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68 lines
2.4 KiB
C
68 lines
2.4 KiB
C
/* Single-precision vector (SVE) sinh function
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Copyright (C) 2024 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include "sv_expm1f_inline.h"
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#include "sv_math.h"
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static const struct data
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{
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struct sv_expm1f_data expm1f_consts;
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uint32_t halff, large_bound;
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} data = {
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.expm1f_consts = SV_EXPM1F_DATA,
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.halff = 0x3f000000,
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/* 0x1.61814ep+6, above which expm1f helper overflows. */
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.large_bound = 0x42b0c0a7,
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};
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static svfloat32_t NOINLINE
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special_case (svfloat32_t x, svfloat32_t y, svbool_t pg)
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{
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return sv_call_f32 (sinhf, x, y, pg);
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}
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/* Approximation for SVE single-precision sinh(x) using expm1.
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sinh(x) = (exp(x) - exp(-x)) / 2.
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The maximum error is 2.26 ULP:
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_ZGVsMxv_sinhf (0x1.e34a9ep-4) got 0x1.e469ep-4
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want 0x1.e469e4p-4. */
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svfloat32_t SV_NAME_F1 (sinh) (svfloat32_t x, const svbool_t pg)
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{
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const struct data *d = ptr_barrier (&data);
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svfloat32_t ax = svabs_x (pg, x);
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svuint32_t sign
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= sveor_x (pg, svreinterpret_u32 (x), svreinterpret_u32 (ax));
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svfloat32_t halfsign = svreinterpret_f32 (svorr_x (pg, sign, d->halff));
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svbool_t special = svcmpge (pg, svreinterpret_u32 (ax), d->large_bound);
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/* Up to the point that expm1f overflows, we can use it to calculate sinhf
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using a slight rearrangement of the definition of asinh. This allows us to
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retain acceptable accuracy for very small inputs. */
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svfloat32_t t = expm1f_inline (ax, pg, &d->expm1f_consts);
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t = svadd_x (pg, t, svdiv_x (pg, t, svadd_x (pg, t, 1.0)));
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/* Fall back to the scalar variant for any lanes which would cause
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expm1f to overflow. */
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if (__glibc_unlikely (svptest_any (pg, special)))
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return special_case (x, svmul_x (pg, t, halfsign), special);
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return svmul_x (pg, t, halfsign);
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}
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