Method get_label_for_constant

cranelift/codegen/src/machinst/buffer.rs:704–723

Returns a label that can be used to refer to the `constant` provided. This will automatically defer a new constant to be emitted for `constant` if it has not been previously emitted. Note that this function may return a different label for the same constant at different points in time. The label is valid to use only from the current location; the MachBuffer takes care to emit the same constant mu

(&mut self, constant: VCodeConstant)

    /// current location; the MachBuffer takes care to emit the same constant
    /// multiple times if needed so the constant is always in range.
    pub fn get_label_for_constant(&mut self, constant: VCodeConstant) -> MachLabel {
        let MachBufferConstant {
            align,
            size,
            upcoming_label,
        } = self.constants[constant];
        if let Some(label) = upcoming_label {
            return label;
        }

        let label = self.get_label();
        trace!(
            "defer constant: eventually emit {size} bytes aligned \
             to {align} at label {label:?}",
        );
        self.pending_constants.push(constant);
        self.pending_constants_size += size as u32;
        self.constants[constant].upcoming_label = Some(label);
        label
    }

    /// Bind a label to the current offset. A label can only be bound once.
    pub fn bind_label(&mut self, label: MachLabel, ctrl_plane: &mut ControlPlane) {