from .insn_rv64i_i_type_shift import *

"""
SRAIW instruction
"""

class InsnSraiw(InsnRV64IITypeShift):
    def __init__(self, params):
        super().__init__(params, 0b010000, 0b101)
    def elaborate(self, platform):
        m = super().elaborate(platform)

        result = Signal(32)
        m.d.comb += result.eq((Value.as_signed(self.rvfi_rs1_rdata[:32]) >> self.insn_shamt) | (-(Value.as_signed(self.rvfi_rs1_rdata[:32]) < 0) << (32 - self.insn_shamt))) # https://stackoverflow.com/a/25207042
        m.d.comb += self.spec_rd_wdata.eq(Mux(self.spec_rd_addr, (Mux(result[31], 2 ** (self.params.xlen - 32) - 1, 0) << 32) | result, 0))

        return m