riscv-formal-nmigen/rvfi/insns/insn_sra.py

17 lines
658 B
Python
Raw Permalink Normal View History

2020-08-17 11:50:53 +08:00
from .insn_rv32i_r_type import *
2020-08-07 15:51:21 +08:00
2020-08-07 16:06:15 +08:00
"""
SRA instruction
"""
2020-08-07 15:51:21 +08:00
class InsnSra(InsnRV32IRType):
def __init__(self, params):
super().__init__(params, 0b0100000, 0b101, 0b0110011)
2020-08-21 10:33:02 +08:00
2020-08-07 15:51:21 +08:00
def elaborate(self, platform):
2020-08-10 11:15:05 +08:00
m = super().elaborate(platform)
2020-08-07 15:51:21 +08:00
m.d.comb += self.spec_rd_wdata.eq(Mux(self.spec_rd_addr, (Value.as_signed(self.rvfi_rs1_rdata) >> Mux(self.params.xlen == 64, self.rvfi_rs2_rdata[:6], self.rvfi_rs2_rdata[:5])) | (-(Value.as_signed(self.rvfi_rs1_rdata) < 0) << (self.params.xlen - Mux(self.params.xlen == 64, self.rvfi_rs2_rdata[:6], self.rvfi_rs2_rdata[:5]))), 0)) # https://stackoverflow.com/a/25207042
2020-08-07 15:51:21 +08:00
return m