1 /*
2 * Single-precision SVE sinpi(x) function.
3 *
4 * Copyright (c) 2023-2024, Arm Limited.
5 * SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception
6 */
7
8 #include "sv_math.h"
9 #include "mathlib.h"
10 #include "test_sig.h"
11 #include "test_defs.h"
12 #include "sv_poly_f32.h"
13
14 static const struct data
15 {
16 float poly[6], range_val;
17 } data = {
18 /* Taylor series coefficents for sin(pi * x). */
19 .poly = { 0x1.921fb6p1f, -0x1.4abbcep2f, 0x1.466bc6p1f, -0x1.32d2ccp-1f,
20 0x1.50783p-4f, -0x1.e30750p-8f },
21 .range_val = 0x1p31,
22 };
23
24 /* A fast SVE implementation of sinpif.
25 Maximum error 2.48 ULP:
26 _ZGVsMxv_sinpif(0x1.d062b6p-2) got 0x1.fa8c06p-1
27 want 0x1.fa8c02p-1. */
SV_NAME_F1(sinpi)28 svfloat32_t SV_NAME_F1 (sinpi) (svfloat32_t x, const svbool_t pg)
29 {
30 const struct data *d = ptr_barrier (&data);
31
32 /* range reduction into -1/2 .. 1/2
33 with n = rint(x) and r = r - n. */
34 svfloat32_t n = svrinta_x (pg, x);
35 svfloat32_t r = svsub_x (pg, x, n);
36
37 /* Result should be negated based on if n is odd or not. */
38 svbool_t cmp = svaclt (pg, x, d->range_val);
39 svuint32_t intn = svreinterpret_u32 (svcvt_s32_z (pg, n));
40 svuint32_t sign = svlsl_z (cmp, intn, 31);
41
42 /* y = sin(r). */
43 svfloat32_t r2 = svmul_x (pg, r, r);
44 svfloat32_t y = sv_horner_5_f32_x (pg, r2, d->poly);
45 y = svmul_x (pg, y, r);
46
47 return svreinterpret_f32 (sveor_x (pg, svreinterpret_u32 (y), sign));
48 }
49
50 #if WANT_TRIGPI_TESTS
51 TEST_ULP (SV_NAME_F1 (sinpi), 1.99)
52 TEST_DISABLE_FENV (SV_NAME_F1 (sinpi))
53 TEST_SYM_INTERVAL (SV_NAME_F1 (sinpi), 0, 0x1p-31, 5000)
54 TEST_SYM_INTERVAL (SV_NAME_F1 (sinpi), 0x1p-31, 0.5, 10000)
55 TEST_SYM_INTERVAL (SV_NAME_F1 (sinpi), 0.5, 0x1p22f, 10000)
56 TEST_SYM_INTERVAL (SV_NAME_F1 (sinpi), 0x1p22f, inf, 10000)
57 #endif
58 CLOSE_SVE_ATTR
59