Improve lookup performance. (#7798)

* Improve lookup performance.

* Cleanup.

* Improve autocompletion latency.

1 files changed, 27 insertions, 19 deletions

diff --git a/source/slang/slang-lookup.cpp b/source/slang/slang-lookup.cpp
index a9b472776..0fd66abc3 100644
--- a/source/slang/slang-lookup.cpp
+++ b/source/slang/slang-lookup.cpp
@@ -357,6 +357,32 @@ static Type* _maybeSpecializeSuperType(
     return superType;
 }
 
+void FacetImpl::init(ASTBuilder* astBuilder)
+{
+    if (directness != Facet::Directness::Self)
+    {
+        // Depending on the type of the facet, we may want to specialize the
+        // declRef that we are going to lookup in. If the facet represents
+        // an extension, we should just lookup in the extension decl.
+        //
+        // If the facet is an extension to an interface type, we should
+        // specialize the interface declRef to the concrete type that this
+        // extension applied to.
+        //
+        // If the facet represents an implementation of interface type,
+        // we should also specialize the interface declRef with the concrete
+        // type info.
+        //
+        declRefForMemberLookup =
+            _maybeSpecializeSuperTypeDeclRef(astBuilder, origin.declRef, getType(), subtypeWitness)
+                .as<ContainerDecl>();
+    }
+    else
+    {
+        declRefForMemberLookup = origin.declRef.as<ContainerDecl>();
+    }
+}
+
 static void _lookUpMembersInType(
     ASTBuilder* astBuilder,
     Name* name,
@@ -490,27 +516,9 @@ static void _lookupMembersInSuperTypeFacets(
 
         BreadcrumbInfo* newBreadcrumbs = inBreadcrumbs;
         BreadcrumbInfo subtypeInfo;
-        auto parentDeclRef = containerDeclRef;
+        auto parentDeclRef = facet->declRefForMemberLookup;
         if (facet->directness != Facet::Directness::Self)
         {
-            // Depending on the type of the facet, we may want to specialize the
-            // declRef that we are going to lookup in. If the facet represents
-            // an extension, we should just lookup in the extension decl.
-            //
-            // If the facet is an extension to an interface type, we should
-            // specialize the interface declRef to the concrete type that this
-            // extension applied to.
-            //
-            // If the facet represents an implementation of interface type,
-            // we should also specialize the interface declRef with the concrete
-            // type info.
-            //
-            parentDeclRef = _maybeSpecializeSuperTypeDeclRef(
-                                astBuilder,
-                                containerDeclRef,
-                                facet->getType(),
-                                facet->subtypeWitness)
-                                .as<ContainerDecl>();
             if (as<ThisTypeDecl>(parentDeclRef.getDecl()) && getText(name) == "This")
             {
                 // If we are going looking for `This` in a `ThisType`, we just need to return the