public override void CGenAddress(CGenState state)
{
if (this.Expr.Type.Kind != ExprTypeKind.STRUCT_OR_UNION)
{
throw new InvalidProgramException();
}
// %eax = address of struct or union
this.Expr.CGenAddress(state);
// offset inside the pack
Int32 offset = ((StructOrUnionType)this.Expr.Type)
.Attribs
.First(_ => _.name == this.Name)
.offset;
state.ADDL(offset, Reg.EAX);
}
public override Reg CGenValue(Env env, CGenState state)
{
// %eax is the address of the struct/union
if (expr.CGenValue(env, state) != Reg.EAX) {
throw new InvalidProgramException();
}
if (expr.type.kind != ExprType.Kind.STRUCT_OR_UNION) {
throw new InvalidProgramException();
}
// size of the struct or union
Int32 struct_size = expr.type.SizeOf;
// offset inside the pack
Int32 attrib_offset = ((TStructOrUnion)expr.type)
.Attribs
.First(_ => _.name == name)
.offset;
// can't be a function designator.
switch (type.kind) {
case ExprType.Kind.ARRAY:
case ExprType.Kind.STRUCT_OR_UNION:
state.ADDL(attrib_offset, Reg.EAX);
return Reg.EAX;
case ExprType.Kind.CHAR:
state.MOVSBL(attrib_offset, Reg.EAX, Reg.EAX);
return Reg.EAX;
case ExprType.Kind.UCHAR:
state.MOVZBL(attrib_offset, Reg.EAX, Reg.EAX);
return Reg.EAX;
case ExprType.Kind.SHORT:
state.MOVSWL(attrib_offset, Reg.EAX, Reg.EAX);
return Reg.EAX;
case ExprType.Kind.USHORT:
state.MOVZWL(attrib_offset, Reg.EAX, Reg.EAX);
return Reg.EAX;
case ExprType.Kind.LONG:
case ExprType.Kind.ULONG:
case ExprType.Kind.POINTER:
state.MOVL(attrib_offset, Reg.EAX, Reg.EAX);
return Reg.EAX;
case ExprType.Kind.FLOAT:
state.FLDS(attrib_offset, Reg.EAX);
return Reg.ST0;
case ExprType.Kind.DOUBLE:
state.FLDL(attrib_offset, Reg.EAX);
return Reg.ST0;
default:
throw new InvalidProgramException();
}
}
public override void CGenAddress(Env env, CGenState state)
{
if (expr.type.kind != ExprType.Kind.STRUCT_OR_UNION) {
throw new InvalidProgramException();
}
// %eax = address of struct or union
expr.CGenAddress(env, state);
// offset inside the pack
Int32 offset = ((TStructOrUnion)expr.type)
.Attribs
.First(_ => _.name == name)
.offset;
state.ADDL(offset, Reg.EAX);
}
public override void CalcAndSaveWord(CGenState state)
{
state.ADDL(1, Reg.EAX);
state.MOVW(Reg.AX, 0, Reg.ECX);
}
public override void CalcAndSavePtr(CGenState state)
{
state.ADDL(expr.type.SizeOf, Reg.EAX);
state.MOVL(Reg.EAX, 0, Reg.ECX);
}
// Before the actual calculation, the state is set to this.
//
// regs:
// %eax = expr
// %ebx = expr
// %ecx = &expr
//
// stack:
// +-------+
// | ..... | <- %esp
// +-------+
//
// Calculate the new value in %eax, and save.
// Leave %eax to be the original value.
//
// regs:
// %eax = expr + 1
// %ebx = expr
// %ecx = &expr
//
// stack:
// +-------+
// | ..... | <- %esp
// +-------+
//
public override void CalcAndSaveLong(CGenState state)
{
state.ADDL(1, Reg.EAX);
state.MOVL(Reg.EAX, 0, Reg.ECX);
}
public override void CalcAndSaveByte(CGenState state)
{
state.ADDL(1, Reg.EAX);
state.MOVB(Reg.AL, 0, Reg.ECX);
}
public override void OperateULong(CGenState state) => state.ADDL(Reg.EBX, Reg.EAX);
public override void OperateULong(CGenState state)
{
state.ADDL(Reg.EBX, Reg.EAX);
}
public override Reg CGenValue(CGenState state)
{
// %eax is the address of the struct/union
if (this.Expr.CGenValue(state) != Reg.EAX)
{
throw new InvalidProgramException();
}
if (this.Expr.Type.Kind != ExprTypeKind.STRUCT_OR_UNION)
{
throw new InvalidProgramException();
}
// size of the struct or union
Int32 struct_size = this.Expr.Type.SizeOf;
// offset inside the pack
Int32 attrib_offset = ((StructOrUnionType)this.Expr.Type)
.Attribs
.First(_ => _.name == this.Name)
.offset;
// can't be a function designator.
switch (this.Type.Kind)
{
case ExprTypeKind.ARRAY:
case ExprTypeKind.STRUCT_OR_UNION:
state.ADDL(attrib_offset, Reg.EAX);
return(Reg.EAX);
case ExprTypeKind.CHAR:
state.MOVSBL(attrib_offset, Reg.EAX, Reg.EAX);
return(Reg.EAX);
case ExprTypeKind.UCHAR:
state.MOVZBL(attrib_offset, Reg.EAX, Reg.EAX);
return(Reg.EAX);
case ExprTypeKind.SHORT:
state.MOVSWL(attrib_offset, Reg.EAX, Reg.EAX);
return(Reg.EAX);
case ExprTypeKind.USHORT:
state.MOVZWL(attrib_offset, Reg.EAX, Reg.EAX);
return(Reg.EAX);
case ExprTypeKind.LONG:
case ExprTypeKind.ULONG:
case ExprTypeKind.POINTER:
state.MOVL(attrib_offset, Reg.EAX, Reg.EAX);
return(Reg.EAX);
case ExprTypeKind.FLOAT:
state.FLDS(attrib_offset, Reg.EAX);
return(Reg.ST0);
case ExprTypeKind.DOUBLE:
state.FLDL(attrib_offset, Reg.EAX);
return(Reg.ST0);
default:
throw new InvalidProgramException();
}
}
public override void CalcAndSavePtr(CGenState state)
{
state.ADDL(this.Expr.Type.SizeOf, Reg.EAX);
state.MOVL(Reg.EAX, 0, Reg.ECX);
}
public override void CalcAndSaveByte(CGenState state)
{
state.ADDL(1, Reg.EAX);
state.MOVB(Reg.AL, 0, Reg.ECX);
}
public override void CalcAndSaveWord(CGenState state)
{
state.ADDL(1, Reg.EAX);
state.MOVW(Reg.AX, 0, Reg.ECX);
}
public override void CalcAndSaveLong(CGenState state)
{
state.ADDL(1, Reg.EAX);
state.MOVL(Reg.EAX, 0, Reg.ECX);
}