eigen/Eigen/src/Core/arch/AVX/MathFunctions.h
Antonio Sanchez 3580a38298 Use native _Float16 for AVX512FP16 and update vectorization.
This allows us to do faster native scalar operations.  Also
updated half/quarter packets to use the native type if available.

Benchmark improvement:
```
Comparing ./2910_without_float16 to ./2910_with_float16
Benchmark                                               Time             CPU      Time Old      Time New       CPU Old       CPU New
------------------------------------------------------------------------------------------------------------------------------------
BM_CalcMat<float>/10000/768/500                      -0.0041         -0.0040      58276392      58039442      58273420      58039582
BM_CalcMat<_Float16>/10000/768/500                   +0.0073         +0.0073     642506339     647214446     642481384     647188303
BM_CalcMat<Eigen::half>/10000/768/500                -0.3170         -0.3170      92511115      63182101      92506771      63179258
BM_CalcVec<float>/10000/768/500                      +0.0022         +0.0022       5198157       5209469       5197913       5209334
BM_CalcVec<_Float16>/10000/768/500                   +0.0025         +0.0026      10133324      10159111      10132641      10158507
BM_CalcVec<Eigen::half>/10000/768/500                -0.7760         -0.7760      45337937      10156952      45336532      10156389
OVERALL_GEOMEAN                                      -0.2677         -0.2677             0             0             0             0
```

Fixes #2910.
2025-03-18 10:46:32 -07:00

130 lines
4.6 KiB
C++

// 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/
*/
// IWYU pragma: private
#include "../../InternalHeaderCheck.h"
namespace Eigen {
namespace internal {
EIGEN_INSTANTIATE_GENERIC_MATH_FUNCS_FLOAT(Packet8f)
EIGEN_DOUBLE_PACKET_FUNCTION(atanh, Packet4d)
EIGEN_DOUBLE_PACKET_FUNCTION(log, Packet4d)
EIGEN_DOUBLE_PACKET_FUNCTION(log2, Packet4d)
EIGEN_DOUBLE_PACKET_FUNCTION(exp, Packet4d)
EIGEN_DOUBLE_PACKET_FUNCTION(tanh, Packet4d)
#ifdef EIGEN_VECTORIZE_AVX2
EIGEN_DOUBLE_PACKET_FUNCTION(sin, Packet4d)
EIGEN_DOUBLE_PACKET_FUNCTION(cos, Packet4d)
#endif
EIGEN_GENERIC_PACKET_FUNCTION(atan, Packet4d)
EIGEN_GENERIC_PACKET_FUNCTION(exp2, Packet4d)
// Notice that for newer processors, it is counterproductive to use Newton
// iteration for square root. In particular, Skylake and Zen2 processors
// have approximately doubled throughput of the _mm_sqrt_ps instruction
// compared to their predecessors.
template <>
EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS Packet8f psqrt<Packet8f>(const Packet8f& _x) {
return _mm256_sqrt_ps(_x);
}
template <>
EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS Packet4d psqrt<Packet4d>(const Packet4d& _x) {
return _mm256_sqrt_pd(_x);
}
// Even on Skylake, using Newton iteration is a win for reciprocal square root.
#if EIGEN_FAST_MATH
template <>
EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS Packet8f prsqrt<Packet8f>(const Packet8f& a) {
// _mm256_rsqrt_ps returns -inf for negative denormals.
// _mm512_rsqrt**_ps returns -NaN for negative denormals. We may want
// consistency here.
// const Packet8f rsqrt = pselect(pcmp_lt(a, pzero(a)),
// pset1<Packet8f>(-NumTraits<float>::quiet_NaN()),
// _mm256_rsqrt_ps(a));
return generic_rsqrt_newton_step<Packet8f, /*Steps=*/1>::run(a, _mm256_rsqrt_ps(a));
}
template <>
EIGEN_STRONG_INLINE Packet8f preciprocal<Packet8f>(const Packet8f& a) {
return generic_reciprocal_newton_step<Packet8f, /*Steps=*/1>::run(a, _mm256_rcp_ps(a));
}
#endif
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)));
}
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)));
}
BF16_PACKET_FUNCTION(Packet8f, Packet8bf, pcos)
BF16_PACKET_FUNCTION(Packet8f, Packet8bf, pexp)
BF16_PACKET_FUNCTION(Packet8f, Packet8bf, pexp2)
BF16_PACKET_FUNCTION(Packet8f, Packet8bf, pexpm1)
BF16_PACKET_FUNCTION(Packet8f, Packet8bf, plog)
BF16_PACKET_FUNCTION(Packet8f, Packet8bf, plog1p)
BF16_PACKET_FUNCTION(Packet8f, Packet8bf, plog2)
BF16_PACKET_FUNCTION(Packet8f, Packet8bf, preciprocal)
BF16_PACKET_FUNCTION(Packet8f, Packet8bf, prsqrt)
BF16_PACKET_FUNCTION(Packet8f, Packet8bf, psin)
BF16_PACKET_FUNCTION(Packet8f, Packet8bf, psqrt)
BF16_PACKET_FUNCTION(Packet8f, Packet8bf, ptanh)
#ifndef EIGEN_VECTORIZE_AVX512FP16
F16_PACKET_FUNCTION(Packet8f, Packet8h, pcos)
F16_PACKET_FUNCTION(Packet8f, Packet8h, pexp)
F16_PACKET_FUNCTION(Packet8f, Packet8h, pexp2)
F16_PACKET_FUNCTION(Packet8f, Packet8h, pexpm1)
F16_PACKET_FUNCTION(Packet8f, Packet8h, plog)
F16_PACKET_FUNCTION(Packet8f, Packet8h, plog1p)
F16_PACKET_FUNCTION(Packet8f, Packet8h, plog2)
F16_PACKET_FUNCTION(Packet8f, Packet8h, preciprocal)
F16_PACKET_FUNCTION(Packet8f, Packet8h, prsqrt)
F16_PACKET_FUNCTION(Packet8f, Packet8h, psin)
F16_PACKET_FUNCTION(Packet8f, Packet8h, psqrt)
F16_PACKET_FUNCTION(Packet8f, Packet8h, ptanh)
#endif
} // end namespace internal
} // end namespace Eigen
#endif // EIGEN_MATH_FUNCTIONS_AVX_H