src/integer/conv/cl_I_from_L.cc

   1 // L_to_I() helper.
   2
   3 // General includes.
   4 #include "cl_sysdep.h"
   5
   6 // Specification.
   7 #include "cl_I.h"
   8
   9
  10 // Implementation.
  11
  12 #include "cl_number.h"
  13
  14 #if (cl_value_len < 32)
  15
  16 #include "cl_DS.h"
  17
  18 cl_private_thing cl_I_constructor_from_L (sint32 wert)
  19 {
  20         var uint32 test = wert & minus_bit(cl_value_len-1);
  21         // test enthält die Bits, die nicht in den Fixnum-Wert >= 0 reinpassen.
  22         if ((test == 0) || (test == (uint32)minus_bit(cl_value_len-1)))
  23                 { return (cl_private_thing)(cl_combine(cl_FN_tag,wert)); }
  24         // Bignum erzeugen:
  25         // (dessen Länge  bn_minlength <= n <= ceiling(32/intDsize)  erfüllt)
  26         if (bn_minlength == ceiling(32,intDsize)) {
  27                 #if (intDsize==8)
  28                 goto bignum4;
  29                 #endif
  30                 #if (intDsize==16)
  31                 goto bignum2;
  32                 #endif
  33                 #if (intDsize==32)
  34                 goto bignum1;
  35                 #endif
  36         }
  37         if (wert >= 0) {
  38                 #define IF_LENGTH(i)  \
  39                   if ((bn_minlength <= i) && (i*intDsize <= 32))        \
  40                     if (!((i+1)*intDsize <= 32)                         \
  41                         || ((uint32)wert < (uint32)bitc(i*intDsize-1))  \
  42                        )
  43                 #if (intDsize <= 32)
  44                 IF_LENGTH(1)
  45                         bignum1:
  46                         { var cl_heap_bignum* ptr = allocate_bignum(1);
  47                           arrayLSref(ptr->data,1,0) = wert;
  48                           return (cl_private_thing)(ptr);
  49                         }
  50                 #if (intDsize <= 16)
  51                 IF_LENGTH(2)
  52                         bignum2:
  53                         { var cl_heap_bignum* ptr = allocate_bignum(2);
  54                           arrayLSref(ptr->data,2,0) = (uintD)wert;
  55                           arrayLSref(ptr->data,2,1) = (uintD)(wert>>intDsize);
  56                           return (cl_private_thing)(ptr);
  57                         }
  58                 #if (intDsize <= 8)
  59                 IF_LENGTH(3)
  60                         bignum3:
  61                         { var cl_heap_bignum* ptr = allocate_bignum(3);
  62                           arrayLSref(ptr->data,3,0) = (uintD)wert; wert >>= intDsize;
  63                           arrayLSref(ptr->data,3,1) = (uintD)wert;
  64                           arrayLSref(ptr->data,3,2) = (uintD)(wert>>intDsize);
  65                           return (cl_private_thing)(ptr);
  66                         }
  67                 IF_LENGTH(4)
  68                         bignum4:
  69                         { var cl_heap_bignum* ptr = allocate_bignum(4);
  70                           arrayLSref(ptr->data,4,0) = (uintD)wert; wert >>= intDsize;
  71                           arrayLSref(ptr->data,4,1) = (uintD)wert; wert >>= intDsize;
  72                           arrayLSref(ptr->data,4,2) = (uintD)wert;
  73                           arrayLSref(ptr->data,4,3) = (uintD)(wert>>intDsize);
  74                           return (cl_private_thing)(ptr);
  75                         }
  76                 #endif
  77                 #endif
  78                 #endif
  79                 #undef IF_LENGTH
  80         } else {
  81                 #define IF_LENGTH(i)  \
  82                   if ((bn_minlength <= i) && (i*intDsize <= 32))        \
  83                     if (!((i+1)*intDsize <= 32)                         \
  84                         || ((uint32)wert >= (uint32)(-bitc(i*intDsize-1))) \
  85                        )
  86                 #if (intDsize <= 32)
  87                 IF_LENGTH(1)
  88                         goto bignum1;
  89                 #if (intDsize <= 16)
  90                 IF_LENGTH(2)
  91                         goto bignum2;
  92                 #if (intDsize <= 8)
  93                 IF_LENGTH(3)
  94                         goto bignum3;
  95                 IF_LENGTH(4)
  96                         goto bignum4;
  97                 #endif
  98                 #endif
  99                 #endif
 100                 #undef IF_LENGTH
 101         }
 102 }
 103
 104 #endif