xref: /netbsd-src/lib/libm/src/math_private.h (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*
2  * ====================================================
3  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
4  *
5  * Developed at SunPro, a Sun Microsystems, Inc. business.
6  * Permission to use, copy, modify, and distribute this
7  * software is freely granted, provided that this notice
8  * is preserved.
9  * ====================================================
10  */
11 
12 /*
13  * from: @(#)fdlibm.h 5.1 93/09/24
14  * $NetBSD: math_private.h,v 1.14 2010/01/11 16:28:39 christos Exp $
15  */
16 
17 #ifndef _MATH_PRIVATE_H_
18 #define _MATH_PRIVATE_H_
19 
20 #include <sys/types.h>
21 
22 /* The original fdlibm code used statements like:
23 	n0 = ((*(int*)&one)>>29)^1;		* index of high word *
24 	ix0 = *(n0+(int*)&x);			* high word of x *
25 	ix1 = *((1-n0)+(int*)&x);		* low word of x *
26    to dig two 32 bit words out of the 64 bit IEEE floating point
27    value.  That is non-ANSI, and, moreover, the gcc instruction
28    scheduler gets it wrong.  We instead use the following macros.
29    Unlike the original code, we determine the endianness at compile
30    time, not at run time; I don't see much benefit to selecting
31    endianness at run time.  */
32 
33 /* A union which permits us to convert between a double and two 32 bit
34    ints.  */
35 
36 /*
37  * The ARM ports are little endian except for the FPA word order which is
38  * big endian.
39  */
40 
41 #if (BYTE_ORDER == BIG_ENDIAN) || (defined(__arm__) && !defined(__VFP_FP__))
42 
43 typedef union
44 {
45   double value;
46   struct
47   {
48     u_int32_t msw;
49     u_int32_t lsw;
50   } parts;
51 } ieee_double_shape_type;
52 
53 #endif
54 
55 #if (BYTE_ORDER == LITTLE_ENDIAN) && \
56     !(defined(__arm__) && !defined(__VFP_FP__))
57 
58 typedef union
59 {
60   double value;
61   struct
62   {
63     u_int32_t lsw;
64     u_int32_t msw;
65   } parts;
66 } ieee_double_shape_type;
67 
68 #endif
69 
70 /* Get two 32 bit ints from a double.  */
71 
72 #define EXTRACT_WORDS(ix0,ix1,d)				\
73 do {								\
74   ieee_double_shape_type ew_u;					\
75   ew_u.value = (d);						\
76   (ix0) = ew_u.parts.msw;					\
77   (ix1) = ew_u.parts.lsw;					\
78 } while (/*CONSTCOND*/0)
79 
80 /* Get the more significant 32 bit int from a double.  */
81 
82 #define GET_HIGH_WORD(i,d)					\
83 do {								\
84   ieee_double_shape_type gh_u;					\
85   gh_u.value = (d);						\
86   (i) = gh_u.parts.msw;						\
87 } while (/*CONSTCOND*/0)
88 
89 /* Get the less significant 32 bit int from a double.  */
90 
91 #define GET_LOW_WORD(i,d)					\
92 do {								\
93   ieee_double_shape_type gl_u;					\
94   gl_u.value = (d);						\
95   (i) = gl_u.parts.lsw;						\
96 } while (/*CONSTCOND*/0)
97 
98 /* Set a double from two 32 bit ints.  */
99 
100 #define INSERT_WORDS(d,ix0,ix1)					\
101 do {								\
102   ieee_double_shape_type iw_u;					\
103   iw_u.parts.msw = (ix0);					\
104   iw_u.parts.lsw = (ix1);					\
105   (d) = iw_u.value;						\
106 } while (/*CONSTCOND*/0)
107 
108 /* Set the more significant 32 bits of a double from an int.  */
109 
110 #define SET_HIGH_WORD(d,v)					\
111 do {								\
112   ieee_double_shape_type sh_u;					\
113   sh_u.value = (d);						\
114   sh_u.parts.msw = (v);						\
115   (d) = sh_u.value;						\
116 } while (/*CONSTCOND*/0)
117 
118 /* Set the less significant 32 bits of a double from an int.  */
119 
120 #define SET_LOW_WORD(d,v)					\
121 do {								\
122   ieee_double_shape_type sl_u;					\
123   sl_u.value = (d);						\
124   sl_u.parts.lsw = (v);						\
125   (d) = sl_u.value;						\
126 } while (/*CONSTCOND*/0)
127 
128 /* A union which permits us to convert between a float and a 32 bit
129    int.  */
130 
131 typedef union
132 {
133   float value;
134   u_int32_t word;
135 } ieee_float_shape_type;
136 
137 /* Get a 32 bit int from a float.  */
138 
139 #define GET_FLOAT_WORD(i,d)					\
140 do {								\
141   ieee_float_shape_type gf_u;					\
142   gf_u.value = (d);						\
143   (i) = gf_u.word;						\
144 } while (/*CONSTCOND*/0)
145 
146 /* Set a float from a 32 bit int.  */
147 
148 #define SET_FLOAT_WORD(d,i)					\
149 do {								\
150   ieee_float_shape_type sf_u;					\
151   sf_u.word = (i);						\
152   (d) = sf_u.value;						\
153 } while (/*CONSTCOND*/0)
154 
155 /*
156  * Attempt to get strict C99 semantics for assignment with non-C99 compilers.
157  */
158 #if FLT_EVAL_METHOD == 0 || __GNUC__ == 0
159 #define	STRICT_ASSIGN(type, lval, rval)	((lval) = (rval))
160 #else
161 #define	STRICT_ASSIGN(type, lval, rval) do {	\
162 	volatile type __lval;			\
163 						\
164 	if (sizeof(type) >= sizeof(double))	\
165 		(lval) = (rval);		\
166 	else {					\
167 		__lval = (rval);		\
168 		(lval) = __lval;		\
169 	}					\
170 } while (/*CONSTCOND*/0)
171 #endif
172 
173 /* ieee style elementary functions */
174 extern double __ieee754_sqrt __P((double));
175 extern double __ieee754_acos __P((double));
176 extern double __ieee754_acosh __P((double));
177 extern double __ieee754_log __P((double));
178 extern double __ieee754_atanh __P((double));
179 extern double __ieee754_asin __P((double));
180 extern double __ieee754_atan2 __P((double,double));
181 extern double __ieee754_exp __P((double));
182 extern double __ieee754_cosh __P((double));
183 extern double __ieee754_fmod __P((double,double));
184 extern double __ieee754_pow __P((double,double));
185 extern double __ieee754_lgamma_r __P((double,int *));
186 extern double __ieee754_gamma_r __P((double,int *));
187 extern double __ieee754_lgamma __P((double));
188 extern double __ieee754_gamma __P((double));
189 extern double __ieee754_log10 __P((double));
190 extern double __ieee754_log2 __P((double));
191 extern double __ieee754_sinh __P((double));
192 extern double __ieee754_hypot __P((double,double));
193 extern double __ieee754_j0 __P((double));
194 extern double __ieee754_j1 __P((double));
195 extern double __ieee754_y0 __P((double));
196 extern double __ieee754_y1 __P((double));
197 extern double __ieee754_jn __P((int,double));
198 extern double __ieee754_yn __P((int,double));
199 extern double __ieee754_remainder __P((double,double));
200 extern int    __ieee754_rem_pio2 __P((double,double*));
201 extern double __ieee754_scalb __P((double,double));
202 
203 /* fdlibm kernel function */
204 extern double __kernel_standard __P((double,double,int));
205 extern double __kernel_sin __P((double,double,int));
206 extern double __kernel_cos __P((double,double));
207 extern double __kernel_tan __P((double,double,int));
208 extern int    __kernel_rem_pio2 __P((double*,double*,int,int,int,const int*));
209 
210 
211 /* ieee style elementary float functions */
212 extern float __ieee754_sqrtf __P((float));
213 extern float __ieee754_acosf __P((float));
214 extern float __ieee754_acoshf __P((float));
215 extern float __ieee754_logf __P((float));
216 extern float __ieee754_atanhf __P((float));
217 extern float __ieee754_asinf __P((float));
218 extern float __ieee754_atan2f __P((float,float));
219 extern float __ieee754_expf __P((float));
220 extern float __ieee754_coshf __P((float));
221 extern float __ieee754_fmodf __P((float,float));
222 extern float __ieee754_powf __P((float,float));
223 extern float __ieee754_lgammaf_r __P((float,int *));
224 extern float __ieee754_gammaf_r __P((float,int *));
225 extern float __ieee754_lgammaf __P((float));
226 extern float __ieee754_gammaf __P((float));
227 extern float __ieee754_log10f __P((float));
228 extern float __ieee754_log2f __P((float));
229 extern float __ieee754_sinhf __P((float));
230 extern float __ieee754_hypotf __P((float,float));
231 extern float __ieee754_j0f __P((float));
232 extern float __ieee754_j1f __P((float));
233 extern float __ieee754_y0f __P((float));
234 extern float __ieee754_y1f __P((float));
235 extern float __ieee754_jnf __P((int,float));
236 extern float __ieee754_ynf __P((int,float));
237 extern float __ieee754_remainderf __P((float,float));
238 extern int   __ieee754_rem_pio2f __P((float,float*));
239 extern float __ieee754_scalbf __P((float,float));
240 
241 /* float versions of fdlibm kernel functions */
242 extern float __kernel_sinf __P((float,float,int));
243 extern float __kernel_cosf __P((float,float));
244 extern float __kernel_tanf __P((float,float,int));
245 extern int   __kernel_rem_pio2f __P((float*,float*,int,int,int,const int*));
246 
247 #endif /* _MATH_PRIVATE_H_ */
248