1 /* 2 * Single-precision SVE cosh(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_expf_inline.h" 13 14 static const struct data 15 { 16 struct sv_expf_data expf_consts; 17 uint32_t special_bound; 18 } data = { 19 .expf_consts = SV_EXPF_DATA, 20 /* 0x1.5a92d8p+6: expf overflows above this, so have to use special case. */ 21 .special_bound = 0x42ad496c, 22 }; 23 24 static svfloat32_t NOINLINE 25 special_case (svfloat32_t x, svfloat32_t y, svbool_t pg) 26 { 27 return sv_call_f32 (coshf, x, y, pg); 28 } 29 30 /* Single-precision vector cosh, using vector expf. 31 Maximum error is 1.89 ULP: 32 _ZGVsMxv_coshf (-0x1.65898cp+6) got 0x1.f00aep+127 33 want 0x1.f00adcp+127. */ 34 svfloat32_t SV_NAME_F1 (cosh) (svfloat32_t x, svbool_t pg) 35 { 36 const struct data *d = ptr_barrier (&data); 37 38 svfloat32_t ax = svabs_x (pg, x); 39 svbool_t special = svcmpge (pg, svreinterpret_u32 (ax), d->special_bound); 40 41 /* Calculate cosh by exp(x) / 2 + exp(-x) / 2. */ 42 svfloat32_t t = expf_inline (ax, pg, &d->expf_consts); 43 svfloat32_t half_t = svmul_x (pg, t, 0.5); 44 svfloat32_t half_over_t = svdivr_x (pg, t, 0.5); 45 46 if (unlikely (svptest_any (pg, special))) 47 return special_case (x, svadd_x (pg, half_t, half_over_t), special); 48 49 return svadd_x (pg, half_t, half_over_t); 50 } 51 52 PL_SIG (SV, F, 1, cosh, -10.0, 10.0) 53 PL_TEST_ULP (SV_NAME_F1 (cosh), 1.39) 54 PL_TEST_SYM_INTERVAL (SV_NAME_F1 (cosh), 0, 0x1p-63, 100) 55 PL_TEST_SYM_INTERVAL (SV_NAME_F1 (cosh), 0, 0x1.5a92d8p+6, 80000) 56 PL_TEST_SYM_INTERVAL (SV_NAME_F1 (cosh), 0x1.5a92d8p+6, inf, 2000) 57