diff --git a/cl/_testpy/pow/in.go b/cl/_testpy/pow/in.go
new file mode 100644
index 00000000..6dc98ead
--- /dev/null
+++ b/cl/_testpy/pow/in.go
@@ -0,0 +1,12 @@
+package main
+
+import (
+	"github.com/goplus/llgo/c"
+	"github.com/goplus/llgo/py"
+	"github.com/goplus/llgo/py/math"
+)
+
+func main() {
+	x := math.Pow(py.Float(2), py.Float(3))
+	c.Printf(c.Str("pow(2, 3) = %f\n"), x.Float64())
+}
diff --git a/cl/_testpy/pow/out.ll b/cl/_testpy/pow/out.ll
new file mode 100644
index 00000000..e1bd0f04
--- /dev/null
+++ b/cl/_testpy/pow/out.ll
@@ -0,0 +1,58 @@
+; ModuleID = 'main'
+source_filename = "main"
+
+@"main.init$guard" = global ptr null
+@__llgo_argc = global ptr null
+@__llgo_argv = global ptr null
+@__llgo_py.math.pow = linkonce global ptr null
+@0 = private unnamed_addr constant [16 x i8] c"pow(2, 3) = %f\0A\00", align 1
+@__llgo_py.math = external global ptr
+@1 = private unnamed_addr constant [4 x i8] c"pow\00", align 1
+
+define void @main.init() {
+_llgo_0:
+  %0 = load i1, ptr @"main.init$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
+  call void @"github.com/goplus/llgo/py/math.init"()
+  %1 = load ptr, ptr @__llgo_py.math, align 8
+  call void (ptr, ...) @llgoLoadPyModSyms(ptr %1, ptr @1, ptr @__llgo_py.math.pow, ptr null)
+  br label %_llgo_2
+
+_llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
+  ret void
+}
+
+define void @main(i32 %0, ptr %1) {
+_llgo_0:
+  call void @Py_Initialize()
+  store i32 %0, ptr @__llgo_argc, align 4
+  store ptr %1, ptr @__llgo_argv, align 8
+  call void @"github.com/goplus/llgo/internal/runtime.init"()
+  call void @main.init()
+  %2 = call ptr @PyFloat_FromDouble(double 2.000000e+00)
+  %3 = call ptr @PyFloat_FromDouble(double 3.000000e+00)
+  %4 = load ptr, ptr @__llgo_py.math.pow, align 8
+  %5 = call ptr (ptr, ...) @PyObject_CallFunctionObjArgs(ptr %4, ptr %2, ptr %3, ptr null)
+  %6 = call double @PyFloat_AsDouble(ptr %5)
+  %7 = call i32 (ptr, ...) @printf(ptr @0, double %6)
+  ret void
+}
+
+declare void @"github.com/goplus/llgo/py/math.init"()
+
+declare void @"github.com/goplus/llgo/internal/runtime.init"()
+
+declare ptr @PyFloat_FromDouble(double)
+
+declare ptr @PyObject_CallFunctionObjArgs(ptr, ...)
+
+declare double @PyFloat_AsDouble(ptr)
+
+declare i32 @printf(ptr, ...)
+
+declare void @llgoLoadPyModSyms(ptr, ...)
+
+declare void @Py_Initialize()
diff --git a/ssa/expr.go b/ssa/expr.go
index 5097234c..b532984a 100644
--- a/ssa/expr.go
+++ b/ssa/expr.go
@@ -78,6 +78,11 @@ func (p Program) Null(t Type) Expr {
 	return Expr{llvm.ConstNull(t.ll), t}
 }
 
+// PyNull returns a null *PyObject constant expression.
+func (p Program) PyNull() Expr {
+	return p.Null(p.PyObjectPtr())
+}
+
 // BoolVal returns a boolean constant expression.
 func (p Program) BoolVal(v bool) Expr {
 	t := p.Bool()
diff --git a/ssa/package.go b/ssa/package.go
index eeee0f24..7de579cb 100644
--- a/ssa/package.go
+++ b/ssa/package.go
@@ -130,6 +130,7 @@ type aProgram struct {
 	voidPtr   Type
 	boolTy    Type
 	cstrTy    Type
+	cintTy    Type
 	stringTy  Type
 	uintptrTy Type
 	intTy     Type
@@ -137,11 +138,17 @@ type aProgram struct {
 	pyObjPtr  Type
 	pyObjPPtr Type
 
-	pyImpTy    *types.Signature
+	pyImpTy *types.Signature
+	//pyNewList  *types.Signature
+	//pyListSetI *types.Signature
+	//callArgs   *types.Signature
 	callNoArgs *types.Signature
 	callOneArg *types.Signature
+	callFOArgs *types.Signature
 	loadPyModS *types.Signature
 
+	paramObjPtr_ *types.Var
+
 	NeedRuntime bool
 	NeedPyInit  bool
 }
@@ -328,6 +335,13 @@ func (p Program) Any() Type {
 	return p.anyTy
 }
 
+func (p Program) CInt() Type {
+	if p.cintTy == nil { // C.int
+		p.cintTy = p.rawType(types.Typ[types.Int32]) // TODO(xsw): support 64-bit
+	}
+	return p.cintTy
+}
+
 // Int returns int type.
 func (p Program) Int() Type {
 	if p.intTy == nil {
@@ -475,12 +489,19 @@ func (p *Package) WriteFile(file string) (err error) {
 
 // -----------------------------------------------------------------------------
 
+func (p Program) paramObjPtr() *types.Var {
+	if p.paramObjPtr_ == nil {
+		objPtr := p.PyObjectPtr().raw.Type
+		p.paramObjPtr_ = types.NewParam(token.NoPos, nil, "", objPtr)
+	}
+	return p.paramObjPtr_
+}
+
 func (p Program) tyImportPyModule() *types.Signature {
 	if p.pyImpTy == nil {
 		charPtr := types.NewPointer(types.Typ[types.Int8])
-		objPtr := p.PyObjectPtr().raw.Type
 		params := types.NewTuple(types.NewParam(token.NoPos, nil, "", charPtr))
-		results := types.NewTuple(types.NewParam(token.NoPos, nil, "", objPtr))
+		results := types.NewTuple(p.paramObjPtr())
 		p.pyImpTy = types.NewSignatureType(nil, nil, nil, params, results, false)
 	}
 	return p.pyImpTy
@@ -488,9 +509,7 @@ func (p Program) tyImportPyModule() *types.Signature {
 
 func (p Program) tyCallNoArgs() *types.Signature {
 	if p.callNoArgs == nil {
-		objPtr := p.PyObjectPtr().raw.Type
-		paramObjPtr := types.NewParam(token.NoPos, nil, "", objPtr)
-		params := types.NewTuple(paramObjPtr)
+		params := types.NewTuple(p.paramObjPtr())
 		p.callNoArgs = types.NewSignatureType(nil, nil, nil, params, params, false)
 	}
 	return p.callNoArgs
@@ -498,8 +517,7 @@ func (p Program) tyCallNoArgs() *types.Signature {
 
 func (p Program) tyCallOneArg() *types.Signature {
 	if p.callOneArg == nil {
-		objPtr := p.PyObjectPtr().raw.Type
-		paramObjPtr := types.NewParam(token.NoPos, nil, "", objPtr)
+		paramObjPtr := p.paramObjPtr()
 		params := types.NewTuple(paramObjPtr, paramObjPtr)
 		results := types.NewTuple(paramObjPtr)
 		p.callOneArg = types.NewSignatureType(nil, nil, nil, params, results, false)
@@ -507,6 +525,50 @@ func (p Program) tyCallOneArg() *types.Signature {
 	return p.callOneArg
 }
 
+func (p Program) tyCallFunctionObjArgs() *types.Signature {
+	if p.callFOArgs == nil {
+		paramObjPtr := p.paramObjPtr()
+		params := types.NewTuple(paramObjPtr, VArg())
+		results := types.NewTuple(paramObjPtr)
+		p.callFOArgs = types.NewSignatureType(nil, nil, nil, params, results, false)
+	}
+	return p.callFOArgs
+}
+
+/*
+func (p Program) tyCall() *types.Signature {
+	if p.callArgs == nil {
+		paramObjPtr := p.paramObjPtr()
+		params := types.NewTuple(paramObjPtr, paramObjPtr, paramObjPtr)
+		results := types.NewTuple(paramObjPtr)
+		p.callArgs = types.NewSignatureType(nil, nil, nil, params, results, false)
+	}
+	return p.callArgs
+}
+
+func (p Program) tyListSetItem() *types.Signature {
+	if p.pyListSetI == nil {
+		paramUintptr := types.NewParam(token.NoPos, nil, "", p.Uintptr().raw.Type)
+		paramCInt := types.NewParam(token.NoPos, nil, "", p.CInt().raw.Type)
+		paramObjPtr := p.paramObjPtr()
+		params := types.NewTuple(paramObjPtr, paramUintptr, paramObjPtr)
+		results := types.NewTuple(paramCInt)
+		p.pyListSetI = types.NewSignatureType(nil, nil, nil, params, results, false)
+	}
+	return p.pyListSetI
+}
+
+func (p Program) tyNewList() *types.Signature {
+	if p.pyNewList == nil {
+		paramUintptr := types.NewParam(token.NoPos, nil, "", p.Uintptr().raw.Type)
+		params := types.NewTuple(paramUintptr)
+		results := types.NewTuple(p.paramObjPtr())
+		p.pyNewList = types.NewSignatureType(nil, nil, nil, params, results, false)
+	}
+	return p.pyNewList
+}
+*/
+
 func (p Program) tyLoadPyModSyms() *types.Signature {
 	if p.loadPyModS == nil {
 		objPtr := p.PyObjectPtr().raw.Type
@@ -586,11 +648,47 @@ func (b Builder) pyCall(fn Expr, args []Expr) (ret Expr) {
 		call := pkg.pyFunc("PyObject_CallOneArg", prog.tyCallOneArg())
 		ret = b.Call(call, fn, args[0])
 	default:
-		panic("todo")
+		call := pkg.pyFunc("PyObject_CallFunctionObjArgs", prog.tyCallFunctionObjArgs())
+		n = len(args)
+		callargs := make([]Expr, n+2)
+		callargs[0] = fn
+		copy(callargs[1:], args)
+		callargs[n+1] = prog.PyNull()
+		ret = b.Call(call, callargs...)
 	}
 	return
 }
 
+/*
+// PyNewList(n uintptr) *Object
+func (b Builder) PyNewList(n Expr) (ret Expr) {
+	prog := b.Prog
+	pkg := b.Func.Pkg
+	fn := pkg.pyFunc("PyList_New", prog.tyNewList())
+	return b.Call(fn, n)
+}
+
+// PyListSetItem(list *Object, index uintptr, item *Object) c.Int
+func (b Builder) PyListSetItem(list, index, item Expr) (ret Expr) {
+	prog := b.Prog
+	pkg := b.Func.Pkg
+	fn := pkg.pyFunc("PyList_SetItem", prog.tyListSetItem())
+	return b.Call(fn, list, index, item)
+}
+
+// PyList(items ...*Object) *Object
+func (b Builder) PyList(args ...Expr) (ret Expr) {
+	prog := b.Prog
+	n := len(args)
+	uintPtr := prog.Uintptr()
+	list := b.PyNewList(prog.IntVal(uint64(n), uintPtr))
+	for i, arg := range args {
+		b.PyListSetItem(list, prog.IntVal(uint64(i), uintPtr), arg)
+	}
+	return list
+}
+*/
+
 // CallPyInit calls Py_Initialize.
 func (b Builder) CallPyInit() (ret Expr) {
 	fn := b.Func.Pkg.pyFunc("Py_Initialize", NoArgsNoRet)