// +build go1.17,!go1.21

// Copyright 2023 CloudWeGo Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package jitdec

import (
    `strconv`
    `unsafe`

    `github.com/bytedance/sonic/internal/jit`
    `github.com/twitchyliquid64/golang-asm/obj`
    `github.com/twitchyliquid64/golang-asm/obj/x86`
)

//go:linkname _runtime_writeBarrier runtime.writeBarrier
var _runtime_writeBarrier uintptr

//go:linkname gcWriteBarrierAX runtime.gcWriteBarrier
func gcWriteBarrierAX()

var (
    _V_writeBarrier = jit.Imm(int64(uintptr(unsafe.Pointer(&_runtime_writeBarrier))))

    _F_gcWriteBarrierAX = jit.Func(gcWriteBarrierAX)
)

func (self *_Assembler) WritePtrAX(i int, rec obj.Addr, saveDI bool) {
    self.Emit("MOVQ", _V_writeBarrier, _R9)
    self.Emit("CMPL", jit.Ptr(_R9, 0), jit.Imm(0))
    self.Sjmp("JE", "_no_writeBarrier" + strconv.Itoa(i) + "_{n}")
    if saveDI {
        self.save(_DI)
    }
    self.Emit("LEAQ", rec, _DI)
    self.call(_F_gcWriteBarrierAX)  
    if saveDI {
        self.load(_DI)
    }    
    self.Sjmp("JMP", "_end_writeBarrier" + strconv.Itoa(i) + "_{n}")
    self.Link("_no_writeBarrier" + strconv.Itoa(i) + "_{n}")
    self.Emit("MOVQ", _AX, rec)
    self.Link("_end_writeBarrier" + strconv.Itoa(i) + "_{n}")
}

func (self *_Assembler) WriteRecNotAX(i int, ptr obj.Addr, rec obj.Addr, saveDI bool, saveAX bool) {
    if rec.Reg == x86.REG_AX || rec.Index == x86.REG_AX {
        panic("rec contains AX!")
    }
    self.Emit("MOVQ", _V_writeBarrier, _R9)
    self.Emit("CMPL", jit.Ptr(_R9, 0), jit.Imm(0))
    self.Sjmp("JE", "_no_writeBarrier" + strconv.Itoa(i) + "_{n}")
    if saveAX {
        self.Emit("XCHGQ", ptr, _AX)
    } else {
        self.Emit("MOVQ", ptr, _AX)
    }
    if saveDI {
        self.save(_DI)
    }
    self.Emit("LEAQ", rec, _DI)
    self.call(_F_gcWriteBarrierAX) 
    if saveDI {
        self.load(_DI)
    } 
    if saveAX {
        self.Emit("XCHGQ", ptr, _AX)
    }    
    self.Sjmp("JMP", "_end_writeBarrier" + strconv.Itoa(i) + "_{n}")
    self.Link("_no_writeBarrier" + strconv.Itoa(i) + "_{n}")
    self.Emit("MOVQ", ptr, rec)
    self.Link("_end_writeBarrier" + strconv.Itoa(i) + "_{n}")
}


func (self *_ValueDecoder) WritePtrAX(i int, rec obj.Addr, saveDI bool) {
    self.Emit("MOVQ", _V_writeBarrier, _R9)
    self.Emit("CMPL", jit.Ptr(_R9, 0), jit.Imm(0))
    self.Sjmp("JE", "_no_writeBarrier" + strconv.Itoa(i) + "_{n}")
    if saveDI {
        self.save(_DI)
    }
    self.Emit("LEAQ", rec, _DI)
    self.call(_F_gcWriteBarrierAX)
    if saveDI {
        self.load(_DI)
    }    
    self.Sjmp("JMP", "_end_writeBarrier" + strconv.Itoa(i) + "_{n}")
    self.Link("_no_writeBarrier" + strconv.Itoa(i) + "_{n}")
    self.Emit("MOVQ", _AX, rec)
    self.Link("_end_writeBarrier" + strconv.Itoa(i) + "_{n}")
}

func (self *_ValueDecoder) WriteRecNotAX(i int, ptr obj.Addr, rec obj.Addr, saveDI bool) {
    if rec.Reg == x86.REG_AX || rec.Index == x86.REG_AX {
        panic("rec contains AX!")
    }
    self.Emit("MOVQ", _V_writeBarrier, _AX)
    self.Emit("CMPL", jit.Ptr(_AX, 0), jit.Imm(0))
    self.Sjmp("JE", "_no_writeBarrier" + strconv.Itoa(i) + "_{n}")
    self.Emit("MOVQ", ptr, _AX)
    if saveDI {
        self.save(_DI)
    }
    self.Emit("LEAQ", rec, _DI)
    self.call(_F_gcWriteBarrierAX)
    if saveDI {
        self.load(_DI)
    }    
    self.Sjmp("JMP", "_end_writeBarrier" + strconv.Itoa(i) + "_{n}")
    self.Link("_no_writeBarrier" + strconv.Itoa(i) + "_{n}")
    self.Emit("MOVQ", ptr, rec)
    self.Link("_end_writeBarrier" + strconv.Itoa(i) + "_{n}")
}
