OpenTTD

Functions related to bit mathematics. More...
Go to the source code of this file.
Functions  
uint8  FindFirstBit (uint32 x) 
Search the first set bit in a 32 bit variable. More...  
uint8  FindLastBit (uint64 x) 
Search the last set bit in a 64 bit variable. More...  
Variables  
const uint8  _ffb_64 [64] 
Lookup table to check which bit is set in a 6 bit variable. More...  
Functions related to bit mathematics.
Definition in file bitmath_func.cpp.
uint8 FindFirstBit  (  uint32  x  ) 
Search the first set bit in a 32 bit variable.
This algorithm is a static implementation of a log congruence search algorithm. It checks the first half if there is a bit set search there further. And this way further. If no bit is set return 0.
x  The value to search 
Definition at line 39 of file bitmath_func.cpp.
Referenced by AllocateMap(), and FindFirstBit2x64().
uint8 FindLastBit  (  uint64  x  ) 
Search the last set bit in a 64 bit variable.
This algorithm is a static implementation of a log congruence search algorithm. It checks the second half if there is a bit set search there further. And this way further. If no bit is set return 0.
x  The value to search 
Definition at line 67 of file bitmath_func.cpp.
const uint8 _ffb_64[64] 
Lookup table to check which bit is set in a 6 bit variable.
Definition at line 17 of file bitmath_func.cpp.