binaryMacro.h

//
//http://bytes.com/topic/c/answers/216333-binary-constant-macros
//

/* Binary constant generator macro
By Tom Torfs - donated to the public domain
*/

/* All macro's evaluate to compile-time constants */

/* *** helper macros *** /

/* turn a numeric literal into a hex constant
(avoids problems with leading zeroes)
8-bit constants max value 0x11111111, always fits in unsigned long
*/
#define HEX__(n) 0x##n##LU

/* 8-bit conversion function */
#define B8__(x) ((x&0x0000000FLU)?1:0)  \
+((x&0x000000F0LU)?2:0)	\
+((x&0x00000F00LU)?4:0)	\
+((x&0x0000F000LU)?8:0)	\
+((x&0x000F0000LU)?16:0)	\
+((x&0x00F00000LU)?32:0)	\
+((x&0x0F000000LU)?64:0)	\
+((x&0xF0000000LU)?128:0)

/* *** user macros *** /

/* for upto 8-bit binary constants */
#define B8(d) ((unsigned char)B8__(HEX__(d)))

/* for upto 16-bit binary constants, MSB first */
#define B16(dmsb,dlsb) (((unsigned short)B8(dmsb)<<8)	\
+ B8(dlsb))

/* for upto 32-bit binary constants, MSB first */
#define B32(dmsb,db2,db3,dlsb) (((unsigned long)B8(dmsb)<<24)	 \
+ ((unsigned long)B8(db2)<<16) \
+ ((unsigned long)B8(db3)<<8)	 \
+ B8(dlsb))

/* Sample usage:
B8(01010101) = 85
B16(10101010,01010101) = 43605
B32(10000000,11111111,10101010,01010101) = 2164238933
*/