diff --git a/cl/_testcgo/any/out.ll b/cl/_testcgo/any/out.ll
index e69de29b..132c18d4 100644
--- a/cl/_testcgo/any/out.ll
+++ b/cl/_testcgo/any/out.ll
@@ -0,0 +1,55 @@
+; ModuleID = 'main'
+source_filename = "main"
+
+%"github.com/goplus/llgo/internal/runtime.iface" = type { ptr, ptr }
+
+@main.format = global ptr null
+@"main.init$guard" = global ptr null
+
+define i64 @main.incVal(%"github.com/goplus/llgo/internal/runtime.iface" %0) {
+_llgo_0:
+  %1 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 2)
+  %2 = call i64 @"github.com/goplus/llgo/internal/runtime.I2Int"(%"github.com/goplus/llgo/internal/runtime.iface" %0, ptr %1)
+  %3 = add i64 %2, 1
+  ret i64 %3
+}
+
+define void @main.init() {
+_llgo_0:
+  %0 = load i1, ptr @"main.init$guard", align 1
+  br i1 %0, label %_llgo_2, label %_llgo_1
+
+_llgo_1:                                          ; preds = %_llgo_0
+  store i1 true, ptr @"main.init$guard", align 1
+  store i8 72, ptr @main.format, align 1
+  store i8 101, ptr getelementptr inbounds (i8, ptr @main.format, i64 1), align 1
+  store i8 108, ptr getelementptr inbounds (i8, ptr @main.format, i64 2), align 1
+  store i8 108, ptr getelementptr inbounds (i8, ptr @main.format, i64 3), align 1
+  store i8 111, ptr getelementptr inbounds (i8, ptr @main.format, i64 4), align 1
+  store i8 32, ptr getelementptr inbounds (i8, ptr @main.format, i64 5), align 1
+  store i8 37, ptr getelementptr inbounds (i8, ptr @main.format, i64 6), align 1
+  store i8 100, ptr getelementptr inbounds (i8, ptr @main.format, i64 7), align 1
+  store i8 10, ptr getelementptr inbounds (i8, ptr @main.format, i64 8), align 1
+  store i8 0, ptr getelementptr inbounds (i8, ptr @main.format, i64 9), align 1
+  br label %_llgo_2
+
+_llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
+  ret void
+}
+
+define void @main() {
+_llgo_0:
+  call void @main.init()
+  %0 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyInt"(i64 100)
+  %1 = call i64 @main.incVal(%"github.com/goplus/llgo/internal/runtime.iface" %0)
+  call void (ptr, ...) @printf(ptr @main.format, i64 %1)
+  ret void
+}
+
+declare void @printf(ptr, ...)
+
+declare i64 @"github.com/goplus/llgo/internal/runtime.I2Int"(%"github.com/goplus/llgo/internal/runtime.iface", ptr)
+
+declare ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64)
+
+declare %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyInt"(ptr, i64)
diff --git a/cl/compile.go b/cl/compile.go
index 58aa435a..4f602c2c 100644
--- a/cl/compile.go
+++ b/cl/compile.go
@@ -324,11 +324,12 @@ func (p *context) compileInstrAndValue(b llssa.Builder, iv instrAndValue) (ret l
 		}
 		ret = b.Alloc(p.prog.Type(t), v.Heap)
 	case *ssa.MakeInterface:
+		const (
+			delayExpr = true // varargs: don't need to convert an expr to any
+		)
 		t := v.Type()
-		if isAny(t) { // varargs: don't need to convert an expr to any
-			return
-		}
-		panic("todo")
+		x := p.compileValue(b, v.X)
+		ret = b.MakeInterface(t, x, delayExpr)
 	case *ssa.TypeAssert:
 		x := p.compileValue(b, v.X)
 		ret = b.TypeAssert(x, p.prog.Type(v.AssertedType), v.CommaOk)
@@ -417,6 +418,9 @@ func (p *context) compileVArg(ret []llssa.Expr, b llssa.Builder, v ssa.Value) []
 	switch v := v.(type) {
 	case *ssa.Slice: // varargs: this is a varargs slice
 		if args, ok := p.isVArgs(v.X); ok {
+			for i, arg := range args {
+				args[i] = arg.Do(true)
+			}
 			return append(ret, args...)
 		}
 	case *ssa.Const:
@@ -431,7 +435,7 @@ func (p *context) compileValues(b llssa.Builder, vals []ssa.Value, hasVArg int)
 	n := len(vals) - hasVArg
 	ret := make([]llssa.Expr, n)
 	for i := 0; i < n; i++ {
-		ret[i] = p.compileValue(b, vals[i])
+		ret[i] = p.compileValue(b, vals[i]).Do(false)
 	}
 	if hasVArg > 0 {
 		ret = p.compileVArg(ret, b, vals[n])
diff --git a/cl/compile_test.go b/cl/compile_test.go
index 249d8274..671f8cba 100644
--- a/cl/compile_test.go
+++ b/cl/compile_test.go
@@ -28,7 +28,7 @@ func testCompile(t *testing.T, src, expected string) {
 }
 
 func TestFromTestcgo(t *testing.T) {
-	cltest.FromDir(t, "any", "./_testcgo", true)
+	cltest.FromDir(t, "", "./_testcgo", true)
 }
 
 func TestFromTestdata(t *testing.T) {
diff --git a/internal/runtime/z_iface.go b/internal/runtime/z_iface.go
index b3ae4d05..e2a07fea 100644
--- a/internal/runtime/z_iface.go
+++ b/internal/runtime/z_iface.go
@@ -30,9 +30,37 @@ var (
 	TyAny = &InterfaceType{}
 )
 
+func MakeAnyInt(typ *Type, data uintptr) Interface {
+	return Interface{
+		tab:  &itab{inter: TyAny, _type: typ, hash: 0, fun: [1]uintptr{0}},
+		data: unsafe.Pointer(data),
+	}
+}
+
 func MakeAny(typ *Type, data unsafe.Pointer) Interface {
 	return Interface{
 		tab:  &itab{inter: TyAny, _type: typ, hash: 0, fun: [1]uintptr{0}},
 		data: data,
 	}
 }
+
+func MakeInterface(inter *InterfaceType, typ *Type, data unsafe.Pointer) Interface {
+	return Interface{
+		tab:  &itab{inter: inter, _type: typ, hash: 0, fun: [1]uintptr{0}},
+		data: data,
+	}
+}
+
+func I2Int(v Interface, t *Type) uintptr {
+	if v.tab._type == t {
+		return uintptr(v.data)
+	}
+	panic("I2Int: type mismatch")
+}
+
+func CheckI2Int(v Interface, t *Type) (uintptr, bool) {
+	if v.tab._type == t {
+		return uintptr(v.data), true
+	}
+	return 0, false
+}
diff --git a/internal/runtime/z_type.go b/internal/runtime/z_type.go
index 41b4f53d..f0ad7723 100644
--- a/internal/runtime/z_type.go
+++ b/internal/runtime/z_type.go
@@ -25,20 +25,6 @@ import (
 
 type Type = abi.Type
 
-func I2Int(v Interface, t *Type) int64 {
-	if v.tab._type == t {
-		return int64(uintptr(v.data))
-	}
-	panic("I2Int: type mismatch")
-}
-
-func CheckI2Int(v Interface, t *Type) (int64, bool) {
-	if v.tab._type == t {
-		return int64(uintptr(v.data)), true
-	}
-	return 0, false
-}
-
 func Basic(kind types.BasicKind) *Type {
 	return basicTypes[kind]
 }
diff --git a/internal/unsafeheader/unsafeheader.go b/internal/unsafeheader/unsafeheader.go
deleted file mode 100644
index 6d092c62..00000000
--- a/internal/unsafeheader/unsafeheader.go
+++ /dev/null
@@ -1,37 +0,0 @@
-// Copyright 2020 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Package unsafeheader contains header declarations for the Go runtime's slice
-// and string implementations.
-//
-// This package allows packages that cannot import "reflect" to use types that
-// are tested to be equivalent to reflect.SliceHeader and reflect.StringHeader.
-package unsafeheader
-
-import (
-	"unsafe"
-)
-
-// Slice is the runtime representation of a slice.
-// It cannot be used safely or portably and its representation may
-// change in a later release.
-//
-// Unlike reflect.SliceHeader, its Data field is sufficient to guarantee the
-// data it references will not be garbage collected.
-type Slice struct {
-	Data unsafe.Pointer
-	Len  int
-	Cap  int
-}
-
-// String is the runtime representation of a string.
-// It cannot be used safely or portably and its representation may
-// change in a later release.
-//
-// Unlike reflect.StringHeader, its Data field is sufficient to guarantee the
-// data it references will not be garbage collected.
-type String struct {
-	Data unsafe.Pointer
-	Len  int
-}
diff --git a/ssa/expr.go b/ssa/expr.go
index e8aaa3ad..932ae445 100644
--- a/ssa/expr.go
+++ b/ssa/expr.go
@@ -41,6 +41,37 @@ func (v Expr) TypeOf() types.Type {
 }
 */
 
+// Do evaluates the delay expression and returns the result.
+func (v Expr) Do(isVArg bool) Expr {
+	if vt := v.Type; vt.kind == vkDelayExpr {
+		delay := vt.t.(*delayExprTy)
+		if f := delay.f; f != nil {
+			delay.f = nil
+			delay.val = f(isVArg)
+		}
+		return delay.val
+	}
+	return v
+}
+
+// DelayExpr returns a delay expression.
+func DelayExpr(f func(isVArg bool) Expr) Expr {
+	return Expr{Type: &aType{t: &delayExprTy{f: f}, kind: vkDelayExpr}}
+}
+
+type delayExprTy struct {
+	f   func(isVArg bool) Expr
+	val Expr
+}
+
+func (p *delayExprTy) Underlying() types.Type {
+	panic("don't call")
+}
+
+func (p *delayExprTy) String() string {
+	return "delayExpr"
+}
+
 // -----------------------------------------------------------------------------
 
 func llvmValues(vals []Expr) []llvm.Value {
@@ -407,6 +438,47 @@ func (b Builder) ChangeType(t Type, x Expr) (ret Expr) {
 	panic("todo")
 }
 
+// MakeInterface constructs an instance of an interface type from a
+// value of a concrete type.
+//
+// Use Program.MethodSets.MethodSet(X.Type()) to find the method-set
+// of X, and Program.MethodValue(m) to find the implementation of a method.
+//
+// To construct the zero value of an interface type T, use:
+//
+//	NewConst(constant.MakeNil(), T, pos)
+//
+// Pos() returns the ast.CallExpr.Lparen, if the instruction arose
+// from an explicit conversion in the source.
+//
+// Example printed form:
+//
+//	t1 = make interface{} <- int (42:int)
+//	t2 = make Stringer <- t0
+func (b Builder) MakeInterface(inter types.Type, x Expr, mayDelay bool) (ret Expr) {
+	if debugInstr {
+		log.Printf("MakeInterface %v, %v\n", inter, x.impl)
+	}
+	t := inter.Underlying().(*types.Interface)
+	isAny := t.Empty()
+	fnDo := func(isVArg bool) Expr {
+		if isVArg { // don't need make interface
+			return x
+		}
+		pkg := b.fn.pkg
+		switch x.kind {
+		case vkSigned, vkUnsigned, vkFloat:
+			fn := pkg.rtFunc("MakeAnyInt")
+			return b.InlineCall(fn, x)
+		}
+		panic("todo")
+	}
+	if mayDelay && isAny {
+		return DelayExpr(fnDo)
+	}
+	return fnDo(false)
+}
+
 // The TypeAssert instruction tests whether interface value X has type
 // AssertedType.
 //
@@ -451,7 +523,7 @@ func (b Builder) TypeAssert(x Expr, assertedTyp Type, commaOk bool) (ret Expr) {
 		log.Printf("TypeAssert %v, %v, %v\n", x.impl, assertedTyp.t, commaOk)
 	}
 	switch assertedTyp.kind {
-	case vkSigned, vkUnsigned:
+	case vkSigned, vkUnsigned, vkFloat:
 		pkg := b.fn.pkg
 		fnName := "I2Int"
 		if commaOk {
diff --git a/ssa/type.go b/ssa/type.go
index 90978212..ffec59b9 100644
--- a/ssa/type.go
+++ b/ssa/type.go
@@ -41,6 +41,7 @@ const (
 	vkBool
 	vkFunc
 	vkTuple
+	vkDelayExpr = -1
 )
 
 // -----------------------------------------------------------------------------