private Rvalue compileImpl(IntermediateCompiler ic, Scope scope, CType leftType, CType rightType)
throws SyntaxException {
// Compile operands.
Rvalue rhs = right.compileWithConversion(ic, scope, rightType);
Lvalue lhs = left.compileAsLvalue(ic, scope, false);
// Load LHS to register.
Rvalue lhsVal = new Rvalue(new VirtualRegister());
ic.emit("load", lhsVal.getRegister(), "0", lhs.getRegister());
lhsVal = left.getType(scope).compileConversion(ic, scope, lhsVal, leftType);
// Compile the binary operator.
String binOp = operator.binaryOperator;
Rvalue retVal;
if (leftType.isPointer()) {
// Scale integer operand if necessary.
int leftIncrSize = left.getType(scope).decay().getIncrementSize();
if (leftIncrSize > 1) ic.emit("mul", rhs.getRegister(), "=" + leftIncrSize);
ic.emit(operator.mnemonic, lhsVal.getRegister(), rhs.getRegister());
retVal = lhsVal;
} else if (operator.type == BinaryExpression.Type.BITWISE)
retVal = leftType.compileBinaryBitwiseOperator(ic, scope, lhsVal, rhs, binOp);
else if (operator.type == BinaryExpression.Type.SHIFT)
retVal = leftType.compileBinaryShiftOperator(ic, scope, lhsVal, rhs, binOp);
else // if (operator.type == BinaryExpression.Type.ARITHMETIC)
retVal = leftType.compileBinaryArithmeticOperator(ic, scope, lhsVal, rhs, binOp);
// Convert to the original type of the left operand.
retVal = leftType.compileConversion(ic, scope, retVal, left.getType(scope));
// Assign result back to lvalue.
ic.emit("store", retVal.getRegister(), "0", lhs.getRegister());
return retVal;
}
@Override
public Rvalue compile(IntermediateCompiler ic, Scope scope) throws SyntaxException {
FunctionType funcType = getFunctionType(scope);
// Reserve space for return value.
if (!funcType.getReturnType().equals(CType.VOID))
ic.emit("add", VirtualRegister.SP, "=" + funcType.getReturnType().getSize());
// Push arguments to stack.
argumentList.compile(ic, scope, funcType.getParameterTypes());
// Evaluate the function pointer.
Rvalue funcPtrVal = functionPointer.compile(ic, scope);
// Make the call.
ic.emit("call", VirtualRegister.SP, funcPtrVal.getRegister());
// Read the return value.
VirtualRegister retReg = null;
if (!funcType.getReturnType().equals(CType.VOID)) {
retReg = new VirtualRegister();
ic.emit("pop", VirtualRegister.SP, retReg);
}
return new Rvalue(retReg);
}
private Rvalue compileSimpleAssignment(IntermediateCompiler ic, Scope scope)
throws SyntaxException {
Rvalue rhs = right.compileWithConversion(ic, scope, left.getType(scope).decay());
Lvalue lhs = left.compileAsLvalue(ic, scope, false);
ic.emit("store", rhs.getRegister(), "0", lhs.getRegister());
return rhs;
}
@Override
public void compile(IntermediateCompiler ic, Scope scope, StackAllocator stack)
throws SyntaxException {
Symbol jumpPosition = scope.find("__Brk");
if (jumpPosition == null)
throw new SyntaxException("Break used outside loop or switch.", getPosition());
// Jump to end of the loop/switch
ic.emit("jump", VirtualRegister.NONE, jumpPosition.getReference());
}