1 /* 2 * Double-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_f64.h" 13 14 static const struct data 15 { 16 double poly[10], range_val; 17 } data = { 18 /* Polynomial coefficients generated using Remez algorithm, 19 see sinpi.sollya for details. */ 20 .poly = { 0x1.921fb54442d184p1, -0x1.4abbce625be53p2, 0x1.466bc6775ab16p1, 21 -0x1.32d2cce62dc33p-1, 0x1.507834891188ep-4, -0x1.e30750a28c88ep-8, 22 0x1.e8f48308acda4p-12, -0x1.6fc0032b3c29fp-16, 23 0x1.af86ae521260bp-21, -0x1.012a9870eeb7dp-25 }, 24 .range_val = 0x1p63, 25 }; 26 27 /* A fast SVE implementation of sinpi. 28 Maximum error 3.10 ULP: 29 _ZGVsMxv_sinpi(0x1.df1a14f1b235p-2) got 0x1.fd64f541606cp-1 30 want 0x1.fd64f541606c3p-1. */ 31 svfloat64_t SV_NAME_D1 (sinpi) (svfloat64_t x, const svbool_t pg) 32 { 33 const struct data *d = ptr_barrier (&data); 34 35 /* range reduction into -1/2 .. 1/2) 36 with n = rint(x) and r = r - n. */ 37 svfloat64_t n = svrinta_x (pg, x); 38 svfloat64_t r = svsub_x (pg, x, n); 39 40 /* Result should be negated based on if n is odd or not. */ 41 svbool_t cmp = svaclt (pg, x, d->range_val); 42 svuint64_t intn = svreinterpret_u64 (svcvt_s64_z (pg, n)); 43 svuint64_t sign = svlsl_z (cmp, intn, 63); 44 45 /* y = sin(r). */ 46 svfloat64_t r2 = svmul_x (pg, r, r); 47 svfloat64_t r4 = svmul_x (pg, r2, r2); 48 svfloat64_t y = sv_pw_horner_9_f64_x (pg, r2, r4, d->poly); 49 y = svmul_x (pg, y, r); 50 51 return svreinterpret_f64 (sveor_x (pg, svreinterpret_u64 (y), sign)); 52 } 53 54 #if WANT_TRIGPI_TESTS 55 TEST_ULP (SV_NAME_D1 (sinpi), 2.61) 56 TEST_DISABLE_FENV (SV_NAME_D1 (sinpi)) 57 TEST_SYM_INTERVAL (SV_NAME_D1 (sinpi), 0, 0x1p-63, 5000) 58 TEST_SYM_INTERVAL (SV_NAME_D1 (sinpi), 0x1p-63, 0.5, 10000) 59 TEST_SYM_INTERVAL (SV_NAME_D1 (sinpi), 0.5, 0x1p51, 10000) 60 TEST_SYM_INTERVAL (SV_NAME_D1 (sinpi), 0x1p51, inf, 10000) 61 #endif 62 CLOSE_SVE_ATTR 63