Simplify Lookup and improve compiler performance. (#2996)

* Simplify lookup.

* Various bug fixes.

* Report type dictionary size in perf benchmark.

* Remove type duplication.

* increase initial dict size.

* Bug fix.

* Fix bugs.

* Fixup.

* Revert type legalization looping.

* Fix specialization pass.

---------

Co-authored-by: Yong He <yhe@nvidia.com>

1 files changed, 12 insertions, 3 deletions

diff --git a/source/slang/slang-check-conformance.cpp b/source/slang/slang-check-conformance.cpp
index 0eb44399d..2696f798d 100644
--- a/source/slang/slang-check-conformance.cpp
+++ b/source/slang/slang-check-conformance.cpp
@@ -50,6 +50,18 @@ namespace Slang
     }
 
     SubtypeWitness* SemanticsVisitor::isSubtype(
+        Type* subType,
+        Type* superType)
+    {
+        SubtypeWitness* result = nullptr;
+        if (getShared()->tryGetSubtypeWitness(subType, superType, result))
+            return result;
+        result = checkAndConstructSubtypeWitness(subType, superType);
+        getShared()->cacheSubtypeWitness(subType, superType, result);
+        return result;
+    }
+
+    SubtypeWitness* SemanticsVisitor::checkAndConstructSubtypeWitness(
         Type*                   subType,
         Type*                   superType)
     {
@@ -92,9 +104,6 @@ namespace Slang
         // For now we are continuing to conflate all the subtype-ish relationships but not
         // tangling convertibility into it.
 
-        // TODO: Evaluate whether it is beneficial to memo-cache
-        // the results of subtype tests on the `SharedSemanticsContext`.
-
         // In the common case, we can use the pre-computed inheritance information for `subType`
         // to enumerate all the types it transitively inherits from.
         //