nsz Git - musl/blob - src/math/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 #ifndef _MATH_PRIVATE_H_
  13 #define _MATH_PRIVATE_H_
  14
  15 #include <inttypes.h>
  16
  17 /*
  18  * The original fdlibm code used statements like:
  19  *      n0 = ((*(int*)&one)>>29)^1;             * index of high word *
  20  *      ix0 = *(n0+(int*)&x);                   * high word of x *
  21  *      ix1 = *((1-n0)+(int*)&x);               * low word of x *
  22  * to dig two 32 bit words out of the 64 bit IEEE floating point
  23  * value.  That is non-ANSI, and, moreover, the gcc instruction
  24  * scheduler gets it wrong.  We instead use the following macros.
  25  * Unlike the original code, we determine the endianness at compile
  26  * time, not at run time; I don't see much benefit to selecting
  27  * endianness at run time.
  28  */
  29
  30 /*
  31  * A union which permits us to convert between a double and two 32 bit
  32  * ints.
  33  */
  34
  35 typedef union
  36 {
  37   double value;
  38   uint64_t words;
  39 } ieee_double_shape_type;
  40
  41 /* Get two 32 bit ints from a double.  */
  42
  43 #define EXTRACT_WORDS(ix0,ix1,d)                                \
  44 do {                                                            \
  45   ieee_double_shape_type ew_u;                                  \
  46   ew_u.value = (d);                                             \
  47   (ix0) = ew_u.words >> 32;                                     \
  48   (ix1) = (uint32_t)ew_u.words;                                 \
  49 } while (0)
  50
  51 /* Get the more significant 32 bit int from a double.  */
  52
  53 #define GET_HIGH_WORD(i,d)                                      \
  54 do {                                                            \
  55   ieee_double_shape_type gh_u;                                  \
  56   gh_u.value = (d);                                             \
  57   (i) = gh_u.words >> 32;                                       \
  58 } while (0)
  59
  60 /* Get the less significant 32 bit int from a double.  */
  61
  62 #define GET_LOW_WORD(i,d)                                       \
  63 do {                                                            \
  64   ieee_double_shape_type gl_u;                                  \
  65   gl_u.value = (d);                                             \
  66   (i) = (uint32_t)gl_u.words;                                   \
  67 } while (0)
  68
  69 /* Set a double from two 32 bit ints.  */
  70
  71 #define INSERT_WORDS(d,ix0,ix1)                                 \
  72 do {                                                            \
  73   ieee_double_shape_type iw_u;                                  \
  74   iw_u.words = ((uint64_t)(ix0) << 32) | (ix1);                 \
  75   (d) = iw_u.value;                                             \
  76 } while (0)
  77
  78 /* Set the more significant 32 bits of a double from an int.  */
  79
  80 #define SET_HIGH_WORD(d,v)                                      \
  81 do {                                                            \
  82   ieee_double_shape_type sh_u;                                  \
  83   sh_u.value = (d);                                             \
  84   sh_u.words &= 0xffffffff;                                     \
  85   sh_u.words |= ((uint64_t)(v) << 32);                          \
  86   (d) = sh_u.value;                                             \
  87 } while (0)
  88
  89 /* Set the less significant 32 bits of a double from an int.  */
  90
  91 #define SET_LOW_WORD(d,v)                                       \
  92 do {                                                            \
  93   ieee_double_shape_type sl_u;                                  \
  94   sl_u.value = (d);                                             \
  95   sl_u.words &= 0xffffffff00000000ull;                          \
  96   sl_u.words |= (uint32_t)(v);                                  \
  97   (d) = sl_u.value;                                             \
  98 } while (0)
  99
 100 /*
 101  * A union which permits us to convert between a float and a 32 bit
 102  * int.
 103  */
 104
 105 typedef union
 106 {
 107   float value;
 108   uint32_t word;
 109 } ieee_float_shape_type;
 110
 111 /* Get a 32 bit int from a float.  */
 112
 113 #define GET_FLOAT_WORD(i,d)                                     \
 114 do {                                                            \
 115   ieee_float_shape_type gf_u;                                   \
 116   gf_u.value = (d);                                             \
 117   (i) = gf_u.word;                                              \
 118 } while (0)
 119
 120 /* Set a float from a 32 bit int.  */
 121
 122 #define SET_FLOAT_WORD(d,i)                                     \
 123 do {                                                            \
 124   ieee_float_shape_type sf_u;                                   \
 125   sf_u.word = (i);                                              \
 126   (d) = sf_u.value;                                             \
 127 } while (0)
 128
 129 /* fdlibm kernel function */
 130 int     __ieee754_rem_pio2(double,double*);
 131 double  __kernel_sin(double,double,int);
 132 double  __kernel_cos(double,double);
 133 double  __kernel_tan(double,double,int);
 134 int     __kernel_rem_pio2(double*,double*,int,int,int,const int*);
 135
 136 /* float versions of fdlibm kernel functions */
 137 int     __ieee754_rem_pio2f(float,float*);
 138 float   __kernel_sinf(float,float,int);
 139 float   __kernel_cosf(float,float);
 140 float   __kernel_tanf(float,float,int);
 141 int     __kernel_rem_pio2f(float*,float*,int,int,int,const int*);
 142
 143 #endif /* !_MATH_PRIVATE_H_ */