Manuel Bouyer <bouyer@antioche.lip6.fr> writes:

 There is a special option, `-fno-builtin', that prevents gcc from
 recognizing and inlining of well known functions like `memcpy', `memcmp' and
 some other (math) functions. Plese consult `info gcc' for more information.

> On Wed, Jul 04, 2001 at 10:03:23AM +0900, minoura@netbsd.org wrote:
> > 
> > >Number:         13369
> > >Category:       kern
> > >Synopsis:       gcc inlines memcpy(3)
> > >Confidential:   no
> > >Severity:       serious
> > >Priority:       high
> > >Responsible:    kern-bug-people
> > >State:          open
> > >Class:          sw-bug
> > >Submitter-Id:   net
> > >Arrival-Date:   Tue Jul 03 18:01:00 PDT 2001
> > >Closed-Date:
> > >Last-Modified:
> > >Originator:     Minoura Makoto
> > >Release:        20010612
> > >Organization:
> > Minoura Makoto <minoura@netbsd.org>
> > The NetBSD Project/Japan NetBSD Users' Group
> > >Environment:
> > System: NetBSD daisy 1.5W NetBSD 1.5W (DAISY) #190: Mon Jun 25 14:28:07 JST 2001 root@daisy:/usr/obj/sys/arch/i386/compile/DAISY i386
> > gcc version egcs-2.91.66 19990314 (egcs-1.1.2 release)
> > Architecture: i386
> > Machine: i386
> > >Description:
> > 	gcc -O inlines the following memcpy(3) call (at least on i386):
> > 
> > #include <string.h>
> > 
> > extern char buf[];
> > 
> > void testfunc(char *src)
> > {
> > 	memcpy(buf, src, 100);
> > }
> > 
> > 	The inlined memcpy() gets insane when the two buffers are
> > 	overlapping.
> > 
> > 	On the other hand, kernel bcopy() is #define'ed as memcpy() in
> > 	/sys/sys/systm.h.
> > 
> > 	This might cause a problem that when the programmer
> > 	wants to transfer overlapping strings using bcopy()
> > 	they might be destroyed as a result.
> 
> Shouldn't we just replace calls to bcopy with memmove or memcpy, as 
> appropriate ?
> 
> --
> Manuel Bouyer <bouyer@antioche.eu.org>
> --

-- 
        -- Oleg Polianski <Oleg.Polianski@clear.co.nz>