4 #include "base/cl_sysdep.h"
7 #include "cln/dfloat.h"
12 #include "float/dfloat/cl_DF.h"
16 double double_approx (const cl_DF& obj)
18 union { dfloat eksplicit; double machine_double; } u;
19 #define val u.eksplicit
20 val = TheDfloat(obj)->dfloat_value;
21 // Der Exponent muß um DF_exp_mid-1022 erniedrigt werden.
23 #if (cl_word_size==64)
24 { var uintL exp = (val >> DF_mant_len) & (bit(DF_exp_len)-1); // e
25 if (exp < DF_exp_mid-1022+1)
26 { // produziere denormalisiertes Float
27 val = (val & minus_bit(DF_exp_len+DF_mant_len)) // selbes Vorzeichen
28 | ((sint64)0 << DF_mant_len) // Exponent 0
29 | (((val & (bit(DF_mant_len)-1)) | bit(DF_mant_len)) // Mantisse shiften
30 >> (DF_exp_mid-1022+1 - exp) // shiften
34 { val -= (sint64)(DF_exp_mid - 1022) << DF_mant_len; }
37 { var uintL exp = (val.semhi >> (DF_mant_len-32)) & (bit(DF_exp_len)-1); // e
38 if (exp < DF_exp_mid-1022+1)
39 { // produziere denormalisiertes Float
40 var uintL shiftcount = DF_exp_mid-1022+1 - exp;
41 val.mlo = val.mlo >> shiftcount; // Mantisse shiften
42 val.mlo |= val.semhi << (32-shiftcount);
43 val.semhi = (val.semhi & minus_bit(DF_exp_len+DF_mant_len-32)) // selbes Vorzeichen
44 | ((sint32)0 << (DF_mant_len-32)) // Exponent 0
45 | (((val.semhi & (bit(DF_mant_len-32)-1)) | bit(DF_mant_len-32)) // Mantisse shiften
46 >> shiftcount // shiften
50 { val.semhi -= (sint32)(DF_exp_mid - 1022) << (DF_mant_len-32); }
54 return u.machine_double;