Add instrumentation

Track the number of comparisons, swaps, and rotations performed in each
part of the sorting algorithm.

1 files changed, 12 insertions, 0 deletions

diff --git a/grailsort.c b/grailsort.c
index 6f63701..9eff4d6 100644
--- a/grailsort.c
+++ b/grailsort.c
@@ -6,6 +6,7 @@
 
 #include "sorters.h"
 #include "common.h"
+#include "counts.h"
 
 static inline void *tail(char *base, size_t nmel, size_t width)
 {
@@ -15,13 +16,19 @@ static inline void *tail(char *base, size_t nmel, size_t width)
 /* get index of last block whose head is less than the previous block's tail */
 static size_t last_overlap(char *base, size_t bcount, size_t bwidth, size_t width, cmpfun cmp)
 {
+	struct counts snapshot = counts[CURRENT];
+
 	for (char *cur = tail(base, bcount, bwidth); --bcount; cur -= bwidth)
 		if (cmp(cur - width, cur) > 0) break;
+
+	add_counts(counts + LAST_OVERLAP, &snapshot);
 	return bcount;
 }
 
 size_t merge(char *buf, char *a, char *b, size_t bufnmel, size_t anmel, size_t bnmel, size_t width, cmpfun cmp)
 {
+	struct counts snapshot = counts[CURRENT];
+
 	while (bnmel) {
 		char *a_tail   = tail(a,   anmel,   width);
 		char *b_tail   = tail(b,   bnmel,   width);
@@ -36,6 +43,8 @@ size_t merge(char *buf, char *a, char *b, size_t bufnmel, size_t anmel, size_t b
 		}
 		bufnmel--;
 	}
+
+	add_counts(counts + MERGE, &snapshot);
 	return anmel;
 }
 
@@ -81,7 +90,10 @@ void grailsort(void *unsorted, size_t nmel, size_t width, cmpfun cmp)
 		blocks    = overlap;
 	}
 
+	struct counts snapshot = counts[CURRENT];
 	rotate(base, buf-base + bufnmel*width, buf-base);
+	add_counts(counts + MOVE_BUFFER, &snapshot);
+
 	grailsort(base, bufnmel, width, cmp);
 	distribute_buffer(base, bufnmel, nmel - bufnmel, width, cmp);
 }