pub(crate) fn compute_opcode<AB: SP1AirBuilder>(
        &self,
        local: &MemoryInstructionsColumns<AB::Var>,
    ) -> AB::Expr {
        local.is_lb * Opcode::LB.as_field::<AB::F>() +
            local.is_lbu * Opcode::LBU.as_field::<AB::F>() +
            local.is_lh * Opcode::LH.as_field::<AB::F>() +
            local.is_lhu * Opcode::LHU.as_field::<AB::F>() +
            local.is_lw * Opcode::LW.as_field::<AB::F>() +
            local.is_sb * Opcode::SB.as_field::<AB::F>() +
            local.is_sh * Opcode::SH.as_field::<AB::F>() +
            local.is_sw * Opcode::SW.as_field::<AB::F>()
    }
Computes the opcode based on the instruction selectors.
crates/core/machine/src/memory/instructions/air.rs