compiler: merge runtime.typecodeID and runtime.typeInInterface

This distinction was useful before when reflect wasn't properly
supported. Back then it made sense to only include method sets that were
actually used in an interface. But now that it is possible to get to
other values (for example, by extracting fields from structs) and it is
possible to turn them back into interfaces, it is necessary to preserve
all method sets that can possibly be used in the program in a type
assert, interface assert or interface method call.

In the future, this logic will need to be revisited again when
reflect.New or reflect.Zero gets implemented.

Code size increases a bit in some cases, but usually in a very limited
way (except for one outlier in the drivers smoke tests). The next commit
will improve the situation significantly.

compiler/compiler.go

@@ -23,7 +23,7 @@ import (
 // Version of the compiler pacakge. Must be incremented each time the compiler
 // package changes in a way that affects the generated LLVM module.
 // This version is independent of the TinyGo version number.
-const Version = 2 // last change: adding wasm-export-name attribute
+const Version = 3 // last change: remove runtime.typeInInterface
 
 func init() {
 	llvm.InitializeAllTargets()

compiler/interface.go

@@ -24,16 +24,7 @@ import (
 func (b *builder) createMakeInterface(val llvm.Value, typ types.Type, pos token.Pos) llvm.Value {
 	itfValue := b.emitPointerPack([]llvm.Value{val})
 	itfTypeCodeGlobal := b.getTypeCode(typ)
-	itfMethodSetGlobal := b.getTypeMethodSet(typ)
+	itfTypeCode := b.CreatePtrToInt(itfTypeCodeGlobal, b.uintptrType, "")
-	itfConcreteTypeGlobal := b.mod.NamedGlobal("typeInInterface:" + itfTypeCodeGlobal.Name())
-	if itfConcreteTypeGlobal.IsNil() {
-		typeInInterface := b.getLLVMRuntimeType("typeInInterface")
-		itfConcreteTypeGlobal = llvm.AddGlobal(b.mod, typeInInterface, "typeInInterface:"+itfTypeCodeGlobal.Name())
-		itfConcreteTypeGlobal.SetInitializer(llvm.ConstNamedStruct(typeInInterface, []llvm.Value{itfTypeCodeGlobal, itfMethodSetGlobal}))
-		itfConcreteTypeGlobal.SetGlobalConstant(true)
-		itfConcreteTypeGlobal.SetLinkage(llvm.LinkOnceODRLinkage)
-	}
-	itfTypeCode := b.CreatePtrToInt(itfConcreteTypeGlobal, b.uintptrType, "")
 	itf := llvm.Undef(b.getLLVMRuntimeType("_interface"))
 	itf = b.CreateInsertValue(itf, itfTypeCode, 0, "")
 	itf = b.CreateInsertValue(itf, itfValue, 1, "")
@@ -54,6 +45,7 @@ func (c *compilerContext) getTypeCode(typ types.Type) llvm.Value {
 		// reflect lowering simpler.
 		var references llvm.Value
 		var length int64
+		var methodSet llvm.Value
 		switch typ := typ.(type) {
 		case *types.Named:
 			references = c.getTypeCode(typ.Underlying())
@@ -71,14 +63,22 @@ func (c *compilerContext) getTypeCode(typ types.Type) llvm.Value {
 			structGlobal := c.makeStructTypeFields(typ)
 			references = llvm.ConstBitCast(structGlobal, global.Type())
 		}
-		if !references.IsNil() {
+		if _, ok := typ.Underlying().(*types.Interface); !ok {
+			methodSet = c.getTypeMethodSet(typ)
+		}
+		if !references.IsNil() || length != 0 || !methodSet.IsNil() {
 			// Set the 'references' field of the runtime.typecodeID struct.
 			globalValue := llvm.ConstNull(global.Type().ElementType())
+			if !references.IsNil() {
 				globalValue = llvm.ConstInsertValue(globalValue, references, []uint32{0})
+			}
 			if length != 0 {
 				lengthValue := llvm.ConstInt(c.uintptrType, uint64(length), false)
 				globalValue = llvm.ConstInsertValue(globalValue, lengthValue, []uint32{1})
 			}
+			if !methodSet.IsNil() {
+				globalValue = llvm.ConstInsertValue(globalValue, methodSet, []uint32{2})
+			}
 			global.SetInitializer(globalValue)
 			global.SetLinkage(llvm.LinkOnceODRLinkage)
 		}

interp/interpreter.go

@@ -286,11 +286,7 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 				if r.debug {
 					fmt.Fprintln(os.Stderr, indent+"typeassert:", operands[1:])
 				}
-				typeInInterfacePtr, err := operands[1].asPointer(r)
+				actualType, err := operands[1].asPointer(r)
-				if err != nil {
-					return nil, mem, r.errorAt(inst, err)
-				}
-				actualType, err := mem.load(typeInInterfacePtr, r.pointerSize).asPointer(r)
 				if err != nil {
 					return nil, mem, r.errorAt(inst, err)
 				}
@@ -310,11 +306,11 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 				}
 
 				// Load various values for the interface implements check below.
-				typeInInterfacePtr, err := operands[1].asPointer(r)
+				typecodePtr, err := operands[1].asPointer(r)
 				if err != nil {
 					return nil, mem, r.errorAt(inst, err)
 				}
-				methodSetPtr, err := mem.load(typeInInterfacePtr.addOffset(r.pointerSize), r.pointerSize).asPointer(r)
+				methodSetPtr, err := mem.load(typecodePtr.addOffset(r.pointerSize*2), r.pointerSize).asPointer(r)
 				if err != nil {
 					return nil, mem, r.errorAt(inst, err)
 				}

interp/memory.go

@@ -1048,7 +1048,7 @@ func (v rawValue) rawLLVMValue(mem *memoryView) llvm.Value {
 				// There are some special pointer types that should be used as a
 				// ptrtoint, so that they can be used in certain optimizations.
 				name := elementType.StructName()
-				if name == "runtime.typeInInterface" || name == "runtime.funcValueWithSignature" {
+				if name == "runtime.typecodeID" || name == "runtime.funcValueWithSignature" {
 					uintptrType := ctx.IntType(int(mem.r.pointerSize) * 8)
 					field = llvm.ConstPtrToInt(field, uintptrType)
 				}

interp/testdata/interface.ll

@@ -1,14 +1,12 @@
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64--linux"
 
-%runtime.typecodeID = type { %runtime.typecodeID*, i64 }
+%runtime.typecodeID = type { %runtime.typecodeID*, i64, %runtime.interfaceMethodInfo* }
 %runtime.interfaceMethodInfo = type { i8*, i64 }
-%runtime.typeInInterface = type { %runtime.typecodeID*, %runtime.interfaceMethodInfo* }
 
 @main.v1 = global i1 0
-@"reflect/types.type:named:main.foo" = private constant %runtime.typecodeID { %runtime.typecodeID* @"reflect/types.type:basic:int", i64 0 }
+@"reflect/types.type:named:main.foo" = private constant %runtime.typecodeID { %runtime.typecodeID* @"reflect/types.type:basic:int", i64 0, %runtime.interfaceMethodInfo* null }
 @"reflect/types.type:basic:int" = external constant %runtime.typecodeID
-@"typeInInterface:reflect/types.type:named:main.foo" = private constant %runtime.typeInInterface { %runtime.typecodeID* @"reflect/types.type:named:main.foo", %runtime.interfaceMethodInfo* null }
 
 
 declare i1 @runtime.typeAssert(i64, %runtime.typecodeID*, i8*, i8*)
@@ -22,7 +20,7 @@ entry:
 define internal void @main.init() unnamed_addr {
 entry:
   ; Test type asserts.
-  %typecode = call i1 @runtime.typeAssert(i64 ptrtoint (%runtime.typeInInterface* @"typeInInterface:reflect/types.type:named:main.foo" to i64), %runtime.typecodeID* @"reflect/types.type:named:main.foo", i8* undef, i8* null)
+  %typecode = call i1 @runtime.typeAssert(i64 ptrtoint (%runtime.typecodeID* @"reflect/types.type:named:main.foo" to i64), %runtime.typecodeID* @"reflect/types.type:named:main.foo", i8* undef, i8* null)
   store i1 %typecode, i1* @main.v1
   ret void
 }

src/internal/task/task_coroutine.go

@@ -11,7 +11,7 @@ import (
 type rawState uint8
 
 //export llvm.coro.resume
-func (s *rawState) resume()
+func coroResume(*rawState)
 
 type state struct{ *rawState }
 
@@ -20,7 +20,7 @@ func noopState() *rawState
 
 // Resume the task until it pauses or completes.
 func (t *Task) Resume() {
-	t.state.resume()
+	coroResume(t.state.rawState)
 }
 
 // setState is used by the compiler to set the state of the function at the beginning of a function call.

src/runtime/interface.go

@@ -107,6 +107,8 @@ type typecodeID struct {
 
 	// The array length, for array types.
 	length uintptr
+
+	methodSet *interfaceMethodInfo // nil or a GEP of an array
 }
 
 // structField is used by the compiler to pass information to the interface
@@ -118,15 +120,6 @@ type structField struct {
 	embedded bool
 }
 
-// Pseudo type used before interface lowering. By using a struct instead of a
-// function call, this is simpler to reason about during init interpretation
-// than a function call. Also, by keeping the method set around it is easier to
-// implement interfaceImplements in the interp package.
-type typeInInterface struct {
-	typecode  *typecodeID          // element type, underlying type, or reference to struct fields
-	methodSet *interfaceMethodInfo // nil or a GEP of an array
-}
-
 // Pseudo function call used during a type assert. It is used during interface
 // lowering, to assign the lowest type numbers to the types with the most type
 // asserts. Also, it is replaced with const false if this type assert can never

testdata/reflect.go

@@ -265,6 +265,19 @@ func main() {
 		println("type assertion failed (but should succeed)")
 	}
 
+	// Test type that is not referenced at all: not when creating the
+	// reflect.Value (except through the field) and not with a type assert.
+	// Previously this would result in a type assert failure because the Int()
+	// method wasn't picked up.
+	v = reflect.ValueOf(struct {
+		X totallyUnreferencedType
+	}{})
+	if v.Field(0).Interface().(interface {
+		Int() int
+	}).Int() != 42 {
+		println("could not call method on totally unreferenced type")
+	}
+
 	if reflect.TypeOf(new(myint)) != reflect.PtrTo(reflect.TypeOf(myint(0))) {
 		println("PtrTo failed for type myint")
 	}
@@ -363,6 +376,12 @@ func assertSize(ok bool, typ string) {
 
 type unreferencedType int
 
+type totallyUnreferencedType int
+
+func (totallyUnreferencedType) Int() int {
+	return 42
+}
+
 func TestStructTag() {
 	type S struct {
 		F string `species:"gopher" color:"blue"`

transform/interface-lowering.go

@@ -46,6 +46,7 @@ import (
 // any method in particular.
 type signatureInfo struct {
 	name       string
+	global     llvm.Value
 	methods    []*methodInfo
 	interfaces []*interfaceInfo
 }
@@ -77,7 +78,6 @@ type typeInfo struct {
 	typecode         llvm.Value
 	methodSet        llvm.Value
 	num              uint64 // the type number after lowering
-	countMakeInterfaces int    // how often this type is used in an interface
 	countTypeAsserts int    // how often a type assert happens on this method
 	methods          []*methodInfo
 }
@@ -104,9 +104,6 @@ func (t typeInfoSlice) Less(i, j int) bool {
 	if t[i].countTypeAsserts != t[j].countTypeAsserts {
 		return t[i].countTypeAsserts < t[j].countTypeAsserts
 	}
-	if t[i].countMakeInterfaces != t[j].countMakeInterfaces {
-		return t[i].countMakeInterfaces < t[j].countMakeInterfaces
-	}
 	return t[i].name < t[j].name
 }
 func (t typeInfoSlice) Swap(i, j int) { t[i], t[j] = t[j], t[i] }
@@ -115,6 +112,7 @@ func (t typeInfoSlice) Swap(i, j int) { t[i], t[j] = t[j], t[i] }
 // methods it has.
 type interfaceInfo struct {
 	name        string                        // name with $interface suffix
+	methodSet   llvm.Value                    // global which this interfaceInfo describes
 	signatures  []*signatureInfo              // method set
 	types       typeInfoSlice                 // types this interface implements
 	assertFunc  llvm.Value                    // runtime.interfaceImplements replacement
@@ -163,9 +161,9 @@ func LowerInterfaces(mod llvm.Module) error {
 // run runs the pass itself.
 func (p *lowerInterfacesPass) run() error {
 	// Collect all type codes.
-	typecodeIDPtr := llvm.PointerType(p.mod.GetTypeByName("runtime.typecodeID"), 0)
+	typecodeID := p.mod.GetTypeByName("runtime.typecodeID")
-	typeInInterfacePtr := llvm.PointerType(p.mod.GetTypeByName("runtime.typeInInterface"), 0)
+	typecodeIDPtr := llvm.PointerType(typecodeID, 0)
-	var typesInInterfaces []llvm.Value
+	var typecodeIDs []llvm.Value
 	for global := p.mod.FirstGlobal(); !global.IsNil(); global = llvm.NextGlobal(global) {
 		switch global.Type() {
 		case typecodeIDPtr:
@@ -174,32 +172,19 @@ func (p *lowerInterfacesPass) run() error {
 			// discarded afterwards.
 			name := global.Name()
 			if _, ok := p.types[name]; !ok {
-				p.types[name] = &typeInfo{
+				typecodeIDs = append(typecodeIDs, global)
+				t := &typeInfo{
 					name:     name,
 					typecode: global,
 				}
-			}
+				p.types[name] = t
-		case typeInInterfacePtr:
-			// Count per type how often it is put in an interface. Also, collect
-			// all methods this type has (if it is named).
-			typesInInterfaces = append(typesInInterfaces, global)
 				initializer := global.Initializer()
-			typecode := llvm.ConstExtractValue(initializer, []uint32{0})
+				if initializer.IsNil() {
-			methodSet := llvm.ConstExtractValue(initializer, []uint32{1})
+					continue
-			typecodeName := typecode.Name()
-			t := p.types[typecodeName]
-			if t == nil {
-				t = &typeInfo{
-					name:     typecodeName,
-					typecode: typecode,
-				}
-				p.types[typecodeName] = t
 				}
+				methodSet := llvm.ConstExtractValue(initializer, []uint32{2})
 				p.addTypeMethods(t, methodSet)
-
+			}
-			// Count the number of MakeInterface instructions, for sorting the
-			// typecodes later.
-			t.countMakeInterfaces += len(getUses(global))
 		}
 	}
 
@@ -363,18 +348,30 @@ func (p *lowerInterfacesPass) run() error {
 	// Assign a type code for each type.
 	assignTypeCodes(p.mod, typeSlice)
 
-	// Replace each use of a runtime.typeInInterface with the constant type
+	// Replace each use of a ptrtoint runtime.typecodeID with the constant type
 	// code.
-	for _, global := range typesInInterfaces {
+	for _, global := range typecodeIDs {
 		for _, use := range getUses(global) {
-			t := p.types[llvm.ConstExtractValue(global.Initializer(), []uint32{0}).Name()]
+			if use.IsAConstantExpr().IsNil() {
+				continue
+			}
+			t := p.types[global.Name()]
 			typecode := llvm.ConstInt(p.uintptrType, t.num, false)
+			switch use.Opcode() {
+			case llvm.PtrToInt:
+				// Already of the correct type.
+			case llvm.BitCast:
+				// Could happen when stored in an interface (which is of type
+				// i8*).
+				typecode = llvm.ConstIntToPtr(typecode, use.Type())
+			default:
+				panic("unexpected constant expression")
+			}
 			use.ReplaceAllUsesWith(typecode)
 		}
 	}
 
-	// Replace each type assert with an actual type comparison or (if the type
+	// Replace each type assert with an actual type comparison.
-	// assert is impossible) the constant false.
 	for _, use := range typeAssertUses {
 		actualType := use.Operand(0)
 		assertedTypeGlobal := use.Operand(1)
@@ -405,20 +402,36 @@ func (p *lowerInterfacesPass) run() error {
 		}
 	}
 
-	// Remove stray runtime.typeInInterface globals. Required for the following
+	// Remove most objects created for interface and reflect lowering.
-	// cleanup.
+	// Unnecessary, but cleans up the IR for inspection and testing.
-	for _, global := range typesInInterfaces {
+	zeroTypeCode := llvm.ConstNull(typecodeID)
-		global.EraseFromParentAsGlobal()
+	for _, typ := range p.types {
+		// Only some typecodes have an initializer.
+		initializer := typ.typecode.Initializer()
+		if !initializer.IsNil() {
+			references := llvm.ConstExtractValue(initializer, []uint32{0})
+			typ.typecode.SetInitializer(zeroTypeCode)
+			if !references.IsAConstantExpr().IsNil() && references.Opcode() == llvm.BitCast {
+				// Structs have a 'references' field that is not a typecode but
+				// a pointer to a runtime.structField array and therefore a
+				// bitcast. This global should be erased separately, otherwise
+				// typecode objects cannot be erased.
+				structFields := references.Operand(0)
+				structFields.EraseFromParentAsGlobal()
+			}
 		}
 
-	// Remove method sets of types. Unnecessary, but cleans up the IR for
-	// inspection.
-	for _, typ := range p.types {
 		if !typ.methodSet.IsNil() {
 			typ.methodSet.EraseFromParentAsGlobal()
 			typ.methodSet = llvm.Value{}
 		}
 	}
+	for _, itf := range p.interfaces {
+		// Remove method sets of interfaces.
+		itf.methodSet.EraseFromParentAsGlobal()
+		itf.methodSet = llvm.Value{}
+	}
+
 	return nil
 }
 
@@ -437,9 +450,10 @@ func (p *lowerInterfacesPass) addTypeMethods(t *typeInfo, methodSet llvm.Value)
 	set := methodSet.Initializer() // get value from global
 	for i := 0; i < set.Type().ArrayLength(); i++ {
 		methodData := llvm.ConstExtractValue(set, []uint32{uint32(i)})
-		signatureName := llvm.ConstExtractValue(methodData, []uint32{0}).Name()
+		signatureGlobal := llvm.ConstExtractValue(methodData, []uint32{0})
+		signatureName := signatureGlobal.Name()
 		function := llvm.ConstExtractValue(methodData, []uint32{1}).Operand(0)
-		signature := p.getSignature(signatureName)
+		signature := p.getSignature(signatureName, signatureGlobal)
 		method := &methodInfo{
 			function:      function,
 			signatureInfo: signature,
@@ -455,12 +469,14 @@ func (p *lowerInterfacesPass) addInterface(methodSet llvm.Value) {
 	name := methodSet.Name()
 	t := &interfaceInfo{
 		name:      name,
+		methodSet: methodSet,
 	}
 	p.interfaces[name] = t
 	methodSet = methodSet.Initializer() // get global value from getelementptr
 	for i := 0; i < methodSet.Type().ArrayLength(); i++ {
-		signatureName := llvm.ConstExtractValue(methodSet, []uint32{uint32(i)}).Name()
+		signatureGlobal := llvm.ConstExtractValue(methodSet, []uint32{uint32(i)})
-		signature := p.getSignature(signatureName)
+		signatureName := signatureGlobal.Name()
+		signature := p.getSignature(signatureName, signatureGlobal)
 		signature.interfaces = append(signature.interfaces, t)
 		t.signatures = append(t.signatures, signature)
 	}
@@ -468,10 +484,11 @@ func (p *lowerInterfacesPass) addInterface(methodSet llvm.Value) {
 
 // getSignature returns a new *signatureInfo, creating it if it doesn't already
 // exist.
-func (p *lowerInterfacesPass) getSignature(name string) *signatureInfo {
+func (p *lowerInterfacesPass) getSignature(name string, global llvm.Value) *signatureInfo {
 	if _, ok := p.signatures[name]; !ok {
 		p.signatures[name] = &signatureInfo{
 			name:   name,
+			global: global,
 		}
 	}
 	return p.signatures[name]

transform/testdata/interface.ll

@@ -1,21 +1,17 @@
 target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
 target triple = "armv7m-none-eabi"
 
-%runtime.typecodeID = type { %runtime.typecodeID*, i32 }
+%runtime.typecodeID = type { %runtime.typecodeID*, i32, %runtime.interfaceMethodInfo* }
-%runtime.typeInInterface = type { %runtime.typecodeID*, %runtime.interfaceMethodInfo* }
 %runtime.interfaceMethodInfo = type { i8*, i32 }
 
 @"reflect/types.type:basic:uint8" = external constant %runtime.typecodeID
 @"reflect/types.type:basic:int" = external constant %runtime.typecodeID
-@"typeInInterface:reflect/types.type:basic:uint8" = private constant %runtime.typeInInterface { %runtime.typecodeID* @"reflect/types.type:basic:uint8", %runtime.interfaceMethodInfo* null }
-@"typeInInterface:reflect/types.type:basic:int" = private constant %runtime.typeInInterface { %runtime.typecodeID* @"reflect/types.type:basic:int", %runtime.interfaceMethodInfo* null }
 @"func NeverImplementedMethod()" = external constant i8
 @"Unmatched$interface" = private constant [1 x i8*] [i8* @"func NeverImplementedMethod()"]
 @"func Double() int" = external constant i8
 @"Doubler$interface" = private constant [1 x i8*] [i8* @"func Double() int"]
 @"Number$methodset" = private constant [1 x %runtime.interfaceMethodInfo] [%runtime.interfaceMethodInfo { i8* @"func Double() int", i32 ptrtoint (i32 (i8*, i8*)* @"(Number).Double$invoke" to i32) }]
-@"reflect/types.type:named:Number" = private constant %runtime.typecodeID { %runtime.typecodeID* @"reflect/types.type:basic:int", i32 0 }
+@"reflect/types.type:named:Number" = private constant %runtime.typecodeID { %runtime.typecodeID* @"reflect/types.type:basic:int", i32 0, %runtime.interfaceMethodInfo* getelementptr inbounds ([1 x %runtime.interfaceMethodInfo], [1 x %runtime.interfaceMethodInfo]* @"Number$methodset", i32 0, i32 0) }
-@"typeInInterface:reflect/types.type:named:Number" = private constant %runtime.typeInInterface { %runtime.typecodeID* @"reflect/types.type:named:Number", %runtime.interfaceMethodInfo* getelementptr inbounds ([1 x %runtime.interfaceMethodInfo], [1 x %runtime.interfaceMethodInfo]* @"Number$methodset", i32 0, i32 0) }
 
 declare i1 @runtime.interfaceImplements(i32, i8**)
 declare i1 @runtime.typeAssert(i32, %runtime.typecodeID*)
@@ -27,9 +23,9 @@ declare void @runtime.printnl()
 declare void @runtime.nilPanic(i8*, i8*)
 
 define void @printInterfaces() {
-  call void @printInterface(i32 ptrtoint (%runtime.typeInInterface* @"typeInInterface:reflect/types.type:basic:int" to i32), i8* inttoptr (i32 5 to i8*))
+  call void @printInterface(i32 ptrtoint (%runtime.typecodeID* @"reflect/types.type:basic:int" to i32), i8* inttoptr (i32 5 to i8*))
-  call void @printInterface(i32 ptrtoint (%runtime.typeInInterface* @"typeInInterface:reflect/types.type:basic:uint8" to i32), i8* inttoptr (i8 120 to i8*))
+  call void @printInterface(i32 ptrtoint (%runtime.typecodeID* @"reflect/types.type:basic:uint8" to i32), i8* inttoptr (i8 120 to i8*))
-  call void @printInterface(i32 ptrtoint (%runtime.typeInInterface* @"typeInInterface:reflect/types.type:named:Number" to i32), i8* inttoptr (i32 3 to i8*))
+  call void @printInterface(i32 ptrtoint (%runtime.typecodeID* @"reflect/types.type:named:Number" to i32), i8* inttoptr (i32 3 to i8*))
 
   ret void
 }

transform/testdata/interface.out.ll

@@ -1,15 +1,14 @@
 target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
 target triple = "armv7m-none-eabi"
 
-%runtime.typecodeID = type { %runtime.typecodeID*, i32 }
+%runtime.typecodeID = type { %runtime.typecodeID*, i32, %runtime.interfaceMethodInfo* }
+%runtime.interfaceMethodInfo = type { i8*, i32 }
 
 @"reflect/types.type:basic:uint8" = external constant %runtime.typecodeID
 @"reflect/types.type:basic:int" = external constant %runtime.typecodeID
 @"func NeverImplementedMethod()" = external constant i8
-@"Unmatched$interface" = private constant [1 x i8*] [i8* @"func NeverImplementedMethod()"]
 @"func Double() int" = external constant i8
-@"Doubler$interface" = private constant [1 x i8*] [i8* @"func Double() int"]
+@"reflect/types.type:named:Number" = private constant %runtime.typecodeID zeroinitializer
-@"reflect/types.type:named:Number" = private constant %runtime.typecodeID { %runtime.typecodeID* @"reflect/types.type:basic:int", i32 0 }
 
 declare i1 @runtime.interfaceImplements(i32, i8**)