i thiiiink if statement peepholes work now?

1 files changed, 22 insertions, 7 deletions

diff --git a/ir.c b/ir.c
index d527bfe..a9fcd44 100644
--- a/ir.c
+++ b/ir.c
@@ -171,6 +171,10 @@ void node_del_in(Node *n, Node *p) {
 }
 
 void node_kill(Node *n, Proc *p) {
+	if (p->ctrl == n) {
+		/* probably this is fine */
+		p->ctrl = CTRL(n);
+	}
 	while (n->refs > 0 && n->in.len > 0) node_remove(p, n->in.data[0], n);
 	while (n->refs > 0 && n->out.len > 0) node_remove(p, n, n->out.data[0]);
 	assert(n->refs == 0);
@@ -462,6 +466,7 @@ static inline int node_known_not_equiv(Node *a, Node *b) {
 
 static int node_equiv_input(Node *a, Node *b) {
 	if (a->in.len != b->in.len) return 0;
+	if (CTRL(a) != CTRL(b)) return 0;
 	/* note that this means the order of inputs isn't guaranteed, so be
 	 * careful what you use this procedure for */
 	if ((node_op_communative(a->type) || node_op_communative(b->type))
@@ -470,7 +475,7 @@ static int node_equiv_input(Node *a, Node *b) {
 		/* assuming input count is 2 */
 		return 1;
 	}
-	for (int i = 0; i < a->in.len; i++) {
+	for (int i = 1; i < a->in.len; i++) {
 		if (!node_equiv(IN(a, i), IN(b, i))) return 0;
 	}
 	return 1;
@@ -548,6 +553,12 @@ Node *node_idealize(Node *n, Proc *p, Lexer *l) {
 		if (T(CDR(n), N_OP_NOT) && !T(CAR(n), N_OP_NOT)) {
 			return NODE(n->type, CDR(n), CAR(n));
 		}
+
+		if (T(CAR(n), N_PHI) && T(CDR(n), N_PHI) && CTRL(CAR(n)) == CTRL(CDR(n))
+				&& ((node_equiv(CAAR(n), CDAR(n)) && node_equiv(CADR(n), CDDR(n)))
+				|| (node_equiv(CADR(n), CDAR(n)) && node_equiv(CAAR(n), CDDR(n))))) {
+			return OP(CAAR(n), CDAR(n));
+		}
 	}
 
 	if (node_op_associative(n->type)) {
@@ -711,14 +722,18 @@ zero_no_effect:	if (node_eql_i64(CAR(n), 0)) return CDR(n);
 		}
 		break;
 
+	case N_PROJ:
+		if (T(CTRL(n), N_IF_ELSE) && CTRL(n)->val.type.t == T_TUPLE) {
+			if (CTRL(n)->val.tuple.data[(n->val.i + 1) % CTRL(n)->val.tuple.len].type.lvl == T_XCTRL) {
+				return CTRL(CTRL(n));
+			}
+		}
+		break;
+
 	case N_PHI:
 		if (same) return CAR(n);
-		if (IN(CTRL(n), 1)->val.type.lvl == T_XCTRL) {
-			return CAR(n);
-		}
-		if (IN(CTRL(n), 0)->val.type.lvl == T_XCTRL) {
-			return CDR(n);
-		}
+		if (IN(CTRL(n), 1)->val.type.lvl == T_XCTRL) return CAR(n);
+		if (IN(CTRL(n), 0)->val.type.lvl == T_XCTRL) return CDR(n);
 		break;
 
 	default: