Specialize generic retrieved from witness table

Author: gtong-nv

source/slang/slang-ir-specialize.cpp

@@ -880,7 +880,28 @@ struct SpecializationContext
         IRInst* satisfyingVal = nullptr;
 
         if (witnessTable)
-            satisfyingVal = findWitnessVal(witnessTable, requirementKey);
+        {
+            satisfyingVal = findWitnessTableEntry(witnessTable, requirementKey);
+            if (const auto genericEntry = as<IRGeneric>(satisfyingVal))
+            {
+                IRBuilder builder(module);
+                // Collect generic params.
+                List<IRInst*> genericParams;
+                for (auto param : genericEntry->getParams())
+                    genericParams.add(param);
+
+                auto specializedFuncType = builder.emitSpecializeInst(
+                    builder.getTypeKind(),
+                    genericEntry->getFullType(),
+                    (UInt)genericParams.getCount(),
+                    genericParams.getBuffer());
+                satisfyingVal = builder.emitSpecializeInst(
+                    (IRType*)specializedFuncType,
+                    genericEntry,
+                    (UInt)genericParams.getCount(),
+                    genericParams.getBuffer());
+            }
+        }
         else
         {
             // If we are specializing ThisTypeWitness, the result of the specialization
@@ -935,27 +956,6 @@ struct SpecializationContext
         return instChanged;
     }
 
-    // The above subroutine needed a way to look up
-    // the satisfying value for a given requirement
-    // key in a concrete witness table, so let's
-    // define that now.
-    //
-    IRInst* findWitnessVal(IRWitnessTable* witnessTable, IRInst* requirementKey)
-    {
-        // A witness table is basically just a container
-        // for key-value pairs, and so the best we can
-        // do for now is a naive linear search.
-        //
-        for (auto entry : witnessTable->getEntries())
-        {
-            if (requirementKey == entry->getRequirementKey())
-            {
-                return entry->getSatisfyingVal();
-            }
-        }
-        return nullptr;
-    }
-
     template<typename TDict>
     void _readSpecializationDictionaryImpl(TDict& dict, IRInst* dictInst)
     {

tests/language-feature/enums/nested-enum.slang

@@ -79,12 +79,12 @@ int testGeneric(int val)
 {
     OuterGeneric<int> outer;
     outer.value = val;
-    outer.channel = OuterGeneric<int>.Channel(val);
+    outer.channel = OuterGeneric<int>.Channel(val % 4);
     int result = 0;
     if (outer.channel == OuterGeneric<int>.Channel.Red) result += 1;
-    if (outer.channel == OuterGeneric<int>.Channel.Green) result += 16;
-    if (outer.channel == OuterGeneric<int>.Channel.Blue) result += 16*16;
-    if (outer.channel == OuterGeneric<int>.Channel.Alpha) result += 16*16*16;
+    if (outer.channel == OuterGeneric<int>.Channel.Green) result += 2;
+    if (outer.channel == OuterGeneric<int>.Channel.Blue) result += 3;
+    if (outer.channel == OuterGeneric<int>.Channel.Alpha) result += 4;
 
     return result;
 }

tests/language-feature/enums/nested-enum.slang.expected.txt

@@ -1,4 +1,4 @@
 1072
-1076
-1426
-4166
+1062
+1173
+74