small size optimization on <= 1-node NodeList

1 files changed, 18 insertions, 3 deletions

diff --git a/ir.h b/ir.h
index 8b963f7..b5992c8 100644
--- a/ir.h
+++ b/ir.h
@@ -100,7 +100,13 @@ typedef enum {
 
 const char *node_type_name(NodeType t);
 
-typedef DYNARR(struct Node *) NodeList;
+typedef struct {
+	unsigned len, cap;
+	union {
+		struct Node *sbo;
+		struct Node **data;
+	};
+} NodeList;
 
 typedef struct Node {
 	int id, refs;
@@ -122,8 +128,9 @@ typedef struct Node {
 
 /* convenience macros (lisp-inspired lol) */
 
-#define IN(n, i) ((n)->in.data[i])
-#define OUT(n, i) ((n)->out.data[i])
+#define Ni(nl, i) (*nodelist_nth(&(nl), i))
+#define IN(n, i) Ni(n->in, i)
+#define OUT(n, i) Ni(n->out, i)
 
 #define CTRL(n) IN(n, 0)
 #define CAR(n) IN(n, 1)
@@ -187,4 +194,12 @@ int node_maybe_uninit(Node *n);
 
 #define node_new(...) node_newv(__VA_ARGS__, NULL)
 
+static inline Node **nodelist_data(NodeList *l) {
+	return l->cap ? l->data : &l->sbo;
+}
+
+static inline Node **nodelist_nth(NodeList *l, uint32_t i) {
+	return nodelist_data(l) + i;
+}
+
 #endif