1/* Complex sine function for float types.
2 Copyright (C) 1997-2020 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
5
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
10
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <https://www.gnu.org/licenses/>. */
19
20#include <complex.h>
21#include <fenv.h>
22#include <math.h>
23#include <math_private.h>
24#include <math-underflow.h>
25#include <float.h>
26
27CFLOAT
28M_DECL_FUNC (__csin) (CFLOAT x)
29{
30 CFLOAT retval;
31 int negate = signbit (__real__ x);
32 int rcls = fpclassify (__real__ x);
33 int icls = fpclassify (__imag__ x);
34
35 __real__ x = M_FABS (__real__ x);
36
37 if (__glibc_likely (icls >= FP_ZERO))
38 {
39 /* Imaginary part is finite. */
40 if (__glibc_likely (rcls >= FP_ZERO))
41 {
42 /* Real part is finite. */
43 const int t = (int) ((M_MAX_EXP - 1) * M_MLIT (M_LN2));
44 FLOAT sinix, cosix;
45
46 if (__glibc_likely (__real__ x > M_MIN))
47 {
48 M_SINCOS (__real__ x, &sinix, &cosix);
49 }
50 else
51 {
52 sinix = __real__ x;
53 cosix = 1;
54 }
55
56 if (negate)
57 sinix = -sinix;
58
59 if (M_FABS (__imag__ x) > t)
60 {
61 FLOAT exp_t = M_EXP (t);
62 FLOAT ix = M_FABS (__imag__ x);
63 if (signbit (__imag__ x))
64 cosix = -cosix;
65 ix -= t;
66 sinix *= exp_t / 2;
67 cosix *= exp_t / 2;
68 if (ix > t)
69 {
70 ix -= t;
71 sinix *= exp_t;
72 cosix *= exp_t;
73 }
74 if (ix > t)
75 {
76 /* Overflow (original imaginary part of x > 3t). */
77 __real__ retval = M_MAX * sinix;
78 __imag__ retval = M_MAX * cosix;
79 }
80 else
81 {
82 FLOAT exp_val = M_EXP (ix);
83 __real__ retval = exp_val * sinix;
84 __imag__ retval = exp_val * cosix;
85 }
86 }
87 else
88 {
89 __real__ retval = M_COSH (__imag__ x) * sinix;
90 __imag__ retval = M_SINH (__imag__ x) * cosix;
91 }
92
93 math_check_force_underflow_complex (retval);
94 }
95 else
96 {
97 if (icls == FP_ZERO)
98 {
99 /* Imaginary part is 0.0. */
100 __real__ retval = __real__ x - __real__ x;
101 __imag__ retval = __imag__ x;
102 }
103 else
104 {
105 __real__ retval = M_NAN;
106 __imag__ retval = M_NAN;
107
108 feraiseexcept (FE_INVALID);
109 }
110 }
111 }
112 else if (icls == FP_INFINITE)
113 {
114 /* Imaginary part is infinite. */
115 if (rcls == FP_ZERO)
116 {
117 /* Real part is 0.0. */
118 __real__ retval = M_COPYSIGN (0, negate ? -1 : 1);
119 __imag__ retval = __imag__ x;
120 }
121 else if (rcls > FP_ZERO)
122 {
123 /* Real part is finite. */
124 FLOAT sinix, cosix;
125
126 if (__glibc_likely (__real__ x > M_MIN))
127 {
128 M_SINCOS (__real__ x, &sinix, &cosix);
129 }
130 else
131 {
132 sinix = __real__ x;
133 cosix = 1;
134 }
135
136 __real__ retval = M_COPYSIGN (M_HUGE_VAL, sinix);
137 __imag__ retval = M_COPYSIGN (M_HUGE_VAL, cosix);
138
139 if (negate)
140 __real__ retval = -__real__ retval;
141 if (signbit (__imag__ x))
142 __imag__ retval = -__imag__ retval;
143 }
144 else
145 {
146 __real__ retval = __real__ x - __real__ x;
147 __imag__ retval = M_HUGE_VAL;
148 }
149 }
150 else
151 {
152 if (rcls == FP_ZERO)
153 __real__ retval = M_COPYSIGN (0, negate ? -1 : 1);
154 else
155 __real__ retval = M_NAN;
156 __imag__ retval = M_NAN;
157 }
158
159 return retval;
160}
161
162declare_mgen_alias (__csin, csin)
163