bool Inst::CastTo(CodeContext& context, RValue& value, SType* type, bool upcast)
{
auto valueType = value.stype();
if (type == valueType) {
// non-assignment and non-comparison operations with enum types
// must result in an int type to keep enum variables within range.
if (upcast && valueType->isEnum())
value.castToSubtype();
return false;
} else if (type->isComplex() || valueType->isComplex()) {
context.addError("can not cast complex types");
return true;
} else if (type->isPointer()) {
if (value.isNullPtr()) {
// NOTE: discard current null value and create
// a new one using the right type
value = RValue::getNullPtr(context, type);
return false;
} else if (type->subType()->isVoid()) {
value = RValue(new BitCastInst(value, *type, "", context), type);
return false;
}
context.addError("can't cast value to pointer type");
return true;
} else if (type->isVec()) {
// unwrap enum type
if (valueType->isEnum())
valueType = value.castToSubtype();
if (valueType->isNumeric()) {
CastTo(context, value, type->subType(), upcast);
auto i32 = SType::getInt(context, 32);
auto mask = RValue::getZero(context, SType::getVec(context, i32, type->size()));
auto udef = UndefValue::get(*SType::getVec(context, type->subType(), 1));
auto instEle = InsertElementInst::Create(udef, value, RValue::getZero(context, i32), "", context);
auto retVal = new ShuffleVectorInst(instEle, udef, mask, "", context);
value = RValue(retVal, type);
return false;
} else if (valueType->isPointer()) {
context.addError("can not cast pointer to vec type");
return true;
} else if (type->size() != valueType->size()) {
context.addError("can not cast vec types of different sizes");
return true;
} else if (type->subType()->isBool()) {
// cast to bool is value != 0
auto pred = getPredicate(ParserBase::TT_NEQ, valueType, context);
auto op = valueType->subType()->isFloating()? Instruction::FCmp : Instruction::ICmp;
auto val = CmpInst::Create(op, pred, value, RValue::getZero(context, valueType), "", context);
value = RValue(val, type);
return false;
} else {
auto op = getCastOp(valueType->subType(), type->subType());
auto val = CastInst::Create(op, value, *type, "", context);
value = RValue(val, type);
return false;
}
} else if (type->isEnum()) {
// casting to enum would violate value constraints
context.addError("can't cast to enum type");
return true;
} else if (type->isBool()) {
if (valueType->isVec()) {
context.addError("can not cast vec type to bool");
return true;
} else if (valueType->isEnum()) {
valueType = value.castToSubtype();
}
// cast to bool is value != 0
auto pred = getPredicate(ParserBase::TT_NEQ, valueType, context);
auto op = valueType->isFloating()? Instruction::FCmp : Instruction::ICmp;
auto val = CmpInst::Create(op, pred, value, RValue::getZero(context, valueType), "", context);
value = RValue(val, type);
return false;
}
if (valueType->isPointer()) {
context.addError("can't cast pointer to numeric type");
return true;
}
// unwrap enum type
if (valueType->isEnum())
valueType = value.castToSubtype();
auto op = getCastOp(valueType, type);
auto val = op != Instruction::AddrSpaceCast? CastInst::Create(op, value, *type, "", context) : value;
value = RValue(val, type);
return false;
}
