__builtin_expect in 1.9.1

I tried to compile ngpt-1.9.1 with gcc 2.95.3.

gcc -c -I. -O2 -pipe test_common.c
./libtool --mode=link --quiet gcc  -o test_pthread test_pthread.o test_common.o libpthread.la -lnsl
.libs/libpthread.so: undefined reference to `__builtin_expect'
collect2: ld returned 1 exit status


in shm_open.c:74

	if (__builtin_expect (flags, 0) != -1) {
	    flags |= FD_CLOEXEC;
	    flags = fcntl (fd, F_SETFD, flags);
	}

change to

! 
if ( flags != -1) {
	    flags |= FD_CLOEXEC;
	    flags = fcntl (fd, F_SETFD, flags);
	}


The __builtin_expect seems like a hint for speculative branching
(like unlikely() in the kernel)

Do you compile with gcc 3.x?


BTW, I get some funny looking warnings:

In file included from ngptc.c:31:
pth_p.h.in:171: warning: `pth_get_native_descr' redefined
_ON_THE_FLY_:113: warning: this is the location of the previous definition
pth_p.h.in:173: warning: `pth_get_current' redefined
_ON_THE_FLY_:110: warning: this is the location of the previous definition
./libtool --mode=link --quiet gcc  -o ngptc ngptc.o shm_open.o shm_unlink.o