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27
28 /**
29 * Wrapper for math.h which makes sure we have definitions of all the c99
30 * functions.
31 */
32
33
34 #ifndef _C99_MATH_H_
35 #define _C99_MATH_H_
36
37 #include <math.h>
38 #include "c99_compat.h"
39
40
41 /* This is to ensure that we get M_PI, etc. definitions */
42 #if defined(_MSC_VER) && !defined(_USE_MATH_DEFINES)
43 #error _USE_MATH_DEFINES define required when building with MSVC
44 #endif
45
46
47 #if !defined(_MSC_VER) && \
48 __STDC_VERSION__ < 199901L && \
49 (!defined(_XOPEN_SOURCE) || _XOPEN_SOURCE < 600) && \
50 !defined(__cplusplus)
51
52 static inline long int
lrint(double d)53 lrint(double d)
54 {
55 long int rounded = (long int)(d + 0.5);
56
57 if (d - floor(d) == 0.5) {
58 if (rounded % 2 != 0)
59 rounded += (d > 0) ? -1 : 1;
60 }
61
62 return rounded;
63 }
64
65 static inline long int
lrintf(float f)66 lrintf(float f)
67 {
68 long int rounded = (long int)(f + 0.5f);
69
70 if (f - floorf(f) == 0.5f) {
71 if (rounded % 2 != 0)
72 rounded += (f > 0) ? -1 : 1;
73 }
74
75 return rounded;
76 }
77
78 static inline long long int
llrint(double d)79 llrint(double d)
80 {
81 long long int rounded = (long long int)(d + 0.5);
82
83 if (d - floor(d) == 0.5) {
84 if (rounded % 2 != 0)
85 rounded += (d > 0) ? -1 : 1;
86 }
87
88 return rounded;
89 }
90
91 static inline long long int
llrintf(float f)92 llrintf(float f)
93 {
94 long long int rounded = (long long int)(f + 0.5f);
95
96 if (f - floorf(f) == 0.5f) {
97 if (rounded % 2 != 0)
98 rounded += (f > 0) ? -1 : 1;
99 }
100
101 return rounded;
102 }
103
104 static inline float
exp2f(float f)105 exp2f(float f)
106 {
107 return powf(2.0f, f);
108 }
109
110 static inline double
exp2(double d)111 exp2(double d)
112 {
113 return pow(2.0, d);
114 }
115
116 #endif /* C99 */
117
118
119 /*
120 * signbit() is a macro on Linux. Not available on Windows.
121 */
122 #ifndef signbit
123 #define signbit(x) ((x) < 0.0f)
124 #endif
125
126
127 #ifndef M_PI
128 #define M_PI (3.14159265358979323846)
129 #endif
130
131 #ifndef M_E
132 #define M_E (2.7182818284590452354)
133 #endif
134
135 #ifndef M_LOG2E
136 #define M_LOG2E (1.4426950408889634074)
137 #endif
138
139 #ifndef FLT_MAX_EXP
140 #define FLT_MAX_EXP 128
141 #endif
142
143
144 #if defined(fpclassify)
145 /* ISO C99 says that fpclassify is a macro. Assume that any implementation
146 * of fpclassify, whether it's in a C99 compiler or not, will be a macro.
147 */
148 #elif defined(__cplusplus)
149 /* For C++, fpclassify() should be defined in <cmath> */
150 #elif defined(_MSC_VER)
151 /* Not required on VS2013 and above. Oddly, the fpclassify() function
152 * doesn't exist in such a form on MSVC. This is an implementation using
153 * slightly different lower-level Windows functions.
154 */
155 #include <float.h>
156
157 static inline enum {FP_NAN, FP_INFINITE, FP_ZERO, FP_SUBNORMAL, FP_NORMAL}
fpclassify(double x)158 fpclassify(double x)
159 {
160 switch(_fpclass(x)) {
161 case _FPCLASS_SNAN: /* signaling NaN */
162 case _FPCLASS_QNAN: /* quiet NaN */
163 return FP_NAN;
164 case _FPCLASS_NINF: /* negative infinity */
165 case _FPCLASS_PINF: /* positive infinity */
166 return FP_INFINITE;
167 case _FPCLASS_NN: /* negative normal */
168 case _FPCLASS_PN: /* positive normal */
169 return FP_NORMAL;
170 case _FPCLASS_ND: /* negative denormalized */
171 case _FPCLASS_PD: /* positive denormalized */
172 return FP_SUBNORMAL;
173 case _FPCLASS_NZ: /* negative zero */
174 case _FPCLASS_PZ: /* positive zero */
175 return FP_ZERO;
176 default:
177 /* Should never get here; but if we do, this will guarantee
178 * that the pattern is not treated like a number.
179 */
180 return FP_NAN;
181 }
182 }
183 #else
184 #error "Need to include or define an fpclassify function"
185 #endif
186
187
188 /* Since C++11, the following functions are part of the std namespace. Their C
189 * counteparts should still exist in the global namespace, however cmath
190 * undefines those functions, which in glibc 2.23, are defined as macros rather
191 * than functions as in glibc 2.22.
192 */
193 #if __cplusplus >= 201103L && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 23))
194 #include <cmath>
195
196 using std::fpclassify;
197 using std::isfinite;
198 using std::isinf;
199 using std::isnan;
200 using std::isnormal;
201 using std::signbit;
202 using std::isgreater;
203 using std::isgreaterequal;
204 using std::isless;
205 using std::islessequal;
206 using std::islessgreater;
207 using std::isunordered;
208 #endif
209
210
211 #endif /* #define _C99_MATH_H_ */
212