public ICodeBlock EmitUnary(ICodeBlock Value, Operator Op)
{
var valBlock = (CodeBlock)Value;
var valType = valBlock.Type;
if (Op.Equals(Operator.Not))
{
return(new UnaryBlock(this, valBlock, valType, BuildNot, ConstNot));
}
else if (Op.Equals(Operator.Subtract))
{
if (valType.GetIsFloatingPoint())
{
return(new UnaryBlock(this, valBlock, valType, BuildFNeg, ConstFNeg));
}
else
{
return(new UnaryBlock(this, valBlock, valType, BuildNeg, ConstNeg));
}
}
else if (Op.Equals(Operator.Box))
{
// To box a value x, we create a struct `{ typeof(x).vtable, x }`
// and store it in the heap.
// So we basically want to do this:
//
// var ptr = gcalloc(sizeof({ byte*, typeof(x) }));
// ptr->vtable = (byte*)T.vtable;
// ptr->value = x;
// ptr
//
var constructedType = valType.MakePointerType(PointerKind.BoxPointer);
var tmp = new SSAVariable("box_tmp", constructedType);
var expr = new InitializedExpression(
new BlockStatement(new IStatement[]
{
tmp.CreateSetStatement(
Allocate(
ToExpression(new SizeOfBlock(this, constructedType, false)),
constructedType)),
new StoreAtAddressStatement(
GetVTablePtrExpr(tmp.CreateGetExpression()),
ToExpression(new TypeVTableBlock(this, (LLVMType)valType))),
new StoreAtAddressStatement(
CreateUnboxExpr(tmp.CreateGetExpression(), valType),
ToExpression(valBlock))
}),
tmp.CreateGetExpression());
return(expr.Emit(this));
}
else
{
throw new NotImplementedException(
string.Format(
"Unsupported unary op: {0} {1}",
Op.Name,
valType.FullName));
}
}
/// <inheritdoc/>
protected override IExpression Transform(IExpression Expression)
{
if (Expression is NewObjectExpression)
{
var expr = (NewObjectExpression)Expression;
var visitedExpr = expr.Accept(this);
var constructedType = expr.Type;
if (!constructedType.GetIsReferenceType())
{
return(visitedExpr);
}
// TODO: a type's finalizer is looked up every time an object is constructed.
// That's a pretty expensive operation and we could speed it up greatly
// by introducing a cache.
var rootAncestor = GetRootAncestor(constructedType);
var rootFinalizer = GetFinalizer(rootAncestor);
if (rootFinalizer == null)
{
return(visitedExpr);
}
var finalizer = rootFinalizer.GetImplementation(constructedType) ?? rootFinalizer;
if (finalizer.HasAttribute(
PrimitiveAttributes.Instance.NopAttribute.AttributeType))
{
return(visitedExpr);
}
var tmp = new SSAVariable(constructedType);
return(new InitializedExpression(
new BlockStatement(
new IStatement[]
{
tmp.CreateSetStatement(visitedExpr),
GarbageCollector.RegisterFinalizer(
new ReinterpretCastExpression(
tmp.CreateGetExpression(),
PrimitiveTypes.Void.MakePointerType(PointerKind.TransientPointer)),
finalizer)
}),
tmp.CreateGetExpression()));
}
else
{
return(Expression.Accept(this));
}
}
public ICodeBlock EmitNewObject(IMethod Constructor, IEnumerable <ICodeBlock> Arguments)
{
var constructedType = Constructor.DeclaringType;
if (constructedType.GetIsValueType())
{
throw new InvalidOperationException(
"cannot create a new 'struct' object; " +
"'struct' object creation must be lowered to " +
"method invocation before codegen");
}
else if (constructedType.GetIsReferenceType())
{
var tmp = new SSAVariable("class_tmp", constructedType);
// Write the following code:
//
// var ptr = gcalloc(sizeof(T));
// ptr->vtable = (byte*)T.vtable;
// ptr->ctor(args...);
// static if (!#builtin_has_attribute(T.Finalize, NopAttribute))
// register_finalizer(ptr, T.Finalize);
// ptr
//
var statements = new List <IStatement>();
statements.Add(
tmp.CreateSetStatement(
Allocate(
ToExpression(new SizeOfBlock(this, constructedType, false)),
constructedType)));
statements.Add(
new StoreAtAddressStatement(
GetVTablePtrExpr(tmp.CreateGetExpression()),
ToExpression(new TypeVTableBlock(this, (LLVMType)constructedType))));
statements.Add(
new ExpressionStatement(
new InvocationExpression(
Constructor,
tmp.CreateGetExpression(),
Arguments.Cast <CodeBlock>()
.Select <CodeBlock, IExpression>(ToExpression)
.ToArray <IExpression>())));
var expr = new InitializedExpression(
new BlockStatement(statements),
tmp.CreateGetExpression());
return(expr.Emit(this));
}
throw new NotImplementedException();
}
public ICodeBlock EmitNewArray(IType ElementType, IEnumerable <ICodeBlock> Dimensions)
{
var arrayType = ElementType.MakeArrayType(Enumerable.Count <ICodeBlock>(Dimensions));
// First, store all dimensions in temporaries.
var statements = new List <IStatement>();
var dimVals = SpillDimensions(Dimensions, statements);
var arrayTmp = new SSAVariable("array_tmp", arrayType);
// The number of elements to allocate is equal to the product of
// the dimensions.
var elemCount = EmitProduct(dimVals);
// The size of the chunk of memory to allocate is
//
// sizeof({ i32, ..., [0 x <element type>]}) + elemCount * sizeof(<element type>)
//
var allocationSize = EmitBinary(
new SizeOfBlock(this, arrayType, false),
EmitBinary(
elemCount,
new SizeOfBlock(this, ElementType, true),
Operator.Multiply),
Operator.Add);
// Allocate the array and store it in a temporary.
statements.Add(
arrayTmp.CreateSetStatement(
Allocate(
new CodeBlockExpression(allocationSize, PrimitiveTypes.Int32),
arrayType)));
// Store the array's dimensions in the array header.
StoreDimensionsInArrayHeader(
(CodeBlock)arrayTmp.CreateGetExpression().Emit(this),
dimVals,
statements);
return(EmitSequence(
new BlockStatement(statements).Emit(this),
arrayTmp.CreateGetExpression().Emit(this)));
}
public IUnmanagedEmitVariable GetUnmanagedElement(ICodeBlock Value, IEnumerable <ICodeBlock> Index)
{
var valBlock = (CodeBlock)Value;
var valType = valBlock.Type;
if (valType.GetIsArray())
{
// Suppose that an n-dimensional array with dimensions
//
// dim_1, dim_2, ..., dim_n
//
// is indexed with
//
// i_1, i_2, ..., i_n.
//
// To compute a pointer to the element with that index, we can
// use the following formula:
//
// offset = i_1 + i_2 * dim_1 + i_3 * dim_1 * dim_2 + ... +
// i_n * dim_1 * dim_2 * ... * dim_n-1
//
// = i_1 + dim_1 * (i_2 + dim_2 * (...))
//
// The latter identity requires fewer multiplications, so we'll use that.
var arrayPtrTmp = new SSAVariable("array_tmp", valBlock.Type);
var arrayPtr = (CodeBlock)arrayPtrTmp.CreateGetExpression().Emit(this);
var indexArray = Index.ToArray <ICodeBlock>();
var offset = EmitInteger(new IntegerValue(0));
for (int i = indexArray.Length - 1; i >= 0; i--)
{
// offset <- i_i + dim_i * offset
offset = EmitBinary(
EmitTypeBinary(indexArray[i], PrimitiveTypes.Int32, Operator.StaticCast),
EmitBinary(
EmitDereferencePointer(new GetDimensionPtrBlock(this, arrayPtr, i)),
offset,
Operator.Multiply),
Operator.Add);
}
// Now add this offset to the data pointer of the array and dereference the result.
return(new AtAddressEmitVariable(
(CodeBlock)EmitSequence(
arrayPtrTmp.CreateSetStatement(ToExpression(valBlock)).Emit(this),
EmitBinary(new GetDataPtrBlock(this, arrayPtr), offset, Operator.Add))));
}
throw new NotImplementedException();
}
private IReadOnlyList <ICodeBlock> SpillDimensions(
IEnumerable <ICodeBlock> Dimensions,
List <IStatement> Statements)
{
var dimVals = new List <ICodeBlock>();
foreach (var dim in Dimensions)
{
var dimTmp = new SSAVariable("dimension_tmp", PrimitiveTypes.Int32);
Statements.Add(
dimTmp.CreateSetStatement(
ToExpression(
(CodeBlock)EmitTypeBinary(dim, PrimitiveTypes.Int32, Operator.StaticCast))));
dimVals.Add(dimTmp.CreateGetExpression().Emit(this));
}
return(dimVals);
}