[Libclc-dev] [PATCH] Implement tanh builtin
Tom Stellard via Libclc-dev
libclc-dev at lists.llvm.org
Mon Sep 28 18:39:07 PDT 2015
On Sat, Sep 26, 2015 at 10:35:06AM +0200, Niels Ole Salscheider via Libclc-dev wrote:
> This is a port from the AMD builtin library.
LGTM.
> ---
> generic/include/clc/clc.h | 1 +
> generic/include/clc/math/{atan.h => tanh.h} | 2 +-
> generic/include/clc/math/{atan.inc => tanh.inc} | 2 +-
> generic/lib/SOURCES | 1 +
> generic/lib/math/tanh.cl | 146 ++++++++++++++++++++++++
> 5 files changed, 150 insertions(+), 2 deletions(-)
> copy generic/include/clc/math/{atan.h => tanh.h} (96%)
> copy generic/include/clc/math/{atan.inc => tanh.inc} (94%)
> create mode 100644 generic/lib/math/tanh.cl
>
> diff --git a/generic/include/clc/clc.h b/generic/include/clc/clc.h
> index cab751d..d34a540 100644
> --- a/generic/include/clc/clc.h
> +++ b/generic/include/clc/clc.h
> @@ -77,6 +77,7 @@
> #include <clc/math/sinpi.h>
> #include <clc/math/sqrt.h>
> #include <clc/math/tan.h>
> +#include <clc/math/tanh.h>
> #include <clc/math/trunc.h>
> #include <clc/math/native_cos.h>
> #include <clc/math/native_divide.h>
> diff --git a/generic/include/clc/math/atan.h b/generic/include/clc/math/tanh.h
> similarity index 96%
> copy from generic/include/clc/math/atan.h
> copy to generic/include/clc/math/tanh.h
> index d969719..e895ee4 100644
> --- a/generic/include/clc/math/atan.h
> +++ b/generic/include/clc/math/tanh.h
> @@ -20,5 +20,5 @@
> * THE SOFTWARE.
> */
>
> -#define __CLC_BODY <clc/math/atan.inc>
> +#define __CLC_BODY <clc/math/tanh.inc>
> #include <clc/math/gentype.inc>
> diff --git a/generic/include/clc/math/atan.inc b/generic/include/clc/math/tanh.inc
> similarity index 94%
> copy from generic/include/clc/math/atan.inc
> copy to generic/include/clc/math/tanh.inc
> index d217c95..f0735e9 100644
> --- a/generic/include/clc/math/atan.inc
> +++ b/generic/include/clc/math/tanh.inc
> @@ -20,4 +20,4 @@
> * THE SOFTWARE.
> */
>
> -_CLC_OVERLOAD _CLC_DECL __CLC_GENTYPE atan(__CLC_GENTYPE a);
> +_CLC_OVERLOAD _CLC_DECL __CLC_GENTYPE tanh(__CLC_GENTYPE a);
> diff --git a/generic/lib/SOURCES b/generic/lib/SOURCES
> index a5ee9f8..ff4e18f 100644
> --- a/generic/lib/SOURCES
> +++ b/generic/lib/SOURCES
> @@ -109,6 +109,7 @@ math/sinpi.cl
> math/clc_sqrt.cl
> math/sqrt.cl
> math/tan.cl
> +math/tanh.cl
> relational/all.cl
> relational/any.cl
> relational/bitselect.cl
> diff --git a/generic/lib/math/tanh.cl b/generic/lib/math/tanh.cl
> new file mode 100644
> index 0000000..e9c4079
> --- /dev/null
> +++ b/generic/lib/math/tanh.cl
> @@ -0,0 +1,146 @@
> +/*
> + * Copyright (c) 2014 Advanced Micro Devices, Inc.
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a copy
> + * of this software and associated documentation files (the "Software"), to deal
> + * in the Software without restriction, including without limitation the rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
> + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> + * THE SOFTWARE.
> + */
> +
> +#include <clc/clc.h>
> +
> +#include "math.h"
> +#include "../clcmacro.h"
> +
> +_CLC_OVERLOAD _CLC_DEF float tanh(float x)
> +{
> + // The definition of tanh(x) is sinh(x)/cosh(x), which is also equivalent
> + // to the following three formulae:
> + // 1. (exp(x) - exp(-x))/(exp(x) + exp(-x))
> + // 2. (1 - (2/(exp(2*x) + 1 )))
> + // 3. (exp(2*x) - 1)/(exp(2*x) + 1)
> + // but computationally, some formulae are better on some ranges.
> +
> + const float large_threshold = 0x1.0a2b24p+3f;
> +
> + uint ux = as_uint(x);
> + uint aux = ux & EXSIGNBIT_SP32;
> + uint xs = ux ^ aux;
> +
> + float y = as_float(aux);
> + float y2 = y*y;
> +
> + float a1 = mad(y2,
> + mad(y2, 0.4891631088530669873e-4F, -0.14628356048797849e-2F),
> + -0.28192806108402678e0F);
> + float b1 = mad(y2, 0.3427017942262751343e0F, 0.845784192581041099e0F);
> +
> + float a2 = mad(y2,
> + mad(y2, 0.3827534993599483396e-4F, -0.12325644183611929e-2F),
> + -0.24069858695196524e0F);
> + float b2 = mad(y2, 0.292529068698052819e0F, 0.72209738473684982e0F);
> +
> + int c = y < 0.9f;
> + float a = c ? a1 : a2;
> + float b = c ? b1 : b2;
> + float zlo = mad(MATH_DIVIDE(a, b), y*y2, y);
> +
> + float p = exp(2.0f * y) + 1.0f;
> + float zhi = 1.0F - MATH_DIVIDE(2.0F, p);
> +
> + float z = y <= 1.0f ? zlo : zhi;
> + z = as_float(xs | as_uint(z));
> +
> + // Edge cases
> + float sone = as_float(0x3f800000U | xs);
> + z = y > large_threshold ? sone : z;
> + z = aux < 0x39000000 | aux > 0x7f800000 ? x : z;
> +
> + return z;
> +}
> +
> +_CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, float, tanh, float);
> +
> +#ifdef cl_khr_fp64
> +
> +#pragma OPENCL EXTENSION cl_khr_fp64 : enable
> +
> +_CLC_OVERLOAD _CLC_DEF double tanh(double x)
> +{
> + // The definition of tanh(x) is sinh(x)/cosh(x), which is also equivalent
> + // to the following three formulae:
> + // 1. (exp(x) - exp(-x))/(exp(x) + exp(-x))
> + // 2. (1 - (2/(exp(2*x) + 1 )))
> + // 3. (exp(2*x) - 1)/(exp(2*x) + 1)
> + // but computationally, some formulae are better on some ranges.
> +
> + // The point at which e^-x is insignificant compared to e^x = ln(2^27)
> + const double large_threshold = 0x1.2b708872320e2p+4;
> +
> + ulong ux = as_ulong(x);
> + ulong ax = ux & ~SIGNBIT_DP64;
> + ulong sx = ux ^ ax;
> + double y = as_double(ax);
> + double y2 = y * y;
> +
> + // y < 0.9
> + double znl = fma(y2,
> + fma(y2,
> + fma(y2, -0.142077926378834722618091e-7, -0.200047621071909498730453e-3),
> + -0.176016349003044679402273e-1),
> + -0.274030424656179760118928e0);
> +
> + double zdl = fma(y2,
> + fma(y2,
> + fma(y2, 0.2091140262529164482568557e-3, 0.201562166026937652780575e-1),
> + 0.381641414288328849317962e0),
> + 0.822091273968539282568011e0);
> +
> + // 0.9 <= y <= 1
> + double znm = fma(y2,
> + fma(y2,
> + fma(y2, -0.115475878996143396378318e-7, -0.165597043903549960486816e-3),
> + -0.146173047288731678404066e-1),
> + -0.227793870659088295252442e0);
> +
> + double zdm = fma(y2,
> + fma(y2,
> + fma(y2, 0.173076050126225961768710e-3, 0.167358775461896562588695e-1),
> + 0.317204558977294374244770e0),
> + 0.683381611977295894959554e0);
> +
> + int c = y < 0.9;
> + double zn = c ? znl : znm;
> + double zd = c ? zdl : zdm;
> + double z = y + y*y2 * MATH_DIVIDE(zn, zd);
> +
> + // y > 1
> + double p = exp(2.0 * y) + 1.0;
> + double zg = 1.0 - 2.0 / p;
> +
> + z = y > 1.0 ? zg : z;
> +
> + // Other cases
> + z = y < 0x1.0p-28 | ax > PINFBITPATT_DP64 ? x : z;
> +
> + z = y > large_threshold ? 1.0 : z;
> +
> + return as_double(sx | as_ulong(z));
> +}
> +
> +_CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, double, tanh, double);
> +
> +#endif // cl_khr_fp64
> --
> 2.5.3
>
> _______________________________________________
> Libclc-dev mailing list
> Libclc-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/libclc-dev
More information about the Libclc-dev
mailing list