src/float/dfloat/conv/cl_DF_to_doublej.cc

   1 // cl_DF_to_double().
   2
   3 // General includes.
   4 #include "cl_sysdep.h"
   5
   6 // Specification.
   7 #include "cl_DF.h"
   8
   9
  10 // Implementation.
  11
  12 namespace cln {
  13
  14 void cl_DF_to_double (const cl_DF& obj, dfloatjanus* val_)
  15 {
  16         var dfloat val = TheDfloat(obj)->dfloat_value;
  17         // Der Exponent muß um DF_exp_mid-1022 erniedrigt werden.
  18         if (DF_exp_mid>1022)
  19           #if (cl_word_size==64)
  20           { var uintL exp = (val >> DF_mant_len) & (bit(DF_exp_len)-1); // e
  21             if (exp < DF_exp_mid-1022+1)
  22               { // produziere denormalisiertes Float
  23                 val = (val & minus_bit(DF_exp_len+DF_mant_len)) // selbes Vorzeichen
  24                       | ((sint64)0 << DF_mant_len) // Exponent 0
  25                       | (((val & (bit(DF_mant_len)-1)) | bit(DF_mant_len)) // Mantisse shiften
  26                          >> (DF_exp_mid-1022+1 - exp) // shiften
  27                         );
  28               }
  29               else
  30               { val -= (sint64)(DF_exp_mid - 1022) << DF_mant_len; }
  31           }
  32           #else
  33           { var uintL exp = (val.semhi >> (DF_mant_len-32)) & (bit(DF_exp_len)-1); // e
  34             if (exp < DF_exp_mid-1022+1)
  35               { // produziere denormalisiertes Float
  36                 var uintL shiftcount = DF_exp_mid-1022+1 - exp;
  37                 val.mlo = val.mlo >> shiftcount; // Mantisse shiften
  38                 val.mlo |= val.semhi << (32-shiftcount);
  39                 val.semhi = (val.semhi & minus_bit(DF_exp_len+DF_mant_len-32)) // selbes Vorzeichen
  40                             | ((sint32)0 << (DF_mant_len-32)) // Exponent 0
  41                             | (((val.semhi & (bit(DF_mant_len-32)-1)) | bit(DF_mant_len-32)) // Mantisse shiften
  42                                >> shiftcount // shiften
  43                               );
  44               }
  45               else
  46               { val.semhi -= (sint32)(DF_exp_mid - 1022) << (DF_mant_len-32); }
  47           }
  48           #endif
  49         val_->eksplicit = val;
  50 }
  51
  52 }  // namespace cln