diff options
| author | Xin LI <delphij@FreeBSD.org> | 2017-05-19 06:37:16 +0000 | 
|---|---|---|
| committer | Xin LI <delphij@FreeBSD.org> | 2017-05-19 06:37:16 +0000 | 
| commit | da31cbbca0f3ce0826f8c0d1f71224b3a0264f37 (patch) | |
| tree | 9467d3f2a57ced05b5134a24237f36f8131a7643 | |
| parent | c9bcbf38004eac1c27ff642224e9f54d351a9849 (diff) | |
Notes
| -rw-r--r-- | sys/libkern/qsort.c | 129 | 
1 files changed, 82 insertions, 47 deletions
diff --git a/sys/libkern/qsort.c b/sys/libkern/qsort.c index 0600a3907c78..9e0db7f44a44 100644 --- a/sys/libkern/qsort.c +++ b/sys/libkern/qsort.c @@ -33,51 +33,57 @@ __FBSDID("$FreeBSD$");  #include <sys/param.h>  #include <sys/libkern.h> -#ifdef	I_AM_QSORT_R -typedef int		cmp_t(void *, const void *, const void *); +#ifdef I_AM_QSORT_R +typedef int		 cmp_t(void *, const void *, const void *);  #else -typedef int		cmp_t(const void *, const void *); +typedef int		 cmp_t(const void *, const void *);  #endif -static __inline char	*med3(char *, char *, char *, cmp_t *, void *); -static __inline void	 swapfunc(char *, char *, int, int); - -#define min(a, b)	(a) < (b) ? (a) : (b) +static inline char	*med3(char *, char *, char *, cmp_t *, void *); +static inline void	 swapfunc(char *, char *, size_t, int, int);  /*   * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".   */ -#define swapcode(TYPE, parmi, parmj, n) { 		\ -	long i = (n) / sizeof (TYPE); 			\ -	TYPE *pi = (TYPE *) (parmi); 			\ -	TYPE *pj = (TYPE *) (parmj); 			\ +#define	swapcode(TYPE, parmi, parmj, n) {		\ +	size_t i = (n) / sizeof (TYPE);			\ +	TYPE *pi = (TYPE *) (parmi);		\ +	TYPE *pj = (TYPE *) (parmj);		\  	do { 						\ -		TYPE	t = *pi;			\ +		TYPE	t = *pi;		\  		*pi++ = *pj;				\  		*pj++ = t;				\ -        } while (--i > 0);				\ +	} while (--i > 0);				\  } -#define SWAPINIT(a, es) swaptype = ((char *)a - (char *)0) % sizeof(long) || \ -	es % sizeof(long) ? 2 : es == sizeof(long)? 0 : 1; +#define	SWAPINIT(TYPE, a, es) swaptype_ ## TYPE =	\ +	((char *)a - (char *)0) % sizeof(TYPE) ||	\ +	es % sizeof(TYPE) ? 2 : es == sizeof(TYPE) ? 0 : 1; -static __inline void -swapfunc(char *a, char *b, int n, int swaptype) +static inline void +swapfunc(char *a, char *b, size_t n, int swaptype_long, int swaptype_int)  { -	if(swaptype <= 1) +	if (swaptype_long <= 1)  		swapcode(long, a, b, n) +	else if (swaptype_int <= 1) +		swapcode(int, a, b, n)  	else  		swapcode(char, a, b, n)  } -#define swap(a, b)					\ -	if (swaptype == 0) {				\ +#define	swap(a, b)					\ +	if (swaptype_long == 0) {			\  		long t = *(long *)(a);			\  		*(long *)(a) = *(long *)(b);		\  		*(long *)(b) = t;			\ +	} else if (swaptype_int == 0) {			\ +		int t = *(int *)(a);			\ +		*(int *)(a) = *(int *)(b);		\ +		*(int *)(b) = t;			\  	} else						\ -		swapfunc(a, b, es, swaptype) +		swapfunc(a, b, es, swaptype_long, swaptype_int) -#define vecswap(a, b, n) 	if ((n) > 0) swapfunc(a, b, n, swaptype) +#define	vecswap(a, b, n)				\ +	if ((n) > 0) swapfunc(a, b, n, swaptype_long, swaptype_int)  #ifdef I_AM_QSORT_R  #define	CMP(t, x, y) (cmp((t), (x), (y))) @@ -85,16 +91,16 @@ swapfunc(char *a, char *b, int n, int swaptype)  #define	CMP(t, x, y) (cmp((x), (y)))  #endif -static __inline char * +static inline char *  med3(char *a, char *b, char *c, cmp_t *cmp, void *thunk -#ifndef	I_AM_QSORT_R +#ifndef I_AM_QSORT_R  __unused  #endif  )  {  	return CMP(thunk, a, b) < 0 ?  	       (CMP(thunk, b, c) < 0 ? b : (CMP(thunk, a, c) < 0 ? c : a )) -              :(CMP(thunk, b, c) > 0 ? b : (CMP(thunk, a, c) < 0 ? a : c )); +	      :(CMP(thunk, b, c) > 0 ? b : (CMP(thunk, a, c) < 0 ? a : c ));  }  #ifdef I_AM_QSORT_R @@ -107,13 +113,17 @@ qsort(void *a, size_t n, size_t es, cmp_t *cmp)  #endif  {  	char *pa, *pb, *pc, *pd, *pl, *pm, *pn; -	int d, r, swaptype, swap_cnt; +	size_t d1, d2; +	int cmp_result; +	int swaptype_long, swaptype_int, swap_cnt; -loop:	SWAPINIT(a, es); +loop:	SWAPINIT(long, a, es); +	SWAPINIT(int, a, es);  	swap_cnt = 0;  	if (n < 7) {  		for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es) -			for (pl = pm; pl > (char *)a && CMP(thunk, pl - es, pl) > 0; +			for (pl = pm;  +			     pl > (char *)a && CMP(thunk, pl - es, pl) > 0;  			     pl -= es)  				swap(pl, pl - es);  		return; @@ -123,7 +133,8 @@ loop:	SWAPINIT(a, es);  		pl = a;  		pn = (char *)a + (n - 1) * es;  		if (n > 40) { -			d = (n / 8) * es; +			size_t d = (n / 8) * es; +  			pl = med3(pl, pl + d, pl + 2 * d, cmp, thunk);  			pm = med3(pm - d, pm, pm + d, cmp, thunk);  			pn = med3(pn - 2 * d, pn - d, pn, cmp, thunk); @@ -135,16 +146,16 @@ loop:	SWAPINIT(a, es);  	pc = pd = (char *)a + (n - 1) * es;  	for (;;) { -		while (pb <= pc && (r = CMP(thunk, pb, a)) <= 0) { -			if (r == 0) { +		while (pb <= pc && (cmp_result = CMP(thunk, pb, a)) <= 0) { +			if (cmp_result == 0) {  				swap_cnt = 1;  				swap(pa, pb);  				pa += es;  			}  			pb += es;  		} -		while (pb <= pc && (r = CMP(thunk, pc, a)) >= 0) { -			if (r == 0) { +		while (pb <= pc && (cmp_result = CMP(thunk, pc, a)) >= 0) { +			if (cmp_result == 0) {  				swap_cnt = 1;  				swap(pc, pd);  				pd -= es; @@ -160,27 +171,51 @@ loop:	SWAPINIT(a, es);  	}  	if (swap_cnt == 0) {  /* Switch to insertion sort */  		for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es) -			for (pl = pm; pl > (char *)a && CMP(thunk, pl - es, pl) > 0; +			for (pl = pm;  +			     pl > (char *)a && CMP(thunk, pl - es, pl) > 0;  			     pl -= es)  				swap(pl, pl - es);  		return;  	}  	pn = (char *)a + n * es; -	r = min(pa - (char *)a, pb - pa); -	vecswap(a, pb - r, r); -	r = min(pd - pc, pn - pd - es); -	vecswap(pb, pn - r, r); -	if ((r = pb - pa) > es) -#ifdef	I_AM_QSORT_R -		qsort_r(a, r / es, es, thunk, cmp); +	d1 = MIN(pa - (char *)a, pb - pa); +	vecswap(a, pb - d1, d1); +	d1 = MIN(pd - pc, pn - pd - es); +	vecswap(pb, pn - d1, d1); + +	d1 = pb - pa; +	d2 = pd - pc; +	if (d1 <= d2) { +		/* Recurse on left partition, then iterate on right partition */ +		if (d1 > es) { +#ifdef I_AM_QSORT_R +			qsort_r(a, d1 / es, es, thunk, cmp); +#else +			qsort(a, d1 / es, es, cmp); +#endif +		} +		if (d2 > es) { +			/* Iterate rather than recurse to save stack space */ +			/* qsort(pn - d2, d2 / es, es, cmp); */ +			a = pn - d2; +			n = d2 / es; +			goto loop; +		} +	} else { +		/* Recurse on right partition, then iterate on left partition */ +		if (d2 > es) { +#ifdef I_AM_QSORT_R +			qsort_r(pn - d2, d2 / es, es, thunk, cmp);  #else -		qsort(a, r / es, es, cmp); +			qsort(pn - d2, d2 / es, es, cmp);  #endif -	if ((r = pd - pc) > es) { -		/* Iterate rather than recurse to save stack space */ -		a = pn - r; -		n = r / es; -		goto loop; +		} +		if (d1 > es) { +			/* Iterate rather than recurse to save stack space */ +			/* qsort(a, d1 / es, es, cmp); */ +			n = d1 / es; +			goto loop; +		}  	}  }  | 
