1 files changed, 30 insertions, 0 deletions
diff --git a/src/sim/instr.cc b/src/sim/instr.cc
new file mode 100644
index 0000000..608b871
--- /dev/null
+++ b/src/sim/instr.cc
@@ -0,0 +1,30 @@
+#include "instr.h"
+#include <functional>
+#include <map>
+
+// clang-format off
+#define INIT_INSTRUCTION(type, opcode, body) \
+	{type, {{opcode, [](signed int &s1, signed int &s2, signed int &s3) { \
+		body; \
+	}}}}
+// clang-format on
+
+namespace instr
+{
+// clang-format off
+const std::map<int,	std::map<int, std::function<void(signed int &s1, signed int &s2, signed int &s3)>>>
+	// clang-format on
+	instr_map = {
+
+		/* R type instructions */
+		// TODO these need to be WRAPPED with a function that sets overflow.
+		// future note to self, if these are more than 2 lines each, you're
+		// doing it wrong
+		INIT_INSTRUCTION(0b00, 0b00001, s3 = s1 + s2),
+		INIT_INSTRUCTION(0b00, 0b00010, s3 = s1 - s2),
+
+		/* I type instructions */
+
+		/* J type instructions */
+};
+} // namespace instr