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Diffstat (limited to 'pl/math/sv_expf_inline.h')
| -rw-r--r-- | pl/math/sv_expf_inline.h | 66 |
1 files changed, 0 insertions, 66 deletions
diff --git a/pl/math/sv_expf_inline.h b/pl/math/sv_expf_inline.h deleted file mode 100644 index 0ef4e0fda946..000000000000 --- a/pl/math/sv_expf_inline.h +++ /dev/null @@ -1,66 +0,0 @@ -/* - * SVE helper for single-precision routines which calculate exp(x) and do - * not need special-case handling - * - * Copyright (c) 2023, Arm Limited. - * SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception - */ - -#ifndef PL_MATH_SV_EXPF_INLINE_H -#define PL_MATH_SV_EXPF_INLINE_H - -#include "sv_math.h" -#include "pl_sig.h" -#include "pl_test.h" - -struct sv_expf_data -{ - float poly[5]; - float inv_ln2, ln2_hi, ln2_lo, shift; -}; - -/* Coefficients copied from the polynomial in AdvSIMD variant, reversed for - compatibility with polynomial helpers. Shift is 1.5*2^17 + 127. */ -#define SV_EXPF_DATA \ - { \ - .poly = { 0x1.ffffecp-1f, 0x1.fffdb6p-2f, 0x1.555e66p-3f, 0x1.573e2ep-5f, \ - 0x1.0e4020p-7f }, \ - \ - .inv_ln2 = 0x1.715476p+0f, .ln2_hi = 0x1.62e4p-1f, \ - .ln2_lo = 0x1.7f7d1cp-20f, .shift = 0x1.803f8p17f, \ - } - -#define C(i) sv_f32 (d->poly[i]) - -static inline svfloat32_t -expf_inline (svfloat32_t x, const svbool_t pg, const struct sv_expf_data *d) -{ - /* exp(x) = 2^n (1 + poly(r)), with 1 + poly(r) in [1/sqrt(2),sqrt(2)] - x = ln2*n + r, with r in [-ln2/2, ln2/2]. */ - - /* Load some constants in quad-word chunks to minimise memory access. */ - svfloat32_t c4_invln2_and_ln2 = svld1rq (svptrue_b32 (), &d->poly[4]); - - /* n = round(x/(ln2/N)). */ - svfloat32_t z = svmla_lane (sv_f32 (d->shift), x, c4_invln2_and_ln2, 1); - svfloat32_t n = svsub_x (pg, z, d->shift); - - /* r = x - n*ln2/N. */ - svfloat32_t r = svmls_lane (x, n, c4_invln2_and_ln2, 2); - r = svmls_lane (r, n, c4_invln2_and_ln2, 3); - - /* scale = 2^(n/N). */ - svfloat32_t scale = svexpa (svreinterpret_u32_f32 (z)); - - /* y = exp(r) - 1 ~= r + C0 r^2 + C1 r^3 + C2 r^4 + C3 r^5 + C4 r^6. */ - svfloat32_t p12 = svmla_x (pg, C (1), C (2), r); - svfloat32_t p34 = svmla_lane (C (3), r, c4_invln2_and_ln2, 0); - svfloat32_t r2 = svmul_f32_x (pg, r, r); - svfloat32_t p14 = svmla_x (pg, p12, p34, r2); - svfloat32_t p0 = svmul_f32_x (pg, r, C (0)); - svfloat32_t poly = svmla_x (pg, p0, r2, p14); - - return svmla_x (pg, scale, scale, poly); -} - -#endif // PL_MATH_SV_EXPF_INLINE_H
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