[LLVMdev] powi_f32

Tim Northover t.p.northover at gmail.com
Thu Dec 13 14:01:24 PST 2012

> I'm trying to get clang/llvm soft float to generate a call to __powisf2 and
> __powidf2.
> How would you do this in C?

How attached are you to the standard? Calling __builtin_powi seems to
do the trick regardless of circumstances in clang; but other than
that, from what I can tell, not even POSIX gives a good route.

C++ seems to define an "double pow(double, int)" overload in cmath,
but think the semantics are explicitly different (it converts to
double first so pow(x, 1 << 62) has to be dodgy).


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