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Diffstat (limited to 'src/3rdparty/eigen/Eigen/src/Core/arch/AVX/MathFunctions.h')
-rw-r--r-- | src/3rdparty/eigen/Eigen/src/Core/arch/AVX/MathFunctions.h | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/src/3rdparty/eigen/Eigen/src/Core/arch/AVX/MathFunctions.h b/src/3rdparty/eigen/Eigen/src/Core/arch/AVX/MathFunctions.h new file mode 100644 index 000000000..67041c812 --- /dev/null +++ b/src/3rdparty/eigen/Eigen/src/Core/arch/AVX/MathFunctions.h @@ -0,0 +1,228 @@ +// This file is part of Eigen, a lightweight C++ template library +// for linear algebra. +// +// Copyright (C) 2014 Pedro Gonnet (pedro.gonnet@gmail.com) +// +// This Source Code Form is subject to the terms of the Mozilla +// Public License v. 2.0. If a copy of the MPL was not distributed +// with this file, You can obtain one at http://mozilla.org/MPL/2.0/. + +#ifndef EIGEN_MATH_FUNCTIONS_AVX_H +#define EIGEN_MATH_FUNCTIONS_AVX_H + +/* The sin and cos functions of this file are loosely derived from + * Julien Pommier's sse math library: http://gruntthepeon.free.fr/ssemath/ + */ + +namespace Eigen { + +namespace internal { + +template <> +EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS EIGEN_UNUSED Packet8f +psin<Packet8f>(const Packet8f& _x) { + return psin_float(_x); +} + +template <> +EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS EIGEN_UNUSED Packet8f +pcos<Packet8f>(const Packet8f& _x) { + return pcos_float(_x); +} + +template <> +EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS EIGEN_UNUSED Packet8f +plog<Packet8f>(const Packet8f& _x) { + return plog_float(_x); +} + +template <> +EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS EIGEN_UNUSED Packet4d +plog<Packet4d>(const Packet4d& _x) { + return plog_double(_x); +} + +template <> +EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS EIGEN_UNUSED Packet8f +plog2<Packet8f>(const Packet8f& _x) { + return plog2_float(_x); +} + +template <> +EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS EIGEN_UNUSED Packet4d +plog2<Packet4d>(const Packet4d& _x) { + return plog2_double(_x); +} + +template<> EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS EIGEN_UNUSED +Packet8f plog1p<Packet8f>(const Packet8f& _x) { + return generic_plog1p(_x); +} + +template<> EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS EIGEN_UNUSED +Packet8f pexpm1<Packet8f>(const Packet8f& _x) { + return generic_expm1(_x); +} + +// Exponential function. Works by writing "x = m*log(2) + r" where +// "m = floor(x/log(2)+1/2)" and "r" is the remainder. The result is then +// "exp(x) = 2^m*exp(r)" where exp(r) is in the range [-1,1). +template <> +EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS EIGEN_UNUSED Packet8f +pexp<Packet8f>(const Packet8f& _x) { + return pexp_float(_x); +} + +// Hyperbolic Tangent function. +template <> +EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS EIGEN_UNUSED Packet8f +ptanh<Packet8f>(const Packet8f& _x) { + return internal::generic_fast_tanh_float(_x); +} + +// Exponential function for doubles. +template <> +EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS EIGEN_UNUSED Packet4d +pexp<Packet4d>(const Packet4d& _x) { + return pexp_double(_x); +} + +// Functions for sqrt. +// The EIGEN_FAST_MATH version uses the _mm_rsqrt_ps approximation and one step +// of Newton's method, at a cost of 1-2 bits of precision as opposed to the +// exact solution. It does not handle +inf, or denormalized numbers correctly. +// The main advantage of this approach is not just speed, but also the fact that +// it can be inlined and pipelined with other computations, further reducing its +// effective latency. This is similar to Quake3's fast inverse square root. +// For detail see here: http://www.beyond3d.com/content/articles/8/ +#if EIGEN_FAST_MATH +template <> +EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS EIGEN_UNUSED +Packet8f psqrt<Packet8f>(const Packet8f& _x) { + Packet8f minus_half_x = pmul(_x, pset1<Packet8f>(-0.5f)); + Packet8f denormal_mask = pandnot( + pcmp_lt(_x, pset1<Packet8f>((std::numeric_limits<float>::min)())), + pcmp_lt(_x, pzero(_x))); + + // Compute approximate reciprocal sqrt. + Packet8f x = _mm256_rsqrt_ps(_x); + // Do a single step of Newton's iteration. + x = pmul(x, pmadd(minus_half_x, pmul(x,x), pset1<Packet8f>(1.5f))); + // Flush results for denormals to zero. + return pandnot(pmul(_x,x), denormal_mask); +} + +#else + +template <> EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS EIGEN_UNUSED +Packet8f psqrt<Packet8f>(const Packet8f& _x) { + return _mm256_sqrt_ps(_x); +} + +#endif + +template <> EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS EIGEN_UNUSED +Packet4d psqrt<Packet4d>(const Packet4d& _x) { + return _mm256_sqrt_pd(_x); +} + +#if EIGEN_FAST_MATH +template<> EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS EIGEN_UNUSED +Packet8f prsqrt<Packet8f>(const Packet8f& _x) { + _EIGEN_DECLARE_CONST_Packet8f_FROM_INT(inf, 0x7f800000); + _EIGEN_DECLARE_CONST_Packet8f(one_point_five, 1.5f); + _EIGEN_DECLARE_CONST_Packet8f(minus_half, -0.5f); + _EIGEN_DECLARE_CONST_Packet8f_FROM_INT(flt_min, 0x00800000); + + Packet8f neg_half = pmul(_x, p8f_minus_half); + + // select only the inverse sqrt of positive normal inputs (denormals are + // flushed to zero and cause infs as well). + Packet8f lt_min_mask = _mm256_cmp_ps(_x, p8f_flt_min, _CMP_LT_OQ); + Packet8f inf_mask = _mm256_cmp_ps(_x, p8f_inf, _CMP_EQ_OQ); + Packet8f not_normal_finite_mask = _mm256_or_ps(lt_min_mask, inf_mask); + + // Compute an approximate result using the rsqrt intrinsic. + Packet8f y_approx = _mm256_rsqrt_ps(_x); + + // Do a single step of Newton-Raphson iteration to improve the approximation. + // This uses the formula y_{n+1} = y_n * (1.5 - y_n * (0.5 * x) * y_n). + // It is essential to evaluate the inner term like this because forming + // y_n^2 may over- or underflow. + Packet8f y_newton = pmul(y_approx, pmadd(y_approx, pmul(neg_half, y_approx), p8f_one_point_five)); + + // Select the result of the Newton-Raphson step for positive normal arguments. + // For other arguments, choose the output of the intrinsic. This will + // return rsqrt(+inf) = 0, rsqrt(x) = NaN if x < 0, and rsqrt(x) = +inf if + // x is zero or a positive denormalized float (equivalent to flushing positive + // denormalized inputs to zero). + return pselect<Packet8f>(not_normal_finite_mask, y_approx, y_newton); +} + +#else +template <> EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS EIGEN_UNUSED +Packet8f prsqrt<Packet8f>(const Packet8f& _x) { + _EIGEN_DECLARE_CONST_Packet8f(one, 1.0f); + return _mm256_div_ps(p8f_one, _mm256_sqrt_ps(_x)); +} +#endif + +template <> EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS EIGEN_UNUSED +Packet4d prsqrt<Packet4d>(const Packet4d& _x) { + _EIGEN_DECLARE_CONST_Packet4d(one, 1.0); + return _mm256_div_pd(p4d_one, _mm256_sqrt_pd(_x)); +} + +F16_PACKET_FUNCTION(Packet8f, Packet8h, psin) +F16_PACKET_FUNCTION(Packet8f, Packet8h, pcos) +F16_PACKET_FUNCTION(Packet8f, Packet8h, plog) +F16_PACKET_FUNCTION(Packet8f, Packet8h, plog2) +F16_PACKET_FUNCTION(Packet8f, Packet8h, plog1p) +F16_PACKET_FUNCTION(Packet8f, Packet8h, pexpm1) +F16_PACKET_FUNCTION(Packet8f, Packet8h, pexp) +F16_PACKET_FUNCTION(Packet8f, Packet8h, ptanh) +F16_PACKET_FUNCTION(Packet8f, Packet8h, psqrt) +F16_PACKET_FUNCTION(Packet8f, Packet8h, prsqrt) + +template <> +EIGEN_STRONG_INLINE Packet8h pfrexp(const Packet8h& a, Packet8h& exponent) { + Packet8f fexponent; + const Packet8h out = float2half(pfrexp<Packet8f>(half2float(a), fexponent)); + exponent = float2half(fexponent); + return out; +} + +template <> +EIGEN_STRONG_INLINE Packet8h pldexp(const Packet8h& a, const Packet8h& exponent) { + return float2half(pldexp<Packet8f>(half2float(a), half2float(exponent))); +} + +BF16_PACKET_FUNCTION(Packet8f, Packet8bf, psin) +BF16_PACKET_FUNCTION(Packet8f, Packet8bf, pcos) +BF16_PACKET_FUNCTION(Packet8f, Packet8bf, plog) +BF16_PACKET_FUNCTION(Packet8f, Packet8bf, plog2) +BF16_PACKET_FUNCTION(Packet8f, Packet8bf, plog1p) +BF16_PACKET_FUNCTION(Packet8f, Packet8bf, pexpm1) +BF16_PACKET_FUNCTION(Packet8f, Packet8bf, pexp) +BF16_PACKET_FUNCTION(Packet8f, Packet8bf, ptanh) +BF16_PACKET_FUNCTION(Packet8f, Packet8bf, psqrt) +BF16_PACKET_FUNCTION(Packet8f, Packet8bf, prsqrt) + +template <> +EIGEN_STRONG_INLINE Packet8bf pfrexp(const Packet8bf& a, Packet8bf& exponent) { + Packet8f fexponent; + const Packet8bf out = F32ToBf16(pfrexp<Packet8f>(Bf16ToF32(a), fexponent)); + exponent = F32ToBf16(fexponent); + return out; +} + +template <> +EIGEN_STRONG_INLINE Packet8bf pldexp(const Packet8bf& a, const Packet8bf& exponent) { + return F32ToBf16(pldexp<Packet8f>(Bf16ToF32(a), Bf16ToF32(exponent))); +} + +} // end namespace internal + +} // end namespace Eigen + +#endif // EIGEN_MATH_FUNCTIONS_AVX_H |