diff options
Diffstat (limited to 'pl/math/sv_acos_2u.c')
| -rw-r--r-- | pl/math/sv_acos_2u.c | 91 |
1 files changed, 0 insertions, 91 deletions
diff --git a/pl/math/sv_acos_2u.c b/pl/math/sv_acos_2u.c deleted file mode 100644 index e06db6cae6af..000000000000 --- a/pl/math/sv_acos_2u.c +++ /dev/null @@ -1,91 +0,0 @@ -/* - * Double-precision SVE acos(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 "pl_sig.h" -#include "pl_test.h" - -static const struct data -{ - float64_t poly[12]; - float64_t pi, pi_over_2; -} data = { - /* Polynomial approximation of (asin(sqrt(x)) - sqrt(x)) / (x * sqrt(x)) - on [ 0x1p-106, 0x1p-2 ], relative error: 0x1.c3d8e169p-57. */ - .poly = { 0x1.555555555554ep-3, 0x1.3333333337233p-4, 0x1.6db6db67f6d9fp-5, - 0x1.f1c71fbd29fbbp-6, 0x1.6e8b264d467d6p-6, 0x1.1c5997c357e9dp-6, - 0x1.c86a22cd9389dp-7, 0x1.856073c22ebbep-7, 0x1.fd1151acb6bedp-8, - 0x1.087182f799c1dp-6, -0x1.6602748120927p-7, 0x1.cfa0dd1f9478p-6, }, - .pi = 0x1.921fb54442d18p+1, - .pi_over_2 = 0x1.921fb54442d18p+0, -}; - -/* Double-precision SVE implementation of vector acos(x). - - For |x| in [0, 0.5], use an order 11 polynomial P such that the final - approximation of asin is an odd polynomial: - - acos(x) ~ pi/2 - (x + x^3 P(x^2)). - - The largest observed error in this region is 1.18 ulps, - _ZGVsMxv_acos (0x1.fbc5fe28ee9e3p-2) got 0x1.0d4d0f55667f6p+0 - want 0x1.0d4d0f55667f7p+0. - - For |x| in [0.5, 1.0], use same approximation with a change of variable - - acos(x) = y + y * z * P(z), with z = (1-x)/2 and y = sqrt(z). - - The largest observed error in this region is 1.52 ulps, - _ZGVsMxv_acos (0x1.24024271a500ap-1) got 0x1.ed82df4243f0dp-1 - want 0x1.ed82df4243f0bp-1. */ -svfloat64_t SV_NAME_D1 (acos) (svfloat64_t x, const svbool_t pg) -{ - const struct data *d = ptr_barrier (&data); - - svuint64_t sign = svand_x (pg, svreinterpret_u64 (x), 0x8000000000000000); - svfloat64_t ax = svabs_x (pg, x); - - svbool_t a_gt_half = svacgt (pg, x, 0.5); - - /* Evaluate polynomial Q(x) = z + z * z2 * P(z2) with - z2 = x ^ 2 and z = |x| , if |x| < 0.5 - z2 = (1 - |x|) / 2 and z = sqrt(z2), if |x| >= 0.5. */ - svfloat64_t z2 = svsel (a_gt_half, svmls_x (pg, sv_f64 (0.5), ax, 0.5), - svmul_x (pg, x, x)); - svfloat64_t z = svsqrt_m (ax, a_gt_half, z2); - - /* Use a single polynomial approximation P for both intervals. */ - svfloat64_t z4 = svmul_x (pg, z2, z2); - svfloat64_t z8 = svmul_x (pg, z4, z4); - svfloat64_t z16 = svmul_x (pg, z8, z8); - svfloat64_t p = sv_estrin_11_f64_x (pg, z2, z4, z8, z16, d->poly); - - /* Finalize polynomial: z + z * z2 * P(z2). */ - p = svmla_x (pg, z, svmul_x (pg, z, z2), p); - - /* acos(|x|) = pi/2 - sign(x) * Q(|x|), for |x| < 0.5 - = 2 Q(|x|) , for 0.5 < x < 1.0 - = pi - 2 Q(|x|) , for -1.0 < x < -0.5. */ - svfloat64_t y - = svreinterpret_f64 (svorr_x (pg, svreinterpret_u64 (p), sign)); - - svbool_t is_neg = svcmplt (pg, x, 0.0); - svfloat64_t off = svdup_f64_z (is_neg, d->pi); - svfloat64_t mul = svsel (a_gt_half, sv_f64 (2.0), sv_f64 (-1.0)); - svfloat64_t add = svsel (a_gt_half, off, sv_f64 (d->pi_over_2)); - - return svmla_x (pg, add, mul, y); -} - -PL_SIG (SV, D, 1, acos, -1.0, 1.0) -PL_TEST_ULP (SV_NAME_D1 (acos), 1.02) -PL_TEST_INTERVAL (SV_NAME_D1 (acos), 0, 0.5, 50000) -PL_TEST_INTERVAL (SV_NAME_D1 (acos), 0.5, 1.0, 50000) -PL_TEST_INTERVAL (SV_NAME_D1 (acos), 1.0, 0x1p11, 50000) -PL_TEST_INTERVAL (SV_NAME_D1 (acos), 0x1p11, inf, 20000) -PL_TEST_INTERVAL (SV_NAME_D1 (acos), -0, -inf, 20000) |