1  /* Manipulation of the bit representation of 'long double' quantities.
       2     Copyright (C) 2001-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #ifndef _MATH_LDBL_H_
      20  #define _MATH_LDBL_H_ 1
      21  
      22  #include <stdint.h>
      23  
      24  /* A union which permits us to convert between a long double and
      25     three 32 bit ints.  */
      26  
      27  typedef union
      28  {
      29    long double value;
      30    struct
      31    {
      32      uint32_t lsw;
      33      uint32_t msw;
      34      int sign_exponent:16;
      35      unsigned int empty1:16;
      36      unsigned int empty0:32;
      37    } parts;
      38  } ieee_long_double_shape_type;
      39  
      40  /* Get three 32 bit ints from a double.  */
      41  
      42  #define GET_LDOUBLE_WORDS(exp,ix0,ix1,d)			\
      43  do {								\
      44    ieee_long_double_shape_type ew_u;				\
      45    ew_u.value = (d);						\
      46    (exp) = ew_u.parts.sign_exponent;				\
      47    (ix0) = ew_u.parts.msw;					\
      48    (ix1) = ew_u.parts.lsw;					\
      49  } while (0)
      50  
      51  /* Set a double from two 32 bit ints.  */
      52  
      53  #define SET_LDOUBLE_WORDS(d,exp,ix0,ix1)			\
      54  do {								\
      55    ieee_long_double_shape_type iw_u;				\
      56    iw_u.parts.sign_exponent = (exp);				\
      57    iw_u.parts.msw = (ix0);					\
      58    iw_u.parts.lsw = (ix1);					\
      59    (d) = iw_u.value;						\
      60  } while (0)
      61  
      62  /* Get the more significant 32 bits of a long double mantissa.  */
      63  
      64  #define GET_LDOUBLE_MSW(v,d)					\
      65  do {								\
      66    ieee_long_double_shape_type sh_u;				\
      67    sh_u.value = (d);						\
      68    (v) = sh_u.parts.msw;						\
      69  } while (0)
      70  
      71  /* Set the more significant 32 bits of a long double mantissa from an int.  */
      72  
      73  #define SET_LDOUBLE_MSW(d,v)					\
      74  do {								\
      75    ieee_long_double_shape_type sh_u;				\
      76    sh_u.value = (d);						\
      77    sh_u.parts.msw = (v);						\
      78    (d) = sh_u.value;						\
      79  } while (0)
      80  
      81  /* Get int from the exponent of a long double.  */
      82  
      83  #define GET_LDOUBLE_EXP(exp,d)					\
      84  do {								\
      85    ieee_long_double_shape_type ge_u;				\
      86    ge_u.value = (d);						\
      87    (exp) = ge_u.parts.sign_exponent;				\
      88  } while (0)
      89  
      90  /* Set exponent of a long double from an int.  */
      91  
      92  #define SET_LDOUBLE_EXP(d,exp)					\
      93  do {								\
      94    ieee_long_double_shape_type se_u;				\
      95    se_u.value = (d);						\
      96    se_u.parts.sign_exponent = (exp);				\
      97    (d) = se_u.value;						\
      98  } while (0)
      99  
     100  #endif /* math_ldbl.h */