hopefully make multiple returns form sensible graphs

1 files changed, 30 insertions, 0 deletions

diff --git a/ir.c b/ir.c
index a9fcd44..3ed9535 100644
--- a/ir.c
+++ b/ir.c
@@ -722,8 +722,17 @@ zero_no_effect:	if (node_eql_i64(CAR(n), 0)) return CDR(n);
 		}
 		break;
 
+	case N_RETURN:
+		if (CTRL(n)->val.type.lvl == T_XCTRL) return CTRL(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].type.lvl == T_XCTRL) {
+				return node_new_lit(p, (Value) {
+					.type = { .lvl = T_XCTRL, .t = T_NONE }
+				});
+			}
 			if (CTRL(n)->val.tuple.data[(n->val.i + 1) % CTRL(n)->val.tuple.len].type.lvl == T_XCTRL) {
 				return CTRL(CTRL(n));
 			}
@@ -736,6 +745,27 @@ zero_no_effect:	if (node_eql_i64(CAR(n), 0)) return CDR(n);
 		if (IN(CTRL(n), 0)->val.type.lvl == T_XCTRL) return CDR(n);
 		break;
 
+	case N_REGION:
+		{
+			int live_in = 0;
+			for (int i = 0; i < n->in.len; i++) {
+				if (IN(n, i)->val.type.lvl != T_XCTRL) live_in++;
+			}
+			if (live_in == 1) {
+				for (int i = 0; i < n->in.len; i++) {
+					if (IN(n, i)->val.type.lvl != T_XCTRL) {
+						return IN(n, i);
+					}
+				}
+			}
+			if (live_in == 0) {
+				return node_new_lit(p, (Value) {
+					.type = { .lvl = T_XCTRL, .t = T_NONE }
+				});
+			}
+		}
+		break;
+
 	default:
 		break;
 	}