// Generates code to compute and push the address of a named variable.
// vname is the program phrase that names this variable.
// currentLevel is the routine level where the vname occurs.
// frameSize is the anticipated size of the local stack frame when
// the variable is addressed at run-time.
void EncodeFetchAddress(Vname vname, Frame frame)
{
var baseObject = vname.Visit(this, frame) as AddressableEntity;
// If indexed = true, code will have been generated to load an index
// value.
baseObject.EncodeFetchAddress(_emitter, frame, vname);
}
public override void EncodeFetchAddress(Emitter emitter, Frame frame, Vname vname)
{
emitter.Emit(OpCode.LOADA, 0, frame.DisplayRegister(Address),
Address.Displacement + vname.Offset);
if (vname.IsIndexed)
{
emitter.Emit(OpCode.CALL, Register.SB, Register.PB, Primitive.ADD);
}
}
// Generates code to fetch the value of a named constant or variable
// and push it on to the stack.
// currentLevel is the routine level where the vname occurs.
// frameSize is the anticipated size of the local stack frame when
// the constant or variable is fetched at run-time.
// valSize is the size of the constant or variable's value.
void EncodeFetch(Vname vname, Frame frame, int valSize)
{
IFetchableEntity baseObject = vname.Visit(this, frame);
// If indexed = true, code will have been generated to load an index
// value.
if (valSize > 255)
{
_errorReporter.ReportRestriction("can't load values larger than 255 words");
valSize = 255; // to allow code generation to continue
}
baseObject.EncodeFetch(_emitter, frame, valSize, vname);
}
public void EncodeFetch(Emitter emitter, Frame frame, int size, Vname vname)
{
if (vname.IsIndexed)
{
emitter.Emit(OpCode.LOADA, 0, frame.DisplayRegister(_address),
_address.Displacement + vname.Offset);
emitter.Emit(OpCode.CALL, Register.SB, Register.PB, Primitive.ADD);
emitter.Emit(OpCode.LOADI, size, 0, 0);
}
else
{
emitter.Emit(OpCode.LOAD, size, frame.DisplayRegister(_address),
_address.Displacement + vname.Offset);
}
}
public override void EncodeStore(Emitter emitter, Frame frame, int size, Vname vname)
{
if (vname.IsIndexed)
{
emitter.Emit(OpCode.LOADA, 0, frame.DisplayRegister(Address),
Address.Displacement + vname.Offset);
emitter.Emit(OpCode.CALL, Register.SB, Register.PB, Primitive.ADD);
emitter.Emit(OpCode.STOREI, size, 0, 0);
}
else
{
emitter.Emit(OpCode.STORE, size, frame.DisplayRegister(Address),
Address.Displacement + vname.Offset);
}
}
public override void EncodeFetchAddress(Emitter emitter, Frame frame, Vname vname)
{
emitter.Emit(OpCode.LOAD, Machine.AddressSize, frame.DisplayRegister(_address),
_address.Displacement);
if (vname.IsIndexed)
{
emitter.Emit(OpCode.CALL, Register.SB, Register.PB, Primitive.ADD);
}
int offset = vname.Offset;
if (offset != 0)
{
emitter.Emit(OpCode.LOADL, offset);
emitter.Emit(OpCode.CALL, Register.SB, Register.PB, Primitive.ADD);
}
}
public abstract void EncodeAssign(Emitter emitter, Frame frame, int size, Vname vname);
public VarActualParameter(Vname vname, SourcePosition position)
: base(position)
{
_vname = vname;
}
public void EncodeFetch(Emitter emitter, Frame frame, int size, Vname vname)
{
// presumably offset = 0 and indexed = false
emitter.Emit(OpCode.LOADL, 0, 0, _value);
}
public override void EncodeFetch(Emitter emitter, Frame frame, int size, Vname vname)
{
emitter.Emit(OpCode.LOAD, Machine.AddressSize, frame.DisplayRegister(_address), _address.Displacement);
emitter.Emit(OpCode.LOADI, size);
}
public AssignCommand(Vname vname, Expression expression, SourcePosition position)
: base(position)
{
_vname = vname;
_expression = expression;
}
public VnameExpression(Vname vname, SourcePosition position)
: base(position)
{
_vname = vname;
}
public override void EncodeFetchAddress(Emitter emitter, Frame frame, Vname vname)
{
emitter.Emit(OpCode.LOADA, Size, frame.DisplayRegister(Address), Address.Displacement);
}
public override void EncodeAssign(Emitter emitter, Frame frame, int size, Vname vname)
{
emitter.Emit(OpCode.STORE, size, frame.DisplayRegister(Address), Address.Displacement);
}
public abstract void EncodeFetchAddress(Emitter emitter, Frame frame, Vname vname);
public abstract void EncodeFetch(Emitter emitter, Frame frame, int size, Vname vname);
public void EncodeFetch(Emitter emitter, Frame frame, int size, Vname vname)
{
emitter.Emit(OpCode.LOADL, 0, 0, _value);
//emitter.Emit(xxxxxx, 0, 0, _value);
}
