Add RV64I I-Type Instruction (Load Variation)

This commit is contained in:
Donald Sebastian Leung 2020-08-27 12:20:17 +08:00
parent 0af1f20423
commit 92e34efe0d

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from .insn_rv64i_i_type import *
"""
RV64I I-Type Instruction (Load Variation)
"""
class InsnRV64IITypeLoad(InsnRV64IIType):
def __init__(self, params, mask_shift, funct3, is_signed):
super().__init__(params)
self.mask_shift = mask_shift
self.funct3 = funct3
self.is_signed = is_signed
def elaborate(self, platform):
m = super().elaborate(platform)
if self.params.aligned_mem:
addr = Signal(self.params.xlen)
m.d.comb += addr.eq(self.rvfi_rs1_rdata + self.insn_imm)
result = Signal(8 * self.mask_shift)
m.d.comb += result.eq(self.rvfi_mem_rdata >> (8 * (addr - self.spec_mem_addr)))
m.d.comb += self.spec_valid.eq(self.rvfi_valid & (~self.insn_padding) & (self.insn_funct3 == self.funct3) & (self.insn_opcode == 0b0000011))
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_mem_addr.eq(addr & ~(self.params.xlen // 8 - 1))
m.d.comb += self.spec_mem_rmask.eq(((1 << self.mask_shift) - 1) << (addr - self.spec_mem_addr))
m.d.comb += self.spec_rd_wdata.eq(Mux(self.spec_rd_addr, Value.as_signed(result) if self.is_signed else result, 0))
m.d.comb += self.spec_pc_wdata.eq(self.rvfi_pc_rdata + 4)
m.d.comb += self.spec_trap.eq(((addr & (self.mask_shift - 1)) != 0) | ~self.misa_ok)
else:
addr = Signal(self.params.xlen)
m.d.comb += addr.eq(self.rvfi_rs1_rdata + self.insn_imm)
result = Signal(8 * self.mask_shift)
m.d.comb += result.eq(sself.rvfi_mem_rdata)
m.d.comb += self.spec_valid.eq(self.rvfi_valid & (self.insn_funct3 == self.funct3) & (self.insn_opcode == 0b0000011))
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_mem_addr.eq(addr)
m.d.comb += self.spec_mem_rmask.eq((1 << self.mask_shift) - 1)
m.d.comb += self.spec_rd_wdata.eq(Mux(self.spec_rd_addr, Value.as_signed(result) if self.is_signed else result, 0))
m.d.comb += self.spec_pc_wdata.eq(self.rvfi_pc_rdata + 4)
m.d.comb += self.spec_trap.eq(~self.misa_ok)
return m