bool TransformArrayInitializers(List<ILNode> body, ILExpression expr, int pos)
{
ILVariable v, v3;
ILExpression newarrExpr;
TypeReference elementType;
ILExpression lengthExpr;
int arrayLength;
if (expr.Match(ILCode.Stloc, out v, out newarrExpr) &&
newarrExpr.Match(ILCode.Newarr, out elementType, out lengthExpr) &&
lengthExpr.Match(ILCode.Ldc_I4, out arrayLength) &&
arrayLength > 0) {
ILExpression[] newArr;
int initArrayPos;
if (ForwardScanInitializeArrayRuntimeHelper(body, pos + 1, v, elementType, arrayLength, out newArr, out initArrayPos)) {
var arrayType = new ArrayType(
elementType,
new[] { new ArrayDimension(0, arrayLength) });
body[pos] = new ILExpression(ILCode.Stloc, v, new ILExpression(ILCode.InitArray, arrayType, newArr));
body.RemoveAt(initArrayPos);
}
// Put in a limit so that we don't consume too much memory if the code allocates a huge array
// and populates it extremely sparsly. However, 255 "null" elements in a row actually occur in the Mono C# compiler!
const int maxConsecutiveDefaultValueExpressions = 300;
List<ILExpression> operands = new List<ILExpression>();
int numberOfInstructionsToRemove = 0;
for (int j = pos + 1; j < body.Count; j++) {
ILExpression nextExpr = body[j] as ILExpression;
int arrayPos;
if (nextExpr != null &&
nextExpr.Code.IsStoreToArray() &&
nextExpr.Arguments[0].Match(ILCode.Ldloc, out v3) &&
v == v3 &&
nextExpr.Arguments[1].Match(ILCode.Ldc_I4, out arrayPos) &&
arrayPos >= operands.Count &&
arrayPos <= operands.Count + maxConsecutiveDefaultValueExpressions) {
while (operands.Count < arrayPos)
operands.Add(new ILExpression(ILCode.DefaultValue, elementType));
operands.Add(nextExpr.Arguments[2]);
numberOfInstructionsToRemove++;
} else {
break;
}
}
if (operands.Count == arrayLength) {
var arrayType = new ArrayType(
elementType,
new[] { new ArrayDimension(0, arrayLength) });
expr.Arguments[0] = new ILExpression(ILCode.InitArray, arrayType, operands);
body.RemoveRange(pos + 1, numberOfInstructionsToRemove);
new ILInlining(method).InlineIfPossible(body, ref pos);
return true;
}
}
return false;
}
bool TransformMultidimensionalArrayInitializers(List<ILNode> body, ILExpression expr, int pos)
{
ILVariable v;
ILExpression newarrExpr;
MethodReference ctor;
List<ILExpression> ctorArgs;
ArrayType arrayType;
if (expr.Match(ILCode.Stloc, out v, out newarrExpr) &&
newarrExpr.Match(ILCode.Newobj, out ctor, out ctorArgs) &&
(arrayType = (ctor.DeclaringType as ArrayType)) != null &&
arrayType.Rank == ctorArgs.Count) {
// Clone the type, so we can muck about with the Dimensions
int[] arrayLengths = new int[arrayType.Rank];
for (int i = 0; i < arrayType.Rank; i++) {
if (!ctorArgs[i].Match(ILCode.Ldc_I4, out arrayLengths[i])) return false;
if (arrayLengths[i] <= 0) return false;
}
arrayType = new ArrayType(
arrayType.ElementType,
from l in arrayLengths
select new ArrayDimension(0, l));
var totalElements = arrayLengths.Aggregate(1, (t, l) => t * l);
ILExpression[] newArr;
int initArrayPos;
if (ForwardScanInitializeArrayRuntimeHelper(body, pos + 1, v, arrayType, totalElements, out newArr, out initArrayPos)) {
var mdArr = Array.CreateInstance(typeof(ILExpression), arrayLengths);
body[pos] = new ILExpression(ILCode.Stloc, v, new ILExpression(ILCode.InitArray, arrayType, newArr));
body.RemoveAt(initArrayPos);
return true;
}
}
return false;
}
static bool AreSame (ArrayType a, ArrayType b)
{
if (a.Rank != b.Rank)
return false;
// TODO: dimensions
return true;
}