diff --git a/encode.go b/encode.go
index eb2f1e3..556bd57 100644
--- a/encode.go
+++ b/encode.go
@@ -164,9 +164,9 @@ func (e *Encoder) encode(v interface{}) error {
 		}
 		ctx := codeSet.ctx.Get().(*encodeRuntimeContext)
 		p := uintptr(header.ptr)
-		ctx.reset()
 		ctx.init(p)
-		err := e.run(ctx, code)
+		seenPtr := map[uintptr]struct{}{}
+		err := e.run(ctx, seenPtr, code)
 		if e.enabledIndent {
 			codeSet.codeIndent.Put(code)
 		} else {
@@ -210,8 +210,7 @@ func (e *Encoder) encode(v interface{}) error {
 		ctx: sync.Pool{
 			New: func() interface{} {
 				return &encodeRuntimeContext{
-					ptrs:    make([]uintptr, codeLength),
-					seenPtr: map[uintptr]struct{}{},
+					ptrs: make([]uintptr, codeLength),
 				}
 			},
 		},
@@ -219,19 +218,22 @@ func (e *Encoder) encode(v interface{}) error {
 	cachedOpcode.set(typeptr, codeSet)
 	p := uintptr(header.ptr)
 	ctx := codeSet.ctx.Get().(*encodeRuntimeContext)
-	ctx.reset()
 	ctx.init(p)
+
+	var c *opcode
 	if e.enabledIndent {
-		err := e.run(ctx, codeIndent)
-		codeSet.ctx.Put(ctx)
-		return err
+		c = codeIndent
+	} else {
+		c = code
 	}
-	if err := e.run(ctx, code); err != nil {
+
+	seenPtr := map[uintptr]struct{}{}
+	if err := e.run(ctx, seenPtr, c); err != nil {
 		codeSet.ctx.Put(ctx)
 		return err
 	}
 	codeSet.ctx.Put(ctx)
-	return err
+	return nil
 }
 
 func (e *Encoder) encodeInt(v int) {
diff --git a/encode_compile.go b/encode_compile.go
index c2e6ed7..eb98048 100644
--- a/encode_compile.go
+++ b/encode_compile.go
@@ -267,11 +267,12 @@ func (e *Encoder) compileBytes(ctx *encodeCompileContext) (*opcode, error) {
 func (e *Encoder) compileInterface(ctx *encodeCompileContext) (*opcode, error) {
 	code := (*opcode)(unsafe.Pointer(&interfaceCode{
 		opcodeHeader: &opcodeHeader{
-			op:     opInterface,
-			typ:    ctx.typ,
-			idx:    ctx.opcodeIndex,
-			indent: ctx.indent,
-			next:   newEndOp(ctx),
+			op:         opInterface,
+			typ:        ctx.typ,
+			displayIdx: ctx.opcodeIndex,
+			idx:        uintptr(ctx.opcodeIndex) * 8,
+			indent:     ctx.indent,
+			next:       newEndOp(ctx),
 		},
 		root: ctx.root,
 	}))
@@ -588,11 +589,12 @@ func (e *Encoder) optimizeStructField(op opType, tag *structTag, withIndent bool
 func (e *Encoder) recursiveCode(ctx *encodeCompileContext, code *compiledCode) *opcode {
 	c := (*opcode)(unsafe.Pointer(&recursiveCode{
 		opcodeHeader: &opcodeHeader{
-			op:     opStructFieldRecursive,
-			typ:    ctx.typ,
-			idx:    ctx.opcodeIndex,
-			indent: ctx.indent,
-			next:   newEndOp(ctx),
+			op:         opStructFieldRecursive,
+			typ:        ctx.typ,
+			displayIdx: ctx.opcodeIndex,
+			idx:        uintptr(ctx.opcodeIndex) * 8,
+			indent:     ctx.indent,
+			next:       newEndOp(ctx),
 		},
 		jmp: code,
 	}))
@@ -726,7 +728,7 @@ func (e *Encoder) optimizeAnonymousFields(head *structFieldCode) {
 			if codeType == codeStructField {
 				if e.isNotExistsField(code.next.toStructFieldCode()) {
 					code.next = code.nextField
-					diff := code.next.idx - code.idx
+					diff := code.next.displayIdx - code.displayIdx
 					for i := 0; i < diff; i++ {
 						code.next.decOpcodeIndex()
 					}
@@ -763,7 +765,7 @@ func (e *Encoder) anonymousStructFieldPairMap(typ *rtype, tags structTags, value
 		} else if f.op == opStructEnd {
 			f.op = opStructAnonymousEnd
 		} else if existsKey {
-			diff := f.nextField.idx - f.idx
+			diff := f.nextField.displayIdx - f.displayIdx
 			for i := 0; i < diff; i++ {
 				f.nextField.decOpcodeIndex()
 			}
@@ -814,7 +816,7 @@ func (e *Encoder) optimizeConflictAnonymousFields(anonymousFields map[string][]s
 						// head operation
 						fieldPair.curField.op = opStructFieldAnonymousHead
 					} else {
-						diff := fieldPair.curField.nextField.idx - fieldPair.curField.idx
+						diff := fieldPair.curField.nextField.displayIdx - fieldPair.curField.displayIdx
 						for i := 0; i < diff; i++ {
 							fieldPair.curField.nextField.decOpcodeIndex()
 						}
@@ -831,7 +833,7 @@ func (e *Encoder) optimizeConflictAnonymousFields(anonymousFields map[string][]s
 						// head operation
 						fieldPair.curField.op = opStructFieldAnonymousHead
 					} else {
-						diff := fieldPair.curField.nextField.idx - fieldPair.curField.idx
+						diff := fieldPair.curField.nextField.displayIdx - fieldPair.curField.displayIdx
 						for i := 0; i < diff; i++ {
 							fieldPair.curField.nextField.decOpcodeIndex()
 						}
@@ -919,10 +921,11 @@ func (e *Encoder) compileStruct(ctx *encodeCompileContext, isPtr bool) (*opcode,
 		key := fmt.Sprintf(`"%s":`, tag.key)
 		fieldCode := &structFieldCode{
 			opcodeHeader: &opcodeHeader{
-				typ:    valueCode.typ,
-				idx:    fieldOpcodeIndex,
-				next:   valueCode,
-				indent: ctx.indent,
+				typ:        valueCode.typ,
+				displayIdx: fieldOpcodeIndex,
+				idx:        uintptr(fieldOpcodeIndex) * 8,
+				next:       valueCode,
+				indent:     ctx.indent,
 			},
 			anonymousKey: field.Anonymous,
 			key:          []byte(key),
@@ -958,10 +961,11 @@ func (e *Encoder) compileStruct(ctx *encodeCompileContext, isPtr bool) (*opcode,
 	if head == nil {
 		head = &structFieldCode{
 			opcodeHeader: &opcodeHeader{
-				op:     opStructFieldHead,
-				typ:    typ,
-				idx:    ctx.opcodeIndex,
-				indent: ctx.indent,
+				op:         opStructFieldHead,
+				typ:        typ,
+				displayIdx: ctx.opcodeIndex,
+				idx:        uintptr(ctx.opcodeIndex) * 8,
+				indent:     ctx.indent,
 			},
 			nextField: structEndCode,
 		}
@@ -972,7 +976,8 @@ func (e *Encoder) compileStruct(ctx *encodeCompileContext, isPtr bool) (*opcode,
 		code = (*opcode)(unsafe.Pointer(head))
 	}
 
-	structEndCode.idx = ctx.opcodeIndex
+	structEndCode.displayIdx = ctx.opcodeIndex
+	structEndCode.idx = uintptr(ctx.opcodeIndex) * 8
 	ctx.incOpcodeIndex()
 
 	if ctx.withIndent {
diff --git a/encode_context.go b/encode_context.go
index 0c7ee1b..ec30d68 100644
--- a/encode_context.go
+++ b/encode_context.go
@@ -59,12 +59,7 @@ func (c *encodeCompileContext) decOpcodeIndex() {
 }
 
 type encodeRuntimeContext struct {
-	ptrs    []uintptr
-	seenPtr map[uintptr]struct{}
-}
-
-func (c *encodeRuntimeContext) reset() {
-	c.seenPtr = map[uintptr]struct{}{}
+	ptrs []uintptr
 }
 
 func (c *encodeRuntimeContext) init(p uintptr) {
diff --git a/encode_opcode.go b/encode_opcode.go
index 0b49ed0..7cc4ae9 100644
--- a/encode_opcode.go
+++ b/encode_opcode.go
@@ -13,20 +13,22 @@ func copyOpcode(code *opcode) *opcode {
 }
 
 type opcodeHeader struct {
-	op     opType
-	typ    *rtype
-	idx    int
-	indent int
-	next   *opcode
+	op         opType
+	typ        *rtype
+	displayIdx int
+	idx        uintptr
+	indent     int
+	next       *opcode
 }
 
 func (h *opcodeHeader) copy(codeMap map[uintptr]*opcode) *opcodeHeader {
 	return &opcodeHeader{
-		op:     h.op,
-		typ:    h.typ,
-		idx:    h.idx,
-		indent: h.indent,
-		next:   h.next.copy(codeMap),
+		op:         h.op,
+		typ:        h.typ,
+		displayIdx: h.displayIdx,
+		idx:        h.idx,
+		indent:     h.indent,
+		next:       h.next.copy(codeMap),
 	}
 }
 
@@ -41,11 +43,12 @@ func newOpCode(ctx *encodeCompileContext, op opType) *opcode {
 func newOpCodeWithNext(ctx *encodeCompileContext, op opType, next *opcode) *opcode {
 	return &opcode{
 		opcodeHeader: &opcodeHeader{
-			op:     op,
-			typ:    ctx.typ,
-			idx:    ctx.opcodeIndex,
-			indent: ctx.indent,
-			next:   next,
+			op:         op,
+			typ:        ctx.typ,
+			displayIdx: ctx.opcodeIndex,
+			idx:        uintptr(ctx.opcodeIndex) * 8,
+			indent:     ctx.indent,
+			next:       next,
 		},
 	}
 }
@@ -79,7 +82,7 @@ func (c *opcode) beforeLastCode() *opcode {
 func (c *opcode) length() int {
 	var idx int
 	for code := c; code.op != opEnd; {
-		idx = code.idx
+		idx = code.displayIdx
 		switch code.op.codeType() {
 		case codeArrayElem:
 			code = code.toArrayElemCode().end
@@ -96,7 +99,8 @@ func (c *opcode) length() int {
 
 func (c *opcode) decOpcodeIndex() {
 	for code := c; code.op != opEnd; {
-		code.idx--
+		code.displayIdx--
+		code.idx -= 8
 		switch code.op.codeType() {
 		case codeArrayElem:
 			code = code.toArrayElemCode().end
@@ -153,22 +157,22 @@ func (c *opcode) dump() string {
 		indent := strings.Repeat(" ", code.indent)
 		switch code.op.codeType() {
 		case codeArrayElem:
-			codes = append(codes, fmt.Sprintf("[%d]%s%s ( %p )", code.idx, indent, code.op, unsafe.Pointer(code)))
+			codes = append(codes, fmt.Sprintf("[%d]%s%s ( %p )", code.displayIdx, indent, code.op, unsafe.Pointer(code)))
 			code = code.toArrayElemCode().end
 		case codeSliceElem:
-			codes = append(codes, fmt.Sprintf("[%d]%s%s ( %p )", code.idx, indent, code.op, unsafe.Pointer(code)))
+			codes = append(codes, fmt.Sprintf("[%d]%s%s ( %p )", code.displayIdx, indent, code.op, unsafe.Pointer(code)))
 			code = code.toSliceElemCode().end
 		case codeMapKey:
-			codes = append(codes, fmt.Sprintf("[%d]%s%s ( %p )", code.idx, indent, code.op, unsafe.Pointer(code)))
+			codes = append(codes, fmt.Sprintf("[%d]%s%s ( %p )", code.displayIdx, indent, code.op, unsafe.Pointer(code)))
 			code = code.toMapKeyCode().end
 		case codeStructField:
 			sf := code.toStructFieldCode()
 			key := sf.displayKey
 			offset := sf.offset
-			codes = append(codes, fmt.Sprintf("[%d]%s%s [%s:%d] ( %p )", code.idx, indent, code.op, key, offset, unsafe.Pointer(code)))
+			codes = append(codes, fmt.Sprintf("[%d]%s%s [%s:%d] ( %p )", code.displayIdx, indent, code.op, key, offset, unsafe.Pointer(code)))
 			code = code.next
 		default:
-			codes = append(codes, fmt.Sprintf("[%d]%s%s ( %p )", code.idx, indent, code.op, unsafe.Pointer(code)))
+			codes = append(codes, fmt.Sprintf("[%d]%s%s ( %p )", code.displayIdx, indent, code.op, unsafe.Pointer(code)))
 			code = code.next
 		}
 	}
@@ -224,9 +228,10 @@ type sliceHeaderCode struct {
 func newSliceHeaderCode(ctx *encodeCompileContext) *sliceHeaderCode {
 	return &sliceHeaderCode{
 		opcodeHeader: &opcodeHeader{
-			op:     opSliceHead,
-			idx:    ctx.opcodeIndex,
-			indent: ctx.indent,
+			op:         opSliceHead,
+			displayIdx: ctx.opcodeIndex,
+			idx:        uintptr(ctx.opcodeIndex) * 8,
+			indent:     ctx.indent,
 		},
 	}
 }
@@ -234,9 +239,10 @@ func newSliceHeaderCode(ctx *encodeCompileContext) *sliceHeaderCode {
 func newSliceElemCode(ctx *encodeCompileContext, size uintptr) *sliceElemCode {
 	return &sliceElemCode{
 		opcodeHeader: &opcodeHeader{
-			op:     opSliceElem,
-			idx:    ctx.opcodeIndex,
-			indent: ctx.indent,
+			op:         opSliceElem,
+			displayIdx: ctx.opcodeIndex,
+			idx:        uintptr(ctx.opcodeIndex) * 8,
+			indent:     ctx.indent,
 		},
 		size: size,
 	}
@@ -307,9 +313,10 @@ type arrayHeaderCode struct {
 func newArrayHeaderCode(ctx *encodeCompileContext, alen int) *arrayHeaderCode {
 	return &arrayHeaderCode{
 		opcodeHeader: &opcodeHeader{
-			op:     opArrayHead,
-			idx:    ctx.opcodeIndex,
-			indent: ctx.indent,
+			op:         opArrayHead,
+			displayIdx: ctx.opcodeIndex,
+			idx:        uintptr(ctx.opcodeIndex) * 8,
+			indent:     ctx.indent,
 		},
 		len: uintptr(alen),
 	}
@@ -318,8 +325,9 @@ func newArrayHeaderCode(ctx *encodeCompileContext, alen int) *arrayHeaderCode {
 func newArrayElemCode(ctx *encodeCompileContext, alen int, size uintptr) *arrayElemCode {
 	return &arrayElemCode{
 		opcodeHeader: &opcodeHeader{
-			op:  opArrayElem,
-			idx: ctx.opcodeIndex,
+			op:         opArrayElem,
+			displayIdx: ctx.opcodeIndex,
+			idx:        uintptr(ctx.opcodeIndex) * 8,
 		},
 		len:  uintptr(alen),
 		size: size,
@@ -536,10 +544,11 @@ func newMapHeaderCode(ctx *encodeCompileContext, withLoad bool) *mapHeaderCode {
 	}
 	return &mapHeaderCode{
 		opcodeHeader: &opcodeHeader{
-			op:     op,
-			typ:    ctx.typ,
-			idx:    ctx.opcodeIndex,
-			indent: ctx.indent,
+			op:         op,
+			typ:        ctx.typ,
+			displayIdx: ctx.opcodeIndex,
+			idx:        uintptr(ctx.opcodeIndex) * 8,
+			indent:     ctx.indent,
 		},
 	}
 }
@@ -547,9 +556,10 @@ func newMapHeaderCode(ctx *encodeCompileContext, withLoad bool) *mapHeaderCode {
 func newMapKeyCode(ctx *encodeCompileContext) *mapKeyCode {
 	return &mapKeyCode{
 		opcodeHeader: &opcodeHeader{
-			op:     opMapKey,
-			idx:    ctx.opcodeIndex,
-			indent: ctx.indent,
+			op:         opMapKey,
+			displayIdx: ctx.opcodeIndex,
+			idx:        uintptr(ctx.opcodeIndex) * 8,
+			indent:     ctx.indent,
 		},
 	}
 }
@@ -557,9 +567,10 @@ func newMapKeyCode(ctx *encodeCompileContext) *mapKeyCode {
 func newMapValueCode(ctx *encodeCompileContext) *mapValueCode {
 	return &mapValueCode{
 		opcodeHeader: &opcodeHeader{
-			op:     opMapValue,
-			idx:    ctx.opcodeIndex,
-			indent: ctx.indent,
+			op:         opMapValue,
+			displayIdx: ctx.opcodeIndex,
+			idx:        uintptr(ctx.opcodeIndex) * 8,
+			indent:     ctx.indent,
 		},
 	}
 }
diff --git a/encode_vm.go b/encode_vm.go
index bc02567..e873ae8 100644
--- a/encode_vm.go
+++ b/encode_vm.go
@@ -11,17 +11,16 @@ import (
 	"unsafe"
 )
 
-func load(base uintptr, idx int) uintptr {
-	return *(*uintptr)(unsafe.Pointer(base + uintptr(idx)*8))
+func load(base uintptr, idx uintptr) uintptr {
+	return *(*uintptr)(unsafe.Pointer(base + idx))
 }
 
-func store(base uintptr, idx int, p uintptr) {
-	*(*uintptr)(unsafe.Pointer(base + uintptr(idx)*8)) = p
+func store(base uintptr, idx uintptr, p uintptr) {
+	*(*uintptr)(unsafe.Pointer(base + idx)) = p
 }
 
-func (e *Encoder) run(ctx *encodeRuntimeContext, code *opcode) error {
+func (e *Encoder) run(ctx *encodeRuntimeContext, seenPtr map[uintptr]struct{}, code *opcode) error {
 	ctxptr := ctx.ptr()
-	seenPtr := ctx.seenPtr
 	for {
 		switch code.op {
 		case opPtr:
@@ -143,11 +142,10 @@ func (e *Encoder) run(ctx *encodeRuntimeContext, code *opcode) error {
 				c = code
 			}
 			ctx := &encodeRuntimeContext{
-				ptrs:    make([]uintptr, c.length()),
-				seenPtr: seenPtr,
+				ptrs: make([]uintptr, c.length()),
 			}
 			ctx.init(uintptr(header.ptr))
-			if err := e.run(ctx, c); err != nil {
+			if err := e.run(ctx, seenPtr, c); err != nil {
 				return err
 			}
 			code = ifaceCode.next
@@ -566,11 +564,10 @@ func (e *Encoder) run(ctx *encodeRuntimeContext, code *opcode) error {
 			recursive.seenPtr = ptr
 			recursiveCode := newRecursiveCode(recursive)
 			ctx := &encodeRuntimeContext{
-				ptrs:    make([]uintptr, recursiveCode.length()),
-				seenPtr: seenPtr,
+				ptrs: make([]uintptr, recursiveCode.length()),
 			}
 			ctx.init(ptr)
-			if err := e.run(ctx, recursiveCode); err != nil {
+			if err := e.run(ctx, seenPtr, recursiveCode); err != nil {
 				return err
 			}
 			code = recursive.next