diff --git a/runtime-testsuite/resources/org/antlr/v4/test/runtime/templates/CSharp.test.stg b/runtime-testsuite/resources/org/antlr/v4/test/runtime/templates/CSharp.test.stg
index 473398ad2..aac1b8186 100644
--- a/runtime-testsuite/resources/org/antlr/v4/test/runtime/templates/CSharp.test.stg
+++ b/runtime-testsuite/resources/org/antlr/v4/test/runtime/templates/CSharp.test.stg
@@ -64,9 +64,9 @@ PlusText(a) ::= <%"<a>" + this.Text%>
 
 InputText() ::= "this.TokenStream.GetText()"
 
-LTEquals(i, v) ::= <%this.TokenStream.Lt(<i>).Text.Equals(<v>)%>
+LTEquals(i, v) ::= <%this.TokenStream.LT(<i>).Text.Equals(<v>)%>
 
-LANotEquals(i, v) ::= <%this.InputStream.La(<i>)!=<v>%>
+LANotEquals(i, v) ::= <%this.InputStream.LA(<i>)!=<v>%>
 
 TokenStartColumnEquals(i) ::= <%this.TokenStartColumn==<i>%>
 
diff --git a/runtime-testsuite/test/org/antlr/v4/test/runtime/csharp/BaseCSharpTest.java b/runtime-testsuite/test/org/antlr/v4/test/runtime/csharp/BaseCSharpTest.java
index 734223522..ded2c9904 100644
--- a/runtime-testsuite/test/org/antlr/v4/test/runtime/csharp/BaseCSharpTest.java
+++ b/runtime-testsuite/test/org/antlr/v4/test/runtime/csharp/BaseCSharpTest.java
@@ -691,7 +691,7 @@ public class BaseCSharpTest implements RuntimeTestSupport, SpecialRuntimeTestAss
 				"        tokens.Fill();\n" +
 				"        foreach (object t in tokens.GetTokens())\n" +
 				"			Console.WriteLine(t);\n" +
-				(showDFA?"Console.Write(lex.Interpreter.GetDFA(Lexer.DefaultMode).ToLexerString());\n":"")+
+				(showDFA?"        Console.Write(lex.Interpreter.GetDFA(Lexer.DEFAULT_MODE).ToLexerString());\n":"")+
 				"    }\n" +
 				"}"
 		);
diff --git a/runtime/CSharp/runtime/CSharp/Antlr4.Runtime/Atn/ParserATNSimulator.cs b/runtime/CSharp/runtime/CSharp/Antlr4.Runtime/Atn/ParserATNSimulator.cs
index ab4522ca7..83cf7ffce 100644
--- a/runtime/CSharp/runtime/CSharp/Antlr4.Runtime/Atn/ParserATNSimulator.cs
+++ b/runtime/CSharp/runtime/CSharp/Antlr4.Runtime/Atn/ParserATNSimulator.cs
@@ -1275,7 +1275,7 @@ namespace Antlr4.Runtime.Atn
 			{
 				if (ambigAlts[c.alt])
 				{
-					altToPred[c.alt] = new SemanticContext.OR(altToPred[c.alt], c.semanticContext);
+					altToPred[c.alt] = SemanticContext.Or(altToPred[c.alt], c.semanticContext);
 				}
 			}
 
@@ -1960,8 +1960,7 @@ namespace Antlr4.Runtime.Atn
 					}
 				}
 				else {
-					SemanticContext newSemCtx =
-						new SemanticContext.AND(config.semanticContext, pt.Predicate);
+					SemanticContext newSemCtx = SemanticContext.And(config.semanticContext, pt.Predicate);
 					c = new ATNConfig(config, pt.target, newSemCtx);
 				}
 			}
@@ -2012,8 +2011,7 @@ namespace Antlr4.Runtime.Atn
 					}
 				}
 				else {
-					SemanticContext newSemCtx =
-						new SemanticContext.AND(config.semanticContext, pt.Predicate);
+					SemanticContext newSemCtx = SemanticContext.And(config.semanticContext, pt.Predicate);
 					c = new ATNConfig(config, pt.target, newSemCtx);
 				}
 			}
diff --git a/runtime/CSharp/runtime/CSharp/Antlr4.Runtime/Atn/SemanticContext.cs b/runtime/CSharp/runtime/CSharp/Antlr4.Runtime/Atn/SemanticContext.cs
index 95a715f26..2c03a6737 100644
--- a/runtime/CSharp/runtime/CSharp/Antlr4.Runtime/Atn/SemanticContext.cs
+++ b/runtime/CSharp/runtime/CSharp/Antlr4.Runtime/Atn/SemanticContext.cs
@@ -399,7 +399,7 @@ namespace Antlr4.Runtime.Atn
                 SemanticContext result = operands[0];
                 for (int i = 1; i < operands.Count; i++)
                 {
-                    result = SemanticContext.AndOp(result, operands[i]);
+                    result = SemanticContext.And(result, operands[i]);
                 }
                 return result;
             }
@@ -531,7 +531,7 @@ namespace Antlr4.Runtime.Atn
                 SemanticContext result = operands[0];
                 for (int i = 1; i < operands.Count; i++)
                 {
-                    result = SemanticContext.OrOp(result, operands[i]);
+                    result = SemanticContext.Or(result, operands[i]);
                 }
                 return result;
             }
@@ -542,7 +542,7 @@ namespace Antlr4.Runtime.Atn
             }
         }
 
-        public static SemanticContext AndOp(SemanticContext a, SemanticContext b)
+        public static SemanticContext And(SemanticContext a, SemanticContext b)
         {
             if (a == null || a == NONE)
             {
@@ -561,7 +561,7 @@ namespace Antlr4.Runtime.Atn
         }
 
         /// <seealso cref="ParserATNSimulator.GetPredsForAmbigAlts(Antlr4.Runtime.Sharpen.BitSet, ATNConfigSet, int)"/>
-        public static SemanticContext OrOp(SemanticContext a, SemanticContext b)
+        public static SemanticContext Or(SemanticContext a, SemanticContext b)
         {
             if (a == null)
             {
diff --git a/runtime/CSharp/runtime/CSharp/Antlr4.Runtime/Dfa/DFA.cs b/runtime/CSharp/runtime/CSharp/Antlr4.Runtime/Dfa/DFA.cs
index c691c434c..b29f15732 100644
--- a/runtime/CSharp/runtime/CSharp/Antlr4.Runtime/Dfa/DFA.cs
+++ b/runtime/CSharp/runtime/CSharp/Antlr4.Runtime/Dfa/DFA.cs
@@ -189,9 +189,10 @@ namespace Antlr4.Runtime.Dfa
 			return serializer.ToString();
 		}
 
-		public String toLexerString()
+		public String ToLexerString()
 		{
-			if (s0 == null) return "";
+			if (s0 == null) 
+				return "";
 			DFASerializer serializer = new LexerDFASerializer(this);
 			return serializer.ToString();
 		}
diff --git a/runtime/CSharp/runtime/CSharp/Antlr4.Runtime/Dfa/DFASerializer.cs b/runtime/CSharp/runtime/CSharp/Antlr4.Runtime/Dfa/DFASerializer.cs
index bf6480ec2..5633d531b 100644
--- a/runtime/CSharp/runtime/CSharp/Antlr4.Runtime/Dfa/DFASerializer.cs
+++ b/runtime/CSharp/runtime/CSharp/Antlr4.Runtime/Dfa/DFASerializer.cs
@@ -82,35 +82,35 @@ namespace Antlr4.Runtime.Dfa
             if (dfa.states != null)
             {
                 List<DFAState> states = new List<DFAState>(dfa.states.Values);
-                states.Sort(new _IComparer_103());
+				states.Sort((x,y)=>x.stateNumber - y.stateNumber);
                 foreach (DFAState s in states)
                 {
-                    foreach (DFAState edge in s.edges)
-                    {
-                        buf.Append(GetStateString(s));
-                    }
-                }
+					int n = s.edges != null ? s.edges.Length : 0;
+					for (int i = 0; i < n; i++)
+					{
+						DFAState t = s.edges[i];
+						if (t != null && t.stateNumber != int.MaxValue)
+						{
+							buf.Append(GetStateString(s));
+							String label = GetEdgeLabel(i);
+							buf.Append("-");
+							buf.Append(label);
+							buf.Append("->");
+							buf.Append(GetStateString(t));
+							buf.Append('\n');
+						}
+					}
+	            }
             }
             string output = buf.ToString();
             if (output.Length == 0)
             {
                 return null;
             }
-            //return Utils.sortLinesInString(output);
             return output;
         }
 
-        private sealed class _IComparer_103 : IComparer<DFAState>
-        {
-            public _IComparer_103()
-            {
-            }
 
-            public int Compare(DFAState o1, DFAState o2)
-            {
-                return o1.stateNumber - o2.stateNumber;
-            }
-        }
 
         protected internal virtual string GetContextLabel(int i)
         {
diff --git a/tool/resources/org/antlr/v4/tool/templates/codegen/CSharp/CSharp.stg b/tool/resources/org/antlr/v4/tool/templates/codegen/CSharp/CSharp.stg
index 4aae5ab67..3fe028749 100644
--- a/tool/resources/org/antlr/v4/tool/templates/codegen/CSharp/CSharp.stg
+++ b/tool/resources/org/antlr/v4/tool/templates/codegen/CSharp/CSharp.stg
@@ -269,6 +269,8 @@ Parser_(parser, funcs, atn, sempredFuncs, ctor, superClass) ::= <<
 [System.CodeDom.Compiler.GeneratedCode("ANTLR", "<file.ANTLRVersion>")]
 [System.CLSCompliant(false)]
 public partial class <csIdentifier.(parser.name)> : <superClass; null="Parser"> {
+	protected static DFA[] decisionToDFA;
+	protected static PredictionContextCache sharedContextCache = new PredictionContextCache();
 	<if(parser.tokens)>
 	public const int
 		<parser.tokens:{k | <k>=<parser.tokens.(k)>}; separator=", ", wrap, anchor>;
@@ -287,6 +289,13 @@ public partial class <csIdentifier.(parser.name)> : <superClass; null="Parser">
 
 	public override string SerializedAtn { get { return _serializedATN; } }
 
+	static <csIdentifier.(parser.name)>() {
+		decisionToDFA = new DFA[_ATN.NumberOfDecisions];
+		for (int i = 0; i \< _ATN.NumberOfDecisions; i++) {
+			decisionToDFA[i] = new DFA(_ATN.GetDecisionState(i), i);
+		}
+	}
+
 	<namedActions.members>
 	<parser:(ctor)()>
 	<funcs; separator="\n">
@@ -351,7 +360,7 @@ parser_ctor(parser) ::= <<
 public <csIdentifier.(parser.name)>(ITokenStream input)
 	: base(input)
 {
-	Interpreter = new ParserATNSimulator(this,_ATN);
+	Interpreter = new ParserATNSimulator(this, _ATN, decisionToDFA, sharedContextCache);
 }
 >>
 
@@ -538,9 +547,9 @@ CodeBlockForAlt(currentAltCodeBlock, locals, preamble, ops) ::= <<
 LL1AltBlock(choice, preamble, alts, error) ::= <<
 State = <choice.stateNumber>;
 ErrorHandler.Sync(this);
-<if(choice.label)><labelref(choice.label)> = TokenStream.Lt(1);<endif>
+<if(choice.label)><labelref(choice.label)> = TokenStream.LT(1);<endif>
 <preamble; separator="\n">
-switch (TokenStream.La(1)) {
+switch (TokenStream.LA(1)) {
 <choice.altLook,alts:{look,alt| <cases(ttypes=look)>
 	<alt>
 	break;}; separator="\n">
@@ -552,7 +561,7 @@ default:
 LL1OptionalBlock(choice, alts, error) ::= <<
 State = <choice.stateNumber>;
 ErrorHandler.Sync(this);
-switch (TokenStream.La(1)) {
+switch (TokenStream.LA(1)) {
 <choice.altLook,alts:{look,alt| <cases(ttypes=look)>
 	<alt>
 	break;}; separator="\n">
@@ -600,7 +609,7 @@ do {
 AltBlock(choice, preamble, alts, error) ::= <<
 State = <choice.stateNumber>;
 ErrorHandler.Sync(this);
-<if(choice.label)><labelref(choice.label)> = TokenStream.Lt(1);<endif>
+<if(choice.label)><labelref(choice.label)> = TokenStream.LT(1);<endif>
 <preamble; separator="\n">
 switch ( Interpreter.AdaptivePredict(TokenStream,<choice.decision>,Context) ) {
 <alts:{alt |
@@ -625,7 +634,7 @@ StarBlock(choice, alts, sync, iteration) ::= <<
 State = <choice.stateNumber>;
 ErrorHandler.Sync(this);
 _alt = Interpreter.AdaptivePredict(TokenStream,<choice.decision>,Context);
-while ( _alt!=<choice.exitAlt> && _alt!=global::Antlr4.Runtime.Atn.ATN.InvalidAltNumber ) {
+while ( _alt!=<choice.exitAlt> && _alt!=global::Antlr4.Runtime.Atn.ATN.INVALID_ALT_NUMBER ) {
 	if ( _alt==1<if(!choice.ast.greedy)>+1<endif> ) {
 		<iteration>
 		<alts> <! should only be one !>
@@ -652,7 +661,7 @@ case <i><if(!choice.ast.greedy)>+1<endif>:
 	State = <choice.loopBackStateNumber>;<! loopback/exit decision !>
 	ErrorHandler.Sync(this);
 	_alt = Interpreter.AdaptivePredict(TokenStream,<choice.decision>,Context);
-} while ( _alt!=<choice.exitAlt> && _alt!=global::Antlr4.Runtime.Atn.ATN.InvalidAltNumber );
+} while ( _alt!=<choice.exitAlt> && _alt!=global::Antlr4.Runtime.Atn.ATN.INVALID_ALT_NUMBER );
 >>
 
 Sync(s) ::= "Sync(<s.expecting.name>);"
@@ -705,7 +714,7 @@ MatchNotSet(m, expr, capture) ::= "<CommonSetStuff(m, expr, capture, true)>"
 
 CommonSetStuff(m, expr, capture, invert) ::= <<
 State = <m.stateNumber>;
-<if(m.labels)><m.labels:{l | <labelref(l)> = }>TokenStream.Lt(1);<endif>
+<if(m.labels)><m.labels:{l | <labelref(l)> = }>TokenStream.LT(1);<endif>
 <capture>
 if ( <if(invert)><m.varName> \<= 0 || <else>!<endif>(<expr>) ) {
 	<if(m.labels)><m.labels:{l | <labelref(l)> = }><endif>ErrorHandler.RecoverInline(this);
@@ -779,7 +788,7 @@ RulePropertyRef_parser(r)	 ::= "this"
 
 ThisRulePropertyRef_start(r) ::= "_localctx.Start"
 ThisRulePropertyRef_stop(r)	 ::= "_localctx.Stop"
-ThisRulePropertyRef_text(r)	 ::= "TokenStream.GetText(_localctx.Start, TokenStream.Lt(-1))"
+ThisRulePropertyRef_text(r)	 ::= "TokenStream.GetText(_localctx.Start, TokenStream.LT(-1))"
 ThisRulePropertyRef_ctx(r)	 ::= "_localctx"
 ThisRulePropertyRef_parser(r)	 ::= "this"
 
@@ -837,8 +846,8 @@ ImplicitRuleLabel(ruleName)	  ::= "_<ruleName>"
 ImplicitSetLabel(id)		  ::= "_tset<id>"
 ListLabelName(label)		  ::= "_<label>"
 
-CaptureNextToken(d) ::= "<d.varName> = TokenStream.Lt(1);"
-CaptureNextTokenType(d) ::= "<d.varName> = TokenStream.La(1);"
+CaptureNextToken(d) ::= "<d.varName> = TokenStream.LT(1);"
+CaptureNextTokenType(d) ::= "<d.varName> = TokenStream.LA(1);"
 
 StructDecl(struct,ctorAttrs,attrs,getters,dispatchMethods,interfaces,extensionMembers,
            superClass={ParserRuleContext}) ::= <<
@@ -902,7 +911,7 @@ typedContext(ctx) ::= "<if(ctx.provideCopyFrom)>((<ctx.name>)_localctx)<else>_lo
 // used for left-recursive rules
 recRuleAltPredicate(ruleName,opPrec)  ::= "Precpred(Context, <opPrec>)"
 recRuleSetReturnAction(src,name)	  ::= "$<name>=$<src>.<name>;"
-recRuleSetStopToken()                 ::= "Context.Stop = TokenStream.Lt(-1);"
+recRuleSetStopToken()                 ::= "Context.Stop = TokenStream.LT(-1);"
 
 recRuleAltStartAction(ruleName, ctxName, label, isListLabel) ::= <<
 _localctx = new <ctxName>Context(_parentctx, _parentState);