svn commit: r335603 - stable/11/lib/libc/stdlib

[Konstantin Belousov]

Author: kib
Date: Sun Jun 24 13:26:31 2018
New Revision: 335603
URL: https://svnweb.freebsd.org/changeset/base/335603

Log:
  MFC r334928:
  libc qsort(3): stop aliasing.
  
  PR:	228780

Modified:
  stable/11/lib/libc/stdlib/qsort.c
Directory Properties:
  stable/11/   (props changed)

Modified: stable/11/lib/libc/stdlib/qsort.c
==============================================================================
--- stable/11/lib/libc/stdlib/qsort.c	Sun Jun 24 13:23:27 2018	(r335602)
+++ stable/11/lib/libc/stdlib/qsort.c	Sun Jun 24 13:26:31 2018	(r335603)
@@ -41,53 +41,27 @@ 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 *, size_t, int, int);
 
 #define	MIN(a, b)	((a) < (b) ? a : b)
 
 /*
  * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
  */
-#define	swapcode(TYPE, parmi, parmj, n) {		\
-	size_t i = (n) / sizeof (TYPE);			\
-	TYPE *pi = (TYPE *) (parmi);		\
-	TYPE *pj = (TYPE *) (parmj);		\
-	do { 						\
-		TYPE	t = *pi;		\
-		*pi++ = *pj;				\
-		*pj++ = t;				\
-	} while (--i > 0);				\
-}
 
-#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, size_t n, int swaptype_long, int swaptype_int)
+swapfunc(char *a, char *b, size_t es)
 {
-	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)
+	char t;
+
+	do {
+		t = *a;
+		*a++ = *b;
+		*b++ = t;
+	} while (--es > 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_long, swaptype_int)
-
 #define	vecswap(a, b, n)				\
-	if ((n) > 0) swapfunc(a, b, n, swaptype_long, swaptype_int)
+	if ((n) > 0) swapfunc(a, b, n)
 
 #ifdef I_AM_QSORT_R
 #define	CMP(t, x, y) (cmp((t), (x), (y)))
@@ -119,17 +93,16 @@ qsort(void *a, size_t n, size_t es, cmp_t *cmp)
 	char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
 	size_t d1, d2;
 	int cmp_result;
-	int swaptype_long, swaptype_int, swap_cnt;
+	int swap_cnt;
 
-loop:	SWAPINIT(long, a, es);
-	SWAPINIT(int, a, es);
+loop:
 	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;
 			     pl -= es)
-				swap(pl, pl - es);
+				swapfunc(pl, pl - es, es);
 		return;
 	}
 	pm = (char *)a + (n / 2) * es;
@@ -145,7 +118,7 @@ loop:	SWAPINIT(long, a, es);
 		}
 		pm = med3(pl, pm, pn, cmp, thunk);
 	}
-	swap(a, pm);
+	swapfunc(a, pm, es);
 	pa = pb = (char *)a + es;
 
 	pc = pd = (char *)a + (n - 1) * es;
@@ -153,7 +126,7 @@ loop:	SWAPINIT(long, a, es);
 		while (pb <= pc && (cmp_result = CMP(thunk, pb, a)) <= 0) {
 			if (cmp_result == 0) {
 				swap_cnt = 1;
-				swap(pa, pb);
+				swapfunc(pa, pb, es);
 				pa += es;
 			}
 			pb += es;
@@ -161,14 +134,14 @@ loop:	SWAPINIT(long, a, es);
 		while (pb <= pc && (cmp_result = CMP(thunk, pc, a)) >= 0) {
 			if (cmp_result == 0) {
 				swap_cnt = 1;
-				swap(pc, pd);
+				swapfunc(pc, pd, es);
 				pd -= es;
 			}
 			pc -= es;
 		}
 		if (pb > pc)
 			break;
-		swap(pb, pc);
+		swapfunc(pb, pc, es);
 		swap_cnt = 1;
 		pb += es;
 		pc -= es;
@@ -178,7 +151,7 @@ loop:	SWAPINIT(long, a, es);
 			for (pl = pm; 
 			     pl > (char *)a && CMP(thunk, pl - es, pl) > 0;
 			     pl -= es)
-				swap(pl, pl - es);
+				swapfunc(pl, pl - es, es);
 		return;
 	}