src/float/dfloat/conv/cl_DF_from_double.cc

   1 // cl_double_to_FF().
   2
   3 // General includes.
   4 #include "cl_sysdep.h"
   5
   6 // Specification.
   7 #include "cl_DF.h"
   8
   9
  10 // Implementation.
  11
  12 cl_heap_dfloat* cl_double_to_DF_pointer (const dfloatjanus& val_)
  13 {
  14       var dfloat val = val_.eksplicit;
  15       #if (cl_word_size==64)
  16       var uintL exp = (val >> DF_mant_len) & (bit(DF_exp_len)-1); // e
  17       if (exp == 0) // e=0 ?
  18         // vorzeichenbehaftete 0.0 oder subnormale Zahl
  19         { if (!((val << 1) == 0) && underflow_allowed())
  20             { cl_error_floating_point_underflow(); }
  21             else
  22             { return cl_DF_0; } // +/- 0.0 -> 0.0
  23         }
  24       elif (exp == 2047) // e=2047 ?
  25         { if (!((val << (64-DF_mant_len)) == 0))
  26             { cl_error_floating_point_nan(); } // NaN
  27             else
  28             { cl_error_floating_point_overflow(); } // Infinity, Overflow
  29         }
  30       else
  31         { // Der Exponent muß um DF_exp_mid-1022 erhöht werden.
  32           if ((DF_exp_mid>1022) && (exp > DF_exp_high-DF_exp_mid+1022))
  33             { cl_error_floating_point_overflow(); } // Overflow
  34           val += (sint64)(DF_exp_mid - 1022) << DF_mant_len;
  35           return allocate_dfloat(val);
  36         }
  37       #else
  38       var uintL exp = (val.semhi >> (DF_mant_len-32)) & (bit(DF_exp_len)-1); // e
  39       if (exp == 0) // e=0 ?
  40         // vorzeichenbehaftete 0.0 oder subnormale Zahl
  41         { if (!(((val.semhi << 1) == 0) && (val.mlo == 0)) && underflow_allowed())
  42             { cl_error_floating_point_underflow(); }
  43             else
  44             { return cl_DF_0; } // +/- 0.0 -> 0.0
  45         }
  46       elif (exp == 2047) // e=2047 ?
  47         { if (!(((val.semhi << (64-DF_mant_len)) == 0) && (val.mlo == 0)))
  48             { cl_error_floating_point_nan(); } // NaN
  49             else
  50             { cl_error_floating_point_overflow(); } // Infinity, Overflow
  51         }
  52       else
  53         { // Der Exponent muß um DF_exp_mid-1022 erhöht werden.
  54           if ((DF_exp_mid>1022) && (exp > DF_exp_high-DF_exp_mid+1022))
  55             { cl_error_floating_point_overflow(); } // Overflow
  56           val.semhi += (sint32)(DF_exp_mid - 1022) << (DF_mant_len-32);
  57           return allocate_dfloat(val.semhi,val.mlo);
  58         }
  59       #endif
  60 }