libc: Sync qsort(3) with FreeBSD revision r318515.
r279663: enhance to handle 32-bit aligned data on 64-bit systems
r279666: qsort(3): small style(9) cleanups.
r288030: Use ANSI C prototypes. Eliminates -Wold-style-definition
warnings.
r318514: Use size_t.
r318515: Reduce the possible recursion level to log2(N) by always
recursing on the smaller partition instead.
Bug: 38450217
Test: builds, ./tests/run-on-host.sh 64
Change-Id: Ieb622e6f54f8f6d6f62e1bdb491d3b5c8e2f9965
diff --git a/libc/upstream-freebsd/lib/libc/stdlib/qsort.c b/libc/upstream-freebsd/lib/libc/stdlib/qsort.c
index 93e22cd..1ccc518 100644
--- a/libc/upstream-freebsd/lib/libc/stdlib/qsort.c
+++ b/libc/upstream-freebsd/lib/libc/stdlib/qsort.c
@@ -41,47 +41,53 @@
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 *, size_t, 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) { \
+ 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); \
+ } 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)
- char *a, *b;
- int n, swaptype;
+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)))
@@ -98,24 +104,25 @@
{
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
{
char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
- size_t d, r;
+ size_t d1, d2;
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)
@@ -130,7 +137,8 @@
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);
@@ -175,21 +183,43 @@
}
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)
+ 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, r / es, es, thunk, cmp);
+ qsort_r(a, d1 / es, es, thunk, cmp);
#else
- qsort(a, r / es, es, cmp);
+ qsort(a, d1 / 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 (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(pn - d2, d2 / es, es, cmp);
+#endif
+ }
+ if (d1 > es) {
+ /* Iterate rather than recurse to save stack space */
+ /* qsort(a, d1 / es, es, cmp); */
+ n = d1 / es;
+ goto loop;
+ }
}
-/* qsort(pn - r, r / es, es, cmp);*/
}
diff --git a/tests/Android.bp b/tests/Android.bp
index a03f1a6..1981457 100644
--- a/tests/Android.bp
+++ b/tests/Android.bp
@@ -88,6 +88,7 @@
"nl_types_test.cpp",
"pthread_test.cpp",
"pty_test.cpp",
+ "qsort_test.cpp",
"regex_test.cpp",
"resolv_test.cpp",
"sched_test.cpp",
diff --git a/tests/qsort_test.cpp b/tests/qsort_test.cpp
new file mode 100644
index 0000000..95b4789
--- /dev/null
+++ b/tests/qsort_test.cpp
@@ -0,0 +1,106 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdlib.h>
+#include <sys/types.h>
+
+#include <gtest/gtest.h>
+
+#include "gtest_globals.h"
+
+#define BUFFER_SIZE 1024
+
+static int cmp_long(const void *l, const void *r)
+{
+
+ return (*(long *)l - *(long *)r);
+}
+
+static int cmp_int(const void *l, const void *r)
+{
+
+ return (*(int *)l - *(int *)r);
+}
+
+#ifndef arc4random_uniform
+static bool seeded;
+
+u_int32_t arc4random_uniform(uint32_t upper_bound)
+{
+ if (!seeded) {
+ srandom((int)time(NULL));
+ seeded = true;
+ }
+
+ return (random() % upper_bound);
+}
+#endif
+
+TEST(qsort_test, long_test) {
+ long buf[BUFFER_SIZE];
+ long i;
+
+ /* Initialize buffer with known numbers */
+ for (i=0; i<BUFFER_SIZE; i++)
+ buf[i] = i;
+
+ /* Stir 1/4 pairs in the buffer */
+ for (i=0; i<BUFFER_SIZE/4; i++) {
+ u_int32_t pos1, pos2;
+ long t;
+
+ pos1 = arc4random_uniform(BUFFER_SIZE);
+ pos2 = arc4random_uniform(BUFFER_SIZE);
+
+ t = buf[pos1];
+ buf[pos1] = buf[pos2];
+ buf[pos2] = t;
+ }
+
+ /* Sort */
+ qsort(buf, BUFFER_SIZE, sizeof(buf[0]), &cmp_long);
+
+ for (i=0; i<BUFFER_SIZE; i++)
+ EXPECT_EQ(i, buf[i]);
+}
+
+TEST(qsort_test, int_test) {
+ int buf[BUFFER_SIZE];
+ int i;
+
+ /* Initialize buffer with known numbers */
+ for (i=0; i<BUFFER_SIZE; i++)
+ buf[i] = i;
+
+ /* Stir 1/4 pairs in the buffer */
+ for (i=0; i<BUFFER_SIZE/4; i++) {
+ u_int32_t pos1, pos2;
+ int t;
+
+ pos1 = arc4random_uniform(BUFFER_SIZE);
+ pos2 = arc4random_uniform(BUFFER_SIZE);
+
+ t = buf[pos1];
+ buf[pos1] = buf[pos2];
+ buf[pos2] = t;
+ }
+
+ /* Sort */
+ qsort(buf, BUFFER_SIZE, sizeof(buf[0]), &cmp_int);
+
+ for (i=0; i<BUFFER_SIZE; i++)
+ EXPECT_EQ(i, buf[i]);
+}