@@ -28,8 +28,6 @@ int has_match(const char *needle, const char *haystack) {

 	return 1;

 }

-#define SWAP(x, y, T) do { T SWAP = x; x = y; y = SWAP; } while (0)

-

 #define max(a, b) (((a) > (b)) ? (a) : (b))

 struct match_struct {

@@ -81,6 +79,8 @@ static inline void match_row(const struct match_struct *match, int row, score_t

 	score_t prev_score = SCORE_MIN;

 	score_t gap_score = i == n - 1 ? SCORE_GAP_TRAILING : SCORE_GAP_INNER;

+	score_t prev_M, prev_D;

+

 	for (int j = 0; j < m; j++) {

 		if (lower_needle[i] == lower_haystack[j]) {

 			score_t score = SCORE_MIN;

@@ -88,14 +88,18 @@ static inline void match_row(const struct match_struct *match, int row, score_t

 				score = (j * SCORE_GAP_LEADING) + match_bonus[j];

 			} else if (j) { /* i > 0 && j > 0*/

 				score = max(

-						last_M[j - 1] + match_bonus[j],

+						prev_M + match_bonus[j],

 						/* consecutive match, doesn't stack with match_bonus */

-						last_D[j - 1] + SCORE_MATCH_CONSECUTIVE);

+						prev_D + SCORE_MATCH_CONSECUTIVE);

 			}

+			prev_D = last_D[j];

+			prev_M = last_M[j];

 			curr_D[j] = score;

 			curr_M[j] = prev_score = max(score, prev_score + gap_score);

 		} else {

+			prev_D = last_D[j];

+			prev_M = last_M[j];

 			curr_D[j] = SCORE_MIN;

 			curr_M[j] = prev_score = prev_score + gap_score;

 		}

@@ -131,24 +135,13 @@ score_t match(const char *needle, const char *haystack) {

 	 * D[][] Stores the best score for this position ending with a match.

 	 * M[][] Stores the best possible score at this position.

 	 */

-	score_t D[2][MATCH_MAX_LEN], M[2][MATCH_MAX_LEN];

-

-	score_t *last_D, *last_M;

-	score_t *curr_D, *curr_M;

-

-	last_D = D[0];

-	last_M = M[0];

-	curr_D = D[1];

-	curr_M = M[1];

+	score_t D[MATCH_MAX_LEN], M[MATCH_MAX_LEN];

 	for (int i = 0; i < n; i++) {

-		match_row(&match, i, curr_D, curr_M, last_D, last_M);

-

-		SWAP(curr_D, last_D, score_t *);

-		SWAP(curr_M, last_M, score_t *);

+		match_row(&match, i, D, M, D, M);

 	}

-	return last_M[m - 1];

+	return M[m - 1];

 }

 score_t match_positions(const char *needle, const char *haystack, size_t *positions) {

@@ -187,17 +180,9 @@ score_t match_positions(const char *needle, const char *haystack, size_t *positi

 	M = malloc(sizeof(score_t) * MATCH_MAX_LEN * n);

 	D = malloc(sizeof(score_t) * MATCH_MAX_LEN * n);

-	score_t *last_D = NULL, *last_M = NULL;

-	score_t *curr_D, *curr_M;

-

-	for (int i = 0; i < n; i++) {

-		curr_D = &D[i][0];

-		curr_M = &M[i][0];

-

-		match_row(&match, i, curr_D, curr_M, last_D, last_M);

-

-		last_D = curr_D;

-		last_M = curr_M;

+	match_row(&match, 0, D[0], M[0], D[0], M[0]);

+	for (int i = 1; i < n; i++) {

+		match_row(&match, i, D[i], M[i], D[i - 1], M[i - 1]);

 	}

 	/* backtrace to find the positions of optimal matching */