1 /* 2 * Single-precision SVE sinpi(x) function. 3 * 4 * Copyright (c) 2023, Arm Limited. 5 * SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception 6 */ 7 8 #include "mathlib.h" 9 #include "sv_math.h" 10 #include "pl_sig.h" 11 #include "pl_test.h" 12 #include "poly_sve_f32.h" 13 14 static const struct data 15 { 16 float poly[6]; 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 }; 22 23 /* A fast SVE implementation of sinpif. 24 Maximum error 2.48 ULP: 25 _ZGVsMxv_sinpif(0x1.d062b6p-2) got 0x1.fa8c06p-1 26 want 0x1.fa8c02p-1. */ 27 svfloat32_t SV_NAME_F1 (sinpi) (svfloat32_t x, const svbool_t pg) 28 { 29 const struct data *d = ptr_barrier (&data); 30 31 /* range reduction into -1/2 .. 1/2 32 with n = rint(x) and r = r - n. */ 33 svfloat32_t n = svrinta_x (pg, x); 34 svfloat32_t r = svsub_x (pg, x, n); 35 36 /* Result should be negated based on if n is odd or not. */ 37 svuint32_t intn = svreinterpret_u32 (svcvt_s32_x (pg, n)); 38 svuint32_t sign = svlsl_z (pg, intn, 31); 39 40 /* y = sin(r). */ 41 svfloat32_t r2 = svmul_x (pg, r, r); 42 svfloat32_t y = sv_horner_5_f32_x (pg, r2, d->poly); 43 y = svmul_x (pg, y, r); 44 45 return svreinterpret_f32 (sveor_x (pg, svreinterpret_u32 (y), sign)); 46 } 47 48 PL_SIG (SV, F, 1, sinpi, -0.9, 0.9) 49 PL_TEST_ULP (SV_NAME_F1 (sinpi), 1.99) 50 PL_TEST_SYM_INTERVAL (SV_NAME_F1 (sinpi), 0, 0x1p-31, 5000) 51 PL_TEST_SYM_INTERVAL (SV_NAME_F1 (sinpi), 0x1p-31, 0.5, 10000) 52 PL_TEST_SYM_INTERVAL (SV_NAME_F1 (sinpi), 0.5, 0x1p22f, 10000) 53 PL_TEST_SYM_INTERVAL (SV_NAME_F1 (sinpi), 0x1p22f, inf, 10000) 54