[Beignet] [PATCH 1/3] Benchmark: Evaluate math performance on intervals

[Song, Ruiling]

> -----Original Message-----
> From: Beignet [mailto:beignet-bounces at lists.freedesktop.org] On Behalf Of
> Grigore Lupescu
> Sent: Monday, May 2, 2016 3:04 AM
> To: beignet at lists.freedesktop.org
> Subject: [Beignet] [PATCH 1/3] Benchmark: Evaluate math performance on
> intervals
> 
> From: Grigore Lupescu <grigore.lupescu at intel.com>
> 
> Functions to benchmark math functions on intervals.
> Tests: sin, cos, exp2, exp, exp10, log2, log, log10
> 
> Signed-off-by: Grigore Lupescu <grigore.lupescu at intel.com>
> ---
>  benchmark/CMakeLists.txt     |   3 +-
>  benchmark/benchmark_math.cpp | 126 ++++++++++++++++++++
>  kernels/bench_math.cl        | 272
> +++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 400 insertions(+), 1 deletion(-)
>  create mode 100644 benchmark/benchmark_math.cpp
>  create mode 100644 kernels/bench_math.cl
> 
> diff --git a/benchmark/CMakeLists.txt b/benchmark/CMakeLists.txt
> index dd33829..4c3c933 100644
> --- a/benchmark/CMakeLists.txt
> +++ b/benchmark/CMakeLists.txt
> @@ -18,7 +18,8 @@ set (benchmark_sources
>    benchmark_copy_buffer_to_image.cpp
>    benchmark_copy_image_to_buffer.cpp
>    benchmark_copy_buffer.cpp
> -  benchmark_copy_image.cpp)
> +  benchmark_copy_image.cpp
> +  benchmark_math.cpp)
> 
> +/* calls internal fast (native) if (x > -0x1.6p1 && x < 0x1.6p1) */
> +kernel void bench_math_exp(
> +  global float *src,
> +  global float *dst,
> +  float pwr,
> +  uint loop)
> +{
> +  float result = src[get_global_id(0)];
> +
> +  for(; loop > 0; loop--)
> +  {
> +#if defined(BENCHMARK_NATIVE)
> +    result = native_exp(-0x1.6p1 - result); /* calls native */
> +#elif defined(BENCHMARK_INTERNAL_FAST)
> +    result = exp(-0x1.6p1 + result); /* calls internal fast */
> +#else
> +    result = exp(-0x1.6p1 - result); /* calls internal slow */
> +#endif

I think we should separate the benchmark test from the real implementation.
Then we can make easy comparison with other driver implementation and
Also the implementation in Beignet may change in the future.
What's your idea on this?

> +  }
> +
> +  dst[get_global_id(0)] = result;
> +}
> +

> +/* benchmark sin performance */
> +kernel void bench_math_sin(
> +  global float *src,
> +  global float *dst,
> +  float pwr,
> +  uint loop)
> +{
> +  float result = src[get_global_id(0)];
> +
> +  for(; loop > 0; loop--)
> +  {
> +#if defined(BENCHMARK_NATIVE)
> +    result = native_sin(result); /* calls native */
> +#else
> +    result = sin(result);	/* calls internal, random complexity */

What's the range of 'result'? Seems very small? I think we need to make sure the input argument to sin() in a large range.
As we need try to optimize for general case.

Thanks!
Ruiling
> +    //result = sin(0.1f + result); /* calls internal, (1) no reduction */
> +    //result = sin(2.f + result); /* calls internal, (2) fast reduction */
> +    //result = sin(4001 + result); /* calls internal, (3) slow reduction */
> +    result *= 0x1p-16;
> +#endif
> +  }
> +
> +  dst[get_global_id(0)] = result;
> +}
> +