1/*
2 * Single-precision SVE asinh(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 "include/mathlib.h"
10#include "pl_sig.h"
11#include "pl_test.h"
12
13#include "sv_log1pf_inline.h"
14
15#define BigBound (0x5f800000)  /* asuint(0x1p64).  */
16
17static svfloat32_t NOINLINE
18special_case (svfloat32_t x, svfloat32_t y, svbool_t special)
19{
20  return sv_call_f32 (asinhf, x, y, special);
21}
22
23/* Single-precision SVE asinh(x) routine. Implements the same algorithm as
24   vector asinhf and log1p.
25
26   Maximum error is 2.48 ULPs:
27   SV_NAME_F1 (asinh) (0x1.008864p-3) got 0x1.ffbbbcp-4
28				     want 0x1.ffbbb8p-4.  */
29svfloat32_t SV_NAME_F1 (asinh) (svfloat32_t x, const svbool_t pg)
30{
31  svfloat32_t ax = svabs_x (pg, x);
32  svuint32_t iax = svreinterpret_u32 (ax);
33  svuint32_t sign = sveor_x (pg, svreinterpret_u32 (x), iax);
34  svbool_t special = svcmpge (pg, iax, BigBound);
35
36  /* asinh(x) = log(x + sqrt(x * x + 1)).
37     For positive x, asinh(x) = log1p(x + x * x / (1 + sqrt(x * x + 1))).  */
38  svfloat32_t ax2 = svmul_x (pg, ax, ax);
39  svfloat32_t d = svadd_x (pg, svsqrt_x (pg, svadd_x (pg, ax2, 1.0f)), 1.0f);
40  svfloat32_t y
41      = sv_log1pf_inline (svadd_x (pg, ax, svdiv_x (pg, ax2, d)), pg);
42
43  if (unlikely (svptest_any (pg, special)))
44    return special_case (
45	x, svreinterpret_f32 (svorr_x (pg, sign, svreinterpret_u32 (y))),
46	special);
47  return svreinterpret_f32 (svorr_x (pg, sign, svreinterpret_u32 (y)));
48}
49
50PL_SIG (SV, F, 1, asinh, -10.0, 10.0)
51PL_TEST_ULP (SV_NAME_F1 (asinh), 1.98)
52PL_TEST_SYM_INTERVAL (SV_NAME_F1 (asinh), 0, 0x1p-12, 4000)
53PL_TEST_SYM_INTERVAL (SV_NAME_F1 (asinh), 0x1p-12, 1.0, 20000)
54PL_TEST_SYM_INTERVAL (SV_NAME_F1 (asinh), 1.0, 0x1p64, 20000)
55PL_TEST_SYM_INTERVAL (SV_NAME_F1 (asinh), 0x1p64, inf, 4000)
56