Add math benchmark latency test

This patch further improves math function benchmarking by adding a latency
test in addition to throughput.  This enables more accurate comparisons of the
math functions. The latency test works by creating a dependency on the previous
iteration: func_res = F (func_res * zero + input[i]). The multiply by zero
avoids changing the input.

It reports reciprocal throughput and latency in nanoseconds (depending on the
timing header used) and max/min throughput in iterations per second:

   "workload-spec2006.wrf": {
    "reciprocal-throughput": 100,
    "latency": 200,
    "max-throughput": 1.0e+07,
    "min-throughput": 5.0e+06
   }

	* benchtests/bench-skeleton.c (main): Add support for
	latency benchmarking.
	* benchtests/scripts/bench.py: Add support for latency benchmarking.

1 files changed, 6 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index f11f6e11c7..08207b1c4e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2017-08-17  Wilco Dijkstra  <wdijkstr@arm.com>
+
+	* benchtests/bench-skeleton.c (main): Add support for
+	latency benchmarking.
+	* benchtests/scripts/bench.py: Add support for latency benchmarking.
+
 2017-08-17  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* Makeconfig (+link-pie-before-libc): Add CRT-* hook to override