ditching combsort in radix sort

diff --git a/test/ksort_test.cc b/test/ksort_test.cc
index 37af58ee0b38ad64a12a7962101330b13f1a19ef..a0da805a9abac637761ded76b5e87cefd946461d 100644 (file)
--- a/test/ksort_test.cc
+++ b/test/ksort_test.cc
@@ -571,7 +571,7 @@ int * tmpArray;
 #define rstype_t unsigned
 #define rskey(x) (x)
 
-#define RS_MIN_SIZE 63
+#define RS_MIN_SIZE 32
 
 typedef struct {
        rstype_t *b, *e;
@@ -586,29 +586,6 @@ static inline void rs_insertsort(rstype_t *s, rstype_t *t)
                }
 }
 
-void rs_combsort(size_t n, rstype_t a[])
-{
-       const double shrink_factor = 1. / 1.2473309501039786540366528676643;
-       int do_swap;
-       size_t gap = n;
-       rstype_t tmp, *i, *j;
-       do {
-               if (gap > 2) {
-                       gap = (size_t)(gap * shrink_factor);
-                       if (gap == 9 || gap == 10) gap = 11;
-               }
-               do_swap = 0;
-               for (i = a; i < a + n - gap; ++i) {
-                       j = i + gap;
-                       if (rskey(*j) < rskey(*i)) {
-                               tmp = *i; *i = *j; *j = tmp;
-                               do_swap = 1;
-                       }
-               }
-       } while (do_swap || gap > 2);
-       if (gap != 1) rs_insertsort(a, a + n);
-}
-
 void rs_classify(rstype_t *beg, rstype_t *end, int n_bits, int s, bucket_t *b)
 {
        rstype_t *i, tmp;
@@ -625,7 +602,7 @@ void rs_classify(rstype_t *beg, rstype_t *end, int n_bits, int s, bucket_t *b)
                if (k->b == k->e) { ++k; continue; }
                l = b + (rskey(*k->b)>>s&m);
                if (k == l) { ++k->b; continue; }
-               while (b + (rskey(*l->b)>>s&m) == l) ++l->b;
+//             while (b + (rskey(*l->b)>>s&m) == l) ++l->b;
                tmp = *l->b; *l->b++ = *k->b; *k->b = tmp;
        }
        for (k = b + 1; k != be; ++k) k->b = (k-1)->e;
@@ -634,20 +611,17 @@ void rs_classify(rstype_t *beg, rstype_t *end, int n_bits, int s, bucket_t *b)
 
 void rs_sort(rstype_t *beg, rstype_t *end, int n_bits, int s)
 {
-       if (end - beg < 2) { // already sorted
-               return;
-       } else if (end - beg > RS_MIN_SIZE) {
+       if (end - beg > RS_MIN_SIZE) {
                bucket_t *b;
                int i;
-               b = (bucket_t*)malloc(sizeof(bucket_t) * (1<<n_bits));
+               b = (bucket_t*)alloca(sizeof(bucket_t) * (1<<n_bits));
                rs_classify(beg, end, n_bits, s, b);
                if (s) {
                        s = s > n_bits? s - n_bits : 0;
                        for (i = 0; i != 1<<n_bits; ++i)
                                if (b[i].e > b[i].b + 1) rs_sort(b[i].b, b[i].e, n_bits, s);
                }
-               free(b);
-       } else rs_combsort(end - beg, beg);
+       } else if (end - beg > 1) rs_insertsort(beg, end);
 }
 
 /*************************