1 /*
2  * Single-precision vector sin function.
3  *
4  * Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5  * See https://llvm.org/LICENSE.txt for license information.
6  * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7  */
8 
9 #include "mathlib.h"
10 #include "v_math.h"
11 #if V_SUPPORTED
12 
13 static const float Poly[] = {
14   /* 1.886 ulp error */
15   0x1.5b2e76p-19f,
16   -0x1.9f42eap-13f,
17   0x1.110df4p-7f,
18   -0x1.555548p-3f,
19 };
20 #define Pi1 v_f32 (0x1.921fb6p+1f)
21 #define Pi2 v_f32 (-0x1.777a5cp-24f)
22 #define Pi3 v_f32 (-0x1.ee59dap-49f)
23 #define A3 v_f32 (Poly[3])
24 #define A5 v_f32 (Poly[2])
25 #define A7 v_f32 (Poly[1])
26 #define A9 v_f32 (Poly[0])
27 #define RangeVal v_f32 (0x1p20f)
28 #define InvPi v_f32 (0x1.45f306p-2f)
29 #define Shift v_f32 (0x1.8p+23f)
30 #define AbsMask v_u32 (0x7fffffff)
31 
32 VPCS_ATTR
33 static v_f32_t
34 specialcase (v_f32_t x, v_f32_t y, v_u32_t cmp)
35 {
36   /* Fall back to scalar code.  */
37   return v_call_f32 (sinf, x, y, cmp);
38 }
39 
40 VPCS_ATTR
41 v_f32_t
42 V_NAME(sinf) (v_f32_t x)
43 {
44   v_f32_t n, r, r2, y;
45   v_u32_t sign, odd, cmp;
46 
47   r = v_as_f32_u32 (v_as_u32_f32 (x) & AbsMask);
48   sign = v_as_u32_f32 (x) & ~AbsMask;
49   cmp = v_cond_u32 (v_as_u32_f32 (r) >= v_as_u32_f32 (RangeVal));
50 
51   /* n = rint(|x|/pi) */
52   n = v_fma_f32 (InvPi, r, Shift);
53   odd = v_as_u32_f32 (n) << 31;
54   n -= Shift;
55 
56   /* r = |x| - n*pi  (range reduction into -pi/2 .. pi/2) */
57   r = v_fma_f32 (-Pi1, n, r);
58   r = v_fma_f32 (-Pi2, n, r);
59   r = v_fma_f32 (-Pi3, n, r);
60 
61   /* y = sin(r) */
62   r2 = r * r;
63   y = v_fma_f32 (A9, r2, A7);
64   y = v_fma_f32 (y, r2, A5);
65   y = v_fma_f32 (y, r2, A3);
66   y = v_fma_f32 (y * r2, r, r);
67 
68   /* sign fix */
69   y = v_as_f32_u32 (v_as_u32_f32 (y) ^ sign ^ odd);
70 
71   if (unlikely (v_any_u32 (cmp)))
72     return specialcase (x, y, cmp);
73   return y;
74 }
75 VPCS_ALIAS
76 #endif
77