from .insn_rv32i_i_type import *

"""
JALR instruction
"""

class InsnJalr(InsnRV32IIType):
    def __init__(self, RISCV_FORMAL_ILEN, RISCV_FORMAL_XLEN, RISCV_FORMAL_CSR_MISA, RISCV_FORMAL_COMPRESSED):
        super().__init__(RISCV_FORMAL_ILEN, RISCV_FORMAL_XLEN, RISCV_FORMAL_CSR_MISA)
        self.RISCV_FORMAL_COMPRESSED = RISCV_FORMAL_COMPRESSED
    def elaborate(self, platform):
        m = super().elaborate(platform)

        if self.RISCV_FORMAL_CSR_MISA:
            m.d.comb += self.misa_ok.eq((self.rvfi_csr_misa_rdata & 0) == 0)
            m.d.comb += self.spec_csr_misa_rmask.eq(4)
            m.d.comb += self.ialign16.eq((self.rvfi_csr_misa_rdata & 4) != 0)
        else:
            m.d.comb += self.misa_ok.eq(1)
            if self.RISCV_FORMAL_COMPRESSED:
                m.d.comb += self.ialign16.eq(1)
            else:
                m.d.comb += self.ialign16.eq(0)

        next_pc = Signal(self.RISCV_FORMAL_XLEN)
        m.d.comb += next_pc.eq((self.rvfi_rs1_rdata + self.insn_imm) & ~1)
        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(self.ialign16, next_pc[0] != 0, next_pc[:2] != 0) | ~self.misa_ok)

        return m