| // This file is part of Eigen, a lightweight C++ template library |
| // for linear algebra. |
| // |
| // 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/. |
| |
| /* The sin, cos, exp, and log functions of this file come from |
| * Julien Pommier's sse math library: http://gruntthepeon.free.fr/ssemath/ |
| */ |
| |
| #ifndef EIGEN_MATH_FUNCTIONS_NEON_H |
| #define EIGEN_MATH_FUNCTIONS_NEON_H |
| |
| namespace Eigen { |
| |
| namespace internal { |
| |
| template<> EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS EIGEN_UNUSED |
| Packet4f pexp<Packet4f>(const Packet4f& _x) |
| { |
| Packet4f x = _x; |
| Packet4f tmp, fx; |
| |
| _EIGEN_DECLARE_CONST_Packet4f(1 , 1.0f); |
| _EIGEN_DECLARE_CONST_Packet4f(half, 0.5f); |
| _EIGEN_DECLARE_CONST_Packet4i(0x7f, 0x7f); |
| _EIGEN_DECLARE_CONST_Packet4f(exp_hi, 88.3762626647950f); |
| _EIGEN_DECLARE_CONST_Packet4f(exp_lo, -88.3762626647949f); |
| _EIGEN_DECLARE_CONST_Packet4f(cephes_LOG2EF, 1.44269504088896341f); |
| _EIGEN_DECLARE_CONST_Packet4f(cephes_exp_C1, 0.693359375f); |
| _EIGEN_DECLARE_CONST_Packet4f(cephes_exp_C2, -2.12194440e-4f); |
| _EIGEN_DECLARE_CONST_Packet4f(cephes_exp_p0, 1.9875691500E-4f); |
| _EIGEN_DECLARE_CONST_Packet4f(cephes_exp_p1, 1.3981999507E-3f); |
| _EIGEN_DECLARE_CONST_Packet4f(cephes_exp_p2, 8.3334519073E-3f); |
| _EIGEN_DECLARE_CONST_Packet4f(cephes_exp_p3, 4.1665795894E-2f); |
| _EIGEN_DECLARE_CONST_Packet4f(cephes_exp_p4, 1.6666665459E-1f); |
| _EIGEN_DECLARE_CONST_Packet4f(cephes_exp_p5, 5.0000001201E-1f); |
| |
| x = vminq_f32(x, p4f_exp_hi); |
| x = vmaxq_f32(x, p4f_exp_lo); |
| |
| /* express exp(x) as exp(g + n*log(2)) */ |
| fx = vmlaq_f32(p4f_half, x, p4f_cephes_LOG2EF); |
| |
| /* perform a floorf */ |
| tmp = vcvtq_f32_s32(vcvtq_s32_f32(fx)); |
| |
| /* if greater, substract 1 */ |
| Packet4ui mask = vcgtq_f32(tmp, fx); |
| mask = vandq_u32(mask, vreinterpretq_u32_f32(p4f_1)); |
| |
| fx = vsubq_f32(tmp, vreinterpretq_f32_u32(mask)); |
| |
| tmp = vmulq_f32(fx, p4f_cephes_exp_C1); |
| Packet4f z = vmulq_f32(fx, p4f_cephes_exp_C2); |
| x = vsubq_f32(x, tmp); |
| x = vsubq_f32(x, z); |
| |
| Packet4f y = vmulq_f32(p4f_cephes_exp_p0, x); |
| z = vmulq_f32(x, x); |
| y = vaddq_f32(y, p4f_cephes_exp_p1); |
| y = vmulq_f32(y, x); |
| y = vaddq_f32(y, p4f_cephes_exp_p2); |
| y = vmulq_f32(y, x); |
| y = vaddq_f32(y, p4f_cephes_exp_p3); |
| y = vmulq_f32(y, x); |
| y = vaddq_f32(y, p4f_cephes_exp_p4); |
| y = vmulq_f32(y, x); |
| y = vaddq_f32(y, p4f_cephes_exp_p5); |
| |
| y = vmulq_f32(y, z); |
| y = vaddq_f32(y, x); |
| y = vaddq_f32(y, p4f_1); |
| |
| /* build 2^n */ |
| int32x4_t mm; |
| mm = vcvtq_s32_f32(fx); |
| mm = vaddq_s32(mm, p4i_0x7f); |
| mm = vshlq_n_s32(mm, 23); |
| Packet4f pow2n = vreinterpretq_f32_s32(mm); |
| |
| y = vmulq_f32(y, pow2n); |
| return y; |
| } |
| |
| } // end namespace internal |
| |
| } // end namespace Eigen |
| |
| #endif // EIGEN_MATH_FUNCTIONS_NEON_H |