Robert Lemmen wrote: > hi folks, > > i want to use the builtin __sync_val_compare_and_swap on 128 bit > datatypes. older versions of ggc always gave me a "incompatible type for > argument 1 of '__sync_val_compare_and_swap'", which took as "not > supported". now i am using a current version of the compiler, and it > does give me a "undefined reference to `__sync_val_compare_and_swap_16", > which i dont understand. obviously the compiler does now know about t, > but does not fully support it. it does of course work with 64 bit > arguments. i sthere anything i need to do? some switch? or link > something in? or does this just mean support for it is not yet fully > there? It depends on the actual processor type you're using. Not every processor has a 128-bit atomic exchange. gcc uses the -mcpu= switch to control the processor. Andrew.
