Move some special cases from ILInlining.FindLoadInNext to the individual ILInstructions.

ICSharpCode.Decompiler/IL/Instructions/BlockContainer.cs

@@ -20,6 +20,7 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
+using ICSharpCode.Decompiler.IL.Transforms;
 using ICSharpCode.Decompiler.Util;
 
 namespace ICSharpCode.Decompiler.IL
@@ -239,6 +240,19 @@ namespace ICSharpCode.Decompiler.IL
 			}
 		}
 
+		internal override bool CanInlineIntoSlot(int childIndex, ILInstruction expressionBeingMoved)
+		{
+			// Inlining into the entry-point is allowed as long as we're not moving code into a loop.
+			// This is used to inline into the switch expression.
+			return childIndex == 0 && this.EntryPoint.IncomingEdgeCount == 1;
+		}
+
+		internal override bool PrepareExtract(int childIndex, ExtractionContext ctx)
+		{
+			// Un-inlining from the entry-point is allowed as long as we're not moving code out of a loop
+			return childIndex == 0 && this.EntryPoint.IncomingEdgeCount == 1;
+		}
+
 		/// <summary>
 		/// Topologically sort the blocks.
 		/// The new order is returned without modifying the BlockContainer.

ICSharpCode.Decompiler/IL/Instructions/ILInstruction.cs

@@ -802,6 +802,15 @@ namespace ICSharpCode.Decompiler.IL
 			}
 			return true;
 		}
+
+		/// <summary>
+		/// Gets whether the specified instruction may be inlined into the specified slot.
+		/// Note: this does not check whether reordering with the previous slots is valid; only wheter the target slot supports inlining at all!
+		/// </summary>
+		internal virtual bool CanInlineIntoSlot(int childIndex, ILInstruction expressionBeingMoved)
+		{
+			return GetChildSlot(childIndex).CanInlineInto;
+		}
 	}
 	
 	public interface IInstructionWithTypeOperand

ICSharpCode.Decompiler/IL/Instructions/NullableInstructions.cs

@@ -63,7 +63,7 @@ namespace ICSharpCode.Decompiler.IL
 		/// </summary>
 		public bool RefOutput { get => ResultType == StackType.Ref; }
 
-		public NullableUnwrap(StackType unwrappedType, ILInstruction argument, bool refInput=false)
+		public NullableUnwrap(StackType unwrappedType, ILInstruction argument, bool refInput = false)
 			: base(OpCode.NullableUnwrap, argument)
 		{
 			this.ResultType = unwrappedType;
@@ -132,5 +132,13 @@ namespace ICSharpCode.Decompiler.IL
 			return base.PrepareExtract(childIndex, ctx)
 				&& (ctx.FlagsBeingMoved & InstructionFlags.MayUnwrapNull) == 0;
 		}
+
+		internal override bool CanInlineIntoSlot(int childIndex, ILInstruction expressionBeingMoved)
+		{
+			// Inlining into nullable.rewrap is OK unless the expression being inlined
+			// contains a nullable.wrap that isn't being re-wrapped within the expression being inlined.
+			return base.CanInlineIntoSlot(childIndex, expressionBeingMoved)
+				&& !expressionBeingMoved.HasFlag(InstructionFlags.MayUnwrapNull);
+		}
 	}
 }

ICSharpCode.Decompiler/IL/Transforms/ILInlining.cs

@@ -589,6 +589,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 			} else if (expr is Block block) {
 				// Inlining into inline-blocks?
 				switch (block.Kind) {
+					case BlockKind.ControlFlow when block.Parent is BlockContainer:
 					case BlockKind.ArrayInitializer:
 					case BlockKind.CollectionInitializer:
 					case BlockKind.ObjectInitializer:
@@ -604,19 +605,9 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 					default:
 						return FindResult.Stop;
 				}
-			} else if (expr is BlockContainer container && container.EntryPoint.IncomingEdgeCount == 1) {
-				// Possibly a switch-container, allow inlining into the switch instruction:
-				return NoContinue(FindLoadInNext(container.EntryPoint.Instructions[0], v, expressionBeingMoved, options));
-				// If FindLoadInNext() returns null, we still can't continue searching
-				// because we can't inline over the remainder of the blockcontainer.
-			} else if (expr is NullableRewrap) {
-				// Inlining into nullable.rewrap is OK unless the expression being inlined
-				// contains a nullable.wrap that isn't being re-wrapped within the expression being inlined.
-				if (expressionBeingMoved.HasFlag(InstructionFlags.MayUnwrapNull))
-					return FindResult.Stop;
 			}
 			foreach (var child in expr.Children) {
-				if (!child.SlotInfo.CanInlineInto)
+				if (!expr.CanInlineIntoSlot(child.ChildIndex, expressionBeingMoved))
 					return FindResult.Stop;
 				
 				// Recursively try to find the load instruction
@@ -672,7 +663,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 		{
 			Debug.Assert(targetLoad.IsDescendantOf(stmt));
 			for (ILInstruction inst = targetLoad; inst != stmt; inst = inst.Parent) {
-				if (!inst.SlotInfo.CanInlineInto)
+				if (!inst.Parent.CanInlineIntoSlot(inst.ChildIndex, expressionBeingMoved))
 					return false;
 				// Check whether re-ordering with predecessors is valid:
 				int childIndex = inst.ChildIndex;