Have to improve reg allocation

11 files changed, 108 insertions, 11 deletions

diff --git a/c_compiler/include/bindings.hpp b/c_compiler/include/bindings.hpp
index 983a10d..5dd1e1f 100644
--- a/c_compiler/include/bindings.hpp
+++ b/c_compiler/include/bindings.hpp
@@ -25,16 +25,21 @@ class VariableStackBindings
 private:
     std::map<std::string, DeclarationData> bindings;
     int32_t stack_counter;
+    int8_t current_register;
 	     
 public:
     VariableStackBindings();
 
     void insertBinding(std::string id, TypePtr type, int32_t stack_position);
     void increaseStackPosition();
+    void resetRegister();
+    void increaseRegister();
 
     int32_t getCurrentStackPosition() const;
     int32_t getStackPosition(const std::string& id) const;
 
+    int8_t getCurrentRegister() const;
+
     bool bindingExists(const std::string& id) const;
 };
 
diff --git a/c_compiler/include/expression.hpp b/c_compiler/include/expression.hpp
index df95a1e..a4939a9 100644
--- a/c_compiler/include/expression.hpp
+++ b/c_compiler/include/expression.hpp
@@ -54,6 +54,18 @@ public:
 };
 
 
+class MultiplicativeExpression : public OperationExpression
+{
+private:
+    std::string operation;
+
+public:
+    MultiplicativeExpression(Expression* _lhs, const std::string& _operation, Expression* _rhs);
+
+    virtual VariableStackBindings printasm(VariableStackBindings bindings) const;
+};
+
+
 class Identifier : public Expression
 {
 private:
diff --git a/c_compiler/src/bindings.cpp b/c_compiler/src/bindings.cpp
index 4315407..80375e7 100644
--- a/c_compiler/src/bindings.cpp
+++ b/c_compiler/src/bindings.cpp
@@ -1,10 +1,12 @@
 #include "bindings.hpp"
 
+#include <iostream>
+
 
 // VariableStackBindings definition
 
 VariableStackBindings::VariableStackBindings()
-    : stack_counter(4)
+    : stack_counter(4), current_register(2)
 {}
 
 void VariableStackBindings::insertBinding(std::string id, TypePtr type, int32_t stack_position)
@@ -21,6 +23,21 @@ void VariableStackBindings::increaseStackPosition()
     stack_counter += 4;
 }
 
+void VariableStackBindings::resetRegister()
+{
+    current_register = 2;
+}
+
+void VariableStackBindings::increaseRegister()
+{
+    if(current_register == 15)
+	current_register = 24;
+    else if(current_register == 25)
+	std::cerr << "Error : cannot allocate more registers" << std::endl;
+    else
+	current_register++;
+}
+
 int32_t VariableStackBindings::getCurrentStackPosition() const
 {
     return stack_counter;
@@ -36,6 +53,11 @@ int32_t VariableStackBindings::getStackPosition(const std::string &id) const
     else return 0;
 }
 
+int8_t VariableStackBindings::getCurrentRegister() const
+{
+    return current_register;
+}
+
 bool VariableStackBindings::bindingExists(const std::string &id) const
 {
     auto binding = bindings.find(id);
diff --git a/c_compiler/src/c_lexer.flex b/c_compiler/src/c_lexer.flex
index f6f2dd3..716e1ac 100644
--- a/c_compiler/src/c_lexer.flex
+++ b/c_compiler/src/c_lexer.flex
@@ -59,9 +59,9 @@ ALL .
 [!][=]		{ return T_EQUALITY_OP; }
 ([<>][=])|[<>]	{ return T_REL_OP; }
 [<>][<>]	{ return T_SHIFT_OP; }
-[*] 		{ return T_MULT; }
-[\/]		{ return T_DIV; }
-[%]		{ return T_REM; }
+[*] 		{ yylval.string = new std::string(yytext); return T_MULT; }
+[\/]		{ yylval.string = new std::string(yytext); return T_DIV; }
+[%]		{ yylval.string = new std::string(yytext); return T_REM; }
 [~]		{ return T_TILDE; }
 [!]		{ return T_NOT; }
 [.]		{ return T_DOT; }
diff --git a/c_compiler/src/c_parser.y b/c_compiler/src/c_parser.y
index f262f58..5a35c63 100644
--- a/c_compiler/src/c_parser.y
+++ b/c_compiler/src/c_parser.y
@@ -283,7 +283,7 @@ AdditiveExpression:
 
 MultiplicativeExpression:
 		CastExpression { $$ = $1; }
-	|	MultiplicativeExpression MultDivRemOP CastExpression { $$ = $3; }
+|	MultiplicativeExpression MultDivRemOP CastExpression { $$ = new MultiplicativeExpression($1, *$2, $3); delete $2; }
 		;
 
 MultDivRemOP:
diff --git a/c_compiler/src/expression.cpp b/c_compiler/src/expression.cpp
index 6c1ba97..dea282f 100644
--- a/c_compiler/src/expression.cpp
+++ b/c_compiler/src/expression.cpp
@@ -69,7 +69,7 @@ VariableStackBindings AdditiveExpression::printasm(VariableStackBindings binding
     // currently using signed and sub because I only have signed numbers implemented
     // must update this as I add more types
     if(operation == "+")
-	std::cout << "\tadd\t$2,$2,$3" << std::endl;
+	std::cout << "\tadd\t$2,$3,$2" << std::endl;
     else if(operation == "-")
 	std::cout << "\tsub\t$2,$3,$2" << std::endl;
     else
@@ -79,6 +79,37 @@ VariableStackBindings AdditiveExpression::printasm(VariableStackBindings binding
 }
 
 
+// Multiplicative Expression definition
+
+
+MultiplicativeExpression::MultiplicativeExpression(Expression* _lhs, const std::string& _operation, Expression* _rhs)
+    : OperationExpression(_lhs, _rhs), operation(_operation)
+{}
+
+VariableStackBindings MultiplicativeExpression::printasm(VariableStackBindings bindings) const
+{
+    lhs->printasm(bindings);
+
+    std::cout << "\tmove\t$3,$2" << std::endl;
+
+    rhs->printasm(bindings);
+
+    // then perform the right operation
+    if(operation == "*")
+	std::cout << "\tmul\t$2,$3,$2" << std::endl;
+    else if(operation == "/" || operation == "%") {
+	std::cout << "\tdiv\t$3,$2" << std::endl;
+	if(operation == "/")
+	    std::cout << "\tmflo\t$2" << std::endl;
+	else
+	    std::cout << "\tmfhi\t$2" << std::endl;
+    } else
+	std::cerr << "Don't recognize symbol '" << operation << "'" << std::endl;
+
+    return bindings;
+}
+
+
 // Identifier definition
 
 Identifier::Identifier(const std::string& id)
diff --git a/c_compiler/src/statement.cpp b/c_compiler/src/statement.cpp
index fa85df0..f86329f 100644
--- a/c_compiler/src/statement.cpp
+++ b/c_compiler/src/statement.cpp
@@ -153,9 +153,12 @@ VariableStackBindings ExpressionStatement::printasm(VariableStackBindings bindin
 {
     if(next_statement != nullptr)
 	next_statement->printasm(bindings);
-
+    
     if(m_expr != nullptr)
+    {
+	bindings.resetRegister();
 	m_expr->printasm(bindings);
+    }
     
     return bindings;
 }
@@ -188,8 +191,11 @@ VariableStackBindings JumpStatement::printasm(VariableStackBindings bindings) co
 	next_statement->printasm(bindings);
     
     if(m_expr != nullptr)
+    {
+	bindings.resetRegister();
 	m_expr->printasm(bindings);
-
+    }
+    
     return bindings;
 }
 
diff --git a/c_compiler/test/in/Add.c b/c_compiler/test/in/Add.c
index 43e557e..b672efb 100644
--- a/c_compiler/test/in/Add.c
+++ b/c_compiler/test/in/Add.c
@@ -8,6 +8,8 @@ int main() {
 			z = x + y + x + y - x;
 		}
 	}
+
+	z = 2 + z - 2;
 	
 	return z;
 }
diff --git a/c_compiler/test/in/AddMult.c b/c_compiler/test/in/AddMult.c
new file mode 100644
index 0000000..a8fa566
--- /dev/null
+++ b/c_compiler/test/in/AddMult.c
@@ -0,0 +1,10 @@
+int main() {
+	int x;
+	int a = 8;
+	int b = 5;
+	int c = 7;
+	int d = 3;	
+	x = a * b + c * d;
+
+	return x;
+}
diff --git a/c_compiler/test/in/Mult.c b/c_compiler/test/in/Mult.c
new file mode 100644
index 0000000..4855b54
--- /dev/null
+++ b/c_compiler/test/in/Mult.c
@@ -0,0 +1,9 @@
+int main() {
+	int x = 4*2;
+	int y = 7;
+	int z = 14 % 8;
+
+	z = x * y * z / z * x;
+
+	return z;
+}
diff --git a/test_compiler.sh b/test_compiler.sh
index 700afe5..65fb311 100755
--- a/test_compiler.sh
+++ b/test_compiler.sh
@@ -30,10 +30,10 @@ for i in c_compiler/test/in/*.c; do
 	BASENAME=$(basename $i .c);
     	cat $i | ./bin/c_compiler > c_compiler/test/out/$BASENAME.s  2> c_compiler/test/out/$BASENAME.stderr.txt
 
-	mips-linux-gnu-gcc -S -c c_compiler/test/in/$BASENAME.c -o c_compiler/test/ref/$BASENAME.s
-	mips-linux-gnu-gcc -static c_compiler/test/ref/$BASENAME.s -o c_compiler/test/ref/$BASENAME
+	mips-linux-gnu-gcc -O0 -S -c c_compiler/test/in/$BASENAME.c -o c_compiler/test/ref/$BASENAME.s
+	mips-linux-gnu-gcc -O0 -static c_compiler/test/ref/$BASENAME.s -o c_compiler/test/ref/$BASENAME
 	
-        mips-linux-gnu-gcc -static c_compiler/test/out/$BASENAME.s -o c_compiler/test/out/$BASENAME
+        mips-linux-gnu-gcc -O0 -static c_compiler/test/out/$BASENAME.s -o c_compiler/test/out/$BASENAME
 
 	qemu-mips c_compiler/test/ref/$BASENAME
 	REFOUTPUT=$?