1 files changed, 50 insertions, 3 deletions
diff --git a/src/sim/stage.cc b/src/sim/stage.cc
index 560cc41..8d9dfc0 100644
--- a/src/sim/stage.cc
+++ b/src/sim/stage.cc
@@ -1,12 +1,59 @@
 #include "stage.h"
+#include "utils.h"
+#include <array>
+#include <set>
 
-Stage::Stage(Stage *next) {
-	this->next = next;
-}
+static Logger *global_log = Logger::getInstance();
+
+Stage::Stage(Stage *next) { this->next = next; }
 
 std::array<int, GPR_NUM> Stage::gprs;
 std::array<int, V_NUM> Stage::vrs;
+std::set<unsigned int> Stage::checked_out;
 unsigned int Stage::pc;
 Storage *Stage::storage;
 bool Stage::is_pipelined;
 int Stage::clock_cycle;
+
+Response Stage::check_out(unsigned int &v)
+{
+	Response r;
+	if (this->is_checked_out(v))
+		r = STALLED;
+	else {
+		r = OK;
+		v = this->check_out_register(v);
+	}
+	return r;
+}
+
+bool Stage::is_checked_out(unsigned int r)
+{
+	return this->checked_out.find(r) != this->checked_out.end();
+}
+
+signed int Stage::check_out_register(unsigned int v)
+{
+	signed int r;
+	this->checked_out.insert(v);
+
+	r = this->dereference_register(v);
+	return r;
+}
+
+signed int Stage::dereference_register(unsigned int v)
+{
+	signed int r;
+
+	if (v >= GPR_NUM + V_NUM) {
+		global_log->log(
+			ERROR, string_format(
+					   "instruction tried to access register %d, which does "
+					   "not exist",
+					   v));
+		exit(EXIT_FAILURE);
+	}
+
+	r = (v >= GPR_NUM) ? this->vrs[v % GPR_NUM] : this->gprs[v];
+	return r;
+}