public static void Transform(ILBlock method)
{
// TODO: move this somewhere else
// Eliminate 'dups':
foreach (ILExpression expr in method.GetSelfAndChildrenRecursive<ILExpression>()) {
for (int i = 0; i < expr.Arguments.Count; i++) {
if (expr.Arguments[i].Code == ILCode.Dup)
expr.Arguments[i] = expr.Arguments[i].Arguments[0];
}
}
var newArrPattern = new StoreToVariable(new ILExpression(ILCode.Newarr, ILExpression.AnyOperand, new ILExpression(ILCode.Ldc_I4, ILExpression.AnyOperand)));
var arg1 = new StoreToVariable(new LoadFromVariable(newArrPattern)) { MustBeGenerated = true };
var arg2 = new StoreToVariable(new LoadFromVariable(newArrPattern)) { MustBeGenerated = true };
var initializeArrayPattern = new ILCall(
"System.Runtime.CompilerServices.RuntimeHelpers", "InitializeArray",
new LoadFromVariable(arg1), new ILExpression(ILCode.Ldtoken, ILExpression.AnyOperand));
foreach (ILBlock block in method.GetSelfAndChildrenRecursive<ILBlock>()) {
for (int i = block.Body.Count - 1; i >= 0; i--) {
if (!newArrPattern.Match(block.Body[i]))
continue;
ILExpression newArrInst = ((ILExpression)block.Body[i]).Arguments[0];
int arrayLength = (int)newArrInst.Arguments[0].Operand;
if (arrayLength == 0)
continue;
if (arg1.Match(block.Body.ElementAtOrDefault(i + 1)) && arg2.Match(block.Body.ElementAtOrDefault(i + 2))) {
if (initializeArrayPattern.Match(block.Body.ElementAtOrDefault(i + 3))) {
if (HandleStaticallyInitializedArray(arg2, block, i, newArrInst, arrayLength)) {
i -= ILInlining.InlineInto(block, i + 1, method) - 1;
}
continue;
}
}
if (i + 1 + arrayLength > block.Body.Count)
continue;
List<ILExpression> operands = new List<ILExpression>();
for (int j = 0; j < arrayLength; j++) {
ILExpression expr = block.Body[i + 1 + j] as ILExpression;
if (expr == null || !IsStoreToArray(expr.Code))
break;
if (!(expr.Arguments[0].Code == ILCode.Ldloc && expr.Arguments[0].Operand == newArrPattern.LastVariable))
break;
if (!(expr.Arguments[1].Code == ILCode.Ldc_I4 && (int)expr.Arguments[1].Operand == j))
break;
operands.Add(expr.Arguments[2]);
}
if (operands.Count == arrayLength) {
((ILExpression)block.Body[i]).Arguments[0] = new ILExpression(
ILCode.InitArray, newArrInst.Operand, operands.ToArray());
block.Body.RemoveRange(i + 1, arrayLength);
i -= ILInlining.InlineInto(block, i + 1, method) - 1;
}
}
}
}
static bool HandleStaticallyInitializedArray(StoreToVariable arg2, ILBlock block, int i, ILExpression newArrInst, int arrayLength)
{
FieldDefinition field = ((ILExpression)block.Body[i + 3]).Arguments[1].Operand as FieldDefinition;
if (field == null || field.InitialValue == null)
return false;
switch (TypeAnalysis.GetTypeCode(newArrInst.Operand as TypeReference)) {
case TypeCode.Int32:
case TypeCode.UInt32:
if (field.InitialValue.Length == arrayLength * 4) {
ILExpression[] newArr = new ILExpression[arrayLength];
for (int j = 0; j < newArr.Length; j++) {
newArr[j] = new ILExpression(ILCode.Ldc_I4, BitConverter.ToInt32(field.InitialValue, j * 4));
}
block.Body[i] = new ILExpression(ILCode.Stloc, arg2.LastVariable, new ILExpression(ILCode.InitArray, newArrInst.Operand, newArr));
block.Body.RemoveRange(i + 1, 3);
return true;
}
break;
}
return false;
}
