import prettytable as pt
import pandas as pd
import numpy as np

# 初始化寄存器(32R + 16F)， 存储器(1024 units)，简化运算，寄存器内容即填充为寄存器编号值
R = [i for i in range(32)]
F = [2.0 * i for i in range(16)]
MEM = [i for i in range(1024)]

# print(R)
# print(F)
# print(MEM)

label2pc = {}
loopNum = 3
prgmSeq = []
# 初始化规则
op2fu = {"L.D": "Load", "S.D": "Store", "MUL.D": "Mult", "DADDUI": "Add", "BNE": "Add",
         "SUB.D": "Add", "DIV.D": "Mult", "ADD.D": "Add"}
op2char = {"MUL.D": "*", "DADDUI": "+", "SUB.D": "-", "DIV.D": "/", "ADD.D": "+"}
FUtime = {"L.D": "1", "S.D": "1", "MUL.D": "10", "DADDUI": "2", "BNE": "1",
          "SUB.D": "2", "DIV.D": "40", "ADD.D": "2"}
FUname = ["Load1", "Load2", "Add1", "Add2", "Add3", "Mult1", "Mult2", "Store1", "Store2"]

# 初始化 InstructionStatusTable, ReservationStations, RegisterStatusTable
def init(prgm) :
    InsS = []
    ResS = pd.DataFrame(np.empty([9, 9], str),
                        index = FUname,
                        columns = ["Busy", "Op", "Vj", "Vk", "Qj", "Qk", "A", "Time", "InsNum"])
    ResS['Busy'] = "No"  # 置空闲

    # F0-F14 R0-R7
    RegS = pd.DataFrame(np.empty([1, 16], str),
                        index=["FU"],
                        columns=["F" + str(i) for i in range(0, 16, 2)] + ["R" + str(i) for i in range(0, 8, 1)])

    return 0, InsS, ResS, RegS

# 译码，得到指令操作码、目的寄存器、源操作数寄存器
def decIns(ins):
    if ins.find("Loop: ") != -1:  # 去Loop
        ins = ins.replace("Loop: ", "")

    ins = ins.replace(",", " ")
    ins = ins.replace("(", " ")
    ins = ins.replace(")", "")
    ins = ins.split(" ")

    op = ins[0]
    dest = ins[1]
    s1 = ins[2]
    s2 = ins[3]

    return op, dest, s1, s2

# 在ReservationStations中为该指令分配功能部件
def getFU(op, ResS):
    fu = op2fu[op]

    if fu == "Load":
        if ResS.loc["Load1", "Busy"] == "No":
            fu = "Load1"
        elif ResS.loc["Load2", "Busy"] == "No":
            fu = "Load2"
        else:
            fu = ""  # 若无空闲部件，则返回空字符串，代表“Busy"

    elif fu == "Add":
        if ResS.loc["Add1", "Busy"] == "No":
            fu = "Add1"
        elif ResS.loc["Add2", "Busy"] == "No":
            fu = "Add2"
        elif ResS.loc["Add3", "Busy"] == "No":
            fu = "Add3"
        else:
            fu = ""

    elif fu == "Mult":
        if ResS.loc["Mult1", "Busy"] == "No":
            fu = "Mult1"
        elif ResS.loc["Mult2", "Busy"] == "No":
            fu = "Mult2"
        else:
            fu = ""

    else:
        if ResS.loc["Store1", "Busy"] == "No":
            fu = "Store1"
        elif ResS.loc["Store2", "Busy"] == "No":
            fu = "Store2"
        else:
            fu = ""
    return fu

# 在ReservationStations中寻找该指令正在使用的功能部件(load1...)
def getFUing(insnum, ResS):
    for name in FUname:
        if ResS.loc[name, "InsNum"] == insnum:
            fu = name
            return fu

# 发射指令
def issue(ins, insnum, clk, InsS, ResS, RegS):
    op, dest, s1, s2 = decIns(ins)
    fu = getFU(op, ResS)

    if fu != "":
        InsS.append(["" for j in range(3)])
        InsS[insnum][0] = clk  # 登记该指令发射时间
        # 登记指令在保留站状态
        ResS.loc[fu, "InsNum"] = insnum
        ResS.loc[fu, "Busy"] = "Yes"
        ResS.loc[fu, "Op"] = op

        if fu.find("Store") != -1:
            # 计算store的内存地址
            addr = int(dest) + R[int(R[int(s1.replace("R", ""))])]  # 寄存器间接寻址
            ResS.loc[fu, "Vj"] = "#%s" % addr
            # RAW
            if RegS.loc["FU", s2] == "":
                # ResS.loc[fu, "Qk"] = "Regs[%s]" % (s2)
                ResS.loc[fu, "Qk"] = "#%s" % F[int(s2.replace("F", "")) // 2]
            else:
                ResS.loc[fu, "Qk"] = RegS.loc["FU", s2]
        elif fu.find("Load") != -1:
            RegS.loc["FU", dest] = fu
            # 计算地址
            addr = int(s1) + R[int(R[int(s2.replace("R", ""))])]  # 寄存器间接寻址
            ResS.loc[fu, "A"] = "#%s" % addr  # 写地址立即数
        elif ins.find("BNE") != -1: # 比较dest和s1，是否跳转s2
            # dest是否有效
            if RegS.loc["FU", dest] == "":
                if dest.find("F") != -1:  # dest是F寄存器
                    ResS.loc[fu, "Vj"] = "#%s" % F[int(dest.replace("F", "")) // 2]
                elif dest.find("R") != -1:  # dest是R寄存器
                    ResS.loc[fu, "Vj"] = "#%s" % R[int(dest.replace("R", ""))]
            else:
                ResS.loc[fu, "Qj"] = RegS.loc["FU", dest]
            # s1是否有效
            if RegS.loc["FU", s1] == "":
                if s1.find("F") != -1:  # s1是F寄存器
                    ResS.loc[fu, "Vk"] = "#%s" % F[int(s1.replace("F", "")) // 2]
                elif s1.find("R") != -1:  # s1是R寄存器
                    ResS.loc[fu, "Vk"] = "#%s" % R[int(s1.replace("R", ""))]
            else:
                ResS.loc[fu, "Qk"] = RegS.loc["FU", s1]
        else:   # 其他指令
            # s1操作数是否有效
            if RegS.loc["FU", s1] == "":
                if s1.find("F") != -1:  # s1是F寄存器
                    ResS.loc[fu, "Vj"] = "#%s" % F[int(s1.replace("F", "")) // 2]
                elif s1.find("R") != -1:  # s1是R寄存器
                    ResS.loc[fu, "Vj"] = "#%s" % R[int(s1.replace("R", ""))]
            else:
                ResS.loc[fu, "Qj"] = RegS.loc["FU", s1]
            # s2操作数是否有效
            if s2.find("#") != -1:  # s2是立即数
                ResS.loc[fu, "Vk"] = s2
            elif RegS.loc["FU", s2] == "":  # s2是F寄存器值
                ResS.loc[fu, "Vk"] = "#%s" % F[int(s2.replace("F", "")) // 2]
            else:
                ResS.loc[fu, "Qk"] = RegS.loc["FU", s2]
            # 寄存器状态表中写入功能部件
            RegS.loc["FU", dest] = fu

    return InsS, ResS, RegS

# 执行指令
def execute(ins, insnum, clk, InsS, ResS):
    op, dest, s1, s2 = decIns(ins)
    fu = getFUing(insnum, ResS)

    if ResS.loc[fu, "Time"] == "":   # 指令未开始执行
        # 操作数就绪，执行
        if ResS.loc[fu, "Qj"] == "" and ResS.loc[fu, "Qk"] == "":
            ResS.loc[fu, "Time"] = FUtime[op]
    else:  # 指令开始执行
        ResS.loc[fu, "Time"] = str(int(ResS.loc[fu, "Time"]) - 1)
        if ResS.loc[fu, "Time"] == "0":
            InsS[insnum][1] = clk
            ResS.loc[fu, "Time"] = ""
    return InsS, ResS

# 写回阶段
def writeResult(ins, insnum, clk, InsS, ResS, RegS, PC):
    op, dest, s1, s2 = decIns(ins)
    fu = getFUing(insnum, ResS)
    InsS[insnum][2] = clk  # 登记时钟
    ResS.loc[fu, "Busy"] = "No"  # 释放所用功能部件
    # 寄存器状态表写回
    if fu.find("Load") != -1:
        RegS.loc["FU", dest] = ""

        F[int(dest.replace("F", "")) // 2] = MEM[int(float(ResS.loc[fu, "A"].replace("#", ""))//1)]
        result = "#%s" % str(F[int(dest.replace("F", "")) // 2])
    elif fu.find("Store") != -1:

        MEM[int(ResS.loc[fu, "Vj"].replace("#", ""))] = float(ResS.loc[fu, "Vk"].replace("#", ""))//1
    elif ins.find("BNE") != -1:
        if ResS.loc[fu, "Vj"] != ResS.loc[fu, "Vk"]:
            PC = label2pc[s2]  # Loop -> #0
    else:
        # 除load、store、bne的其他指令
        RegS.loc["FU", dest] = ""

        if op2char[op] == "+":
            dest_result = float(ResS.loc[fu, "Vj"].replace("#", "")) + float(ResS.loc[fu, "Vk"].replace("#", ""))
        elif op2char[op] == "-":
            dest_result = float(ResS.loc[fu, "Vj"].replace("#", "")) - float(
                ResS.loc[fu, "Vk"].replace("#", ""))
        elif op2char[op] == "*":
            dest_result = float(ResS.loc[fu, "Vj"].replace("#", "")) * float(
                ResS.loc[fu, "Vk"].replace("#", ""))
        elif op2char[op] == "/":
            dest_result = float(ResS.loc[fu, "Vj"].replace("#", "")) / float(
                ResS.loc[fu, "Vk"].replace("#", ""))
        if dest.find("F") != -1:
            F[int(dest.replace("F", "")) // 2] = dest_result
        elif dest.find("R") != -1:
            R[int(dest.replace("R", ""))] = dest_result
        result = "#%s" % str(dest_result)
    ResS.loc[fu, "Op"] = ""
    ResS.loc[fu, "Vj"] = ""
    ResS.loc[fu, "Vk"] = ""
    ResS.loc[fu, "Oj"] = ""
    ResS.loc[fu, "Ok"] = ""
    ResS.loc[fu, "A"] = ""
    ResS.loc[fu, "Time"] = ""
    ResS.loc[fu, "InsNum"] = ""
    # 结果数据广播
    for fuitem in FUname:
        # 遍历 ReservationStations
        if ResS.loc[fuitem, "Qj"] == fu:
            ResS.loc[fuitem, "Qj"] = ""
            ResS.loc[fuitem, "Vj"] = result
            # 广播结束，开始计时
            if ResS.loc[fuitem, "Qk"] == "" and ResS.loc[fuitem, "Time"] == "":
                ResS.loc[fuitem, "Time"] = FUtime[ResS.loc[fuitem, "Op"]]

        if ResS.loc[fuitem, "Qk"] == fu:
            ResS.loc[fuitem, "Qk"] = ""
            ResS.loc[fuitem, "Vk"] = result
            # 广播结束，开始计时
            if ResS.loc[fuitem, "Qj"] == "" and ResS.loc[fuitem, "Time"] == "":
                ResS.loc[fuitem, "Time"] = FUtime[ResS.loc[fuitem, "Op"]]

    return PC, InsS, ResS, RegS
# 输出InstructionStatusTable, ReservationStations, RegisterStatusTable
def printResult(prgm, InsS, ResS, RegS):
    # InstructionStatusTable
    InsST = pt.PrettyTable()
    InsST.field_names = ["Instruction", "issue", "execute", "Write result"]
    for i in range(min(len(InsS),loopNum*(len(prgm)-1))):
        line = [j for j in InsS[i]]
        line.insert(0, prgmSeq[i])
        InsST.add_row(line)

    # ReservationStations
    ResST = pt.PrettyTable()
    ResST.field_names = ["Name", "Busy", "Op", "Vj", "Vk", "Qj", "Qk", "A", "Time", "InsNum"]
    ResList = ResS.values.tolist()
    for i in range(len(ResList)):
        line = ResList[i][:9]
        line.insert(0, FUname[i])
        ResST.add_row(line)

    # RegisterStatusTable
    RegST = pt.PrettyTable()
    RegST.field_names = ["R&F", "F0", "F2", "F4", "F6", "F8", "F10", "F12", "F14", "R0", "R1", "R2", "R3", "R4",
                         "R5", "R6", "R7"]
    line = RegS.values.tolist()[0]
    line.insert(0, "FU")
    RegST.add_row(line)

    print(InsST)
    print(ResST)
    print(RegST)

# 判断指令是否全部执行完成
def PrgmFinish(InsS, prgm):
    # for i in range(len(prgmSeq)):
    for i in range(loopNum*(len(prgm)-1)):
        for j in range(3):
            if InsS[i][j] == "":
                return False
    return True

# 主程序
if __name__ == '__main__':
    prgm = ["Loop: L.D F0,0(R1)",
            "MUL.D F4,F0,F2",
            "S.D 0(R1),F4",
            "DADDUI R1,R1,#-8",
            "BNE R1,R2,Loop",
            "End"]

    clk, InsS, ResS, RegS = init(prgm)
    PC = 0
    while True:
        clk += 1
        if prgm[PC].find("Loop") == 0:
            label2pc["Loop"] = PC  # {'Loop': 0}
            prgm[PC] = prgm[PC].replace("Loop: ", "")
        # 第一个周期 只流出第一条指令
        if clk == 1:
            # 发射指令
            InsS, ResS, RegS = issue(prgm[PC], PC, clk, InsS, ResS, RegS)
            prgmSeq.append(prgm[PC])
            PC += 1
        else:
            for i in range(len(InsS) - 1, -1, -1):
                if InsS[i][1] == "":  # 执行阶段
                    InsS, ResS = execute(prgmSeq[i], i, clk, InsS, ResS)
                elif InsS[i][2] == "":  # 写回阶段
                    PC, InsS, ResS, RegS = writeResult(prgmSeq[i], i, clk, InsS, ResS, RegS, PC)
            # 发射新指令？
            if prgm[PC] != "End" and (PC == 0 or InsS[PC - 1][0] != ""):  # 未执行完，（PC = 0 || 上一条指令已发射）
                InsS, ResS, RegS = issue(prgm[PC], len(InsS), clk, InsS, ResS, RegS)
                prgmSeq.append(prgm[PC])
                PC += 1

        print("clock:%d" % clk)
        print(label2pc)
        printResult(prgm, InsS, ResS, RegS)
        print(prgmSeq)

        if PrgmFinish(InsS, prgm):
            break