[PATCH] Add powf bench tests

[Joseph Myers]

On Fri, 9 Jun 2017, Paul Clarke wrote:

> diff --git a/benchtests/pow-inputs b/benchtests/powf-inputs
> similarity index 99%
> copy from benchtests/pow-inputs
> copy to benchtests/powf-inputs

A large proportion of the pow inputs are sufficiently large or small that 
they would round to 0 or infinity as float values, or the result would 
round to 0, infinity or 1 as a float value.  I don't think such special 
cases should be considered typical and so I don't think copying the pow 
inputs is a good way of producing a set of benchmark inputs to powf.

-- 
Joseph S. Myers
joseph@codesourcery.com