Kernel Functions for Drivers                          ddiffs(9F)



NAME
     ddiffs, ddifls - find first  (last)  bit  set  in  a  long
     integer

SYNOPSIS
     #include 
     #include 
     #include 



     intddiffs(long mask);


     int ddifls(long mask);


INTERFACE LEVEL
     Solaris DI specific (Solaris DI).

PARAMETERS
     mask    A 32-bit argument value to search through.


DESCRIPTION
     The function ddiffs() takes its argument  and  returns  the
     shift  count  that  the first (least significant) bit set in
     the argument corresponds to. The function ddifls() does the
     same,  only  it  returns  the shift count for the last (most
     significant) bit set in the argument.

RETURN VALUES
     0    No bits are set in mask.


     N    Bit  N is the least significant (ddiffs) or most  sig-
          nificant   (ddifls) bit set in mask. Bits are numbered
          from  1 to  32, with bit 1 being the least  significant
          bit position and bit 32 the most significant position.


CONTEXT
     This function can be called from user, interrupt, or  kernel
     context.

SEE ALSO
     Writing Device Drivers








SunOS 5.11          Last change: 16 Jan 2006                    1