__sync_fetch_ prototypes.

[Ian Lance Taylor]

Christian BRUEL <christian.bruel@st.com> writes:

> Can I assume from the gcc sources that the __sync_fetch_ builtins take
> only unsigned value as inputs, and thus also return unsigned values.

These builtins came from Intel.  This page

http://software.intel.com/sites/products/documentation/hpc/compilerpro/en-us/cpp/lin/compiler_c/intref_cls/common/intref_itanium_synchro_prim.htm

suggests but does not clearly state that the return type should be the
same as the value type.  We could probably implement that in gcc, but
I think it would be awkward to simply change the sign of the return
type now; it might break currently working programs.

This is probably worth a bug report in any case.

Ian