Fix more issues caused by negative literals

1 files changed, 65 insertions, 31 deletions

diff --git a/tpu.c b/tpu.c
index 55e4d53..3e8dee6 100644
--- a/tpu.c
+++ b/tpu.c
@@ -138,7 +138,9 @@ tpu_port_init(struct tpu_port *port)
 	port->clr_post_run = false;
 	port->reading = false;
 	port->writing = false;
+	port->in_set = false;
 	port->in = -1;
+	port->out_set = false;
 	port->out = -1;
 }
 
@@ -246,20 +248,22 @@ tpu_update_ports(struct tpu *tpu)
 	for (i = 0; i < 4; i++) {
 		port = &tpu->ports[i];
 		if (!port->attached) continue;
-		if (port->out >= 0 && port->dst_port->in < 0) {
-			port->dst_port->reading = false;
+		if (port->out_set && !port->dst_port->in_set) {
 			port->dst_port->in = port->out;
+			port->dst_port->in_set = true;
+			port->dst_port->reading = false;
+			port->out_set = false;
 			port->writing = false;
-			port->out = -1;
 		}
-		if (port->dst_port->out >= 0 && port->in < 0) {
-			port->reading = false;
+		if (port->dst_port->out_set && !port->in_set) {
 			port->in = port->dst_port->out;
+			port->in_set = true;
+			port->reading = false;
+			port->dst_port->out_set = false;
 			port->dst_port->writing = false;
-			port->dst_port->out = -1;
 		}
 		if (tpu->status == STATUS_RUN && port->clr_post_run) {
-			port->in = -1;
+			port->in_set = false;
 			port->clr_post_run = false;
 		}
 	}
@@ -323,18 +327,19 @@ tpu_add_inst(struct tpu *tpu, enum tpu_inst_type inst_type,
  * (->dst_port->out) -- the read value (->in) is cleared at the end of
  * an instruction step */
 
-static int
-tpu_port_read(struct tpu *tpu, enum tpu_port_dir dir)
+static bool
+tpu_port_read(struct tpu *tpu, enum tpu_port_dir dir, int *lit)
 {
 	struct tpu_port *port;
 
 	port = &tpu->ports[dir];
 	port->clr_post_run = true;
-	if (port->in < 0) {
+	if (!port->in_set) {
 		port->reading = true;
-		return -1;
+		return false;
 	}
-	return port->in;
+	*lit = port->in;
+	return true;
 }
 
 static bool
@@ -343,10 +348,11 @@ tpu_port_write(struct tpu *tpu, enum tpu_port_dir dir, int lit)
 	struct tpu_port *port;
 
 	port = &tpu->ports[dir];
-	if (port->out >= 0) {
+	if (port->out_set) {
 		port->writing = true;
 		return false;
 	}
+	port->out_set = true;
 	port->out = lit;
 	return true;
 }
@@ -359,31 +365,33 @@ tpu_jmp_label(struct tpu *tpu, const char *label)
 }
 
 int
-tpu_exec_get(struct tpu *tpu, struct tpu_inst_op *op)
+tpu_exec_get(struct tpu *tpu, struct tpu_inst_op *op, int *lit)
 {
-	int i, v;
+	int i;
 
 	switch (op->type) {
 	case OP_ACC:
-		return tpu->acc;
+		*lit = tpu->acc;
+		return true;
 	case OP_NIL:
-		return 0;
+		*lit = 0;
+		return true;
 	case OP_LEFT: case OP_RIGHT: case OP_UP: case OP_DOWN:
-		return tpu_port_read(tpu, op_to_dir(op->type));
+		return tpu_port_read(tpu, op_to_dir(op->type), lit);
 	case OP_ANY:
 		for (i = 0; i < 4; i++) {
-			v = tpu_port_read(tpu, (enum tpu_port_dir) i);
-			if (v >= 0) {
+			if (tpu_port_read(tpu, (enum tpu_port_dir) i, lit)) {
 				tpu->last = i;
-				return v;
+				return true;
 			}
 		}
-		return -1;
+		return false;
 	case OP_LAST:
-		if (tpu->last < 0) return 0;
-		return tpu_port_read(tpu, (enum tpu_port_dir) tpu->last);
+		if (tpu->last < 0) return false;
+		return tpu_port_read(tpu, (enum tpu_port_dir) tpu->last, lit);
 	case OP_LIT:
-		return op->val.lit;
+		*lit = op->val.lit;
+		return true;
 	case OP_LABEL:
 		abort();
 	}
@@ -426,8 +434,8 @@ tpu_exec_mov(struct tpu *tpu, struct tpu_inst *inst)
 
 	if (inst->type != INST_MOV) abort();
 
-	lit = tpu_exec_get(tpu, &inst->ops[0]);
-	if (lit < 0) return STATUS_READ;
+	if (!tpu_exec_get(tpu, &inst->ops[0], &lit))
+		return STATUS_READ;
 
 	if (!tpu_exec_put(tpu, &inst->ops[1], lit))
 		return STATUS_WRITE;
@@ -462,14 +470,14 @@ tpu_exec(struct tpu *tpu, struct tpu_inst *inst)
 		tpu->pc += 1;
 		return STATUS_RUN;
 	case INST_ADD:
-		val = tpu_exec_get(tpu, &inst->ops[0]);
-		if (val < 0) return STATUS_READ;
+		if (!tpu_exec_get(tpu, &inst->ops[0], &val))
+			return STATUS_READ;
 		tpu->acc = MIN(MAX(tpu->acc + val, -999), 999);
 		tpu->pc += 1;
 		return STATUS_RUN;
 	case INST_SUB:
-		val = tpu_exec_get(tpu, &inst->ops[0]);
-		if (val < 0) return STATUS_READ;
+		 if (!tpu_exec_get(tpu, &inst->ops[0], &val))
+			 return STATUS_READ;
 		tpu->acc = MIN(MAX(tpu->acc - val, -999), 999);
 		tpu->pc += 1;
 		return STATUS_RUN;
@@ -637,3 +645,29 @@ tis_step(struct tis *tis)
 
 	return running;
 }
+
+void
+tis_communicate(struct tis *tis, FILE *tis_stdin, FILE *tis_stdout)
+{
+	char buf[16], *s;
+	int val;
+
+	if (tis_stdin && tis->stdin_port.attached && !tis->stdin_port.out_set) {
+		while ((s = fgets(buf, sizeof(buf), tis_stdin))) {
+			if ((s = strchr(buf, '\n'))) *s = '\0';
+			if (!*buf) continue;
+			val = (int) strtol(buf, &s, 10);
+			if (!s || *s != '\0')
+				die("communicate: invalid input '%s'", buf);
+			tis->stdin_port.out = val;
+			tis->stdin_port.out_set = true;
+			break;
+		}
+	}
+
+	if (tis->stdout_port.attached && tis->stdout_port.in_set) {
+		if (tis_stdout)
+			fprintf(tis_stdout, "%i\n", tis->stdout_port.in);
+		tis->stdout_port.in_set = false;
+	}
+}