Binary number

How can a Binary number be used in a program?

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  • If you are asking about using binary constants, here are some public domain binary constant macros Tom Torfs published on Usenet. I'm a little concerned because last time I posted this here, the preview was correct, but the forum rendering was not -- here goes:

    ================================================================
    
    From: tomtorfs@village.uunet.be (Tom Torfs)
    Newsgroups: comp.lang.c,comp.arch.embedded
    Subject: Binary constant macros
    Date: 26 Feb 2004 07:36:35 -0800
    
    Hello All,
    
    I've been missing the lack of support for binary numeric literals in
    C. To get around it I wrote the following handy macros, which allows
    you to simply write something like:
    
    whatever = B8(10101010);
    
    and will translate as:
    
    whatever = 85;
    
    (compile-time constant)
    
    Code below... hopefully it's useful to some of you as well.
    
    greetings,
    Tom
    
    /* 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
    */
    
    greetings,
    Tom
    

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  • If you are asking about using binary constants, here are some public domain binary constant macros Tom Torfs published on Usenet. I'm a little concerned because last time I posted this here, the preview was correct, but the forum rendering was not -- here goes:

    ================================================================
    
    From: tomtorfs@village.uunet.be (Tom Torfs)
    Newsgroups: comp.lang.c,comp.arch.embedded
    Subject: Binary constant macros
    Date: 26 Feb 2004 07:36:35 -0800
    
    Hello All,
    
    I've been missing the lack of support for binary numeric literals in
    C. To get around it I wrote the following handy macros, which allows
    you to simply write something like:
    
    whatever = B8(10101010);
    
    and will translate as:
    
    whatever = 85;
    
    (compile-time constant)
    
    Code below... hopefully it's useful to some of you as well.
    
    greetings,
    Tom
    
    /* 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
    */
    
    greetings,
    Tom
    

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