[PATCH] D69013: [AArch64] Don't assume __powidf2 is available on Windows.

[Eli Friedman via Phabricator via llvm-commits]

efriedma added a comment.

> I do believe that we need it for all the targets (x86, x86_64, armv7, aarch64).

Okay.

> Then, I used powi directly from LLVM IR, and I couldn't get it to generate a libcall for x86. It just does repeated multiplication.

We generally don't generate the libcall when the power is constant, only when it's a variable.

To make clang form powi from pow, I think you need -ffast-math.  Try something like the following:

  double pow(double,double);
  double f(double x, int y) { return pow(x,y); }


Repository:
  rL LLVM

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  https://reviews.llvm.org/D69013/new/

https://reviews.llvm.org/D69013