1*f3087befSAndrew Turner /* 2*f3087befSAndrew Turner * Double-precision vector acosh(x) function. 3*f3087befSAndrew Turner * Copyright (c) 2023-2024, Arm Limited. 4*f3087befSAndrew Turner * SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception 5*f3087befSAndrew Turner */ 6*f3087befSAndrew Turner 7*f3087befSAndrew Turner #include "v_math.h" 8*f3087befSAndrew Turner #include "test_sig.h" 9*f3087befSAndrew Turner #include "test_defs.h" 10*f3087befSAndrew Turner 11*f3087befSAndrew Turner #define WANT_V_LOG1P_K0_SHORTCUT 1 12*f3087befSAndrew Turner #include "v_log1p_inline.h" 13*f3087befSAndrew Turner 14*f3087befSAndrew Turner const static struct data 15*f3087befSAndrew Turner { 16*f3087befSAndrew Turner struct v_log1p_data log1p_consts; 17*f3087befSAndrew Turner uint64x2_t one, thresh; 18*f3087befSAndrew Turner } data = { 19*f3087befSAndrew Turner .log1p_consts = V_LOG1P_CONSTANTS_TABLE, 20*f3087befSAndrew Turner .one = V2 (0x3ff0000000000000), 21*f3087befSAndrew Turner .thresh = V2 (0x1ff0000000000000) /* asuint64(0x1p511) - asuint64(1). */ 22*f3087befSAndrew Turner }; 23*f3087befSAndrew Turner 24*f3087befSAndrew Turner static float64x2_t NOINLINE VPCS_ATTR 25*f3087befSAndrew Turner special_case (float64x2_t x, float64x2_t y, uint64x2_t special, 26*f3087befSAndrew Turner const struct v_log1p_data *d) 27*f3087befSAndrew Turner { 28*f3087befSAndrew Turner return v_call_f64 (acosh, x, log1p_inline (y, d), special); 29*f3087befSAndrew Turner } 30*f3087befSAndrew Turner 31*f3087befSAndrew Turner /* Vector approximation for double-precision acosh, based on log1p. 32*f3087befSAndrew Turner The largest observed error is 3.02 ULP in the region where the 33*f3087befSAndrew Turner argument to log1p falls in the k=0 interval, i.e. x close to 1: 34*f3087befSAndrew Turner _ZGVnN2v_acosh(0x1.00798aaf80739p+0) got 0x1.f2d6d823bc9dfp-5 35*f3087befSAndrew Turner want 0x1.f2d6d823bc9e2p-5. */ 36*f3087befSAndrew Turner VPCS_ATTR float64x2_t V_NAME_D1 (acosh) (float64x2_t x) 37*f3087befSAndrew Turner { 38*f3087befSAndrew Turner const struct data *d = ptr_barrier (&data); 39*f3087befSAndrew Turner uint64x2_t special 40*f3087befSAndrew Turner = vcgeq_u64 (vsubq_u64 (vreinterpretq_u64_f64 (x), d->one), d->thresh); 41*f3087befSAndrew Turner float64x2_t special_arg = x; 42*f3087befSAndrew Turner 43*f3087befSAndrew Turner #if WANT_SIMD_EXCEPT 44*f3087befSAndrew Turner if (unlikely (v_any_u64 (special))) 45*f3087befSAndrew Turner x = vbslq_f64 (special, vreinterpretq_f64_u64 (d->one), x); 46*f3087befSAndrew Turner #endif 47*f3087befSAndrew Turner 48*f3087befSAndrew Turner float64x2_t xm1 = vsubq_f64 (x, v_f64 (1.0)); 49*f3087befSAndrew Turner float64x2_t y = vaddq_f64 (x, v_f64 (1.0)); 50*f3087befSAndrew Turner y = vmulq_f64 (y, xm1); 51*f3087befSAndrew Turner y = vsqrtq_f64 (y); 52*f3087befSAndrew Turner y = vaddq_f64 (xm1, y); 53*f3087befSAndrew Turner 54*f3087befSAndrew Turner if (unlikely (v_any_u64 (special))) 55*f3087befSAndrew Turner return special_case (special_arg, y, special, &d->log1p_consts); 56*f3087befSAndrew Turner return log1p_inline (y, &d->log1p_consts); 57*f3087befSAndrew Turner } 58*f3087befSAndrew Turner 59*f3087befSAndrew Turner TEST_SIG (V, D, 1, acosh, 1.0, 10.0) 60*f3087befSAndrew Turner TEST_ULP (V_NAME_D1 (acosh), 2.53) 61*f3087befSAndrew Turner TEST_DISABLE_FENV_IF_NOT (V_NAME_D1 (acosh), WANT_SIMD_EXCEPT) 62*f3087befSAndrew Turner TEST_INTERVAL (V_NAME_D1 (acosh), 1, 0x1p511, 90000) 63*f3087befSAndrew Turner TEST_INTERVAL (V_NAME_D1 (acosh), 0x1p511, inf, 10000) 64*f3087befSAndrew Turner TEST_INTERVAL (V_NAME_D1 (acosh), 0, 1, 1000) 65*f3087befSAndrew Turner TEST_INTERVAL (V_NAME_D1 (acosh), -0, -inf, 10000) 66