Handle Comp in InferType().

ICSharpCode.Decompiler/IL/ILTypeExtensions.cs

@@ -131,7 +131,7 @@ namespace ICSharpCode.Decompiler.IL
 		/// 
 		/// Returns SpecialType.UnknownType for unsupported instructions.
 		/// </summary>
-		public static IType InferType(this ILInstruction inst)
+		public static IType InferType(this ILInstruction inst, ICompilation compilation)
 		{
 			switch (inst) {
 				case NewObj newObj:
@@ -159,12 +159,24 @@ namespace ICSharpCode.Decompiler.IL
 				case LdsFlda ldsflda:
 					return new ByReferenceType(ldsflda.Field.Type);
 				case LdElema ldelema:
-					if (ldelema.Array.InferType() is ArrayType arrayType) {
+					if (ldelema.Array.InferType(compilation) is ArrayType arrayType) {
 						if (TypeUtils.IsCompatibleTypeForMemoryAccess(arrayType.ElementType, ldelema.Type)) {
 							return new ByReferenceType(arrayType.ElementType);
 						}
 					}
 					return new ByReferenceType(ldelema.Type);
+				case Comp comp:
+					if (compilation == null)
+						return SpecialType.UnknownType;
+					switch (comp.LiftingKind) {
+						case ComparisonLiftingKind.None:
+						case ComparisonLiftingKind.CSharp:
+							return compilation.FindType(KnownTypeCode.Boolean);
+						case ComparisonLiftingKind.ThreeValuedLogic:
+							return NullableType.Create(compilation, compilation.FindType(KnownTypeCode.Boolean));
+						default:
+							return SpecialType.UnknownType;
+					}
 				default:
 					return SpecialType.UnknownType;
 			}

ICSharpCode.Decompiler/IL/Instructions/CompoundAssignmentInstruction.cs

@@ -148,7 +148,7 @@ namespace ICSharpCode.Decompiler.IL
 				}
 			}
 			// Can't transform if the RHS value would be need to be truncated for the LHS type.
-			if (Transforms.TransformAssignment.IsImplicitTruncation(binary.Right, type, binary.IsLifted))
+			if (Transforms.TransformAssignment.IsImplicitTruncation(binary.Right, type, null, binary.IsLifted))
 				return false;
 			return true;
 		}

ICSharpCode.Decompiler/IL/SemanticHelper.cs

@@ -44,27 +44,6 @@ namespace ICSharpCode.Decompiler.IL
 			return (inst & ~pureFlags) == 0;
 		}
 		
-		/// <summary>
-		/// Gets whether the instruction sequence 'inst1; inst2;' may be ordered to 'inst2; inst1;'
-		/// </summary>
-		internal static bool MayReorder(InstructionFlags inst1, InstructionFlags inst2)
-		{
-			// If both instructions perform an impure action, we cannot reorder them
-			if (!IsPure(inst1) && !IsPure(inst2))
-				return false;
-			// We cannot reorder if inst2 might write what inst1 looks at
-			if (ConflictingPair(inst1, inst2, InstructionFlags.MayReadLocals, InstructionFlags.MayWriteLocals | InstructionFlags.SideEffect))
-				return false;
-			return true;
-		}
-
-		private static bool ConflictingPair(InstructionFlags inst1, InstructionFlags inst2, InstructionFlags readFlag, InstructionFlags writeFlag)
-		{
-			// if one instruction has the read flag and the other the write flag, that's a conflict
-			return (inst1 & readFlag) != 0 && (inst2 & writeFlag) != 0
-				|| (inst2 & readFlag) != 0 && (inst1 & writeFlag) != 0;
-		}
-		
 		/// <summary>
 		/// Gets whether the instruction sequence 'inst1; inst2;' may be ordered to 'inst2; inst1;'
 		/// </summary>

ICSharpCode.Decompiler/IL/Transforms/AssignVariableNames.cs

@@ -448,7 +448,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 			if (!variableType.IsKnownType(KnownTypeCode.Object))
 				return variableType;
 
-			IType inferredType = inst.InferType();
+			IType inferredType = inst.InferType(context.TypeSystem);
 			if (inferredType.Kind != TypeKind.Unknown)
 				return inferredType;
 			else

ICSharpCode.Decompiler/IL/Transforms/ExpressionTransforms.cs

@@ -498,7 +498,9 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 					}
 					break;
 				case BinaryNumericOperator.BitAnd:
-					if (IsBoolean(inst.Left) && IsBoolean(inst.Right) && SemanticHelper.IsPure(inst.Right.Flags))
+					if (inst.Left.InferType(context.TypeSystem).IsKnownType(KnownTypeCode.Boolean)
+						&& inst.Right.InferType(context.TypeSystem).IsKnownType(KnownTypeCode.Boolean)
+						&& SemanticHelper.IsPure(inst.Right.Flags))
 					{
 						context.Step("Replace bit.and with logic.and", inst);
 						var expr = IfInstruction.LogicAnd(inst.Left, inst.Right);
@@ -508,11 +510,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 					break;
 			}
 		}
-
+		
-		private static bool IsBoolean(ILInstruction inst) => 
-			inst is Comp c && c.ResultType == StackType.I4 || 
-			inst.InferType().IsKnownType(KnownTypeCode.Boolean);
-
 		protected internal override void VisitTryCatchHandler(TryCatchHandler inst)
 		{
 			base.VisitTryCatchHandler(inst);

ICSharpCode.Decompiler/IL/Transforms/NullPropagationTransform.cs

@@ -111,7 +111,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 			if (!IsValidAccessChain(testedVar, mode, nonNullInst, out var varLoad))
 				return null;
 			// note: InferType will be accurate in this case because the access chain consists of calls and field accesses
-			IType returnType = nonNullInst.InferType();
+			IType returnType = nonNullInst.InferType(context.TypeSystem);
 			if (nullInst.MatchLdNull()) {
 				context.Step($"Null propagation (mode={mode}, output=reference type)", nonNullInst);
 				// testedVar != null ? testedVar.AccessChain : null

ICSharpCode.Decompiler/IL/Transforms/RemoveDeadVariableInit.cs

@@ -76,7 +76,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 					IType newType = null;
 					// Multiple store are possible in case of (c ? ref a : ref b) += 1, for example.
 					foreach (var stloc in v.StoreInstructions.OfType<StLoc>()) {
-						var inferredType = stloc.Value.InferType();
+						var inferredType = stloc.Value.InferType(context.TypeSystem);
 						// cancel, if types of values do not match exactly
 						if (newType != null && !newType.Equals(inferredType)) {
 							newType = SpecialType.UnknownType;

ICSharpCode.Decompiler/IL/Transforms/TransformAssignment.cs

@@ -88,7 +88,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 			// in some cases it can be a compiler-generated local
 			if (inst == null || (inst.Variable.Kind != VariableKind.StackSlot && inst.Variable.Kind != VariableKind.Local))
 				return false;
-			if (IsImplicitTruncation(inst.Value, inst.Variable.Type)) {
+			if (IsImplicitTruncation(inst.Value, inst.Variable.Type, context.TypeSystem)) {
 				// 'stloc s' is implicitly truncating the value
 				return false;
 			}
@@ -112,7 +112,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 					return false;
 				if (!SemanticHelper.IsPure(stobj.Target.Flags) || inst.Variable.IsUsedWithin(stobj.Target))
 					return false;
-				var pointerType = stobj.Target.InferType();
+				var pointerType = stobj.Target.InferType(context.TypeSystem);
 				IType newType = stobj.Type;
 				if (TypeUtils.IsCompatiblePointerTypeForMemoryAccess(pointerType, stobj.Type)) {
 					if (pointerType is ByReferenceType byref)
@@ -120,7 +120,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 					else if (pointerType is PointerType pointer)
 						newType = pointer.ElementType;
 				}
-				if (IsImplicitTruncation(inst.Value, newType)) {
+				if (IsImplicitTruncation(inst.Value, newType, context.TypeSystem)) {
 					// 'stobj' is implicitly truncating the value
 					return false;
 				}
@@ -146,7 +146,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 					if (!SemanticHelper.IsPure(arg.Flags) || inst.Variable.IsUsedWithin(arg))
 						return false;
 				}
-				if (IsImplicitTruncation(inst.Value, call.Method.Parameters.Last().Type)) {
+				if (IsImplicitTruncation(inst.Value, call.Method.Parameters.Last().Type, context.TypeSystem)) {
 					// setter call is implicitly truncating the value
 					return false;
 				}
@@ -242,7 +242,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 				// changes the return value of the expression, so this is only valid on block-level.
 				return false;
 			}
-			if (!IsCompoundStore(compoundStore, out var targetType, out var setterValue))
+			if (!IsCompoundStore(compoundStore, out var targetType, out var setterValue, context.TypeSystem))
 				return false;
 			// targetType = The type of the property/field/etc. being stored to.
 			// setterValue = The value being stored.
@@ -342,11 +342,11 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 				return false;
 			if (!nextInst.Value.MatchLdLoc(inst.Variable))
 				return false;
-			if (IsImplicitTruncation(inst.Value, inst.Variable.Type)) {
+			if (IsImplicitTruncation(inst.Value, inst.Variable.Type, context.TypeSystem)) {
 				// 'stloc s' is implicitly truncating the stack value
 				return false;
 			}
-			if (IsImplicitTruncation(inst.Value, nextInst.Variable.Type)) {
+			if (IsImplicitTruncation(inst.Value, nextInst.Variable.Type, context.TypeSystem)) {
 				// 'stloc l' is implicitly truncating the stack value
 				return false;
 			}
@@ -371,7 +371,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 		/// Gets whether 'stobj type(..., value)' would evaluate to a different value than 'value'
 		/// due to implicit truncation.
 		/// </summary>
-		static internal bool IsImplicitTruncation(ILInstruction value, IType type, bool allowNullableValue = false)
+		static internal bool IsImplicitTruncation(ILInstruction value, IType type, ICompilation compilation, bool allowNullableValue = false)
 		{
 			if (!type.IsSmallIntegerType()) {
 				// Implicit truncation in ILAst only happens for small integer types;
@@ -401,10 +401,10 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 			} else if (value is Comp) {
 				return false; // comp returns 0 or 1, which always fits
 			} else if (value is IfInstruction ifInst) {
-				return IsImplicitTruncation(ifInst.TrueInst, type, allowNullableValue)
+				return IsImplicitTruncation(ifInst.TrueInst, type, compilation, allowNullableValue)
-					|| IsImplicitTruncation(ifInst.FalseInst, type, allowNullableValue);
+					|| IsImplicitTruncation(ifInst.FalseInst, type, compilation, allowNullableValue);
 			} else {
-				IType inferredType = value.InferType();
+				IType inferredType = value.InferType(compilation);
 				if (allowNullableValue) {
 					inferredType = NullableType.GetUnderlyingType(inferredType);
 				}
@@ -456,14 +456,14 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 		/// <summary>
 		/// Gets whether 'inst' is a possible store for use as a compound store.
 		/// </summary>
-		static bool IsCompoundStore(ILInstruction inst, out IType storeType, out ILInstruction value)
+		static bool IsCompoundStore(ILInstruction inst, out IType storeType, out ILInstruction value, ICompilation compilation)
 		{
 			value = null;
 			storeType = null;
 			if (inst is StObj stobj) {
 				// stobj.Type may just be 'int' (due to stind.i4) when we're actually operating on a 'ref MyEnum'.
 				// Try to determine the real type of the object we're modifying:
-				storeType = stobj.Target.InferType();
+				storeType = stobj.Target.InferType(compilation);
 				if (storeType is ByReferenceType refType) {
 					storeType = refType.ElementType;
 				} else if (storeType is PointerType pointerType) {
@@ -530,7 +530,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 		bool TransformPostIncDecOperatorWithInlineStore(Block block, int pos)
 		{
 			var store = block.Instructions[pos];
-			if (!IsCompoundStore(store, out var targetType, out var value))
+			if (!IsCompoundStore(store, out var targetType, out var value, context.TypeSystem))
 				return false;
 			StLoc stloc;
 			var binary = UnwrapSmallIntegerConv(value, out var conv) as BinaryNumericInstruction;
@@ -555,7 +555,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 				return false;
 			if (!IsMatchingCompoundLoad(stloc.Value, store, stloc.Variable))
 				return false;
-			if (IsImplicitTruncation(stloc.Value, stloc.Variable.Type))
+			if (IsImplicitTruncation(stloc.Value, stloc.Variable.Type, context.TypeSystem))
 				return false;
 			context.Step("TransformPostIncDecOperatorWithInlineStore", store);
 			if (binary != null) {
@@ -585,9 +585,9 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 			var store = block.Instructions.ElementAtOrDefault(i + 1);
 			if (inst == null || store == null)
 				return false;
-			if (!IsCompoundStore(store, out var targetType, out var value))
+			if (!IsCompoundStore(store, out var targetType, out var value, context.TypeSystem))
 				return false;
-			if (IsImplicitTruncation(inst.Value, targetType)) {
+			if (IsImplicitTruncation(inst.Value, targetType, context.TypeSystem)) {
 				// 'stloc l' is implicitly truncating the value
 				return false;
 			}

ICSharpCode.Decompiler/IL/Transforms/TransformExpressionTrees.cs

@@ -1065,7 +1065,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 				value = call.Arguments[0];
 				if (call.Arguments.Count == 2)
 					return MatchGetTypeFromHandle(call.Arguments[1], out type);
-				type = value.InferType();
+				type = value.InferType(context.TypeSystem);
 				return true;
 			}
 			return false;