mirror
/
OpenTTD
mirror of https://github.com/OpenTTD/OpenTTD
1
0
Fork 0
Code Issues

(svn r11378) -Codechange: optimize KillFirstBit2x64 (skidd13)

release/0.6
truelight 2007-11-04 18:28:52 +00:00
parent 525d239bc2
commit 038817a708
1 changed files with 2 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
src/macros.h
View File

@ -416,21 +416,14 @@ Faster ( or at least cleaner ) implementation below?
* Clear the first bit in an integer. * Clear the first bit in an integer.
* *
* This function returns a value where the first bit (from LSB) * This function returns a value where the first bit (from LSB)
* is cleared. This function checks, similar to FindFirstBit2x64, * is cleared. This function checks only the bits of 0x3F3F!
* the bits at 0x3F3F.
* *
* @param value The value to clear the first bit * @param value The value to clear the first bit
* @return The new value with the first bit cleared * @return The new value with the first bit cleared
* @see KILL_FIRST_BIT
* @see FindFirstBit2x64
*/ */
static inline int KillFirstBit2x64(int value) static inline int KillFirstBit2x64(int value)
{ {
if (GB(value, 0, 8) == 0) { return value &= (int)(value - 1) | 0x3FFFC0C0;
return KILL_FIRST_BIT(GB(value, 8, 6)) << 8;
} else {
return value & (KILL_FIRST_BIT(GB(value, 0, 6)) | 0x3F00);
}
} }
/** /**