src/integer/conv/cl_I_to_L.cc

   1 // cl_I_to_L().
   2
   3 // General includes.
   4 #include "base/cl_sysdep.h"
   5
   6 // Specification.
   7 #include "cln/integer.h"
   8
   9
  10 // Implementation.
  11
  12 #include "cln/number.h"
  13 #include "integer/cl_I.h"
  14 #include "base/digitseq/cl_DS.h"
  15 #include "cln/io.h"
  16 #include "cln/integer_io.h"
  17 #include "cln/exception.h"
  18 #include <sstream>
  19
  20 namespace cln {
  21
  22 sint32 cl_I_to_L (const cl_I& obj)
  23 {
  24         if (fixnump(obj)) {
  25                 // Fixnum
  26                 var sintV wert = FN_to_V(obj);
  27                 #if (intVsize>32)
  28                 if ((sintV)(sint32)wert != wert)
  29                         goto bad;
  30                 #endif
  31                 return (sint32)wert;
  32         } else { // Bignum
  33                 var cl_heap_bignum* bn = TheBignum(obj);
  34                 var uintC len = bn->length;
  35                 if ((sintD)mspref(arrayMSDptr(bn->data,len),0) >= 0) {
  36                         // Bignum > 0
  37                         #define IF_LENGTH(i)  \
  38                           if ((bn_minlength <= i) /* genau i Digits überhaupt möglich? */     \
  39                             && (len == i) /* genau i Digits? */                                 \
  40                             /* 2^((i-1)*intDsize-1) <= obj < 2^(i*intDsize-1) */                \
  41                             && ( (i*intDsize > 32)                                              \
  42                                  && ( ((i-1)*intDsize >= 32)                                    \
  43                                       || (mspref(arrayMSDptr(bn->data,len),0) >= (uintD)bitc(31-(i-1)*intDsize)) \
  44                              ) )    )                                                           \
  45                             goto bad;                                                           \
  46                             else
  47                         IF_LENGTH(1)
  48                                 return get_uint1D_Dptr(arrayLSDptr(bn->data,1));
  49                         IF_LENGTH(2)
  50                                 return get_uint2D_Dptr(arrayLSDptr(bn->data,2));
  51                         IF_LENGTH(3)
  52                                 return get_uint3D_Dptr(arrayLSDptr(bn->data,3));
  53                         IF_LENGTH(4)
  54                                 return get_uint4D_Dptr(arrayLSDptr(bn->data,4));
  55                         #undef IF_LENGTH
  56                 } else {
  57                         // Bignum < 0
  58                         #define IF_LENGTH(i)  \
  59                           if ((bn_minlength <= i) /* genau i Digits überhaupt möglich? */     \
  60                             && (len == i) /* genau i Digits? */                                 \
  61                             /* - 2^(i*intDsize-1) <= obj < - 2^((i-1)*intDsize-1) */            \
  62                             && ( (i*intDsize > 32)                                              \
  63                                  && ( ((i-1)*intDsize >= 32)                                    \
  64                                       || (mspref(arrayMSDptr(bn->data,len),0) < (uintD)(-bitc(31-(i-1)*intDsize))) \
  65                              ) )    )                                                           \
  66                             goto bad;                                                           \
  67                             else
  68                         IF_LENGTH(1)
  69                                 return get_sint1D_Dptr(arrayLSDptr(bn->data,1));
  70                         IF_LENGTH(2)
  71                                 return get_sint2D_Dptr(arrayLSDptr(bn->data,2));
  72                         IF_LENGTH(3)
  73                                 return get_sint3D_Dptr(arrayLSDptr(bn->data,3));
  74                         IF_LENGTH(4)
  75                                 return get_sint4D_Dptr(arrayLSDptr(bn->data,4));
  76                         #undef IF_LENGTH
  77                 }
  78         }
  79         bad: // unpassendes Objekt
  80         std::ostringstream buf;
  81         fprint(buf, "Not a 32-bit integer: ");
  82         fprint(buf, obj);
  83         throw runtime_exception(buf.str());
  84 }
  85
  86 }  // namespace cln