1 /* complex/gsl_complex.h
2  *
3  * Copyright (C) 1996, 1997, 1998, 1999, 2000, 2007 Gerard Jungman, Brian Gough
4  * Copyright (C) 2020, 2021 Patrick Alken
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 3 of the License, or (at
9  * your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful, but
12  * WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
19  */
20 
21 #ifndef __GSL_COMPLEX_H__
22 #define __GSL_COMPLEX_H__
23 
24 #undef __BEGIN_DECLS
25 #undef __END_DECLS
26 #ifdef __cplusplus
27 # define __BEGIN_DECLS extern "C" {
28 # define __END_DECLS }
29 #else
30 # define __BEGIN_DECLS /* empty */
31 # define __END_DECLS /* empty */
32 #endif
33 
34 __BEGIN_DECLS
35 
36 
37 /* two consecutive built-in types as a complex number */
38 typedef double *       gsl_complex_packed ;
39 typedef float *        gsl_complex_packed_float  ;
40 typedef long double *  gsl_complex_packed_long_double ;
41 
42 typedef const double *       gsl_const_complex_packed ;
43 typedef const float *        gsl_const_complex_packed_float  ;
44 typedef const long double *  gsl_const_complex_packed_long_double ;
45 
46 
47 /* 2N consecutive built-in types as N complex numbers */
48 typedef double *       gsl_complex_packed_array ;
49 typedef float *        gsl_complex_packed_array_float  ;
50 typedef long double *  gsl_complex_packed_array_long_double ;
51 
52 typedef const double *       gsl_const_complex_packed_array ;
53 typedef const float *        gsl_const_complex_packed_array_float  ;
54 typedef const long double *  gsl_const_complex_packed_array_long_double ;
55 
56 
57 /* Yes... this seems weird. Trust us. The point is just that
58    sometimes you want to make it obvious that something is
59    an output value. The fact that it lacks a 'const' may not
60    be enough of a clue for people in some contexts.
61  */
62 typedef double *       gsl_complex_packed_ptr ;
63 typedef float *        gsl_complex_packed_float_ptr  ;
64 typedef long double *  gsl_complex_packed_long_double_ptr ;
65 
66 typedef const double *       gsl_const_complex_packed_ptr ;
67 typedef const float *        gsl_const_complex_packed_float_ptr  ;
68 typedef const long double *  gsl_const_complex_packed_long_double_ptr ;
69 
70 /*
71  * If <complex.h> is included, use the C99 complex type.  Otherwise
72  * define a type bit-compatible with C99 complex. The GSL_REAL and GSL_IMAG
73  * macros require C11 functionality also (_Generic)
74  */
75 
76 /* older gcc compilers claim to be C11 compliant but do not support _Generic */
77 #if defined(__GNUC__) && (__GNUC__ < 7)
78 #  define GSL_COMPLEX_LEGACY 1
79 #endif
80 
81 #if !defined(GSL_COMPLEX_LEGACY) &&          \
82      defined(_Complex_I) &&                  \
83      defined(complex) &&                     \
84      defined(I) &&                           \
85      defined(__STDC__) && (__STDC__ == 1) && \
86      defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L) /* C11 */
87 
88 #  define GSL_COMPLEX_DEFINE(R, C) typedef R _Complex C ;
89 
90 #  define GSL_COMPLEX_P(zp)        (&(zp))
91 #  define GSL_COMPLEX_EQ(z1,z2)    ((z1) == (z2))
92 #  define GSL_SET_COMPLEX(zp,x,y)  (*(zp) = (x) + I * (y))
93 
94 #  define GSL_REAL(z)              (_Generic((z),                             \
95                                      complex float       : ((float *) &(z)),  \
96                                      complex double      : ((double *) &(z)), \
97                                      complex long double : ((long double *) &(z)))[0])
98 
99 #  define GSL_IMAG(z)              (_Generic((z),                             \
100                                      complex float       : ((float *) &(z)),  \
101                                      complex double      : ((double *) &(z)), \
102                                      complex long double : ((long double *) &(z)))[1])
103 
104 #  define GSL_COMPLEX_P_REAL(zp)   GSL_REAL(*(zp))
105 #  define GSL_COMPLEX_P_IMAG(zp)   GSL_IMAG(*(zp))
106 #  define GSL_SET_REAL(zp,x)       do { GSL_REAL(*(zp)) = (x); } while(0)
107 #  define GSL_SET_IMAG(zp,x)       do { GSL_IMAG(*(zp)) = (x); } while(0)
108 
109 #else /* legacy complex definitions */
110 
111 /*
112  * According to the C17 standard, 6.2.5 paragraph 13:
113  *
114  * "Each complex type has the same representation and alignment requirements
115  * as an array type containing exactly two elements of the corresponding real
116  * type; the first element is equal to the real part, and the second element to
117  * the imaginary part, of the complex number."
118  */
119 
120 /*#  define GSL_COMPLEX_DEFINE(R, C) typedef R C[2]*/
121 #  define GSL_COMPLEX_DEFINE(R, C) typedef struct { R dat[2]; } C ;
122 
123 #  define GSL_REAL(z)              ((z).dat[0])
124 #  define GSL_IMAG(z)              ((z).dat[1])
125 #  define GSL_COMPLEX_P(zp)        ((zp)->dat)
126 #  define GSL_COMPLEX_P_REAL(zp)   ((zp)->dat[0])
127 #  define GSL_COMPLEX_P_IMAG(zp)   ((zp)->dat[1])
128 #  define GSL_COMPLEX_EQ(z1,z2)    (((z1).dat[0] == (z2).dat[0]) && ((z1).dat[1] == (z2).dat[1]))
129 
130 #  define GSL_SET_COMPLEX(zp,x,y)  do {(zp)->dat[0]=(x); (zp)->dat[1]=(y);} while(0)
131 #  define GSL_SET_REAL(zp,x)       do {(zp)->dat[0]=(x);} while(0)
132 #  define GSL_SET_IMAG(zp,y)       do {(zp)->dat[1]=(y);} while(0)
133 
134 #endif
135 
136 GSL_COMPLEX_DEFINE(double, gsl_complex)
137 GSL_COMPLEX_DEFINE(long double, gsl_complex_long_double)
138 GSL_COMPLEX_DEFINE(float, gsl_complex_float)
139 
140 #define GSL_SET_COMPLEX_PACKED(zp,n,x,y) do {*((zp)+2*(n))=(x); *((zp)+(2*(n)+1))=(y);} while(0)
141 
142 __END_DECLS
143 
144 #endif /* __GSL_COMPLEX_H__ */
145