1 /*
2  * Copyright (C) 2014 The Android Open Source Project
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *  * Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  *  * Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in
12  *    the documentation and/or other materials provided with the
13  *    distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/types.h>
30 
31 #include <math.h>
32 #include <machine/ieee.h>
33 
34 // These aren't declared in our <math.h>.
35 extern "C" int __isinf(double);
36 extern "C" int __isnan(double);
37 
38 union float_u {
39   float f;
40   ieee_single bits;
41 };
42 
43 union double_u {
44   double d;
45   ieee_double bits;
46 };
47 
__fpclassifyd(double d)48 int __fpclassifyd(double d) {
49   double_u u;
50   u.d = d;
51   if (u.bits.dbl_exp == 0) {
52     return ((u.bits.dbl_fracl | u.bits.dbl_frach) == 0) ? FP_ZERO : FP_SUBNORMAL;
53   }
54   if (u.bits.dbl_exp == DBL_EXP_INFNAN) {
55     return ((u.bits.dbl_fracl | u.bits.dbl_frach) == 0) ? FP_INFINITE : FP_NAN;
56   }
57   return FP_NORMAL;
58 }
59 __strong_alias(__fpclassify, __fpclassifyd); // glibc uses __fpclassify, BSD __fpclassifyd.
60 
__fpclassifyf(float f)61 int __fpclassifyf(float f) {
62   float_u u;
63   u.f = f;
64   if (u.bits.sng_exp == 0) {
65     return (u.bits.sng_frac == 0) ? FP_ZERO : FP_SUBNORMAL;
66   }
67   if (u.bits.sng_exp == SNG_EXP_INFNAN) {
68     return (u.bits.sng_frac == 0) ? FP_INFINITE : FP_NAN;
69   }
70   return FP_NORMAL;
71 }
72 
__isinf(double d)73 int __isinf(double d) {
74   return (__fpclassifyd(d) == FP_INFINITE);
75 }
76 __strong_alias(isinf, __isinf);
77 
__isinff(float f)78 int __isinff(float f) {
79   return (__fpclassifyf(f) == FP_INFINITE);
80 }
81 __strong_alias(isinff, __isinff);
82 
__isnan(double d)83 int __isnan(double d) {
84   return (__fpclassifyd(d) == FP_NAN);
85 }
86 __strong_alias(isnan, __isnan);
87 
__isnanf(float f)88 int __isnanf(float f) {
89   return (__fpclassifyf(f) == FP_NAN);
90 }
91 __strong_alias(isnanf, __isnanf);
92 
__isfinite(double d)93 int __isfinite(double d) {
94   int type = __fpclassifyd(d);
95   return ((type != FP_NAN) && (type != FP_INFINITE));
96 }
97 __strong_alias(isfinite, __isfinite);
98 
__isfinitef(float f)99 int __isfinitef(float f) {
100   int type = __fpclassifyf(f);
101   return ((type != FP_NAN) && (type != FP_INFINITE));
102 }
103 __strong_alias(isfinitef, __isfinitef);
104 
__isnormal(double d)105 int __isnormal(double d) {
106   return (__fpclassifyd(d) == FP_NORMAL);
107 }
108 __strong_alias(isnormal, __isnormal);
109 
__isnormalf(float f)110 int __isnormalf(float f) {
111   return (__fpclassifyf(f) == FP_NORMAL);
112 }
113 __strong_alias(isnormalf, __isnormalf);
114 
115 #if __LP64__
116 
117 // LP64 uses 128-bit long doubles.
118 
119 union long_double_u {
120   long double ld;
121   ieee_ext bits;
122 };
123 
124 #define zero_frac(b) ((b.ext_fracl | b.ext_fraclm | b.ext_frachm | b.ext_frach) == 0)
125 
__fpclassifyl(long double ld)126 int __fpclassifyl(long double ld) {
127   long_double_u u;
128   u.ld = ld;
129   if (u.bits.ext_exp == 0) {
130     return zero_frac(u.bits) ? FP_ZERO : FP_SUBNORMAL;
131   }
132   if (u.bits.ext_exp == EXT_EXP_INFNAN) {
133     return zero_frac(u.bits) ? FP_INFINITE : FP_NAN;
134   }
135   return FP_NORMAL;
136 }
137 
__isinfl(long double ld)138 int __isinfl(long double ld) {
139   return (__fpclassifyl(ld) == FP_INFINITE);
140 }
141 
__isnanl(long double ld)142 int __isnanl(long double ld) {
143   return (__fpclassifyl(ld) == FP_NAN);
144 }
145 
__isfinitel(long double ld)146 int __isfinitel(long double ld) {
147   int type = __fpclassifyl(ld);
148   return ((type != FP_NAN) && (type != FP_INFINITE));
149 }
150 
__isnormall(long double ld)151 int __isnormall(long double ld) {
152   return (__fpclassifyl(ld) == FP_NORMAL);
153 }
154 
155 #else
156 
157 // LP32 uses double as long double.
158 
159 __strong_alias(__fpclassifyl, __fpclassify);
160 __strong_alias(__isinfl, __isinf);
161 __strong_alias(__isnanl, __isnan);
162 __strong_alias(__isfinitel, __isfinite);
163 __strong_alias(__isnormall, __isnormal);
164 
165 #endif
166 
167 __strong_alias(isinfl, __isinfl);
168 __strong_alias(isnanl, __isnanl);
169 __strong_alias(isfinitel, __isfinitel);
170 __strong_alias(isnormall, __isnormall);
171