[Libclc-dev] [PATCH 11/14] math: Use precomputed constant for log2(10.0)

[Jeroen Ketema via Libclc-dev]

LGTM (I did not check the correctness of the constant definitions)

With regard to the CTS failure: there isn’t a exp10 implementation in the AMD contributed code?

Jeroen

> On 4 Nov 2017, at 00:07, Jan Vesely via Libclc-dev <libclc-dev at lists.llvm.org> wrote:
> 
> exp10 CTS fails with or withoput this change
> 
> Signed-off-by: Jan Vesely <jan.vesely at rutgers.edu>
> ---
> generic/include/clc/float/definitions.h | 8 ++++++++
> generic/lib/math/exp10.inc              | 4 ++--
> generic/lib/math/native_exp10.inc       | 2 +-
> 3 files changed, 11 insertions(+), 3 deletions(-)
> 
> diff --git a/generic/include/clc/float/definitions.h b/generic/include/clc/float/definitions.h
> index 6010ed2..84a102e 100644
> --- a/generic/include/clc/float/definitions.h
> +++ b/generic/include/clc/float/definitions.h
> @@ -31,6 +31,10 @@
> #define M_SQRT2_F       0x1.6a09e6p+0f
> #define M_SQRT1_2_F     0x1.6a09e6p-1f
> 
> +#ifdef __CLC_INTERNAL
> +#define M_LOG210_F      0x1.a934f0p+1f
> +#endif
> +
> #ifdef cl_khr_fp64
> 
> #define HUGE_VAL        __builtin_huge_val()
> @@ -59,6 +63,10 @@
> #define M_SQRT2         0x1.6a09e667f3bcdp+0
> #define M_SQRT1_2       0x1.6a09e667f3bcdp-1
> 
> +#ifdef __CLC_INTERNAL
> +#define M_LOG210	0x1.a934f0979a371p+1
> +#endif
> +
> #endif
> 
> #ifdef cl_khr_fp16
> diff --git a/generic/lib/math/exp10.inc b/generic/lib/math/exp10.inc
> index a592c19..f5482e4 100644
> --- a/generic/lib/math/exp10.inc
> +++ b/generic/lib/math/exp10.inc
> @@ -1,9 +1,9 @@
> _CLC_OVERLOAD _CLC_DEF __CLC_GENTYPE exp10(__CLC_GENTYPE val) {
>   // exp10(x) = exp2(x * log2(10))
> #if __CLC_FPSIZE == 32
> -  return exp2(val * log2(10.0f));
> +  return exp2(val * M_LOG210_F);
> #elif __CLC_FPSIZE == 64
> -  return exp2(val * log2(10.0));
> +  return exp2(val * M_LOG210);
> #else
> #error unknown _CLC_FPSIZE
> #endif
> diff --git a/generic/lib/math/native_exp10.inc b/generic/lib/math/native_exp10.inc
> index 7f9cb15..9826b4e 100644
> --- a/generic/lib/math/native_exp10.inc
> +++ b/generic/lib/math/native_exp10.inc
> @@ -1,3 +1,3 @@
> _CLC_OVERLOAD _CLC_DEF __CLC_GENTYPE native_exp10(__CLC_GENTYPE val) {
> -  return native_exp2(val * M_LOG10E_F);
> +  return native_exp2(val * M_LOG210_F);
> }
> -- 
> 2.13.6
> 
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