Open albinahlback opened 1 month ago
Is there a reason for not doing m = n_pow(g, n)
and then for (j = 0; j < m; j++)
?
It is cheap compared to searching for all such instances as they don't necessarily have to be contained within for-loops. It can also lead to more readable code.
Personally, I am a big fan of attributes since that hints the compiler that it can assume even more things. Of course, one should still try to optimize the code as much as possible, as this is only valid for GCC-compatible compilers.
I don't think there are too many of these.
One of the drawbacks of this attribute is that the compiler can start to optimize out benchmarked function calls from benchmarking loops :-)
That's true.
I've seen functions which does something like
Assuming that
g
andn
does not change, GCC cannot optimize this as it doesn't know if the output will be different each time. Pushing__attribute__((const))
will make it understand it.This should be pushed onto every function where it applies.
See GCC's documentation for more information.