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(svn r3205) Some more uses for GB/SB

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tron
2005-11-16 13:11:28 +00:00
parent 8cebe2f607
commit ec57ef78a2
5 changed files with 24 additions and 21 deletions
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26
macros.h
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@@ -5,6 +5,13 @@
#include "map.h"
/// Fetch n bits starting at bit s from x
#define GB(x, s, n) (((x) >> (s)) & ((1U << (n)) - 1))
/// Set n bits starting at bit s in x to d
#define SB(x, s, n, d) ((x) = ((x) & ~(((1U << (n)) - 1) << (s))) | ((d) << (s)))
/// Add i to the n bits starting at bit s in x
#define AB(x, s, n, i) ((x) = ((x) & ~(((1U << (n)) - 1) << (s))) | (((x) + ((i) << (s))) & (((1U << (n)) - 1) << (s))))
#ifdef min
#undef min
#endif
@@ -86,20 +93,20 @@ static inline int FindFirstBit2x64(int value)
Faster ( or at least cleaner ) implementation below?
*/
if ( (byte) value == 0) {
return FIND_FIRST_BIT((value >> 8) & 0x3F) + 8;
if (GB(value, 0, 8) == 0) {
return FIND_FIRST_BIT(GB(value, 8, 6)) + 8;
} else {
return FIND_FIRST_BIT(value & 0x3F);
return FIND_FIRST_BIT(GB(value, 0, 6));
}
}
static inline int KillFirstBit2x64(int value)
{
if ( (byte) value == 0) {
return KILL_FIRST_BIT((value >> 8) & 0x3F) << 8;
if (GB(value, 0, 8) == 0) {
return KILL_FIRST_BIT(GB(value, 8, 6)) << 8;
} else {
return value & (KILL_FIRST_BIT(value & 0x3F)|0x3F00);
return value & (KILL_FIRST_BIT(GB(value, 0, 6)) | 0x3F00);
}
}
@@ -144,13 +151,6 @@ static inline void swap_tile(TileIndex *a, TileIndex *b) { TileIndex t = *a; *a
}
#endif
/// Fetch n bits starting at bit s from x
#define GB(x, s, n) (((x) >> (s)) & ((1U << (n)) - 1))
/// Set n bits starting at bit s in x to d
#define SB(x, s, n, d) ((x) = ((x) & ~(((1U << (n)) - 1) << (s))) | ((d) << (s)))
/// Add i to the n bits starting at bit s in x
#define AB(x, s, n, i) ((x) = ((x) & ~(((1U << (n)) - 1) << (s))) | (((x) + ((i) << (s))) & (((1U << (n)) - 1) << (s))))
/**
* ROtate x Left/Right by n (must be >= 0)
* @note Assumes a byte has 8 bits