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authordelphij <delphij@FreeBSD.org>2017-05-31 06:13:33 +0000
committerdelphij <delphij@FreeBSD.org>2017-05-31 06:13:33 +0000
commit6c25a3b3001c6d7f3751728cc02f53f98010348f (patch)
tree0ff915d7b41d0cbf3d4da69bc92aef0834e78536 /lib/libc
parent1a5f55018b250a8e6a152f97a4e497e2e13fb12f (diff)
downloadFreeBSD-src-6c25a3b3001c6d7f3751728cc02f53f98010348f.zip
FreeBSD-src-6c25a3b3001c6d7f3751728cc02f53f98010348f.tar.gz
MFC r279663,r279666 (pfg):
r279663: qsort(3): enhance to handle 32-bit aligned data on 64-bit systems Implement a small enhancement to the original qsort implementation: If the data is 32 bit aligned we can side-step the long type version and use int instead. The change brings a modest but significant improvement in 32 bit workloads. r279666: qsort(3): small style(9) cleanups. Basically spaces vs. tabs. No functional change.
Diffstat (limited to 'lib/libc')
-rw-r--r--lib/libc/stdlib/qsort.c53
1 files changed, 31 insertions, 22 deletions
diff --git a/lib/libc/stdlib/qsort.c b/lib/libc/stdlib/qsort.c
index 93e22cd..e97ea92 100644
--- a/lib/libc/stdlib/qsort.c
+++ b/lib/libc/stdlib/qsort.c
@@ -41,47 +41,55 @@ typedef int cmp_t(void *, 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);
+static inline void swapfunc(char *, char *, int, int, int);
-#define min(a, b) (a) < (b) ? a : b
+#define MIN(a, b) ((a) < (b) ? a : b)
/*
* 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) { \
+ long i = (n) / sizeof (TYPE); \
+ TYPE *pi = (TYPE *) (parmi); \
+ TYPE *pj = (TYPE *) (parmj); \
do { \
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(a, b, n, swaptype)
+swapfunc(a, b, n, swaptype_long, swaptype_int)
char *a, *b;
- int n, swaptype;
+ int n, swaptype_long, 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)))
@@ -98,14 +106,14 @@ __unused
{
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
void
qsort_r(void *a, size_t n, size_t es, void *thunk, cmp_t *cmp)
#else
-#define thunk NULL
+#define thunk NULL
void
qsort(void *a, size_t n, size_t es, cmp_t *cmp)
#endif
@@ -113,9 +121,10 @@ qsort(void *a, size_t n, size_t es, cmp_t *cmp)
char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
size_t d, r;
int cmp_result;
- int swaptype, swap_cnt;
+ 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)
@@ -175,9 +184,9 @@ loop: SWAPINIT(a, es);
}
pn = (char *)a + n * es;
- r = min(pa - (char *)a, pb - pa);
+ r = MIN(pa - (char *)a, pb - pa);
vecswap(a, pb - r, r);
- r = min(pd - pc, pn - pd - es);
+ r = MIN(pd - pc, pn - pd - es);
vecswap(pb, pn - r, r);
if ((r = pb - pa) > es)
#ifdef I_AM_QSORT_R
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