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C/C++ Source or Header  |  1993-02-23  |  347 b   |  20 lines  |  [TEXT/KAHL]
  1. /*
  2. Log2L.c
  3. HISTORY:
  4. 12/3/91 dgp changed zero argument return from -1 to LONG_MIN.
  5. */
  6. #include "VideoToolbox.h"
  7.  
  8. long Log2L(unsigned long j)
  9. // returns the integer part of log2(j)
  10. {
  11.     long L=-1;
  12.     register unsigned long i=j;    // Because THINK C won't put arguments into registers
  13.  
  14.     if(i==0)return LONG_MIN;
  15.     while(i>0){
  16.         i>>=1;
  17.         L++;
  18.     }
  19.     return L;
  20. }