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Diffstat (limited to 'pl/math/v_expm1f_inline.h')
-rw-r--r-- | pl/math/v_expm1f_inline.h | 63 |
1 files changed, 0 insertions, 63 deletions
diff --git a/pl/math/v_expm1f_inline.h b/pl/math/v_expm1f_inline.h deleted file mode 100644 index 6ae94c452de2..000000000000 --- a/pl/math/v_expm1f_inline.h +++ /dev/null @@ -1,63 +0,0 @@ -/* - * Helper for single-precision routines which calculate exp(x) - 1 and do not - * need special-case handling - * - * Copyright (c) 2022-2023, Arm Limited. - * SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception - */ - -#ifndef PL_MATH_V_EXPM1F_INLINE_H -#define PL_MATH_V_EXPM1F_INLINE_H - -#include "v_math.h" -#include "math_config.h" -#include "poly_advsimd_f32.h" - -struct v_expm1f_data -{ - float32x4_t poly[5]; - float32x4_t invln2_and_ln2, shift; - int32x4_t exponent_bias; -}; - -/* Coefficients generated using fpminimax with degree=5 in [-log(2)/2, - log(2)/2]. Exponent bias is asuint(1.0f). - invln2_and_ln2 Stores constants: invln2, ln2_lo, ln2_hi, 0. */ -#define V_EXPM1F_DATA \ - { \ - .poly = { V4 (0x1.fffffep-2), V4 (0x1.5554aep-3), V4 (0x1.555736p-5), \ - V4 (0x1.12287cp-7), V4 (0x1.6b55a2p-10) }, \ - .shift = V4 (0x1.8p23f), .exponent_bias = V4 (0x3f800000), \ - .invln2_and_ln2 = { 0x1.715476p+0f, 0x1.62e4p-1f, 0x1.7f7d1cp-20f, 0 }, \ - } - -static inline float32x4_t -expm1f_inline (float32x4_t x, const struct v_expm1f_data *d) -{ - /* Helper routine for calculating exp(x) - 1. - Copied from v_expm1f_1u6.c, with all special-case handling removed - the - calling routine should handle special values if required. */ - - /* Reduce argument: f in [-ln2/2, ln2/2], i is exact. */ - float32x4_t j = vsubq_f32 ( - vfmaq_laneq_f32 (d->shift, x, d->invln2_and_ln2, 0), d->shift); - int32x4_t i = vcvtq_s32_f32 (j); - float32x4_t f = vfmsq_laneq_f32 (x, j, d->invln2_and_ln2, 1); - f = vfmsq_laneq_f32 (f, j, d->invln2_and_ln2, 2); - - /* Approximate expm1(f) with polynomial P, expm1(f) ~= f + f^2 * P(f). - Uses Estrin scheme, where the main _ZGVnN4v_expm1f routine uses - Horner. */ - float32x4_t f2 = vmulq_f32 (f, f); - float32x4_t f4 = vmulq_f32 (f2, f2); - float32x4_t p = v_estrin_4_f32 (f, f2, f4, d->poly); - p = vfmaq_f32 (f, f2, p); - - /* t = 2^i. */ - int32x4_t u = vaddq_s32 (vshlq_n_s32 (i, 23), d->exponent_bias); - float32x4_t t = vreinterpretq_f32_s32 (u); - /* expm1(x) ~= p * t + (t - 1). */ - return vfmaq_f32 (vsubq_f32 (t, v_f32 (1.0f)), p, t); -} - -#endif // PL_MATH_V_EXPM1F_INLINE_H |