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riscv-formal-nmigen
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Refactor JALR instruction

This commit is contained in:
Donald Sebastian Leung 2020-07-30 13:56:30 +08:00
parent e6c6f0462e
commit f4f5e94843
1 changed files with 10 additions and 75 deletions
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85
insns/insn_jalr.py
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@ -1,86 +1,21 @@
from nmigen import *
from insn_I_type import *
class rvfi_insn_jalr(Elaboratable):
class rvfi_insn_jalr(rvfi_insn_I_type):
def __init__(self, RISCV_FORMAL_ILEN=32, RISCV_FORMAL_XLEN=32):
self.RISCV_FORMAL_ILEN = RISCV_FORMAL_ILEN
self.RISCV_FORMAL_XLEN = RISCV_FORMAL_XLEN
self.rvfi_valid = Signal(1)
self.rvfi_insn = Signal(self.RISCV_FORMAL_ILEN)
self.rvfi_pc_rdata = Signal(self.RISCV_FORMAL_XLEN)
self.rvfi_rs1_rdata = Signal(self.RISCV_FORMAL_XLEN)
self.rvfi_rs2_rdata = Signal(self.RISCV_FORMAL_XLEN)
self.rvfi_mem_rdata = Signal(self.RISCV_FORMAL_XLEN)
self.spec_valid = Signal(1)
self.spec_trap = Signal(1)
self.spec_rs1_addr = Signal(5)
self.spec_rs2_addr = Signal(5)
self.spec_rd_addr = Signal(5)
self.spec_rd_wdata = Signal(self.RISCV_FORMAL_XLEN)
self.spec_pc_wdata = Signal(self.RISCV_FORMAL_XLEN)
self.spec_mem_addr = Signal(self.RISCV_FORMAL_XLEN)
self.spec_mem_rmask = Signal(int(self.RISCV_FORMAL_XLEN // 8))
self.spec_mem_wmask = Signal(int(self.RISCV_FORMAL_XLEN // 8))
self.spec_mem_wdata = Signal(self.RISCV_FORMAL_XLEN)
super(rvfi_insn_jalr, self).__init__(RISCV_FORMAL_ILEN, RISCV_FORMAL_XLEN)
def ports(self):
input_ports = [
self.rvfi_valid,
self.rvfi_insn,
self.rvfi_pc_rdata,
self.rvfi_rs1_rdata,
self.rvfi_rs2_rdata,
self.rvfi_mem_rdata
]
output_ports = [
self.spec_valid,
self.spec_trap,
self.spec_rs1_addr,
self.spec_rs2_addr,
self.spec_rd_addr,
self.spec_rd_wdata,
self.spec_pc_wdata,
self.spec_mem_addr,
self.spec_mem_rmask,
self.spec_mem_wmask,
self.spec_mem_wdata
]
return input_ports + output_ports
return super(rvfi_insn_jalr, self).ports()
def elaborate(self, platform):
m = Module()
# I-type instruction format
insn_padding = Signal(self.RISCV_FORMAL_ILEN)
m.d.comb += insn_padding.eq(self.rvfi_insn >> 32)
insn_imm = Signal(self.RISCV_FORMAL_XLEN)
m.d.comb += insn_imm.eq(Value.as_signed(self.rvfi_insn[20:32]))
insn_rs1 = Signal(5)
m.d.comb += insn_rs1.eq(self.rvfi_insn[15:20])
insn_funct3 = Signal(3)
m.d.comb += insn_funct3.eq(self.rvfi_insn[12:15])
insn_rd = Signal(5)
m.d.comb += insn_rd.eq(self.rvfi_insn[7:12])
insn_opcode = Signal(7)
m.d.comb += insn_opcode.eq(self.rvfi_insn[:7])
misa_ok = Signal(1)
m.d.comb += misa_ok.eq(1)
ialign16 = Signal(1)
m.d.comb += ialign16.eq(0)
m = super(rvfi_insn_jalr, self).elaborate(platform)
# JALR instruction
next_pc = Signal(self.RISCV_FORMAL_XLEN)
m.d.comb += next_pc.eq((self.rvfi_rs1_rdata + insn_imm) & ~Const(1, shape=self.RISCV_FORMAL_XLEN))
m.d.comb += self.spec_valid.eq(self.rvfi_valid & (~insn_padding) & (insn_funct3 == 0b000) & (insn_opcode == 0b1100111))
m.d.comb += self.spec_rs1_addr.eq(insn_rs1)
m.d.comb += self.spec_rd_addr.eq(insn_rd)
m.d.comb += next_pc.eq((self.rvfi_rs1_rdata + self.insn_imm) & ~Const(1, shape=self.RISCV_FORMAL_XLEN))
m.d.comb += self.spec_valid.eq(self.rvfi_valid & (~self.insn_padding) & (self.insn_funct3 == 0b000) & (self.insn_opcode == 0b1100111))
m.d.comb += self.spec_rs1_addr.eq(self.insn_rs1)
m.d.comb += self.spec_rd_addr.eq(self.insn_rd)
m.d.comb += self.spec_rd_wdata.eq(Mux(self.spec_rd_addr, self.rvfi_pc_rdata + 4, 0))
m.d.comb += self.spec_pc_wdata.eq(next_pc)
m.d.comb += self.spec_trap.eq(Mux(ialign16, next_pc[0] != 0, next_pc[:2] != 0) | ~misa_ok)
# default assignments
m.d.comb += self.spec_rs2_addr.eq(0)
m.d.comb += self.spec_mem_addr.eq(0)
m.d.comb += self.spec_mem_rmask.eq(0)
m.d.comb += self.spec_mem_wmask.eq(0)
m.d.comb += self.spec_mem_wdata.eq(0)
m.d.comb += self.spec_trap.eq(Mux(self.ialign16, next_pc[0] != 0, next_pc[:2] != 0) | ~self.misa_ok)
return m