Rewrite for efficiency - partitioning into recursion domains

Find a more efficient algorithm to compose the list of recursion domains when compiling an Elm module. Following this change, we observed savings of circa 30 percent in the total number of performed instructions/invocations in the scenario compiling all Elm compiler modules.
pine-vm · Aug 2, 2024 · fb76785 · fb76785
1 parent 403611e
commit fb76785
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Showing 4 changed files with 39 additions and 61 deletions.
diff --git a/implement/Pine.Core/Pine.Core.csproj b/implement/Pine.Core/Pine.Core.csproj
@@ -3,13 +3,13 @@
   <PropertyGroup>
     <TargetFramework>net8.0</TargetFramework>
     <Nullable>enable</Nullable>
-    <AssemblyVersion>0.3.14</AssemblyVersion>
-    <FileVersion>0.3.14</FileVersion>
+    <AssemblyVersion>0.3.15</AssemblyVersion>
+    <FileVersion>0.3.15</FileVersion>
   </PropertyGroup>
 
   <PropertyGroup>
     <PackageId>Pine.Core</PackageId>
-    <Version>0.3.14</Version>
+    <Version>0.3.15</Version>
     <Description>The cross-platform Elm runtime environment</Description>
     <PackageTags>Functional;Elm;Runtime;Compiler;VM;DBMS</PackageTags>
     <RepositoryUrl>https://github.com/pine-vm/pine.git</RepositoryUrl>

diff --git a/implement/pine/ElmTime/compile-elm-program/src/FirCompiler.elm b/implement/pine/ElmTime/compile-elm-program/src/FirCompiler.elm
@@ -901,63 +901,41 @@ The first element in the list is a set of declarations that do not depend on any
 recursionDomainsFromDeclarationDependencies : List ( String, Set.Set String ) -> List (Set.Set String)
 recursionDomainsFromDeclarationDependencies declarationDependencies =
     let
-        integrateDecl ( declName, declDependencies ) recursionDomains =
-            let
-                -- Inserts the new domain into the list of domains at the position where the none of the following domains depend on it.
-                insertDomainRecursive :
-                    Set.Set String
-                    -> List (Set.Set String)
-                    -> List (Set.Set String)
-                    -> List (Set.Set String)
-                insertDomainRecursive domainToInsert skipped following =
-                    case following of
-                        [] ->
-                            skipped ++ [ domainToInsert ]
-
-                        next :: rest ->
-                            let
-                                allCurrentAndFollowing : Set.Set String
-                                allCurrentAndFollowing =
-                                    List.foldl Set.union next rest
-
-                                dependingOnAnyCurrentOrFollowing : Bool
-                                dependingOnAnyCurrentOrFollowing =
-                                    not (Set.isEmpty (Set.intersect declDependencies allCurrentAndFollowing))
-
-                                allDependenciesOfNext : Set.Set String
-                                allDependenciesOfNext =
-                                    Set.foldl
-                                        (\nextDeclName aggregate ->
-                                            case Common.assocListGet nextDeclName declarationDependencies of
-                                                Nothing ->
-                                                    aggregate
-
-                                                Just nextDeclDependencies ->
-                                                    Set.union nextDeclDependencies aggregate
-                                        )
-                                        Set.empty
-                                        next
-
-                                nextDependingOnNewDomain : Bool
-                                nextDependingOnNewDomain =
-                                    Set.member declName allDependenciesOfNext
-                            in
-                            if dependingOnAnyCurrentOrFollowing then
-                                if nextDependingOnNewDomain then
-                                    -- Merge the new domain into the current domain
-                                    List.concat
-                                        [ skipped, [ Set.union domainToInsert next ], rest ]
-
-                                else
-                                    insertDomainRecursive domainToInsert (skipped ++ [ next ]) rest
+        depsGroups : List (Set.Set String)
+        depsGroups =
+            List.map
+                (\( declName, declDependencies ) -> Set.insert declName declDependencies)
+                declarationDependencies
+
+        depsGroupsUniqueOrdered : List (Set.Set String)
+        depsGroupsUniqueOrdered =
+            List.sortBy Set.size (Common.listUnique depsGroups)
+
+        deriveDomainsRecursive :
+            Set.Set String
+            -> List (Set.Set String)
+            -> List (Set.Set String)
+            -> List (Set.Set String)
+        deriveDomainsRecursive covered groups domains =
+            case groups of
+                [] ->
+                    List.reverse domains
 
-                            else
-                                List.concat
-                                    [ skipped, [ domainToInsert ], following ]
-            in
-            insertDomainRecursive (Set.singleton declName) [] recursionDomains
+                nextGroup :: remainingGroups ->
+                    let
+                        domain : Set.Set String
+                        domain =
+                            Set.filter
+                                (\name -> not (Set.member name covered))
+                                nextGroup
+
+                        coveredNext : Set.Set String
+                        coveredNext =
+                            Set.union nextGroup covered
+                    in
+                    deriveDomainsRecursive coveredNext remainingGroups (domain :: domains)
     in
-    List.foldl integrateDecl [] declarationDependencies
+    deriveDomainsRecursive Set.empty depsGroupsUniqueOrdered []
 
 
 parseFunctionParameters : Expression -> DeclBlockFunctionEntry

diff --git a/implement/pine/Program.cs b/implement/pine/Program.cs
@@ -18,7 +18,7 @@ namespace ElmTime;
 
 public class Program
 {
-    public static string AppVersionId => "0.3.14";
+    public static string AppVersionId => "0.3.15";
 
     private static int AdminInterfaceDefaultPort => 4000;
 

diff --git a/implement/pine/pine.csproj b/implement/pine/pine.csproj
@@ -4,8 +4,8 @@
     <OutputType>Exe</OutputType>
     <TargetFramework>net8.0</TargetFramework>
     <AssemblyName>pine</AssemblyName>
-    <AssemblyVersion>0.3.14</AssemblyVersion>
-    <FileVersion>0.3.14</FileVersion>
+    <AssemblyVersion>0.3.15</AssemblyVersion>
+    <FileVersion>0.3.15</FileVersion>
     <Nullable>enable</Nullable>
     <GenerateEmbeddedFilesManifest>true</GenerateEmbeddedFilesManifest>
   </PropertyGroup>