diff --git a/_demo/rtype/rtype.go b/_demo/rtype/rtype.go
index 48938568..17eb7d5f 100644
--- a/_demo/rtype/rtype.go
+++ b/_demo/rtype/rtype.go
@@ -8,4 +8,7 @@ func main() {
 
 	v := reflect.Zero(tyIntSlice)
 	println(v.Len())
+
+	v = reflect.ValueOf(100)
+	println(v.Int())
 }
diff --git a/internal/lib/reflect/value.go b/internal/lib/reflect/value.go
index 4daf3e44..f2add569 100644
--- a/internal/lib/reflect/value.go
+++ b/internal/lib/reflect/value.go
@@ -101,6 +101,83 @@ func (f flag) ro() flag {
 	return 0
 }
 
+func (v Value) typ() *abi.Type {
+	// Types are either static (for compiler-created types) or
+	// heap-allocated but always reachable (for reflection-created
+	// types, held in the central map). So there is no need to
+	// escape types. noescape here help avoid unnecessary escape
+	// of v.
+	return (*abi.Type)(unsafe.Pointer(v.typ_))
+}
+
+// pointer returns the underlying pointer represented by v.
+// v.Kind() must be Pointer, Map, Chan, Func, or UnsafePointer
+// if v.Kind() == Pointer, the base type must not be not-in-heap.
+func (v Value) pointer() unsafe.Pointer {
+	/*
+		if v.typ().Size() != goarch.PtrSize || !v.typ().Pointers() {
+			panic("can't call pointer on a non-pointer Value")
+		}
+		if v.flag&flagIndir != 0 {
+			return *(*unsafe.Pointer)(v.ptr)
+		}
+		return v.ptr
+	*/
+	panic("todo")
+}
+
+// packEface converts v to the empty interface.
+func packEface(v Value) any {
+	t := v.typ()
+	var i any
+	e := (*emptyInterface)(unsafe.Pointer(&i))
+	// First, fill in the data portion of the interface.
+	switch {
+	case t.IfaceIndir():
+		if v.flag&flagIndir == 0 {
+			panic("bad indir")
+		}
+		// Value is indirect, and so is the interface we're making.
+		ptr := v.ptr
+		if v.flag&flagAddr != 0 {
+			// TODO: pass safe boolean from valueInterface so
+			// we don't need to copy if safe==true?
+			c := unsafe_New(t)
+			typedmemmove(t, c, ptr)
+			ptr = c
+		}
+		e.word = ptr
+	case v.flag&flagIndir != 0:
+		// Value is indirect, but interface is direct. We need
+		// to load the data at v.ptr into the interface data word.
+		e.word = *(*unsafe.Pointer)(v.ptr)
+	default:
+		// Value is direct, and so is the interface.
+		e.word = v.ptr
+	}
+	// Now, fill in the type portion. We're very careful here not
+	// to have any operation between the e.word and e.typ assignments
+	// that would let the garbage collector observe the partially-built
+	// interface value.
+	e.typ = t
+	return i
+}
+
+// unpackEface converts the empty interface i to a Value.
+func unpackEface(i any) Value {
+	e := (*emptyInterface)(unsafe.Pointer(&i))
+	// NOTE: don't read e.word until we know whether it is really a pointer or not.
+	t := e.typ
+	if t == nil {
+		return Value{}
+	}
+	f := flag(t.Kind())
+	if t.IfaceIndir() {
+		f |= flagIndir
+	}
+	return Value{t, e.word, f}
+}
+
 // A ValueError occurs when a Value method is invoked on
 // a Value that does not support it. Such cases are documented
 // in the description of each method.
@@ -227,14 +304,17 @@ func (v Value) Int() int64 {
 	p := v.ptr
 	switch k {
 	case Int:
-		return int64(*(*int)(p))
+		return int64(uintptr(p))
 	case Int8:
-		return int64(*(*int8)(p))
+		return int64(uintptr(p))
 	case Int16:
-		return int64(*(*int16)(p))
+		return int64(uintptr(p))
 	case Int32:
-		return int64(*(*int32)(p))
+		return int64(uintptr(p))
 	case Int64:
+		if unsafe.Sizeof(uintptr(0)) == 8 {
+			return int64(uintptr(p))
+		}
 		return *(*int64)(p)
 	}
 	panic(&ValueError{"reflect.Value.Int", v.kind()})
@@ -520,6 +600,16 @@ func unsafe_New(*abi.Type) unsafe.Pointer
 //go:linkname unsafe_NewArray github.com/goplus/llgo/internal/runtime.NewArray
 func unsafe_NewArray(*abi.Type, int) unsafe.Pointer
 
+// ValueOf returns a new Value initialized to the concrete value
+// stored in the interface i. ValueOf(nil) returns the zero Value.
+func ValueOf(i any) Value {
+	if i == nil {
+		return Value{}
+	}
+
+	return unpackEface(i)
+}
+
 // Zero returns a Value representing the zero value for the specified type.
 // The result is different from the zero value of the Value struct,
 // which represents no value at all.
@@ -546,3 +636,46 @@ func Zero(typ Type) Value {
 // TODO(xsw): check this
 // must match declarations in runtime/map.go.
 const maxZero = runtime.MaxZero
+
+// memmove copies size bytes to dst from src. No write barriers are used.
+//
+//go:linkname memmove C.memmove
+func memmove(dst, src unsafe.Pointer, size uintptr)
+
+// typedmemmove copies a value of type t to dst from src.
+//
+//go:linkname typedmemmove github.com/goplus/llgo/internal/runtime.Typedmemmove
+func typedmemmove(t *abi.Type, dst, src unsafe.Pointer)
+
+/* TODO(xsw):
+// typedmemclr zeros the value at ptr of type t.
+//
+//go:noescape
+func typedmemclr(t *abi.Type, ptr unsafe.Pointer)
+
+// typedmemclrpartial is like typedmemclr but assumes that
+// dst points off bytes into the value and only clears size bytes.
+//
+//go:noescape
+func typedmemclrpartial(t *abi.Type, ptr unsafe.Pointer, off, size uintptr)
+
+// typedslicecopy copies a slice of elemType values from src to dst,
+// returning the number of elements copied.
+//
+//go:noescape
+func typedslicecopy(t *abi.Type, dst, src unsafeheaderSlice) int
+
+// typedarrayclear zeroes the value at ptr of an array of elemType,
+// only clears len elem.
+//
+//go:noescape
+func typedarrayclear(elemType *abi.Type, ptr unsafe.Pointer, len int)
+
+//go:noescape
+func typehash(t *abi.Type, p unsafe.Pointer, h uintptr) uintptr
+
+func verifyNotInHeapPtr(p uintptr) bool
+
+//go:noescape
+func growslice(t *abi.Type, old unsafeheaderSlice, num int) unsafeheaderSlice
+*/
diff --git a/internal/runtime/mbarrier.go b/internal/runtime/mbarrier.go
new file mode 100644
index 00000000..765970c1
--- /dev/null
+++ b/internal/runtime/mbarrier.go
@@ -0,0 +1,340 @@
+// Copyright 2015 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.
+
+// Garbage collector: write barriers.
+//
+// For the concurrent garbage collector, the Go compiler implements
+// updates to pointer-valued fields that may be in heap objects by
+// emitting calls to write barriers. The main write barrier for
+// individual pointer writes is gcWriteBarrier and is implemented in
+// assembly. This file contains write barrier entry points for bulk
+// operations. See also mwbbuf.go.
+
+package runtime
+
+import (
+	"unsafe"
+
+	"github.com/goplus/llgo/c"
+)
+
+// Go uses a hybrid barrier that combines a Yuasa-style deletion
+// barrier—which shades the object whose reference is being
+// overwritten—with Dijkstra insertion barrier—which shades the object
+// whose reference is being written. The insertion part of the barrier
+// is necessary while the calling goroutine's stack is grey. In
+// pseudocode, the barrier is:
+//
+//     writePointer(slot, ptr):
+//         shade(*slot)
+//         if current stack is grey:
+//             shade(ptr)
+//         *slot = ptr
+//
+// slot is the destination in Go code.
+// ptr is the value that goes into the slot in Go code.
+//
+// Shade indicates that it has seen a white pointer by adding the referent
+// to wbuf as well as marking it.
+//
+// The two shades and the condition work together to prevent a mutator
+// from hiding an object from the garbage collector:
+//
+// 1. shade(*slot) prevents a mutator from hiding an object by moving
+// the sole pointer to it from the heap to its stack. If it attempts
+// to unlink an object from the heap, this will shade it.
+//
+// 2. shade(ptr) prevents a mutator from hiding an object by moving
+// the sole pointer to it from its stack into a black object in the
+// heap. If it attempts to install the pointer into a black object,
+// this will shade it.
+//
+// 3. Once a goroutine's stack is black, the shade(ptr) becomes
+// unnecessary. shade(ptr) prevents hiding an object by moving it from
+// the stack to the heap, but this requires first having a pointer
+// hidden on the stack. Immediately after a stack is scanned, it only
+// points to shaded objects, so it's not hiding anything, and the
+// shade(*slot) prevents it from hiding any other pointers on its
+// stack.
+//
+// For a detailed description of this barrier and proof of
+// correctness, see https://github.com/golang/proposal/blob/master/design/17503-eliminate-rescan.md
+//
+//
+//
+// Dealing with memory ordering:
+//
+// Both the Yuasa and Dijkstra barriers can be made conditional on the
+// color of the object containing the slot. We chose not to make these
+// conditional because the cost of ensuring that the object holding
+// the slot doesn't concurrently change color without the mutator
+// noticing seems prohibitive.
+//
+// Consider the following example where the mutator writes into
+// a slot and then loads the slot's mark bit while the GC thread
+// writes to the slot's mark bit and then as part of scanning reads
+// the slot.
+//
+// Initially both [slot] and [slotmark] are 0 (nil)
+// Mutator thread          GC thread
+// st [slot], ptr          st [slotmark], 1
+//
+// ld r1, [slotmark]       ld r2, [slot]
+//
+// Without an expensive memory barrier between the st and the ld, the final
+// result on most HW (including 386/amd64) can be r1==r2==0. This is a classic
+// example of what can happen when loads are allowed to be reordered with older
+// stores (avoiding such reorderings lies at the heart of the classic
+// Peterson/Dekker algorithms for mutual exclusion). Rather than require memory
+// barriers, which will slow down both the mutator and the GC, we always grey
+// the ptr object regardless of the slot's color.
+//
+// Another place where we intentionally omit memory barriers is when
+// accessing mheap_.arena_used to check if a pointer points into the
+// heap. On relaxed memory machines, it's possible for a mutator to
+// extend the size of the heap by updating arena_used, allocate an
+// object from this new region, and publish a pointer to that object,
+// but for tracing running on another processor to observe the pointer
+// but use the old value of arena_used. In this case, tracing will not
+// mark the object, even though it's reachable. However, the mutator
+// is guaranteed to execute a write barrier when it publishes the
+// pointer, so it will take care of marking the object. A general
+// consequence of this is that the garbage collector may cache the
+// value of mheap_.arena_used. (See issue #9984.)
+//
+//
+// Stack writes:
+//
+// The compiler omits write barriers for writes to the current frame,
+// but if a stack pointer has been passed down the call stack, the
+// compiler will generate a write barrier for writes through that
+// pointer (because it doesn't know it's not a heap pointer).
+//
+//
+// Global writes:
+//
+// The Go garbage collector requires write barriers when heap pointers
+// are stored in globals. Many garbage collectors ignore writes to
+// globals and instead pick up global -> heap pointers during
+// termination. This increases pause time, so we instead rely on write
+// barriers for writes to globals so that we don't have to rescan
+// global during mark termination.
+//
+//
+// Publication ordering:
+//
+// The write barrier is *pre-publication*, meaning that the write
+// barrier happens prior to the *slot = ptr write that may make ptr
+// reachable by some goroutine that currently cannot reach it.
+//
+//
+// Signal handler pointer writes:
+//
+// In general, the signal handler cannot safely invoke the write
+// barrier because it may run without a P or even during the write
+// barrier.
+//
+// There is exactly one exception: profbuf.go omits a barrier during
+// signal handler profile logging. That's safe only because of the
+// deletion barrier. See profbuf.go for a detailed argument. If we
+// remove the deletion barrier, we'll have to work out a new way to
+// handle the profile logging.
+
+// typedmemmove copies a value of type typ to dst from src.
+// Must be nosplit, see #16026.
+//
+// TODO: Perfect for go:nosplitrec since we can't have a safe point
+// anywhere in the bulk barrier or memmove.
+func Typedmemmove(typ *Type, dst, src unsafe.Pointer) {
+	if dst == src {
+		return
+	}
+	// There's a race here: if some other goroutine can write to
+	// src, it may change some pointer in src after we've
+	// performed the write barrier but before we perform the
+	// memory copy. This safe because the write performed by that
+	// other goroutine must also be accompanied by a write
+	// barrier, so at worst we've unnecessarily greyed the old
+	// pointer that was in src.
+	c.Memmove(dst, src, typ.Size_)
+}
+
+/*
+// wbZero performs the write barrier operations necessary before
+// zeroing a region of memory at address dst of type typ.
+// Does not actually do the zeroing.
+//
+//go:nowritebarrierrec
+//go:nosplit
+func wbZero(typ *_type, dst unsafe.Pointer) {
+	bulkBarrierPreWrite(uintptr(dst), 0, typ.PtrBytes)
+}
+
+// wbMove performs the write barrier operations necessary before
+// copying a region of memory from src to dst of type typ.
+// Does not actually do the copying.
+//
+//go:nowritebarrierrec
+//go:nosplit
+func wbMove(typ *_type, dst, src unsafe.Pointer) {
+	bulkBarrierPreWrite(uintptr(dst), uintptr(src), typ.PtrBytes)
+}
+
+//go:linkname reflect_typedmemmove reflect.typedmemmove
+func reflect_typedmemmove(typ *_type, dst, src unsafe.Pointer) {
+	if raceenabled {
+		raceWriteObjectPC(typ, dst, getcallerpc(), abi.FuncPCABIInternal(reflect_typedmemmove))
+		raceReadObjectPC(typ, src, getcallerpc(), abi.FuncPCABIInternal(reflect_typedmemmove))
+	}
+	if msanenabled {
+		msanwrite(dst, typ.Size_)
+		msanread(src, typ.Size_)
+	}
+	if asanenabled {
+		asanwrite(dst, typ.Size_)
+		asanread(src, typ.Size_)
+	}
+	typedmemmove(typ, dst, src)
+}
+
+//go:linkname reflectlite_typedmemmove internal/reflectlite.typedmemmove
+func reflectlite_typedmemmove(typ *_type, dst, src unsafe.Pointer) {
+	reflect_typedmemmove(typ, dst, src)
+}
+
+// reflectcallmove is invoked by reflectcall to copy the return values
+// out of the stack and into the heap, invoking the necessary write
+// barriers. dst, src, and size describe the return value area to
+// copy. typ describes the entire frame (not just the return values).
+// typ may be nil, which indicates write barriers are not needed.
+//
+// It must be nosplit and must only call nosplit functions because the
+// stack map of reflectcall is wrong.
+//
+//go:nosplit
+func reflectcallmove(typ *_type, dst, src unsafe.Pointer, size uintptr, regs *abi.RegArgs) {
+	if writeBarrier.needed && typ != nil && typ.PtrBytes != 0 && size >= goarch.PtrSize {
+		bulkBarrierPreWrite(uintptr(dst), uintptr(src), size)
+	}
+	memmove(dst, src, size)
+
+	// Move pointers returned in registers to a place where the GC can see them.
+	for i := range regs.Ints {
+		if regs.ReturnIsPtr.Get(i) {
+			regs.Ptrs[i] = unsafe.Pointer(regs.Ints[i])
+		}
+	}
+}
+
+//go:nosplit
+func typedslicecopy(typ *_type, dstPtr unsafe.Pointer, dstLen int, srcPtr unsafe.Pointer, srcLen int) int {
+	n := dstLen
+	if n > srcLen {
+		n = srcLen
+	}
+	if n == 0 {
+		return 0
+	}
+
+	// The compiler emits calls to typedslicecopy before
+	// instrumentation runs, so unlike the other copying and
+	// assignment operations, it's not instrumented in the calling
+	// code and needs its own instrumentation.
+	if raceenabled {
+		callerpc := getcallerpc()
+		pc := abi.FuncPCABIInternal(slicecopy)
+		racewriterangepc(dstPtr, uintptr(n)*typ.Size_, callerpc, pc)
+		racereadrangepc(srcPtr, uintptr(n)*typ.Size_, callerpc, pc)
+	}
+	if msanenabled {
+		msanwrite(dstPtr, uintptr(n)*typ.Size_)
+		msanread(srcPtr, uintptr(n)*typ.Size_)
+	}
+	if asanenabled {
+		asanwrite(dstPtr, uintptr(n)*typ.Size_)
+		asanread(srcPtr, uintptr(n)*typ.Size_)
+	}
+
+	if goexperiment.CgoCheck2 {
+		cgoCheckSliceCopy(typ, dstPtr, srcPtr, n)
+	}
+
+	if dstPtr == srcPtr {
+		return n
+	}
+
+	// Note: No point in checking typ.PtrBytes here:
+	// compiler only emits calls to typedslicecopy for types with pointers,
+	// and growslice and reflect_typedslicecopy check for pointers
+	// before calling typedslicecopy.
+	size := uintptr(n) * typ.Size_
+	if writeBarrier.needed {
+		pwsize := size - typ.Size_ + typ.PtrBytes
+		bulkBarrierPreWrite(uintptr(dstPtr), uintptr(srcPtr), pwsize)
+	}
+	// See typedmemmove for a discussion of the race between the
+	// barrier and memmove.
+	memmove(dstPtr, srcPtr, size)
+	return n
+}
+
+//go:linkname reflect_typedslicecopy reflect.typedslicecopy
+func reflect_typedslicecopy(elemType *_type, dst, src slice) int {
+	if elemType.PtrBytes == 0 {
+		return slicecopy(dst.array, dst.len, src.array, src.len, elemType.Size_)
+	}
+	return typedslicecopy(elemType, dst.array, dst.len, src.array, src.len)
+}
+
+// typedmemclr clears the typed memory at ptr with type typ. The
+// memory at ptr must already be initialized (and hence in type-safe
+// state). If the memory is being initialized for the first time, see
+// memclrNoHeapPointers.
+//
+// If the caller knows that typ has pointers, it can alternatively
+// call memclrHasPointers.
+//
+// TODO: A "go:nosplitrec" annotation would be perfect for this.
+//
+//go:nosplit
+func typedmemclr(typ *_type, ptr unsafe.Pointer) {
+	if writeBarrier.needed && typ.PtrBytes != 0 {
+		bulkBarrierPreWrite(uintptr(ptr), 0, typ.PtrBytes)
+	}
+	memclrNoHeapPointers(ptr, typ.Size_)
+}
+
+//go:linkname reflect_typedmemclr reflect.typedmemclr
+func reflect_typedmemclr(typ *_type, ptr unsafe.Pointer) {
+	typedmemclr(typ, ptr)
+}
+
+//go:linkname reflect_typedmemclrpartial reflect.typedmemclrpartial
+func reflect_typedmemclrpartial(typ *_type, ptr unsafe.Pointer, off, size uintptr) {
+	if writeBarrier.needed && typ.PtrBytes != 0 {
+		bulkBarrierPreWrite(uintptr(ptr), 0, size)
+	}
+	memclrNoHeapPointers(ptr, size)
+}
+
+//go:linkname reflect_typedarrayclear reflect.typedarrayclear
+func reflect_typedarrayclear(typ *_type, ptr unsafe.Pointer, len int) {
+	size := typ.Size_ * uintptr(len)
+	if writeBarrier.needed && typ.PtrBytes != 0 {
+		bulkBarrierPreWrite(uintptr(ptr), 0, size)
+	}
+	memclrNoHeapPointers(ptr, size)
+}
+
+// memclrHasPointers clears n bytes of typed memory starting at ptr.
+// The caller must ensure that the type of the object at ptr has
+// pointers, usually by checking typ.PtrBytes. However, ptr
+// does not have to point to the start of the allocation.
+//
+//go:nosplit
+func memclrHasPointers(ptr unsafe.Pointer, n uintptr) {
+	bulkBarrierPreWrite(uintptr(ptr), 0, n)
+	memclrNoHeapPointers(ptr, n)
+}
+*/