[RFC][PATCH 0/2] aarch64: Add optimized ASIMD versions of sinf/cosf

[Siddhesh Poyarekar]

On Tuesday 13 June 2017 12:47 PM, Ashwin Sekhar T K wrote:
> The following are the approximate speedups observed over the
> existing implementation on different Aarch64 platforms for
> different input values.
> 
>   SINF
>   ---------------------------------------------------------
>   Input           ThunderX88      ThunderX99      CortexA57
>   ---------------------------------------------------------
>   0.0              1.88x           1.18x           1.17x
>   2.0^-28          1.33x           1.12x           1.03x
>   2.0^-6           1.48x           1.28x           1.27x
>   0.6*Pi/4         0.94x           1.14x           1.21x
>   13*Pi/8          1.41x           2.00x           2.16x
>   17*Pi/8          1.45x           1.93x           2.23x
>   1000*Pi/4       19.68x          37.46x          27.99x
>   2.0^51          12.00x          13.58x          13.49x
>   Inf              1.04x           1.05x           1.12x
>   Nan              0.95x           0.87x           0.82x
>   ---------------------------------------------------------
> 
>   COSF
>   ---------------------------------------------------------
>   Input           ThunderX88      ThunderX99      CortexA57
>   ---------------------------------------------------------
>   0.0              1.25x           1.14x           1.17x
>   2.0^-28          1.24x           1.14x           1.13x
>   2.0^-6           1.38x           1.38x           1.85x
>   0.6*Pi/4         1.15x           1.38x           1.69x
>   13*Pi/8          1.65x           1.94x           2.18x
>   17*Pi/8          1.49x           2.05x           2.09x
>   1000*Pi/4       18.98x          38.39x          27.52x
>   2.0^51          11.35x          13.74x          13.47x
>   Inf              0.99x           1.02x           1.16x
>   Nan              0.88x           0.86x           0.87x
>   ---------------------------------------------------------

Thank you for doing this.  Please:

1. Explain why you chose these input values as optimization targets and
2. Write a microbenchmark test for glibc

Thanks,
Siddhesh

> 
> Ashwin Sekhar T K (2):
>   aarch64: Add optimized ASIMD version of sinf
>   aarch64: Add optimized ASIMD version of cosf
> 
>  sysdeps/aarch64/fpu/multiarch/Makefile       |   3 +
>  sysdeps/aarch64/fpu/multiarch/s_cosf-asimd.S | 367 +++++++++++++++++++++++++
>  sysdeps/aarch64/fpu/multiarch/s_cosf.c       |  31 +++
>  sysdeps/aarch64/fpu/multiarch/s_sinf-asimd.S | 382 +++++++++++++++++++++++++++
>  sysdeps/aarch64/fpu/multiarch/s_sinf.c       |  31 +++
>  5 files changed, 814 insertions(+)
>  create mode 100644 sysdeps/aarch64/fpu/multiarch/Makefile
>  create mode 100644 sysdeps/aarch64/fpu/multiarch/s_cosf-asimd.S
>  create mode 100644 sysdeps/aarch64/fpu/multiarch/s_cosf.c
>  create mode 100644 sysdeps/aarch64/fpu/multiarch/s_sinf-asimd.S
>  create mode 100644 sysdeps/aarch64/fpu/multiarch/s_sinf.c
>