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374 lines
14 KiB
374 lines
14 KiB
// Copyright (c) AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt) |
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// This code is distributed under MIT X11 license (for details please see \doc\license.txt) |
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using System; |
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using System.Collections.Generic; |
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using System.Diagnostics; |
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using System.Linq; |
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using ICSharpCode.NRefactory.Utils; |
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using Mono.Cecil; |
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namespace ICSharpCode.Decompiler.ILAst |
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{ |
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public partial class ILAstOptimizer |
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{ |
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static bool TransformDecimalCtorToConstant(List<ILNode> body, ILExpression expr, int pos) |
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{ |
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MethodReference r; |
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List<ILExpression> args; |
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if (expr.Match(ILCode.Newobj, out r, out args) && |
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r.DeclaringType.Namespace == "System" && |
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r.DeclaringType.Name == "Decimal") |
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{ |
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if (args.Count == 1) { |
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int val; |
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if (args[0].Match(ILCode.Ldc_I4, out val)) { |
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expr.Code = ILCode.Ldc_Decimal; |
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expr.Operand = new decimal(val); |
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expr.InferredType = r.DeclaringType; |
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expr.Arguments.Clear(); |
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return true; |
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} |
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} else if (args.Count == 5) { |
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int lo, mid, hi, isNegative, scale; |
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if (expr.Arguments[0].Match(ILCode.Ldc_I4, out lo) && |
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expr.Arguments[1].Match(ILCode.Ldc_I4, out mid) && |
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expr.Arguments[2].Match(ILCode.Ldc_I4, out hi) && |
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expr.Arguments[3].Match(ILCode.Ldc_I4, out isNegative) && |
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expr.Arguments[4].Match(ILCode.Ldc_I4, out scale)) |
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{ |
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expr.Code = ILCode.Ldc_Decimal; |
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expr.Operand = new decimal(lo, mid, hi, isNegative != 0, (byte)scale); |
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expr.InferredType = r.DeclaringType; |
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expr.Arguments.Clear(); |
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return true; |
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} |
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} |
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} |
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bool modified = false; |
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foreach(ILExpression arg in expr.Arguments) { |
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modified |= TransformDecimalCtorToConstant(null, arg, -1); |
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} |
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return modified; |
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} |
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static bool SimplifyLdObjAndStObj(List<ILNode> body, ILExpression expr, int pos) |
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{ |
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bool modified = false; |
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if (expr.Code == ILCode.Initobj) { |
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expr.Code = ILCode.Stobj; |
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expr.Arguments.Add(new ILExpression(ILCode.DefaultValue, expr.Operand)); |
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modified = true; |
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} |
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ILExpression arg, arg2; |
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TypeReference type; |
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ILCode? newCode = null; |
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if (expr.Match(ILCode.Stobj, out type, out arg, out arg2)) { |
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switch (arg.Code) { |
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case ILCode.Ldelema: newCode = ILCode.Stelem_Any; break; |
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case ILCode.Ldloca: newCode = ILCode.Stloc; break; |
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case ILCode.Ldflda: newCode = ILCode.Stfld; break; |
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case ILCode.Ldsflda: newCode = ILCode.Stsfld; break; |
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} |
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} else if (expr.Match(ILCode.Ldobj, out type, out arg)) { |
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switch (arg.Code) { |
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case ILCode.Ldelema: newCode = ILCode.Ldelem_Any; break; |
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case ILCode.Ldloca: newCode = ILCode.Ldloc; break; |
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case ILCode.Ldflda: newCode = ILCode.Ldfld; break; |
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case ILCode.Ldsflda: newCode = ILCode.Ldsfld; break; |
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} |
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} |
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if (newCode != null) { |
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arg.Code = newCode.Value; |
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if (expr.Code == ILCode.Stobj) |
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arg.Arguments.Add(arg2); |
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arg.ILRanges.AddRange(expr.ILRanges); |
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body[pos] = arg; |
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modified = true; |
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} |
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return modified; |
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} |
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#region CachedDelegateInitialization |
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void CachedDelegateInitialization(ILBlock block, ref int i) |
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{ |
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// if (logicnot(ldsfld(field))) { |
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// stsfld(field, newobj(Action::.ctor, ldnull(), ldftn(method))) |
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// } else { |
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// } |
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// ...(..., ldsfld(field), ...) |
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ILCondition c = block.Body[i] as ILCondition; |
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if (c == null || c.Condition == null && c.TrueBlock == null || c.FalseBlock == null) |
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return; |
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if (!(c.TrueBlock.Body.Count == 1 && c.FalseBlock.Body.Count == 0)) |
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return; |
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if (!c.Condition.Match(ILCode.LogicNot)) |
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return; |
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ILExpression condition = c.Condition.Arguments.Single() as ILExpression; |
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if (condition == null || condition.Code != ILCode.Ldsfld) |
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return; |
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FieldDefinition field = ((FieldReference)condition.Operand).ResolveWithinSameModule(); // field is defined in current assembly |
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if (field == null || !field.IsCompilerGeneratedOrIsInCompilerGeneratedClass()) |
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return; |
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ILExpression stsfld = c.TrueBlock.Body[0] as ILExpression; |
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if (!(stsfld != null && stsfld.Code == ILCode.Stsfld && ((FieldReference)stsfld.Operand).ResolveWithinSameModule() == field)) |
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return; |
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ILExpression newObj = stsfld.Arguments[0]; |
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if (!(newObj.Code == ILCode.Newobj && newObj.Arguments.Count == 2)) |
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return; |
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if (newObj.Arguments[0].Code != ILCode.Ldnull) |
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return; |
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if (newObj.Arguments[1].Code != ILCode.Ldftn) |
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return; |
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MethodDefinition anonymousMethod = ((MethodReference)newObj.Arguments[1].Operand).ResolveWithinSameModule(); // method is defined in current assembly |
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if (!Ast.Transforms.DelegateConstruction.IsAnonymousMethod(context, anonymousMethod)) |
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return; |
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ILNode followingNode = block.Body.ElementAtOrDefault(i + 1); |
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if (followingNode != null && followingNode.GetSelfAndChildrenRecursive<ILExpression>().Count( |
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e => e.Code == ILCode.Ldsfld && ((FieldReference)e.Operand).ResolveWithinSameModule() == field) == 1) |
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{ |
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foreach (ILExpression parent in followingNode.GetSelfAndChildrenRecursive<ILExpression>()) { |
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for (int j = 0; j < parent.Arguments.Count; j++) { |
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if (parent.Arguments[j].Code == ILCode.Ldsfld && ((FieldReference)parent.Arguments[j].Operand).ResolveWithinSameModule() == field) { |
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parent.Arguments[j] = newObj; |
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block.Body.RemoveAt(i); |
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i -= new ILInlining(method).InlineInto(block.Body, i, aggressive: true); |
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return; |
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} |
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} |
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} |
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} |
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} |
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#endregion |
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#region MakeAssignmentExpression |
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bool MakeAssignmentExpression(List<ILNode> body, ILExpression expr, int pos) |
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{ |
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// exprVar = ... |
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// stloc(v, exprVar) |
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// -> |
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// exprVar = stloc(v, ...)) |
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ILExpression nextExpr = body.ElementAtOrDefault(pos + 1) as ILExpression; |
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ILVariable exprVar; |
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ILExpression initializer; |
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ILVariable v; |
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ILExpression stLocArg; |
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if (expr.Match(ILCode.Stloc, out exprVar, out initializer) && |
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exprVar.IsGenerated && |
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nextExpr.Match(ILCode.Stloc, out v, out stLocArg) && |
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stLocArg.Match(ILCode.Ldloc, exprVar)) |
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{ |
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ILExpression store2 = body.ElementAtOrDefault(pos + 2) as ILExpression; |
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if (StoreCanBeConvertedToAssignment(store2, exprVar)) { |
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// expr_44 = ... |
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// stloc(v1, expr_44) |
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// anystore(v2, expr_44) |
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// -> |
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// stloc(v1, anystore(v2, ...)) |
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ILInlining inlining = new ILInlining(method); |
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if (inlining.numLdloc.GetOrDefault(exprVar) == 2 && inlining.numStloc.GetOrDefault(exprVar) == 1) { |
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body.RemoveAt(pos + 2); // remove store2 |
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body.RemoveAt(pos); // remove expr = ... |
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nextExpr.Arguments[0] = store2; |
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store2.Arguments[store2.Arguments.Count - 1] = initializer; |
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inlining.InlineIfPossible(body, ref pos); |
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return true; |
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} |
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} |
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body.RemoveAt(pos + 1); // remove stloc |
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nextExpr.Arguments[0] = initializer; |
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((ILExpression)body[pos]).Arguments[0] = nextExpr; |
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return true; |
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} |
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return false; |
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} |
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bool StoreCanBeConvertedToAssignment(ILExpression store, ILVariable exprVar) |
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{ |
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if (store != null && (store.Code == ILCode.Stloc || store.Code == ILCode.Stfld || store.Code == ILCode.Stsfld)) { |
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return store.Arguments.Last().Code == ILCode.Ldloc && store.Arguments.Last().Operand == exprVar; |
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} |
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return false; |
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} |
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#endregion |
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#region IntroduceFixedStatements |
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bool IntroduceFixedStatements(List<ILNode> body, int i) |
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{ |
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ILExpression initValue; |
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ILVariable pinnedVar; |
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int initEndPos; |
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if (!MatchFixedInitializer(body, i, out pinnedVar, out initValue, out initEndPos)) |
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return false; |
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ILFixedStatement fixedStmt = body.ElementAtOrDefault(initEndPos) as ILFixedStatement; |
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if (fixedStmt != null) { |
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ILExpression expr = fixedStmt.BodyBlock.Body.LastOrDefault() as ILExpression; |
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if (expr != null && expr.Code == ILCode.Stloc && expr.Operand == pinnedVar && IsNullOrZero(expr.Arguments[0])) { |
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// we found a second initializer for the existing fixed statement |
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fixedStmt.Initializers.Insert(0, initValue); |
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body.RemoveRange(i, initEndPos - i); |
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fixedStmt.BodyBlock.Body.RemoveAt(fixedStmt.BodyBlock.Body.Count - 1); |
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if (pinnedVar.Type.IsByReference) |
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pinnedVar.Type = new PointerType(((ByReferenceType)pinnedVar.Type).ElementType); |
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return true; |
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} |
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} |
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// find where pinnedVar is reset to 0: |
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int j; |
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for (j = initEndPos; j < body.Count; j++) { |
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ILVariable v2; |
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ILExpression storedVal; |
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// stloc(pinned_Var, conv.u(ldc.i4(0))) |
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if (body[j].Match(ILCode.Stloc, out v2, out storedVal) && v2 == pinnedVar) { |
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if (IsNullOrZero(storedVal)) { |
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break; |
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} |
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} |
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} |
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// Create fixed statement from i to j |
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fixedStmt = new ILFixedStatement(); |
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fixedStmt.Initializers.Add(initValue); |
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fixedStmt.BodyBlock = new ILBlock(body.GetRange(initEndPos, j - initEndPos)); // from initEndPos to j-1 (inclusive) |
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body.RemoveRange(i + 1, Math.Min(j, body.Count - 1) - i); // from i+1 to j (inclusive) |
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body[i] = fixedStmt; |
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if (pinnedVar.Type.IsByReference) |
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pinnedVar.Type = new PointerType(((ByReferenceType)pinnedVar.Type).ElementType); |
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return true; |
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} |
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bool IsNullOrZero(ILExpression expr) |
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{ |
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if (expr.Code == ILCode.Conv_U || expr.Code == ILCode.Conv_I) |
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expr = expr.Arguments[0]; |
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return (expr.Code == ILCode.Ldc_I4 && (int)expr.Operand == 0) || expr.Code == ILCode.Ldnull; |
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} |
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bool MatchFixedInitializer(List<ILNode> body, int i, out ILVariable pinnedVar, out ILExpression initValue, out int nextPos) |
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{ |
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if (body[i].Match(ILCode.Stloc, out pinnedVar, out initValue) && pinnedVar.IsPinned && !IsNullOrZero(initValue)) { |
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initValue = (ILExpression)body[i]; |
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nextPos = i + 1; |
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HandleStringFixing(pinnedVar, body, ref nextPos, ref initValue); |
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return true; |
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} |
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ILCondition ifStmt = body[i] as ILCondition; |
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ILExpression arrayLoadingExpr; |
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if (ifStmt != null && MatchFixedArrayInitializerCondition(ifStmt.Condition, out arrayLoadingExpr)) { |
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ILVariable arrayVariable = (ILVariable)arrayLoadingExpr.Operand; |
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ILExpression trueValue; |
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if (ifStmt.TrueBlock != null && ifStmt.TrueBlock.Body.Count == 1 |
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&& ifStmt.TrueBlock.Body[0].Match(ILCode.Stloc, out pinnedVar, out trueValue) |
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&& pinnedVar.IsPinned && IsNullOrZero(trueValue)) |
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{ |
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if (ifStmt.FalseBlock != null && ifStmt.FalseBlock.Body.Count == 1 && ifStmt.FalseBlock.Body[0] is ILFixedStatement) { |
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ILFixedStatement fixedStmt = (ILFixedStatement)ifStmt.FalseBlock.Body[0]; |
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ILVariable stlocVar; |
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ILExpression falseValue; |
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if (fixedStmt.Initializers.Count == 1 && fixedStmt.BodyBlock.Body.Count == 0 |
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&& fixedStmt.Initializers[0].Match(ILCode.Stloc, out stlocVar, out falseValue) && stlocVar == pinnedVar) |
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{ |
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ILVariable loadedVariable; |
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if (falseValue.Code == ILCode.Ldelema |
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&& falseValue.Arguments[0].Match(ILCode.Ldloc, out loadedVariable) && loadedVariable == arrayVariable |
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&& IsNullOrZero(falseValue.Arguments[1])) |
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{ |
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initValue = new ILExpression(ILCode.Stloc, pinnedVar, arrayLoadingExpr); |
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nextPos = i + 1; |
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return true; |
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} |
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} |
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} |
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} |
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} |
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initValue = null; |
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nextPos = -1; |
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return false; |
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} |
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bool MatchFixedArrayInitializerCondition(ILExpression condition, out ILExpression initValue) |
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{ |
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ILExpression logicAnd; |
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ILVariable arrayVar1, arrayVar2; |
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if (condition.Match(ILCode.LogicNot, out logicAnd) && logicAnd.Code == ILCode.LogicAnd) { |
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initValue = UnpackDoubleNegation(logicAnd.Arguments[0]); |
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if (initValue.Match(ILCode.Ldloc, out arrayVar1)) { |
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ILExpression arrayLength = logicAnd.Arguments[1]; |
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if (arrayLength.Code == ILCode.Conv_I4) |
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arrayLength = arrayLength.Arguments[0]; |
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if (arrayLength.Code == ILCode.Ldlen && arrayLength.Arguments[0].Match(ILCode.Ldloc, out arrayVar2)) { |
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return arrayVar1 == arrayVar2; |
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} |
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} |
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} |
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initValue = null; |
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return false; |
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} |
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ILExpression UnpackDoubleNegation(ILExpression expr) |
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{ |
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ILExpression negated; |
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if (expr.Match(ILCode.LogicNot, out negated) && negated.Match(ILCode.LogicNot, out negated)) |
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return negated; |
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else |
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return expr; |
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} |
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bool HandleStringFixing(ILVariable pinnedVar, List<ILNode> body, ref int pos, ref ILExpression fixedStmtInitializer) |
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{ |
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// fixed (stloc(pinnedVar, ldloc(text))) { |
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// var1 = var2 = conv.i(ldloc(pinnedVar)) |
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// if (logicnot(logicnot(var1))) { |
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// var2 = add(var1, call(RuntimeHelpers::get_OffsetToStringData)) |
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// } |
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// stloc(ptrVar, var2) |
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// ... |
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if (pos >= body.Count) |
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return false; |
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ILVariable var1, var2; |
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ILExpression varAssignment, ptrInitialization; |
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if (!(body[pos].Match(ILCode.Stloc, out var1, out varAssignment) && varAssignment.Match(ILCode.Stloc, out var2, out ptrInitialization))) |
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return false; |
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if (!(var1.IsGenerated && var2.IsGenerated)) |
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return false; |
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if (ptrInitialization.Code == ILCode.Conv_I || ptrInitialization.Code == ILCode.Conv_U) |
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ptrInitialization = ptrInitialization.Arguments[0]; |
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if (!ptrInitialization.MatchLdloc(pinnedVar)) |
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return false; |
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ILCondition ifStmt = body[pos + 1] as ILCondition; |
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if (!(ifStmt != null && ifStmt.TrueBlock != null && ifStmt.TrueBlock.Body.Count == 1 && (ifStmt.FalseBlock == null || ifStmt.FalseBlock.Body.Count == 0))) |
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return false; |
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if (!UnpackDoubleNegation(ifStmt.Condition).MatchLdloc(var1)) |
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return false; |
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ILVariable assignedVar; |
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ILExpression assignedExpr; |
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if (!(ifStmt.TrueBlock.Body[0].Match(ILCode.Stloc, out assignedVar, out assignedExpr) && assignedVar == var2 && assignedExpr.Code == ILCode.Add)) |
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return false; |
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MethodReference calledMethod; |
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if (!(assignedExpr.Arguments[0].MatchLdloc(var1) && assignedExpr.Arguments[1].Match(ILCode.Call, out calledMethod))) |
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return false; |
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if (!(calledMethod.Name == "get_OffsetToStringData" && calledMethod.DeclaringType.FullName == "System.Runtime.CompilerServices.RuntimeHelpers")) |
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return false; |
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ILVariable pointerVar; |
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if (body[pos + 2].Match(ILCode.Stloc, out pointerVar, out assignedExpr) && assignedExpr.MatchLdloc(var2)) { |
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pos += 3; |
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fixedStmtInitializer.Operand = pointerVar; |
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return true; |
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} |
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return false; |
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} |
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#endregion |
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} |
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}
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