src/float/misc/cl_F_leastpos.cc

   1 // least_positive_float().
   2
   3 // General includes.
   4 #include "cl_sysdep.h"
   5
   6 CL_PROVIDE(cl_F_leastpos)
   7
   8 // Specification.
   9 #include "cln/float.h"
  10
  11 // Implementation.
  12
  13 #include "cl_F.h"
  14 #include "cl_SF.h"
  15 #include "cl_FF.h"
  16 #include "cl_DF.h"
  17 #include "cl_LF.h"
  18 #include "cl_LF_impl.h"
  19
  20 namespace cln {
  21
  22 // Exponent so klein wie möglich, Mantisse 10...0, Vorzeichen +.
  23
  24 static const cl_SF least_positive_SF =
  25         make_SF(0,SF_exp_low,bit(SF_mant_len));
  26
  27 static const cl_FF least_positive_FF =
  28         encode_FF(0,FF_exp_low-FF_exp_mid,bit(FF_mant_len));
  29
  30 static const cl_DF least_positive_DF =
  31         #if (cl_word_size==64)
  32           encode_DF(0,DF_exp_low-DF_exp_mid,bit(DF_mant_len));
  33         #else
  34           encode_DF(0,DF_exp_low-DF_exp_mid,bit(DF_mant_len-32),0);
  35         #endif
  36
  37 inline const cl_LF least_positive_LF (uintC len)
  38 {
  39         var Lfloat erg = allocate_lfloat(len,LF_exp_low,0);
  40         #if CL_DS_BIG_ENDIAN_P
  41           TheLfloat(erg)->data[0] = bit(intDsize-1);
  42           clear_loop_up(&TheLfloat(erg)->data[1],len-1);
  43         #else
  44           var uintD* ptr = clear_loop_up(&TheLfloat(erg)->data[0],len-1);
  45           *ptr = bit(intDsize-1);
  46         #endif
  47         return erg;
  48 }
  49
  50 const cl_F least_positive_float (float_format_t f)
  51 {
  52         floatformatcase((uintC)f
  53         ,       return least_positive_SF;
  54         ,       return least_positive_FF;
  55         ,       return least_positive_DF;
  56         ,       return least_positive_LF(len);
  57         );
  58 }
  59
  60 }  // namespace cln
  61
  62 CL_PROVIDE_END(cl_F_leastpos)