From 71149caffdf89ccd818bab54f358ea74cbff84e8 Mon Sep 17 00:00:00 2001
From: pentp <kaalikas@gmail.com>
Date: Fri, 22 Apr 2011 21:26:46 +0300
Subject: [PATCH 1/2] Remove temporary local variables generated by the C#
 compiler for instance method calls on immutable value type values

---
 ICSharpCode.Decompiler/ILAst/ILInlining.cs | 33 +++++++++++++---------
 1 file changed, 20 insertions(+), 13 deletions(-)

diff --git a/ICSharpCode.Decompiler/ILAst/ILInlining.cs b/ICSharpCode.Decompiler/ILAst/ILInlining.cs
index 647f035a7..78c2e54cd 100644
--- a/ICSharpCode.Decompiler/ILAst/ILInlining.cs
+++ b/ICSharpCode.Decompiler/ILAst/ILInlining.cs
@@ -169,7 +169,10 @@ namespace ICSharpCode.Decompiler.ILAst
 		bool InlineIfPossible(ILVariable v, ILExpression inlinedExpression, ILNode next, bool aggressive)
 		{
 			// ensure the variable is accessed only a single time
-			if (!(numStloc.GetOrDefault(v) == 1 && numLdloc.GetOrDefault(v) == 1 && numLdloca.GetOrDefault(v) == 0))
+			if (numStloc.GetOrDefault(v) != 1)
+				return false;
+			int ldloc = numLdloc.GetOrDefault(v);
+			if (ldloc > 1 || ldloc + numLdloca.GetOrDefault(v) != 1)
 				return false;
 			
 			if (next is ILCondition)
@@ -180,7 +183,12 @@ 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, inlinedExpression))
+				if (ldloc == 0)
+				{
+					if (!IsGeneratedValueTypeTemporary((ILExpression)next, parent, pos, v))
+						return false;
+				}
+				else if (!aggressive && !v.IsGenerated && !NonAggressiveInlineInto((ILExpression)next, parent, inlinedExpression))
 					return false;
 				
 				// Assign the ranges of the ldloc instruction:
@@ -192,6 +200,15 @@ namespace ICSharpCode.Decompiler.ILAst
 			}
 			return false;
 		}
+
+		/// <summary>
+		/// Is this a temporary variable generated by the C# compiler for instance method calls on immutable value type values
+		/// </summary>
+		bool IsGeneratedValueTypeTemporary(ILExpression next, ILExpression parent, int pos, ILVariable v)
+		{
+			return pos == 0 && v.Type != null && v.Type.IsValueType && next.Code == ILCode.Stloc
+				&& (parent.Code == ILCode.Call || parent.Code == ILCode.Callvirt) && ((MethodReference)parent.Operand).HasThis;
+		}
 		
 		bool NonAggressiveInlineInto(ILExpression next, ILExpression parent, ILExpression inlinedExpression)
 		{
@@ -214,16 +231,6 @@ namespace ICSharpCode.Decompiler.ILAst
 			}
 		}
 		
-		/// <summary>
-		/// Gets whether 'expressionBeingMoved' can be inlined into 'expr'.
-		/// </summary>
-		public bool CanInlineInto(ILExpression expr, ILVariable v, ILExpression expressionBeingMoved)
-		{
-			ILExpression parent;
-			int pos;
-			return FindLoadInNext(expr, v, expressionBeingMoved, out parent, out pos) == true;
-		}
-		
 		/// <summary>
 		/// Finds the position to inline to.
 		/// </summary>
@@ -242,7 +249,7 @@ namespace ICSharpCode.Decompiler.ILAst
 				
 				ILExpression arg = expr.Arguments[i];
 				
-				if (arg.Code == ILCode.Ldloc && arg.Operand == v) {
+				if ((arg.Code == ILCode.Ldloc || arg.Code == ILCode.Ldloca) && arg.Operand == v) {
 					parent = expr;
 					pos = i;
 					return true;

From 8c161e51cdd309833485077514cd7b0e7838154a Mon Sep 17 00:00:00 2001
From: pentp <kaalikas@gmail.com>
Date: Sun, 24 Apr 2011 00:32:47 +0300
Subject: [PATCH 2/2] fix changes

---
 ICSharpCode.Decompiler/ILAst/ILInlining.cs | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/ICSharpCode.Decompiler/ILAst/ILInlining.cs b/ICSharpCode.Decompiler/ILAst/ILInlining.cs
index 0b5d642df..ea88c3206 100644
--- a/ICSharpCode.Decompiler/ILAst/ILInlining.cs
+++ b/ICSharpCode.Decompiler/ILAst/ILInlining.cs
@@ -231,6 +231,16 @@ namespace ICSharpCode.Decompiler.ILAst
 					return false;
 			}
 		}
+
+		/// <summary>
+		/// Gets whether 'expressionBeingMoved' can be inlined into 'expr'.
+		/// </summary>
+		public bool CanInlineInto(ILExpression expr, ILVariable v, ILExpression expressionBeingMoved)
+		{
+			ILExpression parent;
+			int pos;
+			return FindLoadInNext(expr, v, expressionBeingMoved, out parent, out pos) == true;
+		}
 		
 		/// <summary>
 		/// Finds the position to inline to.