Joseph Garvin wrote: > On Fri, Jun 5, 2009 at 11:47 AM, Andrew Haley<aph@xxxxxxxxxx> wrote: >> It'll call out to a library function if there isn't a builtin instruction. >> If you want to do a configure check, try running or linking the program. > > If I compile with -march=i386, and do ./a.out, it runs without errors. > Here's my .cpp file: > > int main() > { > int x; > __sync_add_and_fetch(&x, 1); > > return 0; > } > > Since I have a main, if __sync_add_and_fetch were undefined, wouldn't > it already be trying to link and give an error? i386 has lock incl, surely, so __sync_add_and_fetch isn't a problem. It's stuff like __sync_val_compare_and_swap you don't have. Andrew.