do swaps byte-by-byte to remove the need for allocating buffers

2 files changed, 10 insertions, 20 deletions

diff --git a/src/stdlib/_qsort.h b/src/stdlib/_qsort.h
index 298e28a1..28d273cd 100644
--- a/src/stdlib/_qsort.h
+++ b/src/stdlib/_qsort.h
@@ -1,19 +1,22 @@
 #include <stdlib.h>
-#include <string.h>
 
 struct __qs {
 	char *base;
 	size_t size;
 	int (*compar)(const void *, const void *);
-	char buf[64];
-	char *swap;
 };
 
-static void __swap(struct __qs *a, size_t i, size_t j)
+static void __swap(struct __qs *a, size_t b, size_t c)
 {
-	memcpy(a->swap, a->base + (a->size * i), a->size);
-	memcpy(a->base + (a->size * i), a->base + (a->size * j), a->size);
-	memcpy(a->base + (a->size * j), a->swap, a->size);
+	char *x = a->base + (a->size * b);
+	char *y = a->base + (a->size * c);
+	size_t i;
+
+	for (i = 0; i < a->size; i++) {
+		char tmp = x[i];
+		x[i] = y[i];
+		y[i] = tmp;
+	}
 }
 
 static size_t __partition(struct __qs *a, size_t lo, size_t hi)
diff --git a/src/stdlib/qsort.c b/src/stdlib/qsort.c
index f0ccba33..535e8551 100644
--- a/src/stdlib/qsort.c
+++ b/src/stdlib/qsort.c
@@ -9,21 +9,8 @@ void qsort(void * base, size_t nmemb, size_t size, int (*compar)(const void *, c
 		base,
 		size,
 		compar,
-		{ 0 },
-		NULL,
 	};
-
-	if (size <= sizeof(qs.buf)) {
-		qs.swap = qs.buf;
-	} else {
-		qs.swap = malloc(size);
-	}
-
 	__qsort(&qs, 0, nmemb);
-
-	if (qs.swap != qs.buf) {
-		free(qs.swap);
-	}
 }
 
 /***