Killing what can’t be handled – putting a spaghetti demon to eternal rest – Maister's Graphics Adventures

dxil-spirv developer Hans-Kristian Arntzen has abandoned the project's 9,000-line control flow graph structurizer, replacing it with an implementation adapted from Mesa's goto_if approach used by OpenCL for unstructured SPIR-V. The old structurizer, maintained by a single developer, repeatedly broke on oversized game shaders—one was too large for Graphviz to render—prompting the rewrite to prioritize correctness over human-readable generated code while preserving GPU performance. Arntzen validated the Mesa algorithm by adding a SPV_FROG_unstructured_control_flow path that bypasses structurization entirely; games ran at performance parity on RADV, though NVIDIA proprietary driver performance remained an open question during a two-week evaluation. The change matters because dxil-spirv underpins DirectX shader translation to SPIR-V in Vulkan tooling such as DXVK and vkd3d-proton, where structurizer failures can break game compatibility. Next to watch: whether the Mesa-derived structurizer holds up under NVIDIA's proprietary Vulkan driver and whether the expanded structurizer-test suite catches regressions before future game releases.