Method log_value_labels_ranges

cranelift/codegen/src/machinst/vcode.rs:1307–1507

(&self, regalloc: &regalloc2::Output, inst_offsets: &[CodeOffset])

    }

    fn log_value_labels_ranges(&self, regalloc: &regalloc2::Output, inst_offsets: &[CodeOffset]) {
        debug_assert!(trace_log_enabled!());

        // What debug labels do we have? Note we'll skip those that have not been
        // allocated any location at all. They will show up as numeric gaps in the table.
        let mut labels = vec![];
        for &(label, _, _, _) in &regalloc.debug_locations {
            if Some(&label) == labels.last() {
                continue;
            }
            labels.push(label);
        }

        // Reformat the data on what VRegs were the VLs assigned to by lowering, since
        // the array we have is sorted by VReg, and we want it sorted by VL for easy
        // access in the loop below.
        let mut vregs = vec![];
        for &(vreg, start, end, label) in &self.debug_value_labels {
            if matches!(labels.binary_search(&label), Ok(_)) {
                vregs.push((label, start, end, vreg));
            }
        }
        vregs.sort_unstable_by(
            |(l_label, l_start, _, _), (r_label, r_start, _, _)| match l_label.cmp(r_label) {
                Ordering::Equal => l_start.cmp(r_start),
                cmp => cmp,
            },
        );

        #[derive(PartialEq)]
        enum Mode {
            Measure,
            Emit,
        }
        #[derive(PartialEq)]
        enum Row {
            Head,
            Line,
            Inst(usize, usize),
        }

        let mut widths = vec![0; 3 + 2 * labels.len()];
        let mut row = String::new();
        let mut output_row = |row_kind: Row, mode: Mode| {
            let mut column_index = 0;
            row.clear();

            macro_rules! output_cell_impl {
                ($fill:literal, $span:literal, $($cell_fmt:tt)*) => {
                    let column_start = row.len();
                    {
                        row.push('|');
                        write!(row, $($cell_fmt)*).unwrap();
                    }

                    let next_column_index = column_index + $span;
                    let expected_width: usize = widths[column_index..next_column_index].iter().sum();
                    if mode == Mode::Measure {