Hello. I am having problems traying to call __sync_fetch_and_add(int,int). Does anybody know what I'm missing? the program is a.c: ------------------------ a.c ---------------------------- int i = 0; int main() { int b = __sync_fetch_and_add( &i, 1 ); return b; } ----------------------- end of a.c ---------------------- The error is: ----------------------------------------------------------------- $ /usr/local/gcc-4.2.2/bin/gcc -oa a.c /tmp/ccaiRBpH.o(.text+0x21): In function `main': : undefined reference to `__sync_fetch_and_add_4' collect2: ld returned 1 exit status gcc -v shows: ----------------------------------------------------------------- $ /usr/local/gcc-4.2.2/bin/gcc -v Using built-in specs. Target: i686-pc-linux-gnu Configured with: ../gcc-4.2.2/configure --prefix=/usr/local/gcc-4.2.2 --enable-__cxa_atexit --with-system-zlib --enable-threads=posix --enable-languages=c,c++ Thread model: posix gcc version 4.2.2 uname -a shows: ----------------------------------------------------------------- $ uname -a Linux aquila 2.4.21-4.EL #1 Fri Oct 3 18:13:58 EDT 2003 i686 i686 i386 GNU/Linux Thanks. Tarjeta de crédito Yahoo! de Banco Supervielle. Solicitá tu nueva Tarjeta de crédito. De tu PC directo a tu casa. www.tuprimeratarjeta.com.ar