git.distorted.org.uk Git - u/mdw/putty/blob - int64.c

   1 /*
   2  * Handling of the int64 and uint64 types. Done in 32-bit integers,
   3  * for (pre-C99) portability. Hopefully once C99 becomes widespread
   4  * we can kiss this lot goodbye...
   5  */
   6
   7 #include <assert.h>
   8 #include <string.h>
   9
  10 #include "int64.h"
  11
  12 uint64 uint64_div10(uint64 x, int *remainder)
  13 {
  14     uint64 y;
  15     int rem, r2;
  16     y.hi = x.hi / 10;
  17     y.lo = x.lo / 10;
  18     rem = x.lo % 10;
  19     /*
  20      * Now we have to add in the remainder left over from x.hi.
  21      */
  22     r2 = x.hi % 10;
  23     y.lo += r2 * 2 * (0x80000000 / 10);
  24     rem += r2 * 2 * (0x80000000 % 10);
  25     y.lo += rem / 10;
  26     rem %= 10;
  27
  28     if (remainder)
  29         *remainder = rem;
  30     return y;
  31 }
  32
  33 void uint64_decimal(uint64 x, char *buffer)
  34 {
  35     char buf[20];
  36     int start = 20;
  37     int d;
  38
  39     while (x.hi || x.lo) {
  40         x = uint64_div10(x, &d);
  41         assert(start > 0);
  42         buf[--start] = d + '0';
  43     }
  44
  45     memcpy(buffer, buf + start, sizeof(buf) - start);
  46     buffer[sizeof(buf) - start] = '\0';
  47 }
  48
  49 uint64 uint64_make(unsigned long hi, unsigned long lo)
  50 {
  51     uint64 y;
  52     y.hi = hi;
  53     y.lo = lo;
  54     return y;
  55 }
  56
  57 uint64 uint64_add(uint64 x, uint64 y)
  58 {
  59     x.lo += y.lo;
  60     x.hi += y.hi + (x.lo < y.lo ? 1 : 0);
  61     return x;
  62 }
  63
  64 uint64 uint64_add32(uint64 x, unsigned long y)
  65 {
  66     uint64 yy;
  67     yy.hi = 0;
  68     yy.lo = y;
  69     return uint64_add(x, yy);
  70 }
  71
  72 int uint64_compare(uint64 x, uint64 y)
  73 {
  74     if (x.hi != y.hi)
  75         return x.hi < y.hi ? -1 : +1;
  76     if (x.lo != y.lo)
  77         return x.lo < y.lo ? -1 : +1;
  78     return 0;
  79 }