Added chapter 8 docs (#59)

-Fixed chapter 7 to remove manual PHI nodes in conditional expressions.
- Prepared for chapter 9 docs

Author: smaillet

Samples/Kaleidoscope/Chapter6/CodeGenerator.cs

@@ -158,7 +158,7 @@ public override Value VisitConditionalExpression( [NotNull] ConditionalExpressio
 
             var thenBlock = Context.CreateBasicBlock( "then", function );
             var elseBlock = Context.CreateBasicBlock( "else" );
-            var phiMergeBlock = Context.CreateBasicBlock( "ifcont" );
+            var continueBlock = Context.CreateBasicBlock( "ifcont" );
             InstructionBuilder.Branch( condBool, thenBlock, elseBlock );
 
             // generate then block
@@ -169,7 +169,7 @@ public override Value VisitConditionalExpression( [NotNull] ConditionalExpressio
                 return null;
             }
 
-            InstructionBuilder.Branch( phiMergeBlock );
+            InstructionBuilder.Branch( continueBlock );
 
             // capture the insert in case generating else adds new blocks
             thenBlock = InstructionBuilder.InsertBlock;
@@ -183,12 +183,12 @@ public override Value VisitConditionalExpression( [NotNull] ConditionalExpressio
                 return null;
             }
 
-            InstructionBuilder.Branch( phiMergeBlock );
+            InstructionBuilder.Branch( continueBlock );
             elseBlock = InstructionBuilder.InsertBlock;
 
-            // generate PHI merge block
-            function.BasicBlocks.Add( phiMergeBlock );
-            InstructionBuilder.PositionAtEnd( phiMergeBlock );
+            // generate continue block
+            function.BasicBlocks.Add( continueBlock );
+            InstructionBuilder.PositionAtEnd( continueBlock );
             var phiNode = InstructionBuilder.PhiNode( function.Context.DoubleType )
                                             .RegisterName( "iftmp" );
 

Samples/Kaleidoscope/Chapter7/Chapter7.csproj

@@ -7,6 +7,12 @@
     <LangVersion>latest</LangVersion>
   </PropertyGroup>
 
+  <ItemGroup>
+    <None Include="fibi.kls">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </None>
+  </ItemGroup>
+
   <ItemGroup>
     <ProjectReference Include="$(BuildRootDir)src\Llvm.NET\Llvm.NET.csproj">
         <Name>Llvm.NET</Name>

Samples/Kaleidoscope/Chapter7/CodeGenerator.cs

@@ -170,6 +170,8 @@ public override Value VisitExpression( [NotNull] ExpressionContext context )
         // <VisitConditionalExpression>
         public override Value VisitConditionalExpression( [NotNull] ConditionalExpressionContext context )
         {
+            var result = CreateEntryBlockAlloca( InstructionBuilder.InsertBlock.ContainingFunction, "ifresult.alloca" );
+
             var condition = context.Condition.Accept( this );
             if( condition == null )
             {
@@ -183,7 +185,7 @@ public override Value VisitConditionalExpression( [NotNull] ConditionalExpressio
 
             var thenBlock = Context.CreateBasicBlock( "then", function );
             var elseBlock = Context.CreateBasicBlock( "else" );
-            var phiMergeBlock = Context.CreateBasicBlock( "ifcont" );
+            var continueBlock = Context.CreateBasicBlock( "ifcont" );
             InstructionBuilder.Branch( condBool, thenBlock, elseBlock );
 
             // generate then block
@@ -194,7 +196,8 @@ public override Value VisitConditionalExpression( [NotNull] ConditionalExpressio
                 return null;
             }
 
-            InstructionBuilder.Branch( phiMergeBlock );
+            InstructionBuilder.Store( thenValue, result );
+            InstructionBuilder.Branch( continueBlock );
 
             // capture the insert in case generating else adds new blocks
             thenBlock = InstructionBuilder.InsertBlock;
@@ -208,18 +211,15 @@ public override Value VisitConditionalExpression( [NotNull] ConditionalExpressio
                 return null;
             }
 
-            InstructionBuilder.Branch( phiMergeBlock );
+            InstructionBuilder.Store( elseValue, result );
+            InstructionBuilder.Branch( continueBlock );
             elseBlock = InstructionBuilder.InsertBlock;
 
-            // generate PHI merge block
-            function.BasicBlocks.Add( phiMergeBlock );
-            InstructionBuilder.PositionAtEnd( phiMergeBlock );
-            var phiNode = InstructionBuilder.PhiNode( function.Context.DoubleType )
-                                            .RegisterName( "iftmp" );
-
-            phiNode.AddIncoming( thenValue, thenBlock );
-            phiNode.AddIncoming( elseValue, elseBlock );
-            return phiNode;
+            // generate continue block
+            function.BasicBlocks.Add( continueBlock );
+            InstructionBuilder.PositionAtEnd( continueBlock );
+            return InstructionBuilder.Load( result )
+                                     .RegisterName("ifresult");
         }
         // </VisitConditionalExpression>
 

Samples/Kaleidoscope/Chapter8/Chapter8.csproj

@@ -6,7 +6,11 @@
     <RootNamespace>Kaleidoscope</RootNamespace>
     <LangVersion>latest</LangVersion>
   </PropertyGroup>
-
+  <ItemGroup>
+    <Content Include="..\mandel.kls" Link="mandel.kls">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </Content>
+  </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="$(BuildRootDir)src\Llvm.NET\Llvm.NET.csproj">
         <Name>Llvm.NET</Name>