This patch adds 11 new macros to Cygwin's sys/param.h. They include:
setbit(a,i) clrbit(a,i) isset(a,i) isclr(a,i) howmany(x, y) rounddown(x, y) roundup(x, y) roundup2(x, y) powerof2(x) MIN(a,b) MAX(a,b)
I find some to be very useful for many mundane routines (esp. MIN/MAX). It should be noted that I chose to add all 11 of them (as opposed to just the ones I use) because this subset of macros seems to be common across all *bsd and linux distributions. In doing so we improve our interoperability and make porting easier. Although I "peeked" at the param.h header on my linux box to see if they were all defined, the macros I used were copied verbatim from the freebsd cvs src/sys/sys/param.h. Furthermore, I didn't actually check the definition expression in the linux header, so I feel confident that I have violated no licenses. I have an assignment pending, but I was hoping this change would be small enough to go in before then.
Cheers, Nicholas
2003-08-07 Nicholas Wourms <[EMAIL PROTECTED]>
* include/sys/param.h (setbit): Add new bitmap related macro.
(clrbit): Likewise.
(isset): Likewise.
(isclr): Likewise.
(howmany): Add new counting/rounding macro.
(rounddown): Likewise.
(roundup): Likewise.
(roundup2): Likewise.
(powerof2): Likewise
(MIN): Add macro for calculating min.
(MAX): Add macro for calculating max.
Index: cygwin/include/sys/param.h =================================================================== RCS file: /cvs/src/src/winsup/cygwin/include/sys/param.h,v retrieving revision 1.2 diff -u -3 -p -r1.2 param.h --- cygwin/include/sys/param.h 30 May 2003 08:39:02 -0000 1.2 +++ cygwin/include/sys/param.h 7 Aug 2003 17:03:14 -0000 @@ -53,4 +53,23 @@ #define NULL 0L #endif +/* Bit map related macros. */ +#define setbit(a,i) ((a)[(i)/NBBY] |= 1<<((i)%NBBY)) +#define clrbit(a,i) ((a)[(i)/NBBY] &= ~(1<<((i)%NBBY))) +#define isset(a,i) ((a)[(i)/NBBY] & (1<<((i)%NBBY))) +#define isclr(a,i) (((a)[(i)/NBBY] & (1<<((i)%NBBY))) == 0) + +/* Macros for counting and rounding. */ +#ifndef howmany +#define howmany(x, y) (((x)+((y)-1))/(y)) +#endif +#define rounddown(x, y) (((x)/(y))*(y)) +#define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */ +#define roundup2(x, y) (((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */ +#define powerof2(x) ((((x)-1)&(x))==0) + +/* Macros for min/max. */ +#define MIN(a,b) (((a)<(b))?(a):(b)) +#define MAX(a,b) (((a)>(b))?(a):(b)) +
