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