Bit Math

Page last updated 15 Mar 2011, by Wim van der Vegt. 0 replies bitwise, math

<<info>> Some simple Bit Math. <</info>>

Source: stackoverflow.com

 Setting a bit: number |=  (1 << x);
Clearing a bit: number &= ~(1 << x);
Toggling a bit: number ^=  (1 << x);
Checking a bit: bit = number & (1 << x);

Source: stackoverflow.com

/* a=target variable, b=bit number to act upon 0-n */
#define BIT_SET(a,b)   ((a) |=  (1<<(b)))
#define BIT_CLEAR(a,b) ((a) &= ~(1<<(b)))
#define BIT_FLIP(a,b)  ((a) ^=  (1<<(b)))
#define BIT_CHECK(a,b) ((a) &   (1<<(b)))

/* x=target variable, y=mask */
#define BITMASK_SET(x,y)   ((x) |=  (y))
#define BITMASK_CLEAR(x,y) ((x) &= ~(y))
#define BITMASK_FLIP(x,y)  ((x) ^=  (y))
#define BITMASK_CHECK(x,y) ((x) &   (y))

Please log in to post comments.