diff options
Diffstat (limited to 'sys/libkern/qsort.c')
| -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 bb0baee..9c83f60 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); \ - register TYPE *pi = (TYPE *) (parmi); \ - register 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 { \ - register 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; + } } } |
