Remove interfaceType operand from lookup_witness_method inst

7 files changed, 27 insertions, 29 deletions

diff --git a/source/slang/slang-emit-cpp.cpp b/source/slang/slang-emit-cpp.cpp
index a449a2c56..f895b1119 100644
--- a/source/slang/slang-emit-cpp.cpp
+++ b/source/slang/slang-emit-cpp.cpp
@@ -1790,9 +1790,9 @@ void CPPSourceEmitter::_maybeEmitWitnessTableTypeDefinition(
             }
             m_writer->emit(");\n");
         }
-        else if (auto constraintInterfaceType = as<IRInterfaceType>(entry->getRequirementVal()))
+        else if (auto witnessTableType = as<IRWitnessTableType>(entry->getRequirementVal()))
         {
-            emitType(constraintInterfaceType);
+            emitType((IRType*)witnessTableType->getConformanceType());
             m_writer->emit("* ");
             m_writer->emit(getName(entry->getRequirementKey()));
             m_writer->emit(";\n");
diff --git a/source/slang/slang-ir-inst-defs.h b/source/slang/slang-ir-inst-defs.h
index c4fd6edf8..94c29371a 100644
--- a/source/slang/slang-ir-inst-defs.h
+++ b/source/slang/slang-ir-inst-defs.h
@@ -173,7 +173,7 @@ INST(AssociatedType, associated_type, 0, 0)
 INST(TypeType, type_t, 0, 0)
 
 // An `IRWitnessTable` has type `WitnessTableType`.
-INST(WitnessTableType, witness_table_t, 0, 0)
+INST(WitnessTableType, witness_table_t, 1, 0)
 
 INST_RANGE(Type, VoidType, WitnessTableType)
 
diff --git a/source/slang/slang-ir-insts.h b/source/slang/slang-ir-insts.h
index 5d467085e..fcefa8b26 100644
--- a/source/slang/slang-ir-insts.h
+++ b/source/slang/slang-ir-insts.h
@@ -408,11 +408,9 @@ struct IRLookupWitnessMethod : IRInst
 {
     IRUse witnessTable;
     IRUse requirementKey;
-    IRUse interfaceType;
 
     IRInst* getWitnessTable() { return witnessTable.get(); }
     IRInst* getRequirementKey() { return requirementKey.get(); }
-    IRInst* getInterfaceType() { return interfaceType.get(); }
 
     IR_LEAF_ISA(lookup_interface_method)
 };
@@ -1680,8 +1678,7 @@ struct IRBuilder
     IRInst* emitLookupInterfaceMethodInst(
         IRType* type,
         IRInst* witnessTableVal,
-        IRInst* interfaceMethodVal,
-        IRType* interfaceType);
+        IRInst* interfaceMethodVal);
 
     IRInst* emitCallInst(
         IRType*         type,
@@ -1806,7 +1803,7 @@ struct IRBuilder
         IRType* valueType);
     IRGlobalParam* createGlobalParam(
         IRType* valueType);
-
+    
     /// Creates an IRWitnessTable value.
     /// @param baseType: The comformant-to type of this witness.
     IRWitnessTable* createWitnessTable(IRType* baseType);
diff --git a/source/slang/slang-ir-lower-generics.cpp b/source/slang/slang-ir-lower-generics.cpp
index 4b1b267f9..c374f45fa 100644
--- a/source/slang/slang-ir-lower-generics.cpp
+++ b/source/slang/slang-ir-lower-generics.cpp
@@ -224,7 +224,8 @@ namespace Slang
                         // The callee is a result of witness table lookup, we will only
                         // translate the call.
                         IRInst* callee = nullptr;
-                        auto interfaceType = maybeLowerInterfaceType(cast<IRInterfaceType>(interfaceLookup->getInterfaceType()));
+                        auto witnessTableType = cast<IRWitnessTableType>(interfaceLookup->getWitnessTable()->getFullType());
+                        auto interfaceType = maybeLowerInterfaceType(cast<IRInterfaceType>(witnessTableType->getConformanceType()));
                         for (UInt i = 0; i < interfaceType->getOperandCount(); i++)
                         {
                             auto entry = cast<IRInterfaceRequirementEntry>(interfaceType->getOperand(i));
diff --git a/source/slang/slang-ir.cpp b/source/slang/slang-ir.cpp
index 07cb957db..8cf7ab171 100644
--- a/source/slang/slang-ir.cpp
+++ b/source/slang/slang-ir.cpp
@@ -1408,10 +1408,7 @@ namespace Slang
 
         inst->op = op;
 
-        if (type)
-        {
-            inst->typeUse.init(inst, type);
-        }
+        inst->typeUse.init(inst, type);
 
         maybeSetSourceLoc(builder, inst);
 
@@ -1423,6 +1420,10 @@ namespace Slang
             {
                 operand->init(inst, fixedArgs[aa]);
             }
+            else
+            {
+                operand->init(inst, nullptr);
+            }
             operand++;
         }
 
@@ -2518,16 +2519,14 @@ namespace Slang
     IRInst* IRBuilder::emitLookupInterfaceMethodInst(
         IRType* type,
         IRInst* witnessTableVal,
-        IRInst* interfaceMethodVal,
-        IRType* interfaceType)
+        IRInst* interfaceMethodVal)
     {
-        IRInst* args[3] = { witnessTableVal , interfaceMethodVal, interfaceType };
         auto inst = createInst<IRLookupWitnessMethod>(
             this,
             kIROp_lookup_interface_method,
             type,
-            3,
-            args);
+            witnessTableVal,
+            interfaceMethodVal);
 
         addInst(inst);
         return inst;
diff --git a/source/slang/slang-ir.h b/source/slang/slang-ir.h
index 6447deddb..54658980d 100644
--- a/source/slang/slang-ir.h
+++ b/source/slang/slang-ir.h
@@ -1226,6 +1226,10 @@ struct IRTypeType : IRType
 
 struct IRWitnessTableType : IRType
 {
+    IRInst* getConformanceType()
+    {
+        return getOperand(0);
+    }
     IR_LEAF_ISA(WitnessTableType);
 };
 
diff --git a/source/slang/slang-lower-to-ir.cpp b/source/slang/slang-lower-to-ir.cpp
index 96d4b121f..5bd983cab 100644
--- a/source/slang/slang-lower-to-ir.cpp
+++ b/source/slang/slang-lower-to-ir.cpp
@@ -1049,7 +1049,7 @@ struct ValLoweringVisitor : ValVisitor<ValLoweringVisitor, LoweredValInfo, Lower
     {
         return emitDeclRef(context, val->declRef,
             context->irBuilder->getWitnessTableType(
-                lowerType(context, DeclRefType::create(context->astBuilder, val->declRef))));
+                lowerType(context, val->sup)));
     }
 
     LoweredValInfo visitTransitiveSubtypeWitness(
@@ -1071,10 +1071,9 @@ struct ValLoweringVisitor : ValVisitor<ValLoweringVisitor, LoweredValInfo, Lower
         // to reflect the right constraints.
 
         return LoweredValInfo::simple(getBuilder()->emitLookupInterfaceMethodInst(
-            nullptr,
+            getBuilder()->getWitnessTableType(lowerType(context, val->sup)),
             baseWitnessTable,
-            requirementKey,
-            lowerType(context, val->subToMid->sup)));
+            requirementKey));
     }
 
     LoweredValInfo visitTaggedUnionSubtypeWitness(
@@ -1255,8 +1254,7 @@ struct ValLoweringVisitor : ValVisitor<ValLoweringVisitor, LoweredValInfo, Lower
                     auto caseFunc = subBuilder->emitLookupInterfaceMethodInst(
                         caseFuncType,
                         caseWitnessTable,
-                        irReqKey,
-                        irWitnessTableBaseType);
+                        irReqKey);
 
                     // We are going to emit a `call` to the satisfying value
                     // for the case type, so we will collect the arguments for that call.
@@ -5311,7 +5309,7 @@ struct DeclLoweringVisitor : DeclVisitor<DeclLoweringVisitor, LoweredValInfo>
                     auto constraintKey = getInterfaceRequirementKey(constraintDecl);
                     requirementEntries.add(
                         subBuilder->createInterfaceRequirementEntry(constraintKey,
-                            lowerType(context, constraintDecl->getSup().type)));
+                            getBuilder()->getWitnessTableType(lowerType(context, constraintDecl->getSup().type))));
                 }
             }
         }
@@ -6578,9 +6576,9 @@ struct DeclLoweringVisitor : DeclVisitor<DeclLoweringVisitor, LoweredValInfo>
         for (UInt i = 0; i < irInterfaceType->getOperandCount(); i++)
         {
             auto operand = cast<IRInterfaceRequirementEntry>(irInterfaceType->getOperand(i));
-            if (operand->getOperand(0) == key)
+            if (operand->getRequirementKey() == key)
             {
-                operand->setOperand(1, irFuncType);
+                operand->setRequirementVal(irFuncType);
                 return;
             }
         }
@@ -6874,8 +6872,7 @@ LoweredValInfo emitDeclRef(
         auto irSatisfyingVal = context->irBuilder->emitLookupInterfaceMethodInst(
             type,
             irWitnessTable,
-            irRequirementKey,
-            lowerType(context, thisTypeSubst->witness->sup));
+            irRequirementKey);
         return LoweredValInfo::simple(irSatisfyingVal);
     }
     else