Reduce CPU costs under AnalyzerExecutor.ExecuteSyntaxNodeActions

src/Compilers/CSharp/Portable/Emitter/EditAndContinue/PEDeltaAssemblyBuilder.cs

@@ -112,7 +112,7 @@ internal static EmitBaseline.MetadataSymbols GetOrCreateMetadataSymbols(EmitBase
         internal static SynthesizedTypeMaps GetSynthesizedTypesFromMetadata(MetadataReader reader, MetadataDecoder metadataDecoder)
         {
             var anonymousTypes = ImmutableSegmentedDictionary.CreateBuilder<AnonymousTypeKey, AnonymousTypeValue>();
-            var anonymousDelegatesWithIndexedNames = new Dictionary<AnonymousDelegateWithIndexedNamePartialKey, ArrayBuilder<AnonymousTypeValue>>();
+            var anonymousDelegatesWithIndexedNames = PooledDictionary<AnonymousDelegateWithIndexedNamePartialKey, ArrayBuilder<AnonymousTypeValue>>.GetInstance();
             var anonymousDelegates = ImmutableSegmentedDictionary.CreateBuilder<SynthesizedDelegateKey, SynthesizedDelegateValue>();
 
             foreach (var handle in reader.TypeDefinitions)

src/Compilers/Core/Portable/Collections/DictionaryExtensions.cs

@@ -76,7 +76,7 @@ public static bool TryAdd<TKey, TValue>(
         }
 #endif
 
-        public static void AddPooled<K, V>(this IDictionary<K, ArrayBuilder<V>> dictionary, K key, V value)
+        public static void AddPooled<K, V>(this Dictionary<K, ArrayBuilder<V>> dictionary, K key, V value)
             where K : notnull
         {
             if (!dictionary.TryGetValue(key, out var values))
@@ -88,15 +88,22 @@ public static void AddPooled<K, V>(this IDictionary<K, ArrayBuilder<V>> dictiona
             values.Add(value);
         }
 
-        public static ImmutableSegmentedDictionary<K, ImmutableArray<V>> ToImmutableSegmentedDictionaryAndFree<K, V>(this IReadOnlyDictionary<K, ArrayBuilder<V>> builder)
+        /// <summary>
+        /// Converts the passed in dictionary to an <see cref="ImmutableSegmentedDictionary{TKey, TValue}"/>, where all
+        /// the values in the passed builder will be converted to an <see cref="ImmutableArray{T}"/> using <see
+        /// cref="ArrayBuilder{T}.ToImmutableAndFree"/>.  The <paramref name="dictionary"/> will be freed at the end of
+        /// this method as well, and should not be used afterwards.
+        /// </summary>
+        public static ImmutableSegmentedDictionary<K, ImmutableArray<V>> ToImmutableSegmentedDictionaryAndFree<K, V>(this PooledDictionary<K, ArrayBuilder<V>> dictionary)
             where K : notnull
         {
             var result = ImmutableSegmentedDictionary.CreateBuilder<K, ImmutableArray<V>>();
-            foreach (var (key, values) in builder)
+            foreach (var (key, values) in dictionary)
             {
                 result.Add(key, values.ToImmutableAndFree());
             }
 
+            dictionary.Free();
             return result.ToImmutable();
         }
     }

src/Compilers/Core/Portable/DiagnosticAnalyzer/AnalyzerDriver.GroupedAnalyzerActions.cs

@@ -5,6 +5,7 @@
 using System.Collections.Immutable;
 using System.Diagnostics;
 using System.Linq;
+using Microsoft.CodeAnalysis.Collections;
 using Microsoft.CodeAnalysis.PooledObjects;
 using Roslyn.Utilities;
 
@@ -17,16 +18,25 @@ internal partial class AnalyzerDriver<TLanguageKindEnum> : AnalyzerDriver where
         /// </summary>
         private sealed class GroupedAnalyzerActions : IGroupedAnalyzerActions
         {
-            public static readonly GroupedAnalyzerActions Empty = new GroupedAnalyzerActions(ImmutableArray<(DiagnosticAnalyzer, GroupedAnalyzerActionsForAnalyzer)>.Empty, AnalyzerActions.Empty);
+            public static readonly GroupedAnalyzerActions Empty = new GroupedAnalyzerActions(
+                ImmutableArray<(DiagnosticAnalyzer, GroupedAnalyzerActionsForAnalyzer)>.Empty,
+                ImmutableSegmentedDictionary<TLanguageKindEnum, ImmutableArray<DiagnosticAnalyzer>>.Empty,
+                AnalyzerActions.Empty);
 
-            private GroupedAnalyzerActions(ImmutableArray<(DiagnosticAnalyzer, GroupedAnalyzerActionsForAnalyzer)> groupedActionsAndAnalyzers, in AnalyzerActions analyzerActions)
+            private GroupedAnalyzerActions(
+                ImmutableArray<(DiagnosticAnalyzer, GroupedAnalyzerActionsForAnalyzer)> groupedActionsAndAnalyzers,
+                ImmutableSegmentedDictionary<TLanguageKindEnum, ImmutableArray<DiagnosticAnalyzer>> analyzersByKind,
+                in AnalyzerActions analyzerActions)
             {
                 GroupedActionsByAnalyzer = groupedActionsAndAnalyzers;
                 AnalyzerActions = analyzerActions;
+                AnalyzersByKind = analyzersByKind;
             }
 
             public ImmutableArray<(DiagnosticAnalyzer analyzer, GroupedAnalyzerActionsForAnalyzer groupedActions)> GroupedActionsByAnalyzer { get; }
 
+            public ImmutableSegmentedDictionary<TLanguageKindEnum, ImmutableArray<DiagnosticAnalyzer>> AnalyzersByKind { get; }
+
             public AnalyzerActions AnalyzerActions { get; }
 
             public bool IsEmpty
@@ -48,7 +58,8 @@ public static GroupedAnalyzerActions Create(DiagnosticAnalyzer analyzer, in Anal
 
                 var groupedActions = new GroupedAnalyzerActionsForAnalyzer(analyzer, analyzerActions, analyzerActionsNeedFiltering: false);
                 var groupedActionsAndAnalyzers = ImmutableArray<(DiagnosticAnalyzer, GroupedAnalyzerActionsForAnalyzer)>.Empty.Add((analyzer, groupedActions));
-                return new GroupedAnalyzerActions(groupedActionsAndAnalyzers, in analyzerActions);
+                var analyzersByKind = CreateAnalyzersByKind(groupedActionsAndAnalyzers);
+                return new GroupedAnalyzerActions(groupedActionsAndAnalyzers, analyzersByKind, in analyzerActions);
             }
 
             public static GroupedAnalyzerActions Create(ImmutableArray<DiagnosticAnalyzer> analyzers, in AnalyzerActions analyzerActions)
@@ -58,7 +69,8 @@ public static GroupedAnalyzerActions Create(ImmutableArray<DiagnosticAnalyzer> a
                 var groups = analyzers.SelectAsArray(
                     (analyzer, analyzerActions) => (analyzer, new GroupedAnalyzerActionsForAnalyzer(analyzer, analyzerActions, analyzerActionsNeedFiltering: true)),
                     analyzerActions);
-                return new GroupedAnalyzerActions(groups, in analyzerActions);
+                var analyzersByKind = CreateAnalyzersByKind(groups);
+                return new GroupedAnalyzerActions(groups, analyzersByKind, in analyzerActions);
             }
 
             IGroupedAnalyzerActions IGroupedAnalyzerActions.Append(IGroupedAnalyzerActions igroupedAnalyzerActions)
@@ -74,7 +86,22 @@ IGroupedAnalyzerActions IGroupedAnalyzerActions.Append(IGroupedAnalyzerActions i
 
                 var newGroupedActions = GroupedActionsByAnalyzer.AddRange(groupedAnalyzerActions.GroupedActionsByAnalyzer);
                 var newAnalyzerActions = AnalyzerActions.Append(groupedAnalyzerActions.AnalyzerActions);
-                return new GroupedAnalyzerActions(newGroupedActions, newAnalyzerActions);
+                var analyzersByKind = CreateAnalyzersByKind(newGroupedActions);
+                return new GroupedAnalyzerActions(newGroupedActions, analyzersByKind, newAnalyzerActions);
+            }
+
+            private static ImmutableSegmentedDictionary<TLanguageKindEnum, ImmutableArray<DiagnosticAnalyzer>> CreateAnalyzersByKind(ImmutableArray<(DiagnosticAnalyzer, GroupedAnalyzerActionsForAnalyzer)> groupedActionsAndAnalyzers)
+            {
+                var analyzersByKind = PooledDictionary<TLanguageKindEnum, ArrayBuilder<DiagnosticAnalyzer>>.GetInstance();
+                foreach (var (analyzer, groupedActionsForAnalyzer) in groupedActionsAndAnalyzers)
+                {
+                    foreach (var (kind, _) in groupedActionsForAnalyzer.NodeActionsByAnalyzerAndKind)
+                    {
+                        analyzersByKind.AddPooled(kind, analyzer);
+                    }
+                }
+
+                return analyzersByKind.ToImmutableSegmentedDictionaryAndFree();
             }
         }
     }

src/Compilers/Core/Portable/DiagnosticAnalyzer/AnalyzerDriver.cs

@@ -2611,10 +2611,26 @@ void executeNodeActions()
 
             void executeNodeActionsByKind(ArrayBuilder<SyntaxNode> nodesToAnalyze, GroupedAnalyzerActions groupedActions, bool arePerSymbolActions)
             {
+                if (groupedActions.GroupedActionsByAnalyzer.Length == 0)
+                {
+                    return;
+                }
+
+                var analyzersForNodes = PooledHashSet<DiagnosticAnalyzer>.GetInstance();
+                foreach (var node in nodesToAnalyze)
+                {
+                    if (groupedActions.AnalyzersByKind.TryGetValue(_getKind(node), out var analyzersForKind))
+                    {
+                        foreach (var analyzer in analyzersForKind)
+                        {
+                            analyzersForNodes.Add(analyzer);
+                        }
+                    }
+                }
+
                 foreach (var (analyzer, groupedActionsForAnalyzer) in groupedActions.GroupedActionsByAnalyzer)
                 {
-                    var nodeActionsByKind = groupedActionsForAnalyzer.NodeActionsByAnalyzerAndKind;
-                    if (nodeActionsByKind.IsEmpty || !analysisScope.Contains(analyzer))
+                    if (!analyzersForNodes.Contains(analyzer) || !analysisScope.Contains(analyzer))
                     {
                         continue;
                     }
@@ -2642,6 +2658,8 @@ void executeNodeActionsByKind(ArrayBuilder<SyntaxNode> nodesToAnalyze, GroupedAn
                     }
                 }
 
+                analyzersForNodes.Free();
+
                 void executeSyntaxNodeActions(
                     DiagnosticAnalyzer analyzer,
                     GroupedAnalyzerActionsForAnalyzer groupedActionsForAnalyzer,

src/Compilers/Core/Portable/DiagnosticAnalyzer/AnalyzerExecutor.cs

@@ -932,19 +932,11 @@ internal static ImmutableSegmentedDictionary<TLanguageKindEnum, ImmutableArray<S
             {
                 foreach (var kind in nodeAction.Kinds)
                 {
-                    if (!nodeActionsByKind.TryGetValue(kind, out var actionsForKind))
-                    {
-                        nodeActionsByKind.Add(kind, actionsForKind = ArrayBuilder<SyntaxNodeAnalyzerAction<TLanguageKindEnum>>.GetInstance());
-                    }
-
-                    actionsForKind.Add(nodeAction);
+                    nodeActionsByKind.AddPooled(kind, nodeAction);
                 }
             }
 
-            var tuples = nodeActionsByKind.Select(kvp => KeyValuePairUtil.Create(kvp.Key, kvp.Value.ToImmutableAndFree()));
-            var map = ImmutableSegmentedDictionary.CreateRange(tuples);
-            nodeActionsByKind.Free();
-            return map;
+            return nodeActionsByKind.ToImmutableSegmentedDictionaryAndFree();
         }
 
         /// <summary>
@@ -1031,19 +1023,11 @@ internal static ImmutableSegmentedDictionary<OperationKind, ImmutableArray<Opera
             {
                 foreach (var kind in operationAction.Kinds)
                 {
-                    if (!operationActionsByKind.TryGetValue(kind, out var actionsForKind))
-                    {
-                        operationActionsByKind.Add(kind, actionsForKind = ArrayBuilder<OperationAnalyzerAction>.GetInstance());
-                    }
-
-                    actionsForKind.Add(operationAction);
+                    operationActionsByKind.AddPooled(kind, operationAction);
                 }
             }
 
-            var tuples = operationActionsByKind.Select(kvp => KeyValuePairUtil.Create(kvp.Key, kvp.Value.ToImmutableAndFree()));
-            var map = ImmutableSegmentedDictionary.CreateRange(tuples);
-            operationActionsByKind.Free();
-            return map;
+            return operationActionsByKind.ToImmutableSegmentedDictionaryAndFree();
         }
 
         /// <summary>