The RISC-V Vector (RVV) extension introduces powerful yet complex semantics for data-parallel execution, including dynamically sized vectors, per-lane masking, and flexible element widths and groupings. While these features offer high performance and portability, they also complicate debugging, as existing tools, such as GDB, do not present RVV registers in a configuration-aware manner. Consequently, raw and verbose register dumps must be manually interpreted relative to the current vector register state. With register widths of up to 65,536 bits this quickly becomes impractical, making it difficult to understand effects of individual instructions and spot values of interest efficiently.

This demo presents LIBERO, a lightweight visualization tool integrated directly into GDB through its Python API. LIBERO augments GDB’s Text User Interface (TUI) with a custom register view that continuously displays vector contents alongside the relevant configuration state during program execution. LIBERO allows users to select which vector registers to display and automatically renders them based on the width specified in the status register. By embedding these capabilities into GDB, LIBERO enables developers to reason about RVV code more efficiently while preserving the familiar GDB workflow.