX, VOIDmode, 0);
+ /* Give up for non-constant lengths. They are broken on at least
+ i386's. */
+ if (GET_CODE (len_rtx) != CONST_INT)
+ return 0;
+
dest_mem = get_memory_rtx (dest);
set_mem_align (dest_mem, dest_align);
%%%
Bruce
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