remove Node.refs

1 files changed, 23 insertions, 10 deletions

diff --git a/ir.c b/ir.c
index a91db1b..356a606 100644
--- a/ir.c
+++ b/ir.c
@@ -30,7 +30,6 @@ void nodelist_fit(NodeList *l, u32 sz, Arena *a) {
 void nodelist_push(NodeList *l, Node *n, Arena *a) {
 	nodelist_fit(l, l->len + 1, a);
 	Node **p = nodelist_nth(l, l->len++);
-	if (n) n->refs++;
 	*p = n;
 }
 
@@ -38,7 +37,6 @@ void nodelist_remove(NodeList *l, Node *n) {
 	Node **data = nodelist_data(l);
 	for (unsigned i = 0; i < l->len; i++) {
 		if (data[i] == n) {
-			if (n) n->refs--;
 			l->len--;
 			if (i < l->len) {
 				memmove(&data[i], &data[i+1], (l->len - i) * sizeof(Node *));
@@ -54,7 +52,6 @@ void nodelist_remove_unordered(NodeList *l, Node *p) {
 	while (i) {
 		i--;
 		if (data[i] == p) {
-			if (p) p->refs--;
 			l->len--;
 			if (i < l->len) {
 				data[i] = data[l->len];
@@ -76,7 +73,6 @@ const char *node_type_name(NodeType t) {
 }
 
 void node_die(Node *n, Graph *p) {
-	assert(n->refs == 0);
 	assert(n->op != N_DEAD);
 	n->op = N_DEAD;
 	n->prev_free = p->pool->free_list;
@@ -91,14 +87,28 @@ void node_del_in(Node *n, Node *p) {
 	nodelist_remove(&n->in, p);
 }
 
+static inline int node_should_die(Node *n) {
+	return n->in.len == 0 && n->out.len == 0;
+}
+
 void node_kill(Node *n, Graph *p) {
 	if (p->ctrl == n) {
 		/* probably this is fine */
 		p->ctrl = CTRL(n);
 	}
-	while (n->refs > 0 && n->in.len > 0) node_remove(p, IN(n, 0), n);
-	while (n->refs > 0 && n->out.len > 0) node_remove(p, n, OUT(n, 0));
-	assert(n->refs == 0);
+	for (u32 i = 0; i < n->in.len; i++) {
+		Node *o = IN(n, i);
+		if (o) {
+			node_del_out(o, n);
+			if (node_should_die(o)) node_die(o, p);
+		}
+	}
+	for (u32 i = 0; i < n->out.len; i++) {
+		Node *o = OUT(n, i);
+		node_del_in(o, n);
+		if (node_should_die(o)) node_die(o, p);
+	}
+	node_die(n, p);
 }
 
 void node_add_out(Graph *p, Node *a, Node *b) {
@@ -111,7 +121,6 @@ void node_add_in(Graph *p, Node *a, Node *b) {
 
 void node_set_in(Graph *p, Node *n, int idx, Node *to) {
 	Node *in = IN(n, idx);
-	if (in) in->refs--;
 	node_add_out(p, to, n);
 	node_del_out(in, n);
 	IN(n, idx) = to;
@@ -135,7 +144,7 @@ void node_add(Graph *p, Node *src, Node *dest) {
 void node_remove(Graph *p, Node *src, Node *dest) {
 	assert(dest->op != N_DEAD);
 	node_del_in(dest, src);
-	if (dest->refs < 1) node_die(dest, p);
+	if (node_should_die(dest)) node_die(dest, p);
 	if (src) {
 		assert(src->op != N_DEAD);
 		node_del_out(src, dest);
@@ -151,7 +160,11 @@ Node *node_new_empty(Graph *p, NodeType t) {
 		n = p->pool->free_list;
 		assert(n->op == N_DEAD);
 		p->pool->free_list = n->prev_free;
-		memset(n, 0, sizeof(Node));
+		n->in.len = 0;
+		n->out.len = 0;
+		n->walked = 0;
+		n->src_pos = (LexSpan) { 0 };
+		n->val = (Value) { 0 };
 	} else {
 		n = new(p->pool->arena, Node);
 	}