diff options
Diffstat (limited to 'pl/math/sv_tanh_3u.c')
-rw-r--r-- | pl/math/sv_tanh_3u.c | 96 |
1 files changed, 0 insertions, 96 deletions
diff --git a/pl/math/sv_tanh_3u.c b/pl/math/sv_tanh_3u.c deleted file mode 100644 index f54139f1ddbc..000000000000 --- a/pl/math/sv_tanh_3u.c +++ /dev/null @@ -1,96 +0,0 @@ -/* - * Double-precision SVE tanh(x) function. - * Copyright (c) 2023, Arm Limited. - * SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception - */ - -#include "sv_math.h" -#include "poly_sve_f64.h" -#include "mathlib.h" -#include "pl_sig.h" -#include "pl_test.h" - -static const struct data -{ - float64_t poly[11]; - float64_t inv_ln2, ln2_hi, ln2_lo, shift; - uint64_t thresh, tiny_bound; -} data = { - /* Generated using Remez, deg=12 in [-log(2)/2, log(2)/2]. */ - .poly = { 0x1p-1, 0x1.5555555555559p-3, 0x1.555555555554bp-5, - 0x1.111111110f663p-7, 0x1.6c16c16c1b5f3p-10, - 0x1.a01a01affa35dp-13, 0x1.a01a018b4ecbbp-16, - 0x1.71ddf82db5bb4p-19, 0x1.27e517fc0d54bp-22, - 0x1.af5eedae67435p-26, 0x1.1f143d060a28ap-29, }, - - .inv_ln2 = 0x1.71547652b82fep0, - .ln2_hi = -0x1.62e42fefa39efp-1, - .ln2_lo = -0x1.abc9e3b39803fp-56, - .shift = 0x1.8p52, - - .tiny_bound = 0x3e40000000000000, /* asuint64 (0x1p-27). */ - /* asuint64(0x1.241bf835f9d5fp+4) - asuint64(tiny_bound). */ - .thresh = 0x01f241bf835f9d5f, -}; - -static inline svfloat64_t -expm1_inline (svfloat64_t x, const svbool_t pg, const struct data *d) -{ - /* Helper routine for calculating exp(x) - 1. Vector port of the helper from - the scalar variant of tanh. */ - - /* Reduce argument: f in [-ln2/2, ln2/2], i is exact. */ - svfloat64_t j - = svsub_x (pg, svmla_x (pg, sv_f64 (d->shift), x, d->inv_ln2), d->shift); - svint64_t i = svcvt_s64_x (pg, j); - svfloat64_t f = svmla_x (pg, x, j, d->ln2_hi); - f = svmla_x (pg, f, j, d->ln2_lo); - - /* Approximate expm1(f) using polynomial. */ - svfloat64_t f2 = svmul_x (pg, f, f); - svfloat64_t f4 = svmul_x (pg, f2, f2); - svfloat64_t p = svmla_x ( - pg, f, f2, - sv_estrin_10_f64_x (pg, f, f2, f4, svmul_x (pg, f4, f4), d->poly)); - - /* t = 2 ^ i. */ - svfloat64_t t = svscale_x (pg, sv_f64 (1), i); - /* expm1(x) = p * t + (t - 1). */ - return svmla_x (pg, svsub_x (pg, t, 1), p, t); -} - -static svfloat64_t NOINLINE -special_case (svfloat64_t x, svfloat64_t y, svbool_t special) -{ - return sv_call_f64 (tanh, x, y, special); -} - -/* SVE approximation for double-precision tanh(x), using a simplified - version of expm1. The greatest observed error is 2.77 ULP: - _ZGVsMxv_tanh(-0x1.c4a4ca0f9f3b7p-3) got -0x1.bd6a21a163627p-3 - want -0x1.bd6a21a163624p-3. */ -svfloat64_t SV_NAME_D1 (tanh) (svfloat64_t x, svbool_t pg) -{ - const struct data *d = ptr_barrier (&data); - - svuint64_t ia = svreinterpret_u64 (svabs_x (pg, x)); - - /* Trigger special-cases for tiny, boring and infinity/NaN. */ - svbool_t special = svcmpgt (pg, svsub_x (pg, ia, d->tiny_bound), d->thresh); - - svfloat64_t u = svadd_x (pg, x, x); - - /* tanh(x) = (e^2x - 1) / (e^2x + 1). */ - svfloat64_t q = expm1_inline (u, pg, d); - svfloat64_t qp2 = svadd_x (pg, q, 2); - - if (unlikely (svptest_any (pg, special))) - return special_case (x, svdiv_x (pg, q, qp2), special); - return svdiv_x (pg, q, qp2); -} - -PL_SIG (SV, D, 1, tanh, -10.0, 10.0) -PL_TEST_ULP (SV_NAME_D1 (tanh), 2.27) -PL_TEST_SYM_INTERVAL (SV_NAME_D1 (tanh), 0, 0x1p-27, 5000) -PL_TEST_SYM_INTERVAL (SV_NAME_D1 (tanh), 0x1p-27, 0x1.241bf835f9d5fp+4, 50000) -PL_TEST_SYM_INTERVAL (SV_NAME_D1 (tanh), 0x1.241bf835f9d5fp+4, inf, 1000) |