Mail Archives: cygwin/2005/06/11/10:57:14
On Jun 10 20:57, David Rothenberger wrote:
> rsync has started reported negative statistics with the 20050610
> snapshot and a DLL I built from CVS HEAD today using gcc 3.4.4 and the
> latest gcc-mingw release. Interestingly (to me, at least), it works
> correctly with CVS HEAD built today using gcc 3.3.3 and the previous
> gcc-mingw release.
>
> Here's a test case.
>
> % mkdir /tmp/{a,b}
> % date > /tmp/a/x
> % rsync -v --stats /tmp/a/x /tmp/b
> x
>
> Number of files: 1
> Number of files transferred: 1
> Total file size: -29 bytes
> Total transferred file size: -29 bytes
> Literal data: -29 bytes
> Matched data: -0 bytes
> File list size: 20
> Total bytes sent: -105
> Total bytes received: -40
I found this to be a problem in gcc 3.4.x's -funit-at-a-time optimization.
I've also the vague feeling we already discussed this problem when Gerrit
released the first 3.4 based gcc for testing.
I'm far from being a gcc expert, but I recall that we had similar problem
once internally and switching off -funit-at-a-time optimization solved the
problem for us. This was with some 3.4 derived gcc, but I don't know the
exact version number. Anyway, switching off -funit-at-a-time when building
newlib also solves the above rsync problem.
Gerrit, could you please follow up on this? It seems the simplest way is
to just switch off -funit-at-a-time for the -O2 optimization. This is the
patch we applied internally, if that's of any help for you:
Index: gcc/opts.c
===================================================================
RCS file: /cvs/cvsfiles/gcc/opts.c,v
retrieving revision 1.3
diff -c -3 -p -r1.3 opts.c
*** gcc/opts.c 16 Mar 2004 01:43:58 -0000 1.3
--- gcc/opts.c 23 Jul 2004 14:03:41 -0000
*************** decode_options (unsigned int argc, const
*** 564,570 ****
flag_delete_null_pointer_checks = 1;
flag_reorder_blocks = 1;
flag_reorder_functions = 1;
- flag_unit_at_a_time = 1;
}
if (optimize >= 3)
--- 564,569 ----
Otherwise, do you know by any chance, if there exists some fix for that
problem? The above kludge is almost a year old, so there's a chance
that somebody already found the fix.
Corinna
--
Corinna Vinschen Please, send mails regarding Cygwin to
Cygwin Project Co-Leader mailto:cygwin AT cygwin DOT com
Red Hat, Inc.
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