model/riscv_jalr_seq.sail


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/* The definition for the sequential model. */

function clause execute (RISCV_JALR(imm, rs1, rd)) = {
/* For the sequential model, the memory-model definition doesn't work directly
 * if rs1 = rd.  We would effectively have to keep a regfile for reads and another for
 * writes, and swap on instruction completion.  This could perhaps be optimized in
 * some manner, but for now, we just keep a reordered definition to improve simulator
 * performance.
 */
  let t : xlenbits = X(rs1) + EXTS(imm);
  /* Extensions get the first checks on the prospective target address. */
  match ext_control_check_addr(t) {
    Ext_ControlAddr_Error(e) => {
      ext_handle_control_check_error(e);
      RETIRE_FAIL
    },
    Ext_ControlAddr_OK(addr) => {
      let  target = [addr with 0 = bitzero];  /* clear addr[0] */
      if   target[1] & (~ (haveRVC()))
      then {
        handle_mem_exception(target, E_Fetch_Addr_Align);
        RETIRE_FAIL
      } else {
        X(rd) = get_next_pc();
        set_next_pc(target);
        RETIRE_SUCCESS
      }
    }
  }
}