fix peephole bug (communative(phi(a,b), phi(a,b)) =/= communative(a,b))

1 files changed, 18 insertions, 3 deletions

diff --git a/peephole.c b/peephole.c
index b8118db..76d1fbd 100644
--- a/peephole.c
+++ b/peephole.c
@@ -251,6 +251,22 @@ static inline int is_zero(Node *n) {
 /* needs lexer for error reporting */
 Node *node_idealize(Node *n, Proc *p, Lexer *l) {
 	type_check(n, l);
+
+	/* stuff that needs to happen even if optimizations are disabled */
+
+	/*switch (n->op) {
+	case N_PHI:
+		for (int i = 0; i < n->in.len; i++) {
+			if (IN(n,i) && IN(n,i)->op == N_UNINIT) {
+				Node *r = node_new(p, N_UNINIT, p->start);
+				r->type = n->type;
+				return r;
+			}
+		}
+	default:
+		break;
+	}*/
+
 	if (no_opt) return NULL;
 
 	/* try to compute a literal value */
@@ -302,9 +318,8 @@ Node *node_idealize(Node *n, Proc *p, Lexer *l) {
 		}
 
 		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));
+				&& (node_equiv(CADR(n), CDAR(n)) && node_equiv(CAAR(n), CDDR(n)))) {
+			return OP(CAAR(n), CADR(n));
 		}
 	}