From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Stancek Date: Tue, 12 Apr 2016 09:39:37 -0400 (EDT) Subject: [LTP] Pre-release LTP build In-Reply-To: <20160412122307.GA2562@rei.suse.cz> References: <20160411172305.GC3466@rei.lan> <1944071328.394698.1460449773165.JavaMail.zimbra@redhat.com> <20160412084049.GA24915@rei.lan> <1180846583.442810.1460462279148.JavaMail.zimbra@redhat.com> <20160412122307.GA2562@rei.suse.cz> Message-ID: <1314010537.480730.1460468377766.JavaMail.zimbra@redhat.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ltp@lists.linux.it ----- Original Message ----- > From: "Cyril Hrubis" > To: "Jan Stancek" > Cc: ltp@lists.linux.it > Sent: Tuesday, 12 April, 2016 2:23:07 PM > Subject: Re: [LTP] Pre-release LTP build > > Hi! > > As for RHEL5.6 it's only i386. I was able to compile x86_64, ia64, > > ppc/ppc64 > > and s390/s390x with no changes. > > > > Any of these two allow it to compile on x86: > > 1. -march=i486 (or higher) > > 2. > > diff --git a/lib/tst_atomic.c b/lib/tst_atomic.c > > new file mode 100644 > > index 0000000..601fd6c > > --- /dev/null > > +++ b/lib/tst_atomic.c > > @@ -0,0 +1,8 @@ > > +#if defined(__i386__) > > +unsigned int __sync_add_and_fetch_4(unsigned int *v, unsigned value) > > +{ > > + register int val = value; > > + __asm__ __volatile__ ( "lock xadd %1,%0" : "=m" (*v), "=r" (val) : > > "1" (val) : "memory"); > > + return val + value; > > +} > > +#endif > > > > According to gcc docs it should only make external call to above function, > > when it's not provided natively, so it works as fallback. > > Accordingly to: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=34115 > > It does not work with gcc 4.1 when the builtin is returned directly at > the end of the function. > > So storing the return value to a variable may fix that as well. It made no difference for me: ../../lib/libltp.a(tst_test.o): In function `tst_atomic_inc': /root/ltp/lib/../include/tst_atomic.h:23: undefined reference to `__sync_add_and_fetch_4' /root/ltp/lib/../include/tst_atomic.h:23: undefined reference to `__sync_add_and_fetch_4' /root/ltp/lib/../include/tst_atomic.h:23: undefined reference to `__sync_add_and_fetch_4' collect2: ld returned 1 exit status make[1]: *** [test01] Error 1 make[1]: Leaving directory `/root/ltp/lib/newlib_tests' make: *** [all] Error 2 > But I would prefer having fallback definition over working around > compiler bugs. Agreed.