Merge branch 'master' of git://github.com/icsharpcode/ILSpy into Debugger

ICSharpCode.Decompiler/FlowAnalysis/ControlFlowGraph.cs

@@ -120,7 +120,7 @@ namespace ICSharpCode.Decompiler.FlowAnalysis
 					b => b.Successors,
 					b => {
 						if (b != EntryPoint) {
-							ControlFlowNode newIdom = b.Predecessors.First(block => block.Visited);
+							ControlFlowNode newIdom = b.Predecessors.First(block => block.Visited && block != b);
 							// for all other predecessors p of b
 							foreach (ControlFlowNode p in b.Predecessors) {
 								if (p != b && p.ImmediateDominator != null) {

ICSharpCode.Decompiler/ILAst/GotoRemoval.cs

@@ -18,7 +18,8 @@ namespace ICSharpCode.Decompiler.ILAst
 			foreach (ILNode node in method.GetSelfAndChildrenRecursive<ILNode>()) {
 				ILNode previousChild = null;
 				foreach (ILNode child in node.GetChildren()) {
-					Debug.Assert(!parent.ContainsKey(child));
+					if (parent.ContainsKey(child))
+						throw new Exception("The following expression is linked from several locations: " + child.ToString());
 					parent[child] = node;
 					if (previousChild != null)
 						nextSibling[previousChild] = child;

ICSharpCode.Decompiler/ILAst/ILAstOptimizer.cs

@@ -18,34 +18,43 @@ namespace ICSharpCode.Decompiler.ILAst
 		YieldReturn,
 		SplitToMovableBlocks,
 		TypeInference,
-		PeepholeOptimizations,
 		SimplifyShortCircuit,
 		SimplifyTernaryOperator,
 		SimplifyNullCoalescing,
-		MoreSimplifyPasses,
+		TransformDecimalCtorToConstant,
+		SimplifyLdObjAndStObj,
+		TransformArrayInitializers,
+		TransformCollectionInitializers,
+		MakeAssignmentExpression,
+		InlineVariables2,
 		FindLoops,
 		FindConditions,
 		FlattenNestedMovableBlocks,
+		RemoveRedundantCode2,
 		GotoRemoval,
 		DuplicateReturns,
-		FlattenIfStatements,
-		InlineVariables2,
-		PeepholeTransforms,
+		ReduceIfNesting,
+		InlineVariables3,
+		CachedDelegateInitialization,
+		IntroduceFixedStatements,
 		TypeInference2,
+		RemoveRedundantCode3,
 		None
 	}
 	
-	public class ILAstOptimizer
+	public partial class ILAstOptimizer
 	{
 		int nextLabelIndex = 0;
 		
 		DecompilerContext context;
 		TypeSystem typeSystem;
+		ILBlock method;
 		
 		public void Optimize(DecompilerContext context, ILBlock method, ILAstOptimizationStep abortBeforeStep = ILAstOptimizationStep.None)
 		{
 			this.context = context;
 			this.typeSystem = context.CurrentMethod.Module.TypeSystem;
+			this.method = method;
 			
 			if (abortBeforeStep == ILAstOptimizationStep.RemoveRedundantCode) return;
 			RemoveRedundantCode(method);
@@ -77,7 +86,6 @@ namespace ICSharpCode.Decompiler.ILAst
 			// Types are needed for the ternary operator optimization
 			TypeAnalysis.Run(context, method);
 			
-			if (abortBeforeStep == ILAstOptimizationStep.PeepholeOptimizations) return;
 			AnalyseLabels(method);
 			foreach(ILBlock block in method.GetSelfAndChildrenRecursive<ILBlock>()) {
 				bool modified;
@@ -85,18 +93,48 @@ namespace ICSharpCode.Decompiler.ILAst
 					modified = false;
 					
 					if (abortBeforeStep == ILAstOptimizationStep.SimplifyShortCircuit) return;
-					modified |= block.RunPeepholeOptimization(TrySimplifyShortCircuit);
+					modified |= block.RunOptimization(SimplifyShortCircuit);
 					
 					if (abortBeforeStep == ILAstOptimizationStep.SimplifyTernaryOperator) return;
-					modified |= block.RunPeepholeOptimization(TrySimplifyTernaryOperator);
+					modified |= block.RunOptimization(SimplifyTernaryOperator);
 					
 					if (abortBeforeStep == ILAstOptimizationStep.SimplifyNullCoalescing) return;
-					modified |= block.RunPeepholeOptimization(TrySimplifyNullCoalescing);
+					modified |= block.RunOptimization(SimplifyNullCoalescing);
 					
-					if (abortBeforeStep == ILAstOptimizationStep.MoreSimplifyPasses) return;
 				} while(modified);
 			}
 			
+			ILInlining inlining2 = new ILInlining(method);
+			inlining2.InlineAllVariables();
+			inlining2.CopyPropagation();
+			
+			foreach(ILBlock block in method.GetSelfAndChildrenRecursive<ILBlock>()) {
+				
+				// Intentionaly outside the while(modifed) loop,
+				// I will put it there later after more testing
+				
+				bool modified = false;
+				
+				if (abortBeforeStep == ILAstOptimizationStep.TransformDecimalCtorToConstant) return;
+				modified |= block.RunOptimization(TransformDecimalCtorToConstant);
+				
+				if (abortBeforeStep == ILAstOptimizationStep.SimplifyLdObjAndStObj) return;
+				modified |= block.RunOptimization(SimplifyLdObjAndStObj);
+				
+				if (abortBeforeStep == ILAstOptimizationStep.TransformArrayInitializers) return;
+				modified |= block.RunOptimization(Initializers.TransformArrayInitializers);
+				modified |= block.RunOptimization(Initializers.TransformArrayInitializers);
+				
+				if (abortBeforeStep == ILAstOptimizationStep.TransformCollectionInitializers) return;
+				modified |= block.RunOptimization(Initializers.TransformCollectionInitializers);
+				
+				if (abortBeforeStep == ILAstOptimizationStep.MakeAssignmentExpression) return;
+				modified |= block.RunOptimization(MakeAssignmentExpression);
+				
+				if (abortBeforeStep == ILAstOptimizationStep.InlineVariables2) return;
+				modified |= new ILInlining(method).InlineAllInBlock(block);
+			}
+			
 			if (abortBeforeStep == ILAstOptimizationStep.FindLoops) return;
 			foreach(ILBlock block in method.GetSelfAndChildrenRecursive<ILBlock>()) {
 				new LoopsAndConditions(context).FindLoops(block);
@@ -110,29 +148,44 @@ namespace ICSharpCode.Decompiler.ILAst
 			if (abortBeforeStep == ILAstOptimizationStep.FlattenNestedMovableBlocks) return;
 			FlattenBasicBlocks(method);
 			
-			if (abortBeforeStep == ILAstOptimizationStep.GotoRemoval) return;
+			if (abortBeforeStep == ILAstOptimizationStep.RemoveRedundantCode2) return;
 			RemoveRedundantCode(method);
+			
+			if (abortBeforeStep == ILAstOptimizationStep.GotoRemoval) return;
 			new GotoRemoval().RemoveGotos(method);
 			
 			if (abortBeforeStep == ILAstOptimizationStep.DuplicateReturns) return;
 			DuplicateReturnStatements(method);
 			
-			if (abortBeforeStep == ILAstOptimizationStep.FlattenIfStatements) return;
-			FlattenIfStatements(method);
+			if (abortBeforeStep == ILAstOptimizationStep.ReduceIfNesting) return;
+			ReduceIfNesting(method);
 			
-			if (abortBeforeStep == ILAstOptimizationStep.InlineVariables2) return;
+			if (abortBeforeStep == ILAstOptimizationStep.InlineVariables3) return;
 			// The 2nd inlining pass is necessary because DuplicateReturns and the introduction of ternary operators
 			// open up additional inlining possibilities.
 			new ILInlining(method).InlineAllVariables();
 			
-			TypeAnalysis.Reset(method);
+			if (abortBeforeStep == ILAstOptimizationStep.CachedDelegateInitialization) return;
+			foreach(ILBlock block in method.GetSelfAndChildrenRecursive<ILBlock>()) {
+				for (int i = 0; i < block.Body.Count; i++) {
+					// TODO: Move before loops
+					CachedDelegateInitialization(block, ref i);
+				}
+			}
 			
-			if (abortBeforeStep == ILAstOptimizationStep.PeepholeTransforms) return;
-			PeepholeTransforms.Run(context, method);
+			if (abortBeforeStep == ILAstOptimizationStep.IntroduceFixedStatements) return;
+			foreach(ILBlock block in method.GetSelfAndChildrenRecursive<ILBlock>()) {
+				for (int i = 0; i < block.Body.Count; i++) {
+					// TODO: Move before loops
+					IntroduceFixedStatements(block.Body, i);
+				}
+			}
 			
 			if (abortBeforeStep == ILAstOptimizationStep.TypeInference2) return;
+			TypeAnalysis.Reset(method);
 			TypeAnalysis.Run(context, method);
 			
+			if (abortBeforeStep == ILAstOptimizationStep.RemoveRedundantCode3) return;
 			GotoRemoval.RemoveRedundantCode(method);
 			
 			// ReportUnassignedILRanges(method);
@@ -234,59 +287,51 @@ namespace ICSharpCode.Decompiler.ILAst
 			List<ILNode> basicBlocks = new List<ILNode>();
 			
 			ILBasicBlock basicBlock = new ILBasicBlock() {
-				EntryLabel = new ILLabel() { Name = "Block_" + (nextLabelIndex++) }
+				EntryLabel = block.Body.FirstOrDefault() as ILLabel ?? new ILLabel() { Name = "Block_" + (nextLabelIndex++) }
 			};
 			basicBlocks.Add(basicBlock);
 			block.EntryGoto = new ILExpression(ILCode.Br, basicBlock.EntryLabel);
 			
 			if (block.Body.Count > 0) {
-				basicBlock.Body.Add(block.Body[0]);
+				if (block.Body[0] != basicBlock.EntryLabel)
+					basicBlock.Body.Add(block.Body[0]);
 				
 				for (int i = 1; i < block.Body.Count; i++) {
 					ILNode lastNode = block.Body[i - 1];
 					ILNode currNode = block.Body[i];
 					
-					// Insert split
+					// Start a new basic block if necessary
 					if (currNode is ILLabel ||
 					    lastNode is ILTryCatchBlock ||
 					    currNode is ILTryCatchBlock ||
-					    (lastNode is ILExpression) && ((ILExpression)lastNode).IsBranch() ||
-					    (currNode is ILExpression) && (((ILExpression)currNode).IsBranch() && ((ILExpression)currNode).Code.CanFallThough() && basicBlock.Body.Count > 0))
+					    (lastNode is ILExpression && ((ILExpression)lastNode).IsBranch()))
 					{
-						ILBasicBlock lastBlock = basicBlock;
+						// Try to reuse the label
+						ILLabel label = currNode is ILLabel ? ((ILLabel)currNode) : new ILLabel() { Name = "Block_" + (nextLabelIndex++) };
+						
+						// Terminate the last block
+						if (lastNode.CanFallThough()) {
+							// Explicit branch from one block to other
+							basicBlock.FallthoughGoto = new ILExpression(ILCode.Br, label);
+						} else if (lastNode.Match(ILCode.Br)) {
+							// Reuse the existing goto as FallthoughGoto
+							basicBlock.FallthoughGoto = (ILExpression)lastNode;
+							basicBlock.Body.RemoveAt(basicBlock.Body.Count - 1);
+						}
+						
+						// Start the new block						
 						basicBlock = new ILBasicBlock();
 						basicBlocks.Add(basicBlock);
+						basicBlock.EntryLabel = label;
+					}
 					
-						if (currNode is ILLabel) {
-							// Insert as entry label
-							basicBlock.EntryLabel = (ILLabel)currNode;
-						} else {
-							basicBlock.EntryLabel = new ILLabel() { Name = "Block_" + (nextLabelIndex++) };
-							basicBlock.Body.Add(currNode);
-						}
-						
-						// Explicit branch from one block to other
-						// (unless the last expression was unconditional branch)
-						if (!(lastNode is ILExpression) || ((ILExpression)lastNode).Code.CanFallThough()) {
-							lastBlock.FallthoughGoto = new ILExpression(ILCode.Br, basicBlock.EntryLabel);
-						}
-					} else {
+					// Add the node to the basic block
+					if (currNode != basicBlock.EntryLabel) {
 						basicBlock.Body.Add(currNode);
 					}
 				}
 			}
 			
-			foreach (ILBasicBlock bb in basicBlocks) {
-				if (bb.Body.Count > 0 &&
-				    bb.Body.Last() is ILExpression &&
-				    ((ILExpression)bb.Body.Last()).Code == ILCode.Br)
-				{
-					Debug.Assert(bb.FallthoughGoto == null);
-					bb.FallthoughGoto = (ILExpression)bb.Body.Last();
-					bb.Body.RemoveAt(bb.Body.Count - 1);
-				}
-			}
-			
 			block.Body = basicBlocks;
 			return;
 		}
@@ -311,10 +356,9 @@ namespace ICSharpCode.Decompiler.ILAst
 			}
 		}
 		
-		// scope is modified if successful
-		bool TrySimplifyTernaryOperator(List<ILNode> scope, ILBasicBlock head, int index)
+		bool SimplifyTernaryOperator(List<ILNode> body, ILBasicBlock head, int pos)
 		{
-			Debug.Assert(scope.Contains(head));
+			Debug.Assert(body.Contains(head));
 			
 			ILExpression condExpr;
 			ILLabel trueLabel;
@@ -327,17 +371,17 @@ namespace ICSharpCode.Decompiler.ILAst
 			ILLabel falseFall;
 			object unused;
 			
-			if (head.Match(ILCode.Brtrue, out trueLabel, out condExpr, out falseLabel) &&
+			if (head.MatchLast(ILCode.Brtrue, out trueLabel, out condExpr, out falseLabel) &&
 			    labelGlobalRefCount[trueLabel] == 1 &&
 			    labelGlobalRefCount[falseLabel] == 1 &&
-			    ((labelToBasicBlock[trueLabel].Match(ILCode.Stloc, out trueLocVar, out trueExpr, out trueFall) &&
-			      labelToBasicBlock[falseLabel].Match(ILCode.Stloc, out falseLocVar, out falseExpr, out falseFall)) ||
-			     (labelToBasicBlock[trueLabel].Match(ILCode.Ret, out unused, out trueExpr, out trueFall) &&
-			      labelToBasicBlock[falseLabel].Match(ILCode.Ret, out unused, out falseExpr, out falseFall))) &&
+			    ((labelToBasicBlock[trueLabel].MatchSingle(ILCode.Stloc, out trueLocVar, out trueExpr, out trueFall) &&
+			      labelToBasicBlock[falseLabel].MatchSingle(ILCode.Stloc, out falseLocVar, out falseExpr, out falseFall)) ||
+			     (labelToBasicBlock[trueLabel].MatchSingle(ILCode.Ret, out unused, out trueExpr, out trueFall) &&
+			      labelToBasicBlock[falseLabel].MatchSingle(ILCode.Ret, out unused, out falseExpr, out falseFall))) &&
 			    trueLocVar == falseLocVar &&
 			    trueFall == falseFall &&
-			    scope.Contains(labelToBasicBlock[trueLabel]) &&
-			    scope.Contains(labelToBasicBlock[falseLabel])
+			    body.Contains(labelToBasicBlock[trueLabel]) &&
+			    body.Contains(labelToBasicBlock[falseLabel])
 			   )
 			{
 				ILCode opCode = trueLocVar != null ? ILCode.Stloc : ILCode.Ret;
@@ -385,12 +429,12 @@ namespace ICSharpCode.Decompiler.ILAst
 					// Create ternary expression
 					newExpr = new ILExpression(ILCode.TernaryOp, null, condExpr, trueExpr, falseExpr);
 				}
-				head.Body = new List<ILNode>() { new ILExpression(opCode, trueLocVar, newExpr) };
+				head.Body[head.Body.Count - 1] = new ILExpression(opCode, trueLocVar, newExpr);
 				head.FallthoughGoto = trueFall != null ? new ILExpression(ILCode.Br, trueFall) : null;
 				
 				// Remove the old basic blocks
 				foreach(ILLabel deleteLabel in new [] { trueLabel, falseLabel }) {
-					scope.RemoveOrThrow(labelToBasicBlock[deleteLabel]);
+					body.RemoveOrThrow(labelToBasicBlock[deleteLabel]);
 					labelGlobalRefCount.RemoveOrThrow(deleteLabel);
 					labelToBasicBlock.RemoveOrThrow(deleteLabel);
 				}
@@ -400,75 +444,62 @@ namespace ICSharpCode.Decompiler.ILAst
 			return false;
 		}
 		
-		bool TrySimplifyNullCoalescing(List<ILNode> scope, ILBasicBlock head, int index)
+		bool SimplifyNullCoalescing(List<ILNode> body, ILBasicBlock head, int pos)
 		{
 			// ...
 			// v = ldloc(leftVar)
-			// br(condBBLabel)
-			//
-			// condBBLabel:
 			// brtrue(endBBLabel, ldloc(leftVar))
 			// br(rightBBLabel)
 			//
 			// rightBBLabel:
 			// v = rightExpr
 			// br(endBBLabel)
-			//
-			// endBBLabel:
 			// ...
+			// =>
+			// ...
+			// v = NullCoalescing(ldloc(leftVar), rightExpr)
+			// br(endBBLabel)
 				
 			ILVariable v, v2;
 			ILExpression leftExpr, leftExpr2;
-			ILVariable leftVar, leftVar2;
-			ILLabel condBBLabel;
-			ILBasicBlock condBB;
+			ILVariable leftVar;
 			ILLabel endBBLabel, endBBLabel2;
 			ILLabel rightBBLabel;
 			ILBasicBlock rightBB;
 			ILExpression rightExpr;
-			ILBasicBlock endBB;
-			if (head.Body.LastOrDefault().Match(ILCode.Stloc, out v, out leftExpr) &&
+			if (head.Body.Count >= 2 &&
+				head.Body[head.Body.Count - 2].Match(ILCode.Stloc, out v, out leftExpr) &&
 			    leftExpr.Match(ILCode.Ldloc, out leftVar) &&
-			    head.FallthoughGoto.Match(ILCode.Br, out condBBLabel) &&
-			    labelToBasicBlock.TryGetValue(condBBLabel, out condBB) &&
-			    condBB.Match(ILCode.Brtrue, out endBBLabel, out leftExpr2, out rightBBLabel) &&
-			    leftExpr2.Match(ILCode.Ldloc, out leftVar2) &&
-			    leftVar == leftVar2 &&
+			    head.MatchLast(ILCode.Brtrue, out endBBLabel, out leftExpr2, out rightBBLabel) &&
+			    leftExpr2.Match(ILCode.Ldloc, leftVar) &&
 			    labelToBasicBlock.TryGetValue(rightBBLabel, out rightBB) &&
-			    rightBB.Match(ILCode.Stloc, out v2, out rightExpr, out endBBLabel2) &&
+			    rightBB.MatchSingle(ILCode.Stloc, out v2, out rightExpr, out endBBLabel2) &&
 			    v == v2 &&
 			    endBBLabel == endBBLabel2 &&
-			    labelToBasicBlock.TryGetValue(endBBLabel, out endBB) &&
-			    labelGlobalRefCount.GetOrDefault(condBBLabel) == 1 &&
 			    labelGlobalRefCount.GetOrDefault(rightBBLabel) == 1 &&
-			    labelGlobalRefCount.GetOrDefault(endBBLabel) == 2 &&
-			    scope.Contains(condBB) &&
-			    scope.Contains(rightBB) &&
-			    scope.Contains(endBB)
+			    body.Contains(rightBB)
 			   )
 			{
-				head.Body[head.Body.Count - 1] = new ILExpression(ILCode.Stloc, v, new ILExpression(ILCode.NullCoalescing, null, leftExpr, rightExpr));
+				head.Body[head.Body.Count - 2] = new ILExpression(ILCode.Stloc, v, new ILExpression(ILCode.NullCoalescing, null, leftExpr, rightExpr));
+				head.Body.RemoveAt(head.Body.Count - 1);
 				head.FallthoughGoto = new ILExpression(ILCode.Br, endBBLabel);
 				
-				foreach(ILLabel deleteLabel in new [] { condBBLabel, rightBBLabel }) {
-					scope.RemoveOrThrow(labelToBasicBlock[deleteLabel]);
-					labelGlobalRefCount.RemoveOrThrow(deleteLabel);
-					labelToBasicBlock.RemoveOrThrow(deleteLabel);
-				}
+				body.RemoveOrThrow(labelToBasicBlock[rightBBLabel]);
+				labelGlobalRefCount.RemoveOrThrow(rightBBLabel);
+				labelToBasicBlock.RemoveOrThrow(rightBBLabel);
 				return true;
 			}
 			return false;
 		}
 		
-		// scope is modified if successful
-		bool TrySimplifyShortCircuit(List<ILNode> scope, ILBasicBlock head, int index)
+		bool SimplifyShortCircuit(List<ILNode> body, ILBasicBlock head, int pos)
 		{
-			Debug.Assert(scope.Contains(head));
+			Debug.Assert(body.Contains(head));
 			
 			ILExpression condExpr;
 			ILLabel trueLabel;
 			ILLabel falseLabel;
-			if(head.Match(ILCode.Brtrue, out trueLabel, out condExpr, out falseLabel)) {
+			if(head.MatchLast(ILCode.Brtrue, out trueLabel, out condExpr, out falseLabel)) {
 				for (int pass = 0; pass < 2; pass++) {
 					
 					// On the second pass, swap labels and negate expression of the first branch
@@ -481,24 +512,24 @@ namespace ICSharpCode.Decompiler.ILAst
 					ILExpression nextCondExpr;
 					ILLabel nextTrueLablel;
 					ILLabel nextFalseLabel;
-					if (scope.Contains(nextBasicBlock) &&
+					if (body.Contains(nextBasicBlock) &&
 					    nextBasicBlock != head &&
 					    labelGlobalRefCount[nextBasicBlock.EntryLabel] == 1 &&
-					    nextBasicBlock.Match(ILCode.Brtrue, out nextTrueLablel, out nextCondExpr, out nextFalseLabel) &&
+					    nextBasicBlock.MatchSingle(ILCode.Brtrue, out nextTrueLablel, out nextCondExpr, out nextFalseLabel) &&
 					    (otherLablel == nextFalseLabel || otherLablel == nextTrueLablel))
 					{
 						// Create short cicuit branch
 						if (otherLablel == nextFalseLabel) {
-							head.Body[0] = new ILExpression(ILCode.Brtrue, nextTrueLablel, new ILExpression(ILCode.LogicAnd, null, negate ? new ILExpression(ILCode.LogicNot, null, condExpr) : condExpr, nextCondExpr));
+							head.Body[head.Body.Count - 1] = new ILExpression(ILCode.Brtrue, nextTrueLablel, new ILExpression(ILCode.LogicAnd, null, negate ? new ILExpression(ILCode.LogicNot, null, condExpr) : condExpr, nextCondExpr));
 						} else {
-							head.Body[0] = new ILExpression(ILCode.Brtrue, nextTrueLablel, new ILExpression(ILCode.LogicOr, null, negate ? condExpr : new ILExpression(ILCode.LogicNot, null, condExpr), nextCondExpr));
+							head.Body[head.Body.Count - 1] = new ILExpression(ILCode.Brtrue, nextTrueLablel, new ILExpression(ILCode.LogicOr, null, negate ? condExpr : new ILExpression(ILCode.LogicNot, null, condExpr), nextCondExpr));
 						}
 						head.FallthoughGoto = new ILExpression(ILCode.Br, nextFalseLabel);
 						
 						// Remove the inlined branch from scope
 						labelGlobalRefCount.RemoveOrThrow(nextBasicBlock.EntryLabel);
 						labelToBasicBlock.RemoveOrThrow(nextBasicBlock.EntryLabel);
-						scope.RemoveOrThrow(nextBasicBlock);
+						body.RemoveOrThrow(nextBasicBlock);
 						
 						return true;
 					}
@@ -589,7 +620,7 @@ namespace ICSharpCode.Decompiler.ILAst
 		/// Reduce the nesting of conditions.
 		/// It should be done on flat data that already had most gotos removed
 		/// </summary>
-		void FlattenIfStatements(ILNode node)
+		void ReduceIfNesting(ILNode node)
 		{
 			ILBlock block = node as ILBlock;
 			if (block != null) {
@@ -624,7 +655,7 @@ namespace ICSharpCode.Decompiler.ILAst
 			// We are changing the number of blocks so we use plain old recursion to get all blocks
 			foreach(ILNode child in node.GetChildren()) {
 				if (child != null && !(child is ILExpression))
-					FlattenIfStatements(child);
+					ReduceIfNesting(child);
 			}
 		}
 		
@@ -642,7 +673,7 @@ namespace ICSharpCode.Decompiler.ILAst
 		/// Perform one pass of a given optimization on this block.
 		/// This block must consist of only basicblocks.
 		/// </summary>
-		public static bool RunPeepholeOptimization(this ILBlock block, Func<List<ILNode>, ILBasicBlock, int, bool> optimization)
+		public static bool RunOptimization(this ILBlock block, Func<List<ILNode>, ILBasicBlock, int, bool> optimization)
 		{
 			bool modified = false;
 			List<ILNode> body = block.Body;
@@ -657,6 +688,23 @@ namespace ICSharpCode.Decompiler.ILAst
 			return modified;
 		}
 		
+		public static bool RunOptimization(this ILBlock block, Func<List<ILNode>, ILExpression, int, bool> optimization)
+		{
+			bool modified = false;
+			foreach (ILBasicBlock bb in block.Body) {
+				for (int j = 0; j < bb.Body.Count;) {
+					ILExpression expr = bb.Body[j] as ILExpression;
+					if (expr != null && optimization(bb.Body, expr, j)) {
+						modified = true;
+						j = Math.Max(0, j - 1); // Go back one step
+					} else {
+						j++;
+					}
+				}
+			}
+			return modified;
+		}
+		
 		public static bool CanFallThough(this ILNode node)
 		{
 			ILExpression expr = node as ILExpression;
@@ -689,6 +737,24 @@ namespace ICSharpCode.Decompiler.ILAst
 			}
 		}
 		
+		public static bool IsStoreToArray(this ILCode code)
+		{
+			switch (code) {
+				case ILCode.Stelem_Any:
+				case ILCode.Stelem_I:
+				case ILCode.Stelem_I1:
+				case ILCode.Stelem_I2:
+				case ILCode.Stelem_I4:
+				case ILCode.Stelem_I8:
+				case ILCode.Stelem_R4:
+				case ILCode.Stelem_R8:
+				case ILCode.Stelem_Ref:
+					return true;
+				default:
+					return false;
+			}
+		}
+		
 		/// <summary>
 		/// Can the expression be used as a statement in C#?
 		/// </summary>

ICSharpCode.Decompiler/ILAst/ILInlining.cs

@@ -48,41 +48,66 @@ namespace ICSharpCode.Decompiler.ILAst
 			}
 		}
 		
-		public void InlineAllVariables()
+		public bool InlineAllVariables()
 		{
+			bool modified = false;
 			ILInlining i = new ILInlining(method);
 			foreach (ILBlock block in method.GetSelfAndChildrenRecursive<ILBlock>())
-				i.InlineAllInBlock(block);
+				modified |= i.InlineAllInBlock(block);
+			return modified;
 		}
 		
-		public void InlineAllInBlock(ILBlock block)
+		public bool InlineAllInBlock(ILBlock block)
 		{
+			bool modified = false;
 			List<ILNode> body = block.Body;
 			for(int i = 0; i < body.Count - 1;) {
 				ILVariable locVar;
 				ILExpression expr;
-				if (body[i].Match(ILCode.Stloc, out locVar, out expr) && InlineOneIfPossible(block, i, aggressive: false)) {
+				if (body[i].Match(ILCode.Stloc, out locVar, out expr) && InlineOneIfPossible(block.Body, i, aggressive: false)) {
+					modified = true;
 					i = Math.Max(0, i - 1); // Go back one step
 				} else {
 					i++;
 				}
 			}
+			foreach(ILBasicBlock bb in body.OfType<ILBasicBlock>()) {
+				modified |= InlineAllInBasicBlock(bb);
+		}
+			return modified;
+		}
+		
+		public bool InlineAllInBasicBlock(ILBasicBlock bb)
+		{
+			bool modified = false;
+			List<ILNode> body = bb.Body;
+			for(int i = 0; i < body.Count - 1;) {
+				ILVariable locVar;
+				ILExpression expr;
+				if (body[i].Match(ILCode.Stloc, out locVar, out expr) && InlineOneIfPossible(bb.Body, i, aggressive: false)) {
+					modified = true;
+					i = Math.Max(0, i - 1); // Go back one step
+				} else {
+					i++;
+				}
+			}
+			return modified;
 		}
 		
 		/// <summary>
 		/// Inlines instructions before pos into block.Body[pos].
 		/// </summary>
 		/// <returns>The number of instructions that were inlined.</returns>
-		public int InlineInto(ILBlock block, int pos, bool aggressive)
+		public int InlineInto(List<ILNode> body, int pos, bool aggressive)
 		{
-			if (pos >= block.Body.Count)
+			if (pos >= body.Count)
 				return 0;
 			int count = 0;
 			while (--pos >= 0) {
-				ILExpression expr = block.Body[pos] as ILExpression;
+				ILExpression expr = body[pos] as ILExpression;
 				if (expr == null || expr.Code != ILCode.Stloc)
 					break;
-				if (InlineOneIfPossible(block, pos, aggressive))
+				if (InlineOneIfPossible(body, pos, aggressive))
 					count++;
 				else
 					break;
@@ -97,10 +122,10 @@ namespace ICSharpCode.Decompiler.ILAst
 		/// <remarks>
 		/// After the operation, pos will point to the new combined instruction.
 		/// </remarks>
-		public bool InlineIfPossible(ILBlock block, ref int pos)
+		public bool InlineIfPossible(List<ILNode> body, ref int pos)
 		{
-			if (InlineOneIfPossible(block, pos, true)) {
-				pos -= InlineInto(block, pos, false);
+			if (InlineOneIfPossible(body, pos, true)) {
+				pos -= InlineInto(body, pos, false);
 				return true;
 			}
 			return false;
@@ -109,28 +134,28 @@ namespace ICSharpCode.Decompiler.ILAst
 		/// <summary>
 		/// Inlines the stloc instruction at block.Body[pos] into the next instruction, if possible.
 		/// </summary>
-		public bool InlineOneIfPossible(ILBlock block, int pos, bool aggressive)
+		public bool InlineOneIfPossible(List<ILNode> body, int pos, bool aggressive)
 		{
 			ILVariable v;
 			ILExpression inlinedExpression;
-			if (block.Body[pos].Match(ILCode.Stloc, out v, out inlinedExpression) && !v.IsPinned) {
-				if (InlineIfPossible(v, inlinedExpression, block.Body.ElementAtOrDefault(pos+1), aggressive)) {
+			if (body[pos].Match(ILCode.Stloc, out v, out inlinedExpression) && !v.IsPinned) {
+				if (InlineIfPossible(v, inlinedExpression, body.ElementAtOrDefault(pos+1), aggressive)) {
 					// Assign the ranges of the stloc instruction:
-					inlinedExpression.ILRanges.AddRange(((ILExpression)block.Body[pos]).ILRanges);
+					inlinedExpression.ILRanges.AddRange(((ILExpression)body[pos]).ILRanges);
 					// Remove the stloc instruction:
-					block.Body.RemoveAt(pos);
+					body.RemoveAt(pos);
 					return true;
 				} else if (numLdloc.GetOrDefault(v) == 0 && numLdloca.GetOrDefault(v) == 0) {
 					// The variable is never loaded
 					if (inlinedExpression.HasNoSideEffects()) {
 						// Remove completely
-						block.Body.RemoveAt(pos);
+						body.RemoveAt(pos);
 						return true;
 					} else if (inlinedExpression.CanBeExpressionStatement() && v.IsGenerated) {
 						// Assign the ranges of the stloc instruction:
-						inlinedExpression.ILRanges.AddRange(((ILExpression)block.Body[pos]).ILRanges);
+						inlinedExpression.ILRanges.AddRange(((ILExpression)body[pos]).ILRanges);
 						// Remove the stloc, but keep the inner expression
-						block.Body[pos] = inlinedExpression;
+						body[pos] = inlinedExpression;
 						return true;
 					}
 				}
@@ -155,7 +180,7 @@ namespace ICSharpCode.Decompiler.ILAst
 			ILExpression parent;
 			int pos;
 			if (FindLoadInNext(next as ILExpression, v, inlinedExpression, out parent, out pos) == true) {
-				if (!aggressive && !v.IsGenerated && !NonAggressiveInlineInto((ILExpression)next, parent))
+				if (!aggressive && !v.IsGenerated && !NonAggressiveInlineInto((ILExpression)next, parent, inlinedExpression))
 					return false;
 				
 				// Assign the ranges of the ldloc instruction:
@@ -168,8 +193,15 @@ namespace ICSharpCode.Decompiler.ILAst
 			return false;
 		}
 		
-		bool NonAggressiveInlineInto(ILExpression next, ILExpression parent)
+		bool NonAggressiveInlineInto(ILExpression next, ILExpression parent, ILExpression inlinedExpression)
 		{
+			switch (inlinedExpression.Code) {
+				case ILCode.InitArray:
+				case ILCode.InitCollection:
+				case ILCode.DefaultValue:
+					return true;
+			}
+			
 			switch (next.Code) {
 				case ILCode.Ret:
 					return parent.Code == ILCode.Ret;
@@ -300,7 +332,7 @@ namespace ICSharpCode.Decompiler.ILAst
 							// if we un-inlined stuff; we need to update the usage counters
 							AnalyzeMethod();
 						}
-						InlineInto(block, i, aggressive: false); // maybe inlining gets possible after the removal of block.Body[i]
+						InlineInto(block.Body, i, aggressive: false); // maybe inlining gets possible after the removal of block.Body[i]
 						i -= uninlinedArgs.Length + 1;
 					}
 				}

ICSharpCode.Decompiler/ILAst/InitializerPeepholeTransforms.cs

@@ -12,25 +12,16 @@ namespace ICSharpCode.Decompiler.ILAst
 	/// <summary>
 	/// IL AST transformation that introduces array, object and collection initializers.
 	/// </summary>
-	public class InitializerPeepholeTransforms
+	public class Initializers
 	{
-		readonly ILBlock method;
-		
-		#region Array Initializers
-		
-		public InitializerPeepholeTransforms(ILBlock method)
-		{
-			this.method = method;
-		}
-		
-		public void TransformArrayInitializers(ILBlock block, ref int i)
+		public static bool TransformArrayInitializers(List<ILNode> body, ILExpression expr, int pos)
 		{
 			ILVariable v, v2, v3;
 			ILExpression newarrExpr;
 			TypeReference arrayType;
 			ILExpression lengthExpr;
 			int arrayLength;
-			if (block.Body[i].Match(ILCode.Stloc, out v, out newarrExpr) &&
+			if (expr.Match(ILCode.Stloc, out v, out newarrExpr) &&
 			    newarrExpr.Match(ILCode.Newarr, out arrayType, out lengthExpr) &&
 			    lengthExpr.Match(ILCode.Ldc_I4, out arrayLength) &&
 			    arrayLength > 0)
@@ -39,7 +30,7 @@ namespace ICSharpCode.Decompiler.ILAst
 				ILExpression methodArg1;
 				ILExpression methodArg2;
 				FieldDefinition field;
-				if (block.Body.ElementAtOrDefault(i + 1).Match(ILCode.Call, out methodRef, out methodArg1, out methodArg2) &&
+				if (body.ElementAtOrDefault(pos + 1).Match(ILCode.Call, out methodRef, out methodArg1, out methodArg2) &&
 				    methodRef.DeclaringType.FullName == "System.Runtime.CompilerServices.RuntimeHelpers" &&
 				    methodRef.Name == "InitializeArray" &&
 				    methodArg1.Match(ILCode.Ldloc, out v2) &&
@@ -49,59 +40,41 @@ namespace ICSharpCode.Decompiler.ILAst
 				{
 					ILExpression[] newArr = new ILExpression[arrayLength];
 					if (DecodeArrayInitializer(TypeAnalysis.GetTypeCode(arrayType), field.InitialValue, newArr)) {
-						block.Body[i] = new ILExpression(ILCode.Stloc, v, new ILExpression(ILCode.InitArray, arrayType, newArr));
-						block.Body.RemoveAt(i + 1);
-						i -= new ILInlining(method).InlineInto(block, i + 1, aggressive: true) - 1;
-						return;
+						body[pos] = new ILExpression(ILCode.Stloc, v, new ILExpression(ILCode.InitArray, arrayType, newArr));
+						body.RemoveAt(pos + 1);
+						return true;
 					}
 				}
 				
 				const int maxConsecutiveDefaultValueExpressions = 10;
 				List<ILExpression> operands = new List<ILExpression>();
 				int numberOfInstructionsToRemove = 0;
-				for (int j = i + 1; j < block.Body.Count; j++) {
-					ILExpression expr = block.Body[j] as ILExpression;
-					int pos;
-					if (expr != null &&
-					    IsStoreToArray(expr.Code) &&
-					    expr.Arguments[0].Match(ILCode.Ldloc, out v3) &&
+				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 &&
-					    expr.Arguments[1].Match(ILCode.Ldc_I4, out pos) &&
-					    pos >= operands.Count &&
-					    pos <= operands.Count + maxConsecutiveDefaultValueExpressions)
+					    nextExpr.Arguments[1].Match(ILCode.Ldc_I4, out arrayPos) &&
+					    arrayPos >= operands.Count &&
+					    arrayPos <= operands.Count + maxConsecutiveDefaultValueExpressions)
 					{
-						while (operands.Count < pos)
+						while (operands.Count < arrayPos)
 							operands.Add(new ILExpression(ILCode.DefaultValue, arrayType));
-						operands.Add(expr.Arguments[2]);
+						operands.Add(nextExpr.Arguments[2]);
 						numberOfInstructionsToRemove++;
 					} else {
 						break;
 					}
 				}
 				if (operands.Count == arrayLength) {
-					((ILExpression)block.Body[i]).Arguments[0] = new ILExpression(ILCode.InitArray, arrayType, operands);
-					block.Body.RemoveRange(i + 1, numberOfInstructionsToRemove);
-					i -= new ILInlining(method).InlineInto(block, i + 1, aggressive: true) - 1;
-				}
-			}
-		}
-		
-		static bool IsStoreToArray(ILCode code)
-		{
-			switch (code) {
-				case ILCode.Stelem_Any:
-				case ILCode.Stelem_I:
-				case ILCode.Stelem_I1:
-				case ILCode.Stelem_I2:
-				case ILCode.Stelem_I4:
-				case ILCode.Stelem_I8:
-				case ILCode.Stelem_R4:
-				case ILCode.Stelem_R8:
-				case ILCode.Stelem_Ref:
+					expr.Arguments[0] = new ILExpression(ILCode.InitArray, arrayType, operands);
+					body.RemoveRange(pos + 1, numberOfInstructionsToRemove);
 					return true;
-				default:
-					return false;
+				}
 			}
+			return false;
 		}
 		
 		static bool DecodeArrayInitializer(TypeCode elementType, byte[] initialValue, ILExpression[] output)
@@ -165,50 +138,50 @@ namespace ICSharpCode.Decompiler.ILAst
 					return false;
 			}
 		}
-		#endregion
 		
-		#region Collection Initilializers
-		public void TransformCollectionInitializers(ILBlock block, ref int i)
+		public static bool TransformCollectionInitializers(List<ILNode> body, ILExpression expr, int pos)
 		{
-			ILVariable v;
-			ILExpression expr;
-			if (!block.Body[i].Match(ILCode.Stloc, out v, out expr) || expr.Code != ILCode.Newobj)
-				return;
-			MethodReference ctor = (MethodReference)expr.Operand;
-			TypeDefinition td = ctor.DeclaringType.Resolve();
-			if (td == null || !td.Interfaces.Any(intf => intf.Name == "IEnumerable" && intf.Namespace == "System.Collections"))
-				return;
-			// This is a collection: we can convert Add() calls into a collection initializer
-			ILExpression collectionInitializer = new ILExpression(ILCode.InitCollection, null, expr);
-			for (int j = i + 1; j < block.Body.Count; j++) {
-				MethodReference addMethod;
-				List<ILExpression> args;
-				if (!block.Body[j].Match(ILCode.Callvirt, out addMethod, out args))
-					break;
-				if (addMethod.Name != "Add" || !addMethod.HasThis || args.Count < 2 || args[0].Code != ILCode.Ldloc || args[0].Operand != v)
-					break;
-				collectionInitializer.Arguments.Add((ILExpression)block.Body[j]);
-			}
-			// ensure we added at least one additional arg to the collection initializer:
-			if (collectionInitializer.Arguments.Count == 1)
-				return;
-			ILInlining inline = new ILInlining(method);
-			ILExpression followingExpr = block.Body.ElementAtOrDefault(i + collectionInitializer.Arguments.Count) as ILExpression;
-			if (inline.CanInlineInto(followingExpr, v, collectionInitializer)) {
-				block.Body.RemoveRange(i + 1, collectionInitializer.Arguments.Count - 1);
-				((ILExpression)block.Body[i]).Arguments[0] = collectionInitializer;
+			ILVariable v, v2;
+			ILExpression newObjExpr;
+			MethodReference ctor;
+			List<ILExpression> ctorArgs;
+			if (expr.Match(ILCode.Stloc, out v, out newObjExpr) &&
+			    newObjExpr.Match(ILCode.Newobj, out ctor, out ctorArgs))
+			{
+				TypeDefinition td = ctor.DeclaringType.Resolve();
+				if (td == null || !td.Interfaces.Any(intf => intf.Name == "IEnumerable" && intf.Namespace == "System.Collections"))
+					return false;
 				
-				// Change add methods into InitCollectionAddMethod:
-				for (int j = 1; j < collectionInitializer.Arguments.Count; j++) {
-					collectionInitializer.Arguments[j].Arguments.RemoveAt(0);
-					collectionInitializer.Arguments[j].Code = ILCode.InitCollectionAddMethod;
+				// This is a collection: we can convert Add() calls into a collection initializer
+				ILExpression collectionInitializer = new ILExpression(ILCode.InitCollection, null, newObjExpr);
+				bool anyAdded = false;
+				while(pos + 1 < body.Count) {
+					ILExpression nextExpr = body[pos + 1] as ILExpression;
+					MethodReference addMethod;
+					List<ILExpression> args;
+					if (nextExpr.Match(ILCode.Callvirt, out addMethod, out args) &&
+					    addMethod.Name == "Add" &&
+					    addMethod.HasThis &&
+					    args.Count == 2 &&
+					    args[0].Match(ILCode.Ldloc, out v2) &&
+					    v == v2)
+					{
+						nextExpr.Code = ILCode.InitCollectionAddMethod;
+						nextExpr.Arguments.RemoveAt(0);
+						collectionInitializer.Arguments.Add(nextExpr);
+						body.RemoveAt(pos + 1);
+						anyAdded = true;
+					} else {
+						break;
+					}
+				}
+				// ensure we added at least one additional arg to the collection initializer:
+				if (anyAdded) {
+					expr.Arguments[0] = collectionInitializer;
+					return true;
 				}
-				
-				inline = new ILInlining(method); // refresh variable usage info
-				if (inline.InlineIfPossible(block, ref i))
-					i++; // retry transformations on the new combined instruction
 			}
+			return false;
 		}
-		#endregion
 	}
 }

ICSharpCode.Decompiler/ILAst/LoopsAndConditions.cs

@@ -27,20 +27,24 @@ namespace ICSharpCode.Decompiler.ILAst
 		
 		public void FindLoops(ILBlock block)
 		{
-			ControlFlowGraph graph;
-			graph = BuildGraph(block.Body, (ILLabel)block.EntryGoto.Operand);
-			graph.ComputeDominance(context.CancellationToken);
-			graph.ComputeDominanceFrontier();
-			block.Body = FindLoops(new HashSet<ControlFlowNode>(graph.Nodes.Skip(3)), graph.EntryPoint, false);
+			if (block.Body.Count > 0) {
+				ControlFlowGraph graph;
+				graph = BuildGraph(block.Body, (ILLabel)block.EntryGoto.Operand);
+				graph.ComputeDominance(context.CancellationToken);
+				graph.ComputeDominanceFrontier();
+				block.Body = FindLoops(new HashSet<ControlFlowNode>(graph.Nodes.Skip(3)), graph.EntryPoint, false);
+			}
 		}
 		
 		public void FindConditions(ILBlock block)
 		{
-			ControlFlowGraph graph;
-			graph = BuildGraph(block.Body, (ILLabel)block.EntryGoto.Operand);
-			graph.ComputeDominance(context.CancellationToken);
-			graph.ComputeDominanceFrontier();
-			block.Body = FindConditions(new HashSet<ControlFlowNode>(graph.Nodes.Skip(3)), graph.EntryPoint);
+			if (block.Body.Count > 0) {
+				ControlFlowGraph graph;
+				graph = BuildGraph(block.Body, (ILLabel)block.EntryGoto.Operand);
+				graph.ComputeDominance(context.CancellationToken);
+				graph.ComputeDominanceFrontier();
+				block.Body = FindConditions(new HashSet<ControlFlowNode>(graph.Nodes.Skip(3)), graph.EntryPoint);
+			}
 		}
 		
 		ControlFlowGraph BuildGraph(List<ILNode> nodes, ILLabel entryLabel)
@@ -57,7 +61,7 @@ namespace ICSharpCode.Decompiler.ILAst
 			// Create graph nodes
 			labelToCfNode = new Dictionary<ILLabel, ControlFlowNode>();
 			Dictionary<ILNode, ControlFlowNode> astNodeToCfNode = new Dictionary<ILNode, ControlFlowNode>();
-			foreach(ILNode node in nodes) {
+			foreach(ILBasicBlock node in nodes) {
 				ControlFlowNode cfNode = new ControlFlowNode(index++, -1, ControlFlowNodeType.Normal);
 				cfNodes.Add(cfNode);
 				astNodeToCfNode[node] = cfNode;
@@ -76,22 +80,18 @@ namespace ICSharpCode.Decompiler.ILAst
 			entryNode.Incoming.Add(entryEdge);
 			
 			// Create edges
-			foreach(ILNode node in nodes) {
+			foreach(ILBasicBlock node in nodes) {
 				ControlFlowNode source = astNodeToCfNode[node];
 				
 				// Find all branches
-				foreach(ILExpression child in node.GetSelfAndChildrenRecursive<ILExpression>()) {
-					IEnumerable<ILLabel> targets = child.GetBranchTargets();
-					if (targets != null) {
-						foreach(ILLabel target in targets) {
-							ControlFlowNode destination;
-							// Labels which are out of out scope will not be int the collection
-							if (labelToCfNode.TryGetValue(target, out destination) && destination != source) {
-								ControlFlowEdge edge = new ControlFlowEdge(source, destination, JumpType.Normal);
-								source.Outgoing.Add(edge);
-								destination.Incoming.Add(edge);
-							}
-						}
+				foreach(ILLabel target in node.GetSelfAndChildrenRecursive<ILExpression>(e => e.IsBranch()).SelectMany(e => e.GetBranchTargets())) {
+					ControlFlowNode destination;
+					// Labels which are out of out scope will not be int the collection
+					// Insert self edge only if we are sure we are a loop
+					if (labelToCfNode.TryGetValue(target, out destination) && (destination != source || target == node.EntryLabel)) {
+						ControlFlowEdge edge = new ControlFlowEdge(source, destination, JumpType.Normal);
+						source.Outgoing.Add(edge);
+						destination.Incoming.Add(edge);
 					}
 				}
 			}
@@ -123,7 +123,7 @@ namespace ICSharpCode.Decompiler.ILAst
 					ILExpression condExpr;
 					ILLabel trueLabel;
 					ILLabel falseLabel;
-					if(basicBlock.Match(ILCode.Brtrue, out trueLabel, out condExpr, out falseLabel))
+					if(basicBlock.MatchSingle(ILCode.Brtrue, out trueLabel, out condExpr, out falseLabel))
 					{
 						ControlFlowNode trueTarget;
 						labelToCfNode.TryGetValue(trueLabel, out trueTarget);
@@ -138,7 +138,7 @@ namespace ICSharpCode.Decompiler.ILAst
 							scope.RemoveOrThrow(node);
 							
 							// If false means enter the loop
-							if (loopContents.Contains(falseTarget))
+							if (loopContents.Contains(falseTarget) || falseTarget == node)
 							{
 								// Negate the condition
 								condExpr = new ILExpression(ILCode.LogicNot, null, condExpr);
@@ -156,42 +156,39 @@ namespace ICSharpCode.Decompiler.ILAst
 								loopContents.UnionWith(pullIn);
 							}
 							
-							// Use loop to implement the condition
-							result.Add(new ILBasicBlock() {
-							           	EntryLabel = basicBlock.EntryLabel,
-							           	Body = new List<ILNode>() {
-							           		new ILWhileLoop() {
-							           			Condition = condExpr,
-							           			BodyBlock = new ILBlock() {
-							           				EntryGoto = new ILExpression(ILCode.Br, trueLabel),
-							           				Body = FindLoops(loopContents, node, true)
-							           			}
-							           		},
-							           		new ILExpression(ILCode.Br, falseLabel)
-							           	},
-							           	FallthoughGoto = null
-							           });
+							// Use loop to implement the brtrue
+							basicBlock.Body.RemoveAt(basicBlock.Body.Count - 1);
+							basicBlock.Body.Add(new ILWhileLoop() {
+								Condition = condExpr,
+								BodyBlock = new ILBlock() {
+									EntryGoto = new ILExpression(ILCode.Br, trueLabel),
+									Body = FindLoops(loopContents, node, false)
+								}
+							});
+							basicBlock.FallthoughGoto = new ILExpression(ILCode.Br, falseLabel);
+							result.Add(basicBlock);
+							
+							scope.ExceptWith(loopContents);
 						}
 					}
 					
 					// Fallback method: while(true)
 					if (scope.Contains(node)) {
 						result.Add(new ILBasicBlock() {
-						           	EntryLabel = new ILLabel() { Name = "Loop_" + (nextLabelIndex++) },
-						           	Body = new List<ILNode>() {
-						           		new ILWhileLoop() {
-						           			BodyBlock = new ILBlock() {
-						           				EntryGoto = new ILExpression(ILCode.Br, basicBlock.EntryLabel),
-						           				Body = FindLoops(loopContents, node, true)
-						           			}
-						           		},
-						           	},
-						           	FallthoughGoto = null
-						           });
-					}
+							EntryLabel = new ILLabel() { Name = "Loop_" + (nextLabelIndex++) },
+							Body = new List<ILNode>() {
+								new ILWhileLoop() {
+									BodyBlock = new ILBlock() {
+										EntryGoto = new ILExpression(ILCode.Br, basicBlock.EntryLabel),
+										Body = FindLoops(loopContents, node, true)
+									}
+								},
+							},
+							FallthoughGoto = null
+						});
 						
-					// Move the content into loop block
-					scope.ExceptWith(loopContents);
+						scope.ExceptWith(loopContents);
+					}
 				}
 
 				// Using the dominator tree should ensure we find the the widest loop first
@@ -229,24 +226,20 @@ namespace ICSharpCode.Decompiler.ILAst
 				// Find a block that represents a simple condition
 				if (scope.Contains(node)) {
 					
-					ILBasicBlock block = node.UserData as ILBasicBlock;
-					
-					if (block != null && block.Body.Count == 1) {
-						
-						ILExpression condBranch = block.Body[0] as ILExpression;
+					ILBasicBlock block = (ILBasicBlock)node.UserData;
 					
+					{
 						// Switch
 						ILLabel[] caseLabels;
-						List<ILExpression> switchArgs;
-						if (condBranch.Match(ILCode.Switch, out caseLabels, out switchArgs)) {
-							
-							ILSwitch ilSwitch = new ILSwitch() { Condition = switchArgs.Single() };
-							ILBasicBlock newBB = new ILBasicBlock() {
-								EntryLabel = block.EntryLabel,  // Keep the entry label
-								Body = { ilSwitch },
-								FallthoughGoto = block.FallthoughGoto
-							};
-							result.Add(newBB);
+						ILExpression switchArg;
+						ILLabel fallLabel;
+						if (block.MatchLast(ILCode.Switch, out caseLabels, out switchArg, out fallLabel)) {
+							
+							// Replace the switch code with ILSwitch
+							ILSwitch ilSwitch = new ILSwitch() { Condition = switchArg };
+							block.Body.RemoveAt(block.Body.Count - 1);
+							block.Body.Add(ilSwitch);
+							result.Add(block);
 
 							// Remove the item so that it is not picked up as content
 							scope.RemoveOrThrow(node);
@@ -259,19 +252,18 @@ namespace ICSharpCode.Decompiler.ILAst
 							}
 							
 							// Pull in code of cases
-							ILLabel fallLabel = (ILLabel)block.FallthoughGoto.Operand;
 							ControlFlowNode fallTarget = null;
 							labelToCfNode.TryGetValue(fallLabel, out fallTarget);
 							
 							HashSet<ControlFlowNode> frontiers = new HashSet<ControlFlowNode>();
 							if (fallTarget != null)
-								frontiers.UnionWith(fallTarget.DominanceFrontier);
+								frontiers.UnionWith(fallTarget.DominanceFrontier.Except(new [] { fallTarget }));
 							
 							foreach(ILLabel condLabel in caseLabels) {
 								ControlFlowNode condTarget = null;
 								labelToCfNode.TryGetValue(condLabel, out condTarget);
 								if (condTarget != null)
-									frontiers.UnionWith(condTarget.DominanceFrontier);
+									frontiers.UnionWith(condTarget.DominanceFrontier.Except(new [] { condTarget }));
 							}
 							
 							for (int i = 0; i < caseLabels.Length; i++) {
@@ -305,7 +297,7 @@ namespace ICSharpCode.Decompiler.ILAst
 								if (content.Any()) {
 									var caseBlock = new ILSwitch.CaseBlock() { EntryGoto = new ILExpression(ILCode.Br, fallLabel) };
 									ilSwitch.CaseBlocks.Add(caseBlock);
-									newBB.FallthoughGoto = null;
+									block.FallthoughGoto = null;
 									
 									scope.ExceptWith(content);
 									caseBlock.Body.AddRange(FindConditions(content, fallTarget));
@@ -319,7 +311,7 @@ namespace ICSharpCode.Decompiler.ILAst
 						ILExpression condExpr;
 						ILLabel trueLabel;
 						ILLabel falseLabel;
-						if(block.Match(ILCode.Brtrue, out trueLabel, out condExpr, out falseLabel)) {
+						if(block.MatchLast(ILCode.Brtrue, out trueLabel, out condExpr, out falseLabel)) {
 							
 							// Swap bodies since that seems to be the usual C# order
 							ILLabel temp = trueLabel;
@@ -327,16 +319,16 @@ namespace ICSharpCode.Decompiler.ILAst
 							falseLabel = temp;
 							condExpr = new ILExpression(ILCode.LogicNot, null, condExpr);
 							
-							// Convert the basic block to ILCondition
+							// Convert the brtrue to ILCondition
 							ILCondition ilCond = new ILCondition() {
 								Condition  = condExpr,
 								TrueBlock  = new ILBlock() { EntryGoto = new ILExpression(ILCode.Br, trueLabel) },
 								FalseBlock = new ILBlock() { EntryGoto = new ILExpression(ILCode.Br, falseLabel) }
 							};
-							result.Add(new ILBasicBlock() {
-							           	EntryLabel = block.EntryLabel,  // Keep the entry label
-							           	Body = { ilCond }
-							           });
+							block.Body.RemoveAt(block.Body.Count - 1);
+							block.Body.Add(ilCond);
+							block.FallthoughGoto = null;
+							result.Add(block);
 							
 							// Remove the item immediately so that it is not picked up as content
 							scope.RemoveOrThrow(node);
@@ -349,9 +341,9 @@ namespace ICSharpCode.Decompiler.ILAst
 							// Pull in the conditional code
 							HashSet<ControlFlowNode> frontiers = new HashSet<ControlFlowNode>();
 							if (trueTarget != null)
-								frontiers.UnionWith(trueTarget.DominanceFrontier);
+								frontiers.UnionWith(trueTarget.DominanceFrontier.Except(new [] { trueTarget }));
 							if (falseTarget != null)
-								frontiers.UnionWith(falseTarget.DominanceFrontier);
+								frontiers.UnionWith(falseTarget.DominanceFrontier.Except(new [] { falseTarget }));
 							
 							if (trueTarget != null && !frontiers.Contains(trueTarget)) {
 								HashSet<ControlFlowNode> content = FindDominatedNodes(scope, trueTarget);

ICSharpCode.Decompiler/ILAst/PatternMatching.cs

@@ -4,7 +4,7 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
-
+using System.Linq;
 using Mono.Cecil;
 
 namespace ICSharpCode.Decompiler.ILAst
@@ -28,6 +28,16 @@ namespace ICSharpCode.Decompiler.ILAst
 			return false;
 		}
 		
+		public static bool Match<T>(this ILNode node, ILCode code, T operand)
+		{
+			ILExpression expr = node as ILExpression;
+			if (expr != null && expr.Prefixes == null && expr.Code == code) {
+				Debug.Assert(expr.Arguments.Count == 0);
+				return operand.Equals(expr.Operand);
+			}
+			return false;
+		}
+		
 		public static bool Match(this ILNode node, ILCode code, out List<ILExpression> args)
 		{
 			ILExpression expr = node as ILExpression;
@@ -88,7 +98,7 @@ namespace ICSharpCode.Decompiler.ILAst
 			return false;
 		}
 		
-		public static bool Match<T>(this ILBasicBlock bb, ILCode code, out T operand, out ILExpression arg, out ILLabel fallLabel)
+		public static bool MatchSingle<T>(this ILBasicBlock bb, ILCode code, out T operand, out ILExpression arg, out ILLabel fallLabel)
 		{
 			if (bb.Body.Count == 1) {
 				if (bb.Body[0].Match(code, out operand, out arg)) {
@@ -102,6 +112,18 @@ namespace ICSharpCode.Decompiler.ILAst
 			return false;
 		}
 		
+		public static bool MatchLast<T>(this ILBasicBlock bb, ILCode code, out T operand, out ILExpression arg, out ILLabel fallLabel)
+		{
+			if (bb.Body.LastOrDefault().Match(code, out operand, out arg)) {
+				fallLabel = bb.FallthoughGoto != null ? (ILLabel)bb.FallthoughGoto.Operand : null;
+				return true;
+			}
+			operand = default(T);
+			arg = null;
+			fallLabel = null;
+			return false;
+		}
+		
 		public static bool MatchThis(this ILNode node)
 		{
 			ILVariable v;

ICSharpCode.Decompiler/ILAst/PeepholeTransform.cs

@@ -11,179 +11,83 @@ using Mono.Cecil;
 
 namespace ICSharpCode.Decompiler.ILAst
 {
-	public delegate void PeepholeTransform(ILBlock block, ref int i);
-	
-	/// <summary>
-	/// Handles peephole transformations on the ILAst.
-	/// </summary>
-	public class PeepholeTransforms
+	public partial class ILAstOptimizer
 	{
-		DecompilerContext context;
-		ILBlock method;
-		
-		public static void Run(DecompilerContext context, ILBlock method)
+		static bool TransformDecimalCtorToConstant(List<ILNode> body, ILExpression expr, int pos)
 		{
-			PeepholeTransforms transforms = new PeepholeTransforms();
-			transforms.context = context;
-			transforms.method = method;
-			
-			InitializerPeepholeTransforms initializerTransforms = new InitializerPeepholeTransforms(method);
-			PeepholeTransform[] blockTransforms = {
-				initializerTransforms.TransformArrayInitializers,
-				initializerTransforms.TransformCollectionInitializers,
-				transforms.CachedDelegateInitialization,
-				transforms.MakeAssignmentExpression,
-				transforms.IntroduceFixedStatements
-			};
-			Func<ILExpression, ILExpression>[] exprTransforms = {
-				HandleDecimalConstants,
-				SimplifyLdObjAndStObj
-			};
-			// Traverse in post order so that nested blocks are transformed first. This is required so that
-			// patterns on the parent block can assume that all nested blocks are already transformed.
-			foreach (var node in TreeTraversal.PostOrder<ILNode>(method, c => c != null ? c.GetChildren() : null)) {
-				ILBlock block = node as ILBlock;
-				ILExpression expr;
-				if (block != null) {
-					// go through the instructions in reverse so that transforms can build up nested structures inside-out
-					for (int i = block.Body.Count - 1; i >= 0; i--) {
-						context.CancellationToken.ThrowIfCancellationRequested();
-						expr = block.Body[i] as ILExpression;
-						if (expr != null) {
-							// apply expr transforms to top-level expr in block
-							bool modified = ApplyExpressionTransforms(ref expr, exprTransforms);
-							block.Body[i] = expr;
-							if (modified) {
-								ILInlining inlining = new ILInlining(method);
-								if (inlining.InlineIfPossible(block, ref i)) {
-									i++; // retry all transforms on the new combined instruction
-									continue;
-								}
-							}
-						}
-						// apply block transforms
-						foreach (var t in blockTransforms) {
-							t(block, ref i);
-							Debug.Assert(i <= block.Body.Count && i >= 0);
-							if (i == block.Body.Count) // special case: retry all transforms
-								break;
-						}
+			MethodReference r;
+			List<ILExpression> args;
+			if (expr.Match(ILCode.Newobj, out r, out args) &&
+			    r.DeclaringType.Namespace == "System" &&
+			    r.DeclaringType.Name == "Decimal")
+			{
+				if (args.Count == 1) {
+					int val;
+					if (args[0].Match(ILCode.Ldc_I4, out val)) {
+						expr.Code = ILCode.Ldc_Decimal;
+						expr.Operand = new decimal(val);
+						expr.InferredType = r.DeclaringType;
+						expr.Arguments.Clear();
+						return true;
 					}
-				}
-				expr = node as ILExpression;
-				if (expr != null) {
-					// apply expr transforms to all arguments
-					for (int i = 0; i < expr.Arguments.Count; i++) {
-						ILExpression arg = expr.Arguments[i];
-						ApplyExpressionTransforms(ref arg, exprTransforms);
-						expr.Arguments[i] = arg;
+				} else if (args.Count == 5) {
+					int lo, mid, hi, isNegative, scale;
+					if (expr.Arguments[0].Match(ILCode.Ldc_I4, out lo) &&
+					    expr.Arguments[1].Match(ILCode.Ldc_I4, out mid) &&
+					    expr.Arguments[2].Match(ILCode.Ldc_I4, out hi) &&
+					    expr.Arguments[3].Match(ILCode.Ldc_I4, out isNegative) &&
+					    expr.Arguments[4].Match(ILCode.Ldc_I4, out scale))
+					{
+						expr.Code = ILCode.Ldc_Decimal;
+						expr.Operand = new decimal(lo, mid, hi, isNegative != 0, (byte)scale);
+						expr.InferredType = r.DeclaringType;
+						expr.Arguments.Clear();
+						return true;
 					}
 				}
 			}
-		}
-		
-		static bool ApplyExpressionTransforms(ref ILExpression expr, Func<ILExpression, ILExpression>[] exprTransforms)
-		{
-			bool modifiedInAnyIteration = false;
-			bool modified;
-			do {
-				modified = false;
-				ILExpression oldExpr = expr;
-				ILCode oldOpCode = oldExpr.Code;
-				foreach (var t in exprTransforms)
-					expr = t(expr);
-				if (expr != oldExpr || oldOpCode != expr.Code) {
-					modified = true;
-					modifiedInAnyIteration = true;
-				}
-			} while (modified);
-			return modifiedInAnyIteration;
-		}
-		
-		#region HandleDecimalConstants
-		static ILExpression HandleDecimalConstants(ILExpression expr)
-		{
-			if (expr.Code == ILCode.Newobj) {
-				MethodReference r = (MethodReference)expr.Operand;
-				if (r.DeclaringType.Name == "Decimal" && r.DeclaringType.Namespace == "System") {
-					if (expr.Arguments.Count == 1) {
-						int? val = GetI4Constant(expr.Arguments[0]);
-						if (val != null) {
-							expr.Arguments.Clear();
-							expr.Code = ILCode.Ldc_Decimal;
-							expr.Operand = new decimal(val.Value);
-							expr.InferredType = r.DeclaringType;
-						}
-					} else if (expr.Arguments.Count == 5) {
-						int? lo = GetI4Constant(expr.Arguments[0]);
-						int? mid = GetI4Constant(expr.Arguments[1]);
-						int? hi = GetI4Constant(expr.Arguments[2]);
-						int? isNegative = GetI4Constant(expr.Arguments[3]);
-						int? scale = GetI4Constant(expr.Arguments[4]);
-						if (lo != null && mid != null && hi != null && isNegative != null && scale != null) {
-							expr.Arguments.Clear();
-							expr.Code = ILCode.Ldc_Decimal;
-							expr.Operand = new decimal(lo.Value, mid.Value, hi.Value, isNegative.Value != 0, (byte)scale);
-							expr.InferredType = r.DeclaringType;
-						}
-					}
-				}
+			bool modified = false;
+			foreach(ILExpression arg in expr.Arguments) {
+				modified |= TransformDecimalCtorToConstant(null, arg, -1);
 			}
-			return expr;
+			return modified;
 		}
 		
-		static int? GetI4Constant(ILExpression expr)
-		{
-			if (expr != null && expr.Code == ILCode.Ldc_I4)
-				return (int)expr.Operand;
-			else
-				return null;
-		}
-		#endregion
-		
-		#region SimplifyLdObjAndStObj
-		static ILExpression SimplifyLdObjAndStObj(ILExpression expr)
+		static bool SimplifyLdObjAndStObj(List<ILNode> body, ILExpression expr, int pos)
 		{
 			if (expr.Code == ILCode.Initobj) {
 				expr.Code = ILCode.Stobj;
 				expr.Arguments.Add(new ILExpression(ILCode.DefaultValue, expr.Operand));
+				return true;
 			}
-			if (expr.Code == ILCode.Stobj) {
-				switch (expr.Arguments[0].Code) {
-					case ILCode.Ldelema:
-						return SimplifyLdObjOrStObj(expr, ILCode.Stelem_Any);
-					case ILCode.Ldloca:
-						return SimplifyLdObjOrStObj(expr, ILCode.Stloc);
-					case ILCode.Ldflda:
-						return SimplifyLdObjOrStObj(expr, ILCode.Stfld);
-					case ILCode.Ldsflda:
-						return SimplifyLdObjOrStObj(expr, ILCode.Stsfld);
+			ILExpression arg, arg2;
+			TypeReference type;
+			ILCode? newCode = null;
+			if (expr.Match(ILCode.Stobj, out type, out arg, out arg2)) {
+				switch (arg.Code) {
+					case ILCode.Ldelema: newCode = ILCode.Stelem_Any; break;
+					case ILCode.Ldloca:  newCode = ILCode.Stloc; break;
+					case ILCode.Ldflda:  newCode = ILCode.Stfld; break;
+					case ILCode.Ldsflda: newCode = ILCode.Stsfld; break;
 				}
-			} else if (expr.Code == ILCode.Ldobj) {
-				switch (expr.Arguments[0].Code) {
-					case ILCode.Ldelema:
-						return SimplifyLdObjOrStObj(expr, ILCode.Ldelem_Any);
-					case ILCode.Ldloca:
-						return SimplifyLdObjOrStObj(expr, ILCode.Ldloc);
-					case ILCode.Ldflda:
-						return SimplifyLdObjOrStObj(expr, ILCode.Ldfld);
-					case ILCode.Ldsflda:
-						return SimplifyLdObjOrStObj(expr, ILCode.Ldsfld);
+			} else if (expr.Match(ILCode.Ldobj, out type, out arg)) {
+				switch (arg.Code) {
+					case ILCode.Ldelema: newCode = ILCode.Ldelem_Any; break;
+					case ILCode.Ldloca:  newCode = ILCode.Ldloc; break;
+					case ILCode.Ldflda:  newCode = ILCode.Ldfld; break;
+					case ILCode.Ldsflda: newCode = ILCode.Ldsfld; break;
 				}
 			}
-			return expr;
-		}
-		
-		static ILExpression SimplifyLdObjOrStObj(ILExpression expr, ILCode newCode)
-		{
-			ILExpression lda = expr.Arguments[0];
-			lda.Code = newCode;
-			if (expr.Code == ILCode.Stobj)
-				lda.Arguments.Add(expr.Arguments[1]);
-			lda.ILRanges.AddRange(expr.ILRanges);
-			return lda;
+			if (newCode != null) {
+				arg.Code = newCode.Value;
+				if (expr.Code == ILCode.Stobj)
+					arg.Arguments.Add(arg2);
+				arg.ILRanges.AddRange(expr.ILRanges);
+				body[pos] = arg;
+				return true;
+			}
+			return false;
 		}
-		#endregion
 		
 		#region CachedDelegateInitialization
 		void CachedDelegateInitialization(ILBlock block, ref int i)
@@ -230,7 +134,7 @@ namespace ICSharpCode.Decompiler.ILAst
 						if (parent.Arguments[j].Code == ILCode.Ldsfld && ((FieldReference)parent.Arguments[j].Operand).ResolveWithinSameModule() == field) {
 							parent.Arguments[j] = newObj;
 							block.Body.RemoveAt(i);
-							i -= new ILInlining(method).InlineInto(block, i, aggressive: true);
+							i -= new ILInlining(method).InlineInto(block.Body, i, aggressive: true);
 							return;
 						}
 					}
@@ -240,51 +144,48 @@ namespace ICSharpCode.Decompiler.ILAst
 		#endregion
 		
 		#region MakeAssignmentExpression
-		void MakeAssignmentExpression(ILBlock block, ref int i)
+		bool MakeAssignmentExpression(List<ILNode> body, ILExpression expr, int pos)
 		{
-			// expr_44 = ...
-			// stloc(v, expr_44)
+			// exprVar = ...
+			// stloc(v, exprVar)
 			// ->
-			// expr_44 = stloc(v, ...))
+			// exprVar = stloc(v, ...))
+			ILExpression nextExpr = body.ElementAtOrDefault(pos + 1) as ILExpression;
 			ILVariable exprVar;
 			ILExpression initializer;
-			if (!(block.Body[i].Match(ILCode.Stloc, out exprVar, out initializer) && exprVar.IsGenerated))
-				return;
-			ILExpression stloc1 = block.Body.ElementAtOrDefault(i + 1) as ILExpression;
-			if (!(stloc1 != null && stloc1.Code == ILCode.Stloc && stloc1.Arguments[0].Code == ILCode.Ldloc && stloc1.Arguments[0].Operand == exprVar))
-				return;
-			
-			ILInlining inlining;
-			ILExpression store2 = block.Body.ElementAtOrDefault(i + 2) as ILExpression;
-			if (StoreCanBeConvertedToAssignment(store2, exprVar)) {
-				// expr_44 = ...
-				// stloc(v1, expr_44)
-				// anystore(v2, expr_44)
-				// ->
-				// stloc(v1, anystore(v2, ...))
-				inlining = new ILInlining(method);
-				if (inlining.numLdloc.GetOrDefault(exprVar) == 2 && inlining.numStloc.GetOrDefault(exprVar) == 1) {
-					block.Body.RemoveAt(i + 2); // remove store2
-					block.Body.RemoveAt(i); // remove expr = ...
-					stloc1.Arguments[0] = store2;
-					store2.Arguments[store2.Arguments.Count - 1] = initializer;
-					
-					if (inlining.InlineIfPossible(block, ref i)) {
-						i++; // retry transformations on the new combined instruction
+			ILVariable v;
+			ILExpression stLocArg;
+			if (expr.Match(ILCode.Stloc, out exprVar, out initializer) &&
+			    exprVar.IsGenerated &&
+			    nextExpr.Match(ILCode.Stloc, out v, out stLocArg) &&
+			    stLocArg.Match(ILCode.Ldloc, exprVar))
+			{
+				ILExpression store2 = body.ElementAtOrDefault(pos + 2) as ILExpression;
+				if (StoreCanBeConvertedToAssignment(store2, exprVar)) {
+					// expr_44 = ...
+					// stloc(v1, expr_44)
+					// anystore(v2, expr_44)
+					// ->
+					// stloc(v1, anystore(v2, ...))
+					ILInlining inlining = new ILInlining(method);
+					if (inlining.numLdloc.GetOrDefault(exprVar) == 2 && inlining.numStloc.GetOrDefault(exprVar) == 1) {
+						body.RemoveAt(pos + 2); // remove store2
+						body.RemoveAt(pos); // remove expr = ...
+						nextExpr.Arguments[0] = store2;
+						store2.Arguments[store2.Arguments.Count - 1] = initializer;
+						
+						inlining.InlineIfPossible(body, ref pos);
+						
+						return true;
 					}
-					return;
 				}
-			}
-			
-			
-			block.Body.RemoveAt(i + 1); // remove stloc
-			stloc1.Arguments[0] = initializer;
-			((ILExpression)block.Body[i]).Arguments[0] = stloc1;
 				
-			inlining = new ILInlining(method);
-			if (inlining.InlineIfPossible(block, ref i)) {
-				i++; // retry transformations on the new combined instruction
+				body.RemoveAt(pos + 1); // remove stloc
+				nextExpr.Arguments[0] = initializer;
+				((ILExpression)body[pos]).Arguments[0] = nextExpr;
+				return true;
 			}
+			return false;
 		}
 		
 		bool StoreCanBeConvertedToAssignment(ILExpression store, ILVariable exprVar)
@@ -297,35 +198,35 @@ namespace ICSharpCode.Decompiler.ILAst
 		#endregion
 		
 		#region IntroduceFixedStatements
-		void IntroduceFixedStatements(ILBlock block, ref int i)
+		bool IntroduceFixedStatements(List<ILNode> body, int i)
 		{
 			ILExpression initValue;
 			ILVariable pinnedVar;
 			int initEndPos;
-			if (!MatchFixedInitializer(block, i, out pinnedVar, out initValue, out initEndPos))
-				return;
+			if (!MatchFixedInitializer(body, i, out pinnedVar, out initValue, out initEndPos))
+				return false;
 			
-			ILFixedStatement fixedStmt = block.Body.ElementAtOrDefault(initEndPos) as ILFixedStatement;
+			ILFixedStatement fixedStmt = body.ElementAtOrDefault(initEndPos) as ILFixedStatement;
 			if (fixedStmt != null) {
 				ILExpression expr = fixedStmt.BodyBlock.Body.LastOrDefault() as ILExpression;
 				if (expr != null && expr.Code == ILCode.Stloc && expr.Operand == pinnedVar && IsNullOrZero(expr.Arguments[0])) {
 					// we found a second initializer for the existing fixed statement
 					fixedStmt.Initializers.Insert(0, initValue);
-					block.Body.RemoveRange(i, initEndPos - i);
+					body.RemoveRange(i, initEndPos - i);
 					fixedStmt.BodyBlock.Body.RemoveAt(fixedStmt.BodyBlock.Body.Count - 1);
 					if (pinnedVar.Type.IsByReference)
 						pinnedVar.Type = new PointerType(((ByReferenceType)pinnedVar.Type).ElementType);
-					return;
+					return true;
 				}
 			}
 			
 			// find where pinnedVar is reset to 0:
 			int j;
-			for (j = initEndPos; j < block.Body.Count; j++) {
+			for (j = initEndPos; j < body.Count; j++) {
 				ILVariable v2;
 				ILExpression storedVal;
 				// stloc(pinned_Var, conv.u(ldc.i4(0)))
-				if (block.Body[j].Match(ILCode.Stloc, out v2, out storedVal) && v2 == pinnedVar) {
+				if (body[j].Match(ILCode.Stloc, out v2, out storedVal) && v2 == pinnedVar) {
 					if (IsNullOrZero(storedVal)) {
 						break;
 					}
@@ -334,11 +235,13 @@ namespace ICSharpCode.Decompiler.ILAst
 			// Create fixed statement from i to j
 			fixedStmt = new ILFixedStatement();
 			fixedStmt.Initializers.Add(initValue);
-			fixedStmt.BodyBlock = new ILBlock(block.Body.GetRange(initEndPos, j - initEndPos)); // from initEndPos to j-1 (inclusive)
-			block.Body.RemoveRange(i + 1, Math.Min(j, block.Body.Count - 1) - i); // from i+1 to j (inclusive)
-			block.Body[i] = fixedStmt;
+			fixedStmt.BodyBlock = new ILBlock(body.GetRange(initEndPos, j - initEndPos)); // from initEndPos to j-1 (inclusive)
+			body.RemoveRange(i + 1, Math.Min(j, body.Count - 1) - i); // from i+1 to j (inclusive)
+			body[i] = fixedStmt;
 			if (pinnedVar.Type.IsByReference)
 				pinnedVar.Type = new PointerType(((ByReferenceType)pinnedVar.Type).ElementType);
+			
+			return true;
 		}
 		
 		bool IsNullOrZero(ILExpression expr)
@@ -348,15 +251,15 @@ namespace ICSharpCode.Decompiler.ILAst
 			return (expr.Code == ILCode.Ldc_I4 && (int)expr.Operand == 0) || expr.Code == ILCode.Ldnull;
 		}
 		
-		bool MatchFixedInitializer(ILBlock block, int i, out ILVariable pinnedVar, out ILExpression initValue, out int nextPos)
+		bool MatchFixedInitializer(List<ILNode> body, int i, out ILVariable pinnedVar, out ILExpression initValue, out int nextPos)
 		{
-			if (block.Body[i].Match(ILCode.Stloc, out pinnedVar, out initValue) && pinnedVar.IsPinned && !IsNullOrZero(initValue)) {
-				initValue = (ILExpression)block.Body[i];
+			if (body[i].Match(ILCode.Stloc, out pinnedVar, out initValue) && pinnedVar.IsPinned && !IsNullOrZero(initValue)) {
+				initValue = (ILExpression)body[i];
 				nextPos = i + 1;
-				HandleStringFixing(pinnedVar, block.Body, ref nextPos, ref initValue);
+				HandleStringFixing(pinnedVar, body, ref nextPos, ref initValue);
 				return true;
 			}
-			ILCondition ifStmt = block.Body[i] as ILCondition;
+			ILCondition ifStmt = body[i] as ILCondition;
 			ILExpression arrayLoadingExpr;
 			if (ifStmt != null && MatchFixedArrayInitializerCondition(ifStmt.Condition, out arrayLoadingExpr)) {
 				ILVariable arrayVariable = (ILVariable)arrayLoadingExpr.Operand;

ICSharpCode.Decompiler/ILAst/TypeAnalysis.cs

@@ -490,8 +490,7 @@ namespace ICSharpCode.Decompiler.ILAst
 				case ILCode.Ldc_R8:
 					return typeSystem.Double;
 				case ILCode.Ldc_Decimal:
-					Debug.Assert(expr.InferredType != null && expr.InferredType.FullName == "System.Decimal");
-					return expr.InferredType;
+					return new TypeReference("System", "Decimal", module, module, true);
 				case ILCode.Ldtoken:
 					if (expr.Operand is TypeReference)
 						return new TypeReference("System", "RuntimeTypeHandle", module, module, true);