Merge pull request #67 from bdunahu/bdunahu

add RET instruction, JAL ob1 error (full subroutine support), condition codes for everything but shifts

4 files changed, 46 insertions, 5 deletions

diff --git a/src/sim/ex.cc b/src/sim/ex.cc
index f098917..d345ecf 100644
--- a/src/sim/ex.cc
+++ b/src/sim/ex.cc
@@ -39,6 +39,8 @@ EX::EX(Stage *stage) : Stage(stage)
 		INIT_INSTRUCTION(
 			ADD,
 			{
+				this->set_condition(OF, ADDITION_OF_GUARD(s1, s2));
+				this->set_condition(UF, ADDITION_UF_GUARD(s1, s2));
 				s1 = s1 + s2;
 				(void)pc;
 				(void)s3;
@@ -48,6 +50,8 @@ EX::EX(Stage *stage) : Stage(stage)
 		INIT_INSTRUCTION(
 			SUB,
 			{
+				this->set_condition(OF, SUBTRACTION_OF_GUARD(s1, s2));
+				this->set_condition(UF, SUBTRACTION_UF_GUARD(s1, s2));
 				s1 = s1 - s2;
 				(void)pc;
 				(void)s3;
@@ -57,6 +61,8 @@ EX::EX(Stage *stage) : Stage(stage)
 		INIT_INSTRUCTION(
 			MUL,
 			{
+				this->set_condition(OF, MULTIPLICATION_OF_GUARD(s1, s2));
+				this->set_condition(UF, MULTIPLICATION_UF_GUARD(s1, s2));
 				s1 = s1 * s2;
 				(void)pc;
 				(void)s3;
@@ -75,7 +81,6 @@ EX::EX(Stage *stage) : Stage(stage)
 			REM,
 			{
 				this->handle_divide(s1, s2, true);
-				s1 = s1 % s2;
 				(void)pc;
 				(void)s3;
 				(void)this;
@@ -102,6 +107,8 @@ EX::EX(Stage *stage) : Stage(stage)
 		INIT_INSTRUCTION(
 			AND,
 			{
+				this->set_condition(OF, false);
+				this->set_condition(UF, false);
 				s1 = s1 & s2;
 				(void)pc;
 				(void)s3;
@@ -111,6 +118,8 @@ EX::EX(Stage *stage) : Stage(stage)
 		INIT_INSTRUCTION(
 			OR,
 			{
+				this->set_condition(OF, false);
+				this->set_condition(UF, false);
 				s1 = s1 | s2;
 				(void)pc;
 				(void)s3;
@@ -120,6 +129,8 @@ EX::EX(Stage *stage) : Stage(stage)
 		INIT_INSTRUCTION(
 			NOT,
 			{
+				this->set_condition(OF, false);
+				this->set_condition(UF, false);
 				s1 = ~s1;
 				(void)pc;
 				(void)s3;
@@ -130,6 +141,8 @@ EX::EX(Stage *stage) : Stage(stage)
 		INIT_INSTRUCTION(
 			XOR,
 			{
+				this->set_condition(OF, false);
+				this->set_condition(UF, false);
 				s1 = s1 ^ s2;
 				(void)pc;
 				(void)s3;
@@ -220,6 +233,8 @@ EX::EX(Stage *stage) : Stage(stage)
 		INIT_INSTRUCTION(
 			ADDI,
 			{
+				this->set_condition(OF, ADDITION_OF_GUARD(s1, s3));
+				this->set_condition(UF, ADDITION_UF_GUARD(s1, s3));
 				s1 = s1 + s3;
 				(void)pc;
 				(void)s2;
@@ -229,6 +244,8 @@ EX::EX(Stage *stage) : Stage(stage)
 		INIT_INSTRUCTION(
 			SUBI,
 			{
+				this->set_condition(OF, SUBTRACTION_OF_GUARD(s1, s3));
+				this->set_condition(UF, SUBTRACTION_UF_GUARD(s1, s3));
 				s1 = s1 - s3;
 				(void)pc;
 				(void)s2;
@@ -256,6 +273,8 @@ EX::EX(Stage *stage) : Stage(stage)
 		INIT_INSTRUCTION(
 			ANDI,
 			{
+				this->set_condition(OF, false);
+				this->set_condition(UF, false);
 				s1 = s1 & s3;
 				(void)pc;
 				(void)s2;
@@ -265,6 +284,8 @@ EX::EX(Stage *stage) : Stage(stage)
 		INIT_INSTRUCTION(
 			ORI,
 			{
+				this->set_condition(OF, false);
+				this->set_condition(UF, false);
 				s1 = s1 | s3;
 				(void)pc;
 				(void)s2;
@@ -274,6 +295,8 @@ EX::EX(Stage *stage) : Stage(stage)
 		INIT_INSTRUCTION(
 			XORI,
 			{
+				this->set_condition(OF, false);
+				this->set_condition(UF, false);
 				s1 = s1 ^ s3;
 				(void)pc;
 				(void)s2;
@@ -372,6 +395,16 @@ EX::EX(Stage *stage) : Stage(stage)
 				(void)this;
 			}),
 
+		INIT_INSTRUCTION(
+			RET,
+			{
+				(void)pc;
+				(void)s3;
+				(void)s2;
+				(void)s1;
+				(void)this;
+			}),
+
 		/* NOP */
 		INIT_INSTRUCTION(
 			NOP,
@@ -405,12 +438,17 @@ void EX::advance_helper()
 
 void EX::handle_divide(signed int &s1, signed int s2, bool is_mod)
 {
+	this->set_condition(OF, DIVISION_OF_GUARD(s1, s2));
+	this->set_condition(UF, false);
 	if (s2 == 0) {
 		// handle everything here
 		this->curr_instr->set_s1(MAX_INT);
 		this->status = OK;
 		throw HaltException();
+	} else if ((s1 == -(MAX_INT)-1) && s2 == -1) {
+		// undefined in C++
+		s1 = -(MAX_INT)-1;
 	} else {
-		s1 = (is_mod) ? s1 % s2 : s1 / s2;
+		s1 = (is_mod) ? (s1 % s2) : (s1 / s2);
 	}
 }
diff --git a/src/sim/id.cc b/src/sim/id.cc
index 3753f83..cdbaba9 100644
--- a/src/sim/id.cc
+++ b/src/sim/id.cc
@@ -211,8 +211,11 @@ void ID::decode_J_type(
 		}
 		this->status = r1;
 		break;
+	case RET:
+		s1 = 1; // link register
+		[[fallthrough]];
 	default:
-		this->status = this->read_guard(*&s1);
+		this->status = this->read_guard(s1);
 	}
 
 }
diff --git a/src/sim/instr.cc b/src/sim/instr.cc
index c8d1039..9bd951b 100644
--- a/src/sim/instr.cc
+++ b/src/sim/instr.cc
@@ -35,6 +35,6 @@ const std::unordered_map<unsigned int, Mnemonic> mnemonic_map = {
 	{0b0101101, STOREV}, {0b0000110, JMP},	 {0b0001010, JRL},
 	{0b0001110, JAL},	 {0b0010010, BEQ},	 {0b0010110, BGT},
 	{0b0011010, BUF},	 {0b0011110, BOF},	 {0b0100010, PUSH},
-	{0b0100110, POP},
+	{0b0100110, POP},	 {0b0101010, RET},
 };
 } // namespace instr
diff --git a/src/sim/wb.cc b/src/sim/wb.cc
index fbbdd4c..0348b51 100644
--- a/src/sim/wb.cc
+++ b/src/sim/wb.cc
@@ -62,7 +62,7 @@ void WB::jump_handler()
 {
 	if (this->curr_instr->get_s1() > 0) {
 		if (this->curr_instr->get_mnemonic() == JAL)
-			this->gprs[1] = this->pc + 1;
+			this->gprs[1] = this->curr_instr->get_pc() + 1;;
 		this->pc = this->curr_instr->get_s1();
 		this->checked_out = {};
 		this->next->squash();