Hey, I found out that atomic operations on doubles are not permitted on x64 architecture in Pelles C 9.00 giving error #2513. Example:
double x[100] = {1}, sum = 0;
#pragma omp parallel for
for(int i = 0; i < 100; ++i)
#pragma omp atomic
sum += x[i];
Is it possible to implement them?
It should be possible, at least by (mis)using integer instructions, but it's too late for the upcoming version 10.
Will have to wait until another version (it's not exactly a five minute job).
(I think there were some concerns about floating-point atomics when _Atomic was added to C11, but I no longer remember the details.)
Thanks a lot! I'm using critical sections as a workaround, but atomics should be faster.