Replacing certain operations with function calls

[Jean Christophe Beyler]

Dear all,

I have been also been looking into how to generate a function call for
certain operations. I've looked at various other targets for a similar
problem/solution but have not seen anything. On my target
architecture, we have certain optimized versions of the multiplication
for example.

I wanted to replace certain mutliplications with a function call. The
solution I found was to do perform a FAIL on the define_expand of the
multiplication for these cases. This forces the compiler to generate a
function call to __multdi3.

I then go in the define_expand of the function call and check the
symbol_ref to see what function is called. I can then modify the call
at that point.

My question is: is this a good approach or is there another solution
that you would use?

Thanks again for your time,
Jean Christophe Beyler