diff options
Diffstat (limited to 'pl/math/sv_sin_3u5.c')
-rw-r--r-- | pl/math/sv_sin_3u5.c | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/pl/math/sv_sin_3u5.c b/pl/math/sv_sin_3u5.c new file mode 100644 index 000000000000..a81f3fc80f3d --- /dev/null +++ b/pl/math/sv_sin_3u5.c @@ -0,0 +1,96 @@ +/* + * Double-precision SVE sin(x) function. + * + * Copyright (c) 2019-2023, Arm Limited. + * SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception + */ + +#include "sv_math.h" +#include "pl_sig.h" +#include "pl_test.h" + +static const struct data +{ + double inv_pi, pi_1, pi_2, pi_3, shift, range_val; + double poly[7]; +} data = { + .poly = { -0x1.555555555547bp-3, 0x1.1111111108a4dp-7, -0x1.a01a019936f27p-13, + 0x1.71de37a97d93ep-19, -0x1.ae633919987c6p-26, + 0x1.60e277ae07cecp-33, -0x1.9e9540300a1p-41, }, + + .inv_pi = 0x1.45f306dc9c883p-2, + .pi_1 = 0x1.921fb54442d18p+1, + .pi_2 = 0x1.1a62633145c06p-53, + .pi_3 = 0x1.c1cd129024e09p-106, + .shift = 0x1.8p52, + .range_val = 0x1p23, +}; + +#define C(i) sv_f64 (d->poly[i]) + +static svfloat64_t NOINLINE +special_case (svfloat64_t x, svfloat64_t y, svbool_t cmp) +{ + return sv_call_f64 (sin, x, y, cmp); +} + +/* A fast SVE implementation of sin. + Maximum observed error in [-pi/2, pi/2], where argument is not reduced, + is 2.87 ULP: + _ZGVsMxv_sin (0x1.921d5c6a07142p+0) got 0x1.fffffffa7dc02p-1 + want 0x1.fffffffa7dc05p-1 + Maximum observed error in the entire non-special domain ([-2^23, 2^23]) + is 3.22 ULP: + _ZGVsMxv_sin (0x1.5702447b6f17bp+22) got 0x1.ffdcd125c84fbp-3 + want 0x1.ffdcd125c84f8p-3. */ +svfloat64_t SV_NAME_D1 (sin) (svfloat64_t x, const svbool_t pg) +{ + const struct data *d = ptr_barrier (&data); + + /* Load some values in quad-word chunks to minimise memory access. */ + const svbool_t ptrue = svptrue_b64 (); + svfloat64_t shift = sv_f64 (d->shift); + svfloat64_t inv_pi_and_pi1 = svld1rq (ptrue, &d->inv_pi); + svfloat64_t pi2_and_pi3 = svld1rq (ptrue, &d->pi_2); + + /* n = rint(|x|/pi). */ + svfloat64_t n = svmla_lane (shift, x, inv_pi_and_pi1, 0); + svuint64_t odd = svlsl_x (pg, svreinterpret_u64 (n), 63); + n = svsub_x (pg, n, shift); + + /* r = |x| - n*(pi/2) (range reduction into -pi/2 .. pi/2). */ + svfloat64_t r = x; + r = svmls_lane (r, n, inv_pi_and_pi1, 1); + r = svmls_lane (r, n, pi2_and_pi3, 0); + r = svmls_lane (r, n, pi2_and_pi3, 1); + + /* sin(r) poly approx. */ + svfloat64_t r2 = svmul_x (pg, r, r); + svfloat64_t r3 = svmul_x (pg, r2, r); + svfloat64_t r4 = svmul_x (pg, r2, r2); + + svfloat64_t t1 = svmla_x (pg, C (4), C (5), r2); + svfloat64_t t2 = svmla_x (pg, C (2), C (3), r2); + svfloat64_t t3 = svmla_x (pg, C (0), C (1), r2); + + svfloat64_t y = svmla_x (pg, t1, C (6), r4); + y = svmla_x (pg, t2, y, r4); + y = svmla_x (pg, t3, y, r4); + y = svmla_x (pg, r, y, r3); + + svbool_t cmp = svacle (pg, x, d->range_val); + cmp = svnot_z (pg, cmp); + if (unlikely (svptest_any (pg, cmp))) + return special_case (x, + svreinterpret_f64 (sveor_z ( + svnot_z (pg, cmp), svreinterpret_u64 (y), odd)), + cmp); + + /* Copy sign. */ + return svreinterpret_f64 (sveor_z (pg, svreinterpret_u64 (y), odd)); +} + +PL_SIG (SV, D, 1, sin, -3.1, 3.1) +PL_TEST_ULP (SV_NAME_D1 (sin), 2.73) +PL_TEST_SYM_INTERVAL (SV_NAME_D1 (sin), 0, 0x1p23, 1000000) +PL_TEST_SYM_INTERVAL (SV_NAME_D1 (sin), 0x1p23, inf, 10000) |