1/*
2 * Single-precision SVE acosh(x) function.
3 * Copyright (c) 2023, Arm Limited.
4 * SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception
5 */
6
7#include "sv_math.h"
8#include "pl_sig.h"
9#include "pl_test.h"
10
11#define One 0x3f800000
12#define Thres 0x20000000 /* asuint(0x1p64) - One.  */
13
14#include "sv_log1pf_inline.h"
15
16static svfloat32_t NOINLINE
17special_case (svfloat32_t x, svfloat32_t y, svbool_t special)
18{
19  return sv_call_f32 (acoshf, x, y, special);
20}
21
22/* Single-precision SVE acosh(x) routine. Implements the same algorithm as
23   vector acoshf and log1p.
24
25   Maximum error is 2.78 ULPs:
26   SV_NAME_F1 (acosh) (0x1.01e996p+0) got 0x1.f45b42p-4
27				     want 0x1.f45b3cp-4.  */
28svfloat32_t SV_NAME_F1 (acosh) (svfloat32_t x, const svbool_t pg)
29{
30  svuint32_t ix = svreinterpret_u32 (x);
31  svbool_t special = svcmpge (pg, svsub_x (pg, ix, One), Thres);
32
33  svfloat32_t xm1 = svsub_x (pg, x, 1.0f);
34  svfloat32_t u = svmul_x (pg, xm1, svadd_x (pg, x, 1.0f));
35  svfloat32_t y = sv_log1pf_inline (svadd_x (pg, xm1, svsqrt_x (pg, u)), pg);
36
37  if (unlikely (svptest_any (pg, special)))
38    return special_case (x, y, special);
39  return y;
40}
41
42PL_SIG (SV, F, 1, acosh, 1.0, 10.0)
43PL_TEST_ULP (SV_NAME_F1 (acosh), 2.29)
44PL_TEST_INTERVAL (SV_NAME_F1 (acosh), 0, 1, 500)
45PL_TEST_INTERVAL (SV_NAME_F1 (acosh), 1, 0x1p64, 100000)
46PL_TEST_INTERVAL (SV_NAME_F1 (acosh), 0x1p64, inf, 1000)
47PL_TEST_INTERVAL (SV_NAME_F1 (acosh), -0, -inf, 1000)
48