lib/libm/src/math_private.h

   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 1.11 2001/02/21 18:09:26 bjh21 Exp $
  15  * $DragonFly: src/lib/libm/src/math_private.h,v 1.1 2005/07/26 21:15:20 joerg Exp $
  16  */
  17
  18 #ifndef _MATH_PRIVATE_H_
  19 #define _MATH_PRIVATE_H_
  20
  21 #include <sys/types.h>
  22
  23 /* The original fdlibm code used statements like:
  24         n0 = ((*(int*)&one)>>29)^1;             * index of high word *
  25         ix0 = *(n0+(int*)&x);                   * high word of x *
  26         ix1 = *((1-n0)+(int*)&x);               * low word of x *
  27    to dig two 32 bit words out of the 64 bit IEEE floating point
  28    value.  That is non-ANSI, and, moreover, the gcc instruction
  29    scheduler gets it wrong.  We instead use the following macros.
  30    Unlike the original code, we determine the endianness at compile
  31    time, not at run time; I don't see much benefit to selecting
  32    endianness at run time.  */
  33
  34 /* A union which permits us to convert between a double and two 32 bit
  35    ints.  */
  36
  37 /*
  38  * The ARM ports are little endian except for the FPA word order which is
  39  * big endian.
  40  */
  41
  42 #if (BYTE_ORDER == BIG_ENDIAN) || (defined(__arm__) && !defined(__VFP_FP__))
  43
  44 typedef union
  45 {
  46   double value;
  47   struct
  48   {
  49     u_int32_t msw;
  50     u_int32_t lsw;
  51   } parts;
  52 } ieee_double_shape_type;
  53
  54 #endif
  55
  56 #if (BYTE_ORDER == LITTLE_ENDIAN) && \
  57     !(defined(__arm__) && !defined(__VFP_FP__))
  58
  59 typedef union
  60 {
  61   double value;
  62   struct
  63   {
  64     u_int32_t lsw;
  65     u_int32_t msw;
  66   } parts;
  67 } ieee_double_shape_type;
  68
  69 #endif
  70
  71 /* Get two 32 bit ints from a double.  */
  72
  73 #define EXTRACT_WORDS(ix0,ix1,d)                                \
  74 do {                                                            \
  75   ieee_double_shape_type ew_u;                                  \
  76   ew_u.value = (d);                                             \
  77   (ix0) = ew_u.parts.msw;                                       \
  78   (ix1) = ew_u.parts.lsw;                                       \
  79 } while (0)
  80
  81 /* Get the more significant 32 bit int from a double.  */
  82
  83 #define GET_HIGH_WORD(i,d)                                      \
  84 do {                                                            \
  85   ieee_double_shape_type gh_u;                                  \
  86   gh_u.value = (d);                                             \
  87   (i) = gh_u.parts.msw;                                         \
  88 } while (0)
  89
  90 /* Get the less significant 32 bit int from a double.  */
  91
  92 #define GET_LOW_WORD(i,d)                                       \
  93 do {                                                            \
  94   ieee_double_shape_type gl_u;                                  \
  95   gl_u.value = (d);                                             \
  96   (i) = gl_u.parts.lsw;                                         \
  97 } while (0)
  98
  99 /* Set a double from two 32 bit ints.  */
 100
 101 #define INSERT_WORDS(d,ix0,ix1)                                 \
 102 do {                                                            \
 103   ieee_double_shape_type iw_u;                                  \
 104   iw_u.parts.msw = (ix0);                                       \
 105   iw_u.parts.lsw = (ix1);                                       \
 106   (d) = iw_u.value;                                             \
 107 } while (0)
 108
 109 /* Set the more significant 32 bits of a double from an int.  */
 110
 111 #define SET_HIGH_WORD(d,v)                                      \
 112 do {                                                            \
 113   ieee_double_shape_type sh_u;                                  \
 114   sh_u.value = (d);                                             \
 115   sh_u.parts.msw = (v);                                         \
 116   (d) = sh_u.value;                                             \
 117 } while (0)
 118
 119 /* Set the less significant 32 bits of a double from an int.  */
 120
 121 #define SET_LOW_WORD(d,v)                                       \
 122 do {                                                            \
 123   ieee_double_shape_type sl_u;                                  \
 124   sl_u.value = (d);                                             \
 125   sl_u.parts.lsw = (v);                                         \
 126   (d) = sl_u.value;                                             \
 127 } while (0)
 128
 129 /* A union which permits us to convert between a float and a 32 bit
 130    int.  */
 131
 132 typedef union
 133 {
 134   float value;
 135   u_int32_t word;
 136 } ieee_float_shape_type;
 137
 138 /* Get a 32 bit int from a float.  */
 139
 140 #define GET_FLOAT_WORD(i,d)                                     \
 141 do {                                                            \
 142   ieee_float_shape_type gf_u;                                   \
 143   gf_u.value = (d);                                             \
 144   (i) = gf_u.word;                                              \
 145 } while (0)
 146
 147 /* Set a float from a 32 bit int.  */
 148
 149 #define SET_FLOAT_WORD(d,i)                                     \
 150 do {                                                            \
 151   ieee_float_shape_type sf_u;                                   \
 152   sf_u.word = (i);                                              \
 153   (d) = sf_u.value;                                             \
 154 } while (0)
 155
 156 #ifdef _COMPLEX_H
 157
 158 /*
 159  * C99 specifies that complex numbers have the same representation as
 160  * an array of two elements, where the first element is the real part
 161  * and the second element is the imaginary part.
 162  */
 163 typedef union {
 164         float complex f;
 165         float a[2];
 166 } float_complex;
 167 typedef union {
 168         double complex f;
 169         double a[2];
 170 } double_complex;
 171 typedef union {
 172         long double complex f;
 173         long double a[2];
 174 } long_double_complex;
 175 #define REALPART(z)     ((z).a[0])
 176 #define IMAGPART(z)     ((z).a[1])
 177
 178 /*
 179  * Inline functions that can be used to construct complex values.
 180  *
 181  * The C99 standard intends x+I*y to be used for this, but x+I*y is
 182  * currently unusable in general since gcc introduces many overflow,
 183  * underflow, sign and efficiency bugs by rewriting I*y as
 184  * (0.0+I)*(y+0.0*I) and laboriously computing the full complex product.
 185  * In particular, I*Inf is corrupted to NaN+I*Inf, and I*-0 is corrupted
 186  * to -0.0+I*0.0.
 187  */
 188 static __inline float complex
 189 cpackf(float x, float y)
 190 {
 191         float_complex z;
 192
 193         REALPART(z) = x;
 194         IMAGPART(z) = y;
 195         return (z.f);
 196 }
 197
 198 static __inline double complex
 199 cpack(double x, double y)
 200 {
 201         double_complex z;
 202
 203         REALPART(z) = x;
 204         IMAGPART(z) = y;
 205         return (z.f);
 206 }
 207
 208 static __inline long double complex
 209 cpackl(long double x, long double y)
 210 {
 211         long_double_complex z;
 212
 213         REALPART(z) = x;
 214         IMAGPART(z) = y;
 215         return (z.f);
 216 }
 217
 218 #endif /* _COMPLEX_H */
 219
 220 __BEGIN_DECLS
 221 #pragma GCC visibility push(hidden)
 222
 223 /* ieee style elementary functions */
 224 int     __libm_rem_pio2(double, double*);
 225
 226 /* fdlibm kernel function */
 227 double  __kernel_sin(double, double, int);
 228 double  __kernel_cos(double, double);
 229 double  __kernel_tan(double, double, int);
 230 int     __kernel_rem_pio2(double*, double*, int, int, int, const int*);
 231
 232
 233 /* ieee style elementary float functions */
 234 int     __libm_rem_pio2f(float,float*);
 235
 236 /* float versions of fdlibm kernel functions */
 237 float   __kernel_sinf(float, float, int);
 238 float   __kernel_cosf(float, float);
 239 float   __kernel_tanf(float, float, int);
 240 int     __kernel_rem_pio2f(float*, float*, int, int, int, const int*);
 241
 242 #pragma GCC visibility pop
 243 __END_DECLS
 244
 245 #endif /* _MATH_PRIVATE_H_ */