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63551311 | 1 | /* Complex sine function for double. |
b168057a | 2 | Copyright (C) 1997-2015 Free Software Foundation, Inc. |
63551311 UD |
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 | |
41bdb6e2 AJ |
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. | |
63551311 UD |
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 | |
41bdb6e2 | 14 | Lesser General Public License for more details. |
63551311 | 15 | |
41bdb6e2 | 16 | You should have received a copy of the GNU Lesser General Public |
59ba27a6 PE |
17 | License along with the GNU C Library; if not, see |
18 | <http://www.gnu.org/licenses/>. */ | |
63551311 UD |
19 | |
20 | #include <complex.h> | |
779ae82e | 21 | #include <fenv.h> |
63551311 | 22 | #include <math.h> |
9277c064 | 23 | #include <math_private.h> |
e0b16cc2 | 24 | #include <float.h> |
63551311 UD |
25 | |
26 | __complex__ double | |
27 | __csin (__complex__ double x) | |
28 | { | |
779ae82e UD |
29 | __complex__ double retval; |
30 | int negate = signbit (__real__ x); | |
31 | int rcls = fpclassify (__real__ x); | |
32 | int icls = fpclassify (__imag__ x); | |
33 | ||
34 | __real__ x = fabs (__real__ x); | |
63551311 | 35 | |
a1ffb40e | 36 | if (__glibc_likely (icls >= FP_ZERO)) |
63551311 | 37 | { |
779ae82e | 38 | /* Imaginary part is finite. */ |
a1ffb40e | 39 | if (__glibc_likely (rcls >= FP_ZERO)) |
63551311 | 40 | { |
779ae82e | 41 | /* Real part is finite. */ |
e0b16cc2 | 42 | const int t = (int) ((DBL_MAX_EXP - 1) * M_LN2); |
779ae82e UD |
43 | double sinix, cosix; |
44 | ||
a1ffb40e | 45 | if (__glibc_likely (rcls != FP_SUBNORMAL)) |
6d3bf199 LD |
46 | { |
47 | __sincos (__real__ x, &sinix, &cosix); | |
48 | } | |
49 | else | |
50 | { | |
51 | sinix = __real__ x; | |
52 | cosix = 1.0; | |
53 | } | |
779ae82e | 54 | |
e0b16cc2 JM |
55 | if (fabs (__imag__ x) > t) |
56 | { | |
57 | double exp_t = __ieee754_exp (t); | |
58 | double ix = fabs (__imag__ x); | |
59 | if (signbit (__imag__ x)) | |
60 | cosix = -cosix; | |
61 | ix -= t; | |
62 | sinix *= exp_t / 2.0; | |
63 | cosix *= exp_t / 2.0; | |
64 | if (ix > t) | |
65 | { | |
66 | ix -= t; | |
67 | sinix *= exp_t; | |
68 | cosix *= exp_t; | |
69 | } | |
70 | if (ix > t) | |
71 | { | |
72 | /* Overflow (original imaginary part of x > 3t). */ | |
73 | __real__ retval = DBL_MAX * sinix; | |
74 | __imag__ retval = DBL_MAX * cosix; | |
75 | } | |
76 | else | |
77 | { | |
78 | double exp_val = __ieee754_exp (ix); | |
79 | __real__ retval = exp_val * sinix; | |
80 | __imag__ retval = exp_val * cosix; | |
81 | } | |
82 | } | |
83 | else | |
84 | { | |
85 | __real__ retval = __ieee754_cosh (__imag__ x) * sinix; | |
86 | __imag__ retval = __ieee754_sinh (__imag__ x) * cosix; | |
87 | } | |
779ae82e UD |
88 | |
89 | if (negate) | |
90 | __real__ retval = -__real__ retval; | |
f0302940 JM |
91 | |
92 | if (fabs (__real__ retval) < DBL_MIN) | |
93 | { | |
94 | volatile double force_underflow | |
95 | = __real__ retval * __real__ retval; | |
96 | (void) force_underflow; | |
97 | } | |
98 | if (fabs (__imag__ retval) < DBL_MIN) | |
99 | { | |
100 | volatile double force_underflow | |
101 | = __imag__ retval * __imag__ retval; | |
102 | (void) force_underflow; | |
103 | } | |
63551311 UD |
104 | } |
105 | else | |
106 | { | |
779ae82e UD |
107 | if (icls == FP_ZERO) |
108 | { | |
109 | /* Imaginary part is 0.0. */ | |
110 | __real__ retval = __nan (""); | |
111 | __imag__ retval = __imag__ x; | |
112 | ||
779ae82e UD |
113 | if (rcls == FP_INFINITE) |
114 | feraiseexcept (FE_INVALID); | |
779ae82e UD |
115 | } |
116 | else | |
117 | { | |
118 | __real__ retval = __nan (""); | |
119 | __imag__ retval = __nan (""); | |
120 | ||
779ae82e | 121 | feraiseexcept (FE_INVALID); |
779ae82e | 122 | } |
63551311 UD |
123 | } |
124 | } | |
779ae82e | 125 | else if (icls == FP_INFINITE) |
63551311 | 126 | { |
779ae82e UD |
127 | /* Imaginary part is infinite. */ |
128 | if (rcls == FP_ZERO) | |
129 | { | |
130 | /* Real part is 0.0. */ | |
131 | __real__ retval = __copysign (0.0, negate ? -1.0 : 1.0); | |
132 | __imag__ retval = __imag__ x; | |
133 | } | |
134 | else if (rcls > FP_ZERO) | |
135 | { | |
136 | /* Real part is finite. */ | |
137 | double sinix, cosix; | |
138 | ||
a1ffb40e | 139 | if (__glibc_likely (rcls != FP_SUBNORMAL)) |
6d3bf199 LD |
140 | { |
141 | __sincos (__real__ x, &sinix, &cosix); | |
142 | } | |
143 | else | |
144 | { | |
145 | sinix = __real__ x; | |
146 | cosix = 1.0; | |
147 | } | |
63551311 | 148 | |
779ae82e UD |
149 | __real__ retval = __copysign (HUGE_VAL, sinix); |
150 | __imag__ retval = __copysign (HUGE_VAL, cosix); | |
63551311 | 151 | |
779ae82e UD |
152 | if (negate) |
153 | __real__ retval = -__real__ retval; | |
154 | if (signbit (__imag__ x)) | |
155 | __imag__ retval = -__imag__ retval; | |
156 | } | |
157 | else | |
158 | { | |
159 | /* The addition raises the invalid exception. */ | |
160 | __real__ retval = __nan (""); | |
161 | __imag__ retval = HUGE_VAL; | |
63551311 | 162 | |
779ae82e UD |
163 | if (rcls == FP_INFINITE) |
164 | feraiseexcept (FE_INVALID); | |
779ae82e UD |
165 | } |
166 | } | |
167 | else | |
168 | { | |
169 | if (rcls == FP_ZERO) | |
170 | __real__ retval = __copysign (0.0, negate ? -1.0 : 1.0); | |
171 | else | |
172 | __real__ retval = __nan (""); | |
173 | __imag__ retval = __nan (""); | |
63551311 UD |
174 | } |
175 | ||
779ae82e | 176 | return retval; |
63551311 UD |
177 | } |
178 | weak_alias (__csin, csin) | |
179 | #ifdef NO_LONG_DOUBLE | |
180 | strong_alias (__csin, __csinl) | |
181 | weak_alias (__csin, csinl) | |
182 | #endif |