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60 lines
1.4 KiB
60 lines
1.4 KiB
from instruction.instruction import Instruction
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#RI类指令
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class RegImmInstr(Instruction):
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def instrDecode(self):
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super().instrDecode()
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instr = self.hw.pplReg[1][0].read()
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mask = (1 << 5) - 1
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rs = (instr >> 21) & mask
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rsData = self.hw.genReg[rs].read()
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rt = (instr >> 16) & mask
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self.hw.pplReg[2][0].write(rsData)
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self.hw.pplReg[2][2].write(rt)
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def memAccess(self):
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super().memAccess()
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res = self.hw.pplReg[3][0].read()
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rt = self.hw.pplReg[3][1].read()
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self.hw.genReg[rt].write(res)
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#进行零扩展的RI类指令
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class ZeroExtRegImmInstr(RegImmInstr):
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def instrDecode(self):
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super().instrDecode()
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instr = self.hw.pplReg[1][0].read()
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mask = (1 << 16) - 1
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imm = instr & mask
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self.hw.pplReg[2][1].write(imm)
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#进行符号扩展的RI类指令
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class SignExtRegImmInstr(RegImmInstr):
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#符号扩展
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#输入：
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# imm为16bit数据
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#输出：
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# imm的32bit符号扩展
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def signedExtend(imm):
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mask = (1 << 16) - 1 << 16
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if (imm >> 15) & 1:
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return imm | mask
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else:
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return imm
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def instrDecode(self):
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super().instrDecode()
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instr = self.hw.pplReg[1][0].read()
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mask = (1 << 16) - 1
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imm = instr & mask
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imm = SignExtRegImmInstr.signedExtend(imm)
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self.hw.pplReg[2][1].write(imm)
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