compilers/pcc/pcc-libs-1.0.0/libpcc/bitcnt.c

   1
   2 int __builtin_clz(unsigned int);
   3 int __builtin_ctz(unsigned int);
   4 int __builtin_clzl(unsigned long);
   5 int __builtin_ctzl(unsigned long);
   6
   7 int
   8 __builtin_clz(unsigned int v)
   9 {
  10         int i, n = v;
  11
  12         for (i = 0; i < 100; i++)
  13                 if ((n << i) < 0)
  14                         break;
  15         return i;
  16 }
  17
  18 int
  19 __builtin_ctz(unsigned int v)
  20 {
  21         int i, n = v;
  22
  23         for (i = 0; i < 100; i++)
  24                 if ((n >> i) & 1)
  25                         break;
  26         return i;
  27 }
  28
  29 int
  30 __builtin_clzl(unsigned long v)
  31 {
  32         int i;
  33         long n = v;
  34
  35         for (i = 0; i < 100; i++)
  36                 if ((n << i) < 0)
  37                         break;
  38         return i;
  39 }
  40
  41 int
  42 __builtin_ctzl(unsigned long v)
  43 {
  44         int i, n = v;
  45
  46         for (i = 0; i < 100; i++)
  47                 if ((n >> i) & 1)
  48                         break;
  49         return i;
  50 }