[gsoc-diff] reduce number of rec accesses

raw.foo.diff

diff --git a/xdiff/xhistogram.c b/xdiff/xhistogram.c
index ea7b82d..d26c57c 100644
--- a/xdiff/xhistogram.c
+++ b/xdiff/xhistogram.c
@@ -52,7 +52,7 @@ struct region {
 #define get_rec(env, s, l) \
 	(env->xdf##s.recs[l-1])
 
-static int cmp_recs(xpparam_t const *xpp, xdfenv_t *env,
+static int cmp_recs(xpparam_t const *xpp,
 	xrecord_t *r1, xrecord_t *r2)
 {
 	return r1->ha == r2->ha &&
@@ -60,14 +60,17 @@ static int cmp_recs(xpparam_t const *xpp, xdfenv_t *env,
 			    xpp->flags);
 }
 
+#define cmp_xrecord_t(index, r1, s, l) \
+	(cmp_recs(index->xpp, r1, get_rec(index->env, s, l)))
+
 #define cmp_env(xpp, env, s1, l1, s2, l2) \
-	(cmp_recs(xpp, env, get_rec(env, s1, l1), get_rec(env, s2, l2)))
+	(cmp_recs(xpp, get_rec(env, s1, l1), get_rec(env, s2, l2)))
 
 #define cmp(i, s1, l1, s2, l2) \
 	(cmp_env(i->xpp, i->env, s1, l1, s2, l2))
 
-#define table_hash(index, side, line) \
-	XDL_HASHLONG((get_rec(index->env, side, line))->ha, index->table_bits)
+#define table_hash(index, rec) \
+	XDL_HASHLONG(rec->ha, index->table_bits)
 
 static int scanA(struct histindex *index, int line1, int count1)
 {
@@ -75,14 +78,16 @@ static int scanA(struct histindex *index, int line1, int count1)
 	unsigned int chain_len;
 	unsigned int new_cnt;
 	unsigned long rec;
+	xrecord_t *arec;
 
 	for (ptr = LINE_END(1); line1 <= ptr; ptr--) {
-		tbl_idx = table_hash(index, 1, ptr);
+		arec = get_rec(index->env, 1, ptr);
+		tbl_idx = table_hash(index, arec);
 
 		chain_len = 0;
 		for (rec_idx = index->table[tbl_idx]; rec_idx != 0; ) {
 			rec = index->recs[rec_idx];
-			if (cmp(index, 1, REC_PTR(rec), 1, ptr)) {
+			if (cmp_xrecord_t(index, arec, 1, REC_PTR(rec))) {
 				new_cnt = REC_CNT(rec) + 1;
 				if (new_cnt > MAX_CNT)
 					new_cnt = MAX_CNT;
@@ -123,7 +128,8 @@ static int try_lcs(struct histindex *index, struct region *lcs, int b_ptr,
 	int line1, int count1, int line2, int count2)
 {
 	unsigned int b_next = b_ptr + 1;
-	unsigned int rec_idx = index->table[table_hash(index, 2, b_ptr)];
+	xrecord_t *brec = get_rec(index->env, 2, b_ptr);
+	unsigned int rec_idx = index->table[table_hash(index, brec)];
 	unsigned long rec;
 	unsigned int as, ae, bs, be, np, rc;
 	int should_break;
@@ -138,7 +144,7 @@ static int try_lcs(struct histindex *index, struct region *lcs, int b_ptr,
 		}
 
 		as = REC_PTR(rec);
-		if (!cmp(index, 1, as, 2, b_ptr))
+		if (!cmp_xrecord_t(index, brec, 1, as))
 			continue;
 
 		index->has_common = 1;