Add powf bench tests

Add powf() bench test with input which covers these cases:
- positive base to positive exponent
- exponent 0
- negative base to even exponent
- exponent 1
- exponent -1
- squared
- squareroot
- 1 to negative exponent
- -1 to negative exponent
- base 0
- -1 to even exponent
- small base
- small exponent

	* benchtests/Makefile (bench-math): Add powf.
	* benchtests/powf-inputs: New file.

1 files changed, 5 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index cae2982dbe..d33157eaef 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2017-06-20  Paul A. Clarke  <pc@us.ibm.com>
+
+	* benchtests/Makefile (bench-math): Add powf.
+	* benchtests/powf-inputs: New file.
+
 2017-06-20  Zack Weinberg  <zackw@panix.com>
 
 	* bits/string.h, string/bits/string.h