1 /* 2 * Single-precision SVE sinh(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 "sv_math.h" 9 #include "pl_sig.h" 10 #include "pl_test.h" 11 12 #include "sv_expm1f_inline.h" 13 14 static const struct data 15 { 16 struct sv_expm1f_data expm1f_consts; 17 uint32_t halff, large_bound; 18 } data = { 19 .expm1f_consts = SV_EXPM1F_DATA, 20 .halff = 0x3f000000, 21 /* 0x1.61814ep+6, above which expm1f helper overflows. */ 22 .large_bound = 0x42b0c0a7, 23 }; 24 25 static svfloat32_t NOINLINE 26 special_case (svfloat32_t x, svfloat32_t y, svbool_t pg) 27 { 28 return sv_call_f32 (sinhf, x, y, pg); 29 } 30 31 /* Approximation for SVE single-precision sinh(x) using expm1. 32 sinh(x) = (exp(x) - exp(-x)) / 2. 33 The maximum error is 2.26 ULP: 34 _ZGVsMxv_sinhf (0x1.e34a9ep-4) got 0x1.e469ep-4 35 want 0x1.e469e4p-4. */ 36 svfloat32_t SV_NAME_F1 (sinh) (svfloat32_t x, const svbool_t pg) 37 { 38 const struct data *d = ptr_barrier (&data); 39 svfloat32_t ax = svabs_x (pg, x); 40 svuint32_t sign 41 = sveor_x (pg, svreinterpret_u32 (x), svreinterpret_u32 (ax)); 42 svfloat32_t halfsign = svreinterpret_f32 (svorr_x (pg, sign, d->halff)); 43 44 svbool_t special = svcmpge (pg, svreinterpret_u32 (ax), d->large_bound); 45 46 /* Up to the point that expm1f overflows, we can use it to calculate sinhf 47 using a slight rearrangement of the definition of asinh. This allows us to 48 retain acceptable accuracy for very small inputs. */ 49 svfloat32_t t = expm1f_inline (ax, pg, &d->expm1f_consts); 50 t = svadd_x (pg, t, svdiv_x (pg, t, svadd_x (pg, t, 1.0))); 51 52 /* Fall back to the scalar variant for any lanes which would cause 53 expm1f to overflow. */ 54 if (unlikely (svptest_any (pg, special))) 55 return special_case (x, svmul_x (pg, t, halfsign), special); 56 57 return svmul_x (pg, t, halfsign); 58 } 59 60 PL_SIG (SV, F, 1, sinh, -10.0, 10.0) 61 PL_TEST_ULP (SV_NAME_F1 (sinh), 1.76) 62 PL_TEST_SYM_INTERVAL (SV_NAME_F1 (sinh), 0, 0x1.6a09e8p-32, 1000) 63 PL_TEST_SYM_INTERVAL (SV_NAME_F1 (sinh), 0x1.6a09e8p-32, 0x42b0c0a7, 100000) 64 PL_TEST_SYM_INTERVAL (SV_NAME_F1 (sinh), 0x42b0c0a7, inf, 1000) 65