1*412f47f9SXin Li /*
2*412f47f9SXin Li * Single-precision SVE asinh(x) function.
3*412f47f9SXin Li *
4*412f47f9SXin Li * Copyright (c) 2023, Arm Limited.
5*412f47f9SXin Li * SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception
6*412f47f9SXin Li */
7*412f47f9SXin Li
8*412f47f9SXin Li #include "sv_math.h"
9*412f47f9SXin Li #include "include/mathlib.h"
10*412f47f9SXin Li #include "pl_sig.h"
11*412f47f9SXin Li #include "pl_test.h"
12*412f47f9SXin Li
13*412f47f9SXin Li #include "sv_log1pf_inline.h"
14*412f47f9SXin Li
15*412f47f9SXin Li #define BigBound (0x5f800000) /* asuint(0x1p64). */
16*412f47f9SXin Li
17*412f47f9SXin Li static svfloat32_t NOINLINE
special_case(svfloat32_t x,svfloat32_t y,svbool_t special)18*412f47f9SXin Li special_case (svfloat32_t x, svfloat32_t y, svbool_t special)
19*412f47f9SXin Li {
20*412f47f9SXin Li return sv_call_f32 (asinhf, x, y, special);
21*412f47f9SXin Li }
22*412f47f9SXin Li
23*412f47f9SXin Li /* Single-precision SVE asinh(x) routine. Implements the same algorithm as
24*412f47f9SXin Li vector asinhf and log1p.
25*412f47f9SXin Li
26*412f47f9SXin Li Maximum error is 2.48 ULPs:
27*412f47f9SXin Li SV_NAME_F1 (asinh) (0x1.008864p-3) got 0x1.ffbbbcp-4
28*412f47f9SXin Li want 0x1.ffbbb8p-4. */
SV_NAME_F1(asinh)29*412f47f9SXin Li svfloat32_t SV_NAME_F1 (asinh) (svfloat32_t x, const svbool_t pg)
30*412f47f9SXin Li {
31*412f47f9SXin Li svfloat32_t ax = svabs_x (pg, x);
32*412f47f9SXin Li svuint32_t iax = svreinterpret_u32 (ax);
33*412f47f9SXin Li svuint32_t sign = sveor_x (pg, svreinterpret_u32 (x), iax);
34*412f47f9SXin Li svbool_t special = svcmpge (pg, iax, BigBound);
35*412f47f9SXin Li
36*412f47f9SXin Li /* asinh(x) = log(x + sqrt(x * x + 1)).
37*412f47f9SXin Li For positive x, asinh(x) = log1p(x + x * x / (1 + sqrt(x * x + 1))). */
38*412f47f9SXin Li svfloat32_t ax2 = svmul_x (pg, ax, ax);
39*412f47f9SXin Li svfloat32_t d = svadd_x (pg, svsqrt_x (pg, svadd_x (pg, ax2, 1.0f)), 1.0f);
40*412f47f9SXin Li svfloat32_t y
41*412f47f9SXin Li = sv_log1pf_inline (svadd_x (pg, ax, svdiv_x (pg, ax2, d)), pg);
42*412f47f9SXin Li
43*412f47f9SXin Li if (unlikely (svptest_any (pg, special)))
44*412f47f9SXin Li return special_case (
45*412f47f9SXin Li x, svreinterpret_f32 (svorr_x (pg, sign, svreinterpret_u32 (y))),
46*412f47f9SXin Li special);
47*412f47f9SXin Li return svreinterpret_f32 (svorr_x (pg, sign, svreinterpret_u32 (y)));
48*412f47f9SXin Li }
49*412f47f9SXin Li
50*412f47f9SXin Li PL_SIG (SV, F, 1, asinh, -10.0, 10.0)
51*412f47f9SXin Li PL_TEST_ULP (SV_NAME_F1 (asinh), 1.98)
52*412f47f9SXin Li PL_TEST_SYM_INTERVAL (SV_NAME_F1 (asinh), 0, 0x1p-12, 4000)
53*412f47f9SXin Li PL_TEST_SYM_INTERVAL (SV_NAME_F1 (asinh), 0x1p-12, 1.0, 20000)
54*412f47f9SXin Li PL_TEST_SYM_INTERVAL (SV_NAME_F1 (asinh), 1.0, 0x1p64, 20000)
55*412f47f9SXin Li PL_TEST_SYM_INTERVAL (SV_NAME_F1 (asinh), 0x1p64, inf, 4000)
56