1*f3087befSAndrew Turner /*
2*f3087befSAndrew Turner * Single-precision vector cosh(x) function.
3*f3087befSAndrew Turner *
4*f3087befSAndrew Turner * Copyright (c) 2022-2024, Arm Limited.
5*f3087befSAndrew Turner * SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception
6*f3087befSAndrew Turner */
7*f3087befSAndrew Turner
8*f3087befSAndrew Turner #include "v_expf_inline.h"
9*f3087befSAndrew Turner #include "v_math.h"
10*f3087befSAndrew Turner #include "test_sig.h"
11*f3087befSAndrew Turner #include "test_defs.h"
12*f3087befSAndrew Turner
13*f3087befSAndrew Turner static const struct data
14*f3087befSAndrew Turner {
15*f3087befSAndrew Turner struct v_expf_data expf_consts;
16*f3087befSAndrew Turner uint32x4_t tiny_bound;
17*f3087befSAndrew Turner float32x4_t bound;
18*f3087befSAndrew Turner #if WANT_SIMD_EXCEPT
19*f3087befSAndrew Turner uint32x4_t special_bound;
20*f3087befSAndrew Turner #endif
21*f3087befSAndrew Turner } data = {
22*f3087befSAndrew Turner .expf_consts = V_EXPF_DATA,
23*f3087befSAndrew Turner .tiny_bound = V4 (0x20000000), /* 0x1p-63: Round to 1 below this. */
24*f3087befSAndrew Turner /* 0x1.5a92d8p+6: expf overflows above this, so have to use special case. */
25*f3087befSAndrew Turner .bound = V4 (0x1.5a92d8p+6),
26*f3087befSAndrew Turner #if WANT_SIMD_EXCEPT
27*f3087befSAndrew Turner .special_bound = V4 (0x42ad496c),
28*f3087befSAndrew Turner #endif
29*f3087befSAndrew Turner };
30*f3087befSAndrew Turner
31*f3087befSAndrew Turner #if !WANT_SIMD_EXCEPT
32*f3087befSAndrew Turner static float32x4_t NOINLINE VPCS_ATTR
special_case(float32x4_t x,float32x4_t half_t,float32x4_t half_over_t,uint32x4_t special)33*f3087befSAndrew Turner special_case (float32x4_t x, float32x4_t half_t, float32x4_t half_over_t,
34*f3087befSAndrew Turner uint32x4_t special)
35*f3087befSAndrew Turner {
36*f3087befSAndrew Turner return v_call_f32 (coshf, x, vaddq_f32 (half_t, half_over_t), special);
37*f3087befSAndrew Turner }
38*f3087befSAndrew Turner #endif
39*f3087befSAndrew Turner
40*f3087befSAndrew Turner /* Single-precision vector cosh, using vector expf.
41*f3087befSAndrew Turner Maximum error is 2.38 ULP:
42*f3087befSAndrew Turner _ZGVnN4v_coshf (0x1.e8001ep+1) got 0x1.6a491ep+4
43*f3087befSAndrew Turner want 0x1.6a4922p+4. */
V_NAME_F1(cosh)44*f3087befSAndrew Turner float32x4_t VPCS_ATTR NOINLINE V_NAME_F1 (cosh) (float32x4_t x)
45*f3087befSAndrew Turner {
46*f3087befSAndrew Turner const struct data *d = ptr_barrier (&data);
47*f3087befSAndrew Turner
48*f3087befSAndrew Turner #if WANT_SIMD_EXCEPT
49*f3087befSAndrew Turner /* If fp exceptions are to be triggered correctly, fall back to the scalar
50*f3087befSAndrew Turner variant for all inputs if any input is a special value or above the bound
51*f3087befSAndrew Turner at which expf overflows. */
52*f3087befSAndrew Turner float32x4_t ax = vabsq_f32 (x);
53*f3087befSAndrew Turner uint32x4_t iax = vreinterpretq_u32_f32 (ax);
54*f3087befSAndrew Turner uint32x4_t special = vcgeq_u32 (iax, d->special_bound);
55*f3087befSAndrew Turner if (unlikely (v_any_u32 (special)))
56*f3087befSAndrew Turner return v_call_f32 (coshf, x, x, v_u32 (-1));
57*f3087befSAndrew Turner
58*f3087befSAndrew Turner uint32x4_t tiny = vcleq_u32 (iax, d->tiny_bound);
59*f3087befSAndrew Turner /* If any input is tiny, avoid underflow exception by fixing tiny lanes of
60*f3087befSAndrew Turner input to 0, which will generate no exceptions. */
61*f3087befSAndrew Turner if (unlikely (v_any_u32 (tiny)))
62*f3087befSAndrew Turner ax = v_zerofy_f32 (ax, tiny);
63*f3087befSAndrew Turner float32x4_t t = v_expf_inline (ax, &d->expf_consts);
64*f3087befSAndrew Turner #else
65*f3087befSAndrew Turner uint32x4_t special = vcageq_f32 (x, d->bound);
66*f3087befSAndrew Turner float32x4_t t = v_expf_inline (x, &d->expf_consts);
67*f3087befSAndrew Turner #endif
68*f3087befSAndrew Turner
69*f3087befSAndrew Turner /* Calculate cosh by exp(x) / 2 + exp(-x) / 2. */
70*f3087befSAndrew Turner float32x4_t half_t = vmulq_n_f32 (t, 0.5);
71*f3087befSAndrew Turner float32x4_t half_over_t = vdivq_f32 (v_f32 (0.5), t);
72*f3087befSAndrew Turner
73*f3087befSAndrew Turner #if WANT_SIMD_EXCEPT
74*f3087befSAndrew Turner if (unlikely (v_any_u32 (tiny)))
75*f3087befSAndrew Turner return vbslq_f32 (tiny, v_f32 (1), vaddq_f32 (half_t, half_over_t));
76*f3087befSAndrew Turner #else
77*f3087befSAndrew Turner if (unlikely (v_any_u32 (special)))
78*f3087befSAndrew Turner return special_case (x, half_t, half_over_t, special);
79*f3087befSAndrew Turner #endif
80*f3087befSAndrew Turner
81*f3087befSAndrew Turner return vaddq_f32 (half_t, half_over_t);
82*f3087befSAndrew Turner }
83*f3087befSAndrew Turner
84*f3087befSAndrew Turner HALF_WIDTH_ALIAS_F1 (cosh)
85*f3087befSAndrew Turner
86*f3087befSAndrew Turner TEST_SIG (V, F, 1, cosh, -10.0, 10.0)
87*f3087befSAndrew Turner TEST_ULP (V_NAME_F1 (cosh), 1.89)
88*f3087befSAndrew Turner TEST_DISABLE_FENV_IF_NOT (V_NAME_F1 (cosh), WANT_SIMD_EXCEPT)
89*f3087befSAndrew Turner TEST_SYM_INTERVAL (V_NAME_F1 (cosh), 0, 0x1p-63, 100)
90*f3087befSAndrew Turner TEST_SYM_INTERVAL (V_NAME_F1 (cosh), 0x1p-63, 1, 1000)
91*f3087befSAndrew Turner TEST_SYM_INTERVAL (V_NAME_F1 (cosh), 1, 0x1.5a92d8p+6, 80000)
92*f3087befSAndrew Turner TEST_SYM_INTERVAL (V_NAME_F1 (cosh), 0x1.5a92d8p+6, inf, 2000)
93