[JJenkx]

What

The bundled redundancy-elimination traversal copies inherited value maps for sibling branches. Replace those copies with an iterative depth-first traversal, one scoped value map, and a log of values inserted by each subtree. Roll back each subtree's insertions on return so ancestor reuse is preserved and sibling values remain isolated. Optimization passes, type restrictions, value numbering and validation are unchanged.

CMake patches a build-directory copy of the pinned SPIRV-Tools source and rejects drift in the traversal and elimination helper. The dependency checkout is untouched. This extends SPIRV-Tools #6962, which releases processed maps but retains sibling map copies; it does not replace the separate AnyPS5 IR work in boykopovar#4948.

Tested

Current published head b00931842321f466b8ce1e7a48ac952d4f06f1ec is three topic/documentation commits directly above main 56429064fc3074ed5192e32a06ba0cf7813af4fc, with zero merge commits. Additive shader-debt conflicts were resolved while retaining main's structurizer entry. Conventions and whitespace checks pass. The production patch and optimizer regression file are byte-for-byte identical to measured head 5aea65b4b1c363c8783beb804f7e7579a2e9001e. The current-head Linux Release runtime builds with bundled SPIRV-Tools; default/full/none optimizer checks pass (3 passed, 0 skipped). Fresh full Linux/Windows CI passes this head against base 56429064fc3074ed5192e32a06ba0cf7813af4fc: Linux 1,073 passed / 48 skipped / 1,121 total; Windows 739 passed / 406 skipped / 1,145 total. All three optimizer modes pass on Linux. Windows disables SPIRV-Tools and does not validate the traversal patch; skipped cases remain unvalidated. The measurements below retain their original revisions; no performance measurement against the new base is claimed.

• At measured head 5aea65b4b1c3, Linux Release builds with bundled SPIRV-Tools enabled pass. Default/full/none optimizer checks pass on both main and this PR, with zero skips, including ancestor reuse, sibling scopes, conditional control flow, volatile stores and storage-only byte output. The earlier omitted-rollback negative control fails validation because the sibling value does not dominate its use.
• Existing generated-workload measurements demonstrate reduced map-copy work, but are synthetic compiler evidence and establish no title speed gain.
• Historical full Linux/Windows CI passes at topic 5aea65b4b1c363c8783beb804f7e7579a2e9001e and base 1e7272196389c30eff9af9e91a51c72d781f46c6: Linux 1068 passed / 46 skipped / 1114 total; Windows 735 passed / 402 skipped / 1137 total. Linux exercises all three optimizer modes. The Windows configuration does not enable SPIRV-Tools and does not validate the dependency traversal patch. Skips remain unvalidated.

Cold-title measurements

Astro Bot PPSA21564, untouched startup with no input, main 1e7272196389 versus main plus this PR 5aea65b4b1c3. Same machine, executable, modules, assets and settings; separate empty AnyPS5 shader, Vulkan pipeline and Mesa caches. Both builds enable APS5_ENABLE_TIMING_LOG=ON to retain preparation before first present. Official APS5_TRACE_SECONDS=0:60 traces start at first present; no other trace/profile switch and console output not redirected. This deliberately measures cold loading, as requested, rather than the performance form's warm-cache gameplay protocol.

First-flip boundary metric	Main, pair 1	PR, pair 1	Main, reverse-order repeat	PR, reverse-order repeat
First submit to flip completion, seconds	349.480	303.908	344.934	289.638
Inclusive shader preparation elapsed, seconds	1578.487	1206.310	1537.397	1128.035
Preparation calls	2243	2245	2245	2245
Maximum preparation call, seconds	13.907	8.457	14.065	8.021

First-flip wait is 13.0% shorter in the first pair and 16.0% shorter in the reverse-order repeat. Inclusive preparation is 23.6% / 26.6% lower. Repeat call counts are identical (2,245); the first pair differs by two calls. Both repeat runs reached the ASTRO BOT title screen in PID-matched snapshots at approximately 612 seconds, without input, and closed normally (exit 0); temporary kernel settings were restored.

Shader preparation includes translation, optimization and cache work. It sums inclusive elapsed calls across concurrent threads, so it exceeds wall-clock time and is not optimizer-only CPU time. First flip completion has display_confirmed=0; it is not the time to a visible frame or completed title loading. Sparse title-screen snapshots establish the destination, not a precisely measured time-to-menu gain. The traces cover initial loading, with different present counts (the seconds-based window ends after its final present). No gameplay or steady-FPS improvement is claimed. Build timing adds overhead to both builds. Two pairs establish a repeated observed gain on this host, not broad hardware coverage.

The first pair closed earlier during resource loading and both processes exited 139 after the close request. Those unresolved shutdown observations remain recorded; both longer repeat runs closed normally. No game assets, screenshots, core dumps or raw console logs are published.

Download all four traces, summary lines, digests and extracted timing comparison. The fork prerelease is a timing attachment, not an emulator build release; each .json.gz opens in Perfetto.

Official summary lines (pair 1 main/PR, then reverse-order repeat main/PR):

{"commit":"1e7272196389","dirty":false,"env":{"APS5_DRAW_CACHE_ENTRIES":"4096","APS5_HOST_IMPORT_MIB":"16384","APS5_PAD_INPUT_FILE":"<path>","APS5_PIPELINED_DRAWS":"1","APS5_TRACE_SECONDS":"0:60"},"gpu":"AMD Radeon RX 6650 XT (RADV NAVI23)","driver":"radv Mesa 26.2.4-arch1.1","os":"Linux 7.2.9-arch1-1","resolution":"3840x2160","window":{"spec":"seconds 0:60","first_present":0,"ms":64056.804},"presents":105,"frame_ms":{"p50":37.269,"p90":2364.364,"p99":4295.703,"max":4548.802},"gpu_busy_ms_per_present":33.152,"worker_busy_pct":{"queue worker 0x0":7.853,"queue worker 0x48":5.405,"queue worker 0x40":7.332},"top_phases_ms_per_frame":{"Driver.Packet":125.119,"Driver.Packet.memory_wait":68.363,"Shader.PrepareArtifact":43.275,"Driver.Packet.dispatch":31.749,"Driver.Dispatch":31.69,"Vulkan.Dispatch":19.241,"Vulkan.Dispatch.shader_resources":18.996,"Vulkan.GraphicsPipelinePrebuild":16.309},"trace_dropped":false,"trace":"aps5-trace-1e7272196389-3451464.json.gz"}
{"commit":"5aea65b4b1c3","dirty":false,"env":{"APS5_DRAW_CACHE_ENTRIES":"4096","APS5_HOST_IMPORT_MIB":"16384","APS5_PAD_INPUT_FILE":"<path>","APS5_PIPELINED_DRAWS":"1","APS5_TRACE_SECONDS":"0:60"},"gpu":"AMD Radeon RX 6650 XT (RADV NAVI23)","driver":"radv Mesa 26.2.4-arch1.1","os":"Linux 7.2.9-arch1-1","resolution":"3840x2160","window":{"spec":"seconds 0:60","first_present":0,"ms":62409.625},"presents":105,"frame_ms":{"p50":37.947,"p90":2207.181,"p99":3281.585,"max":3371.253},"gpu_busy_ms_per_present":34.569,"worker_busy_pct":{"queue worker 0x0":7.324,"queue worker 0x40":6.717,"queue worker 0x48":4.487},"top_phases_ms_per_frame":{"Driver.Packet":109.736,"Driver.Packet.memory_wait":57.306,"Shader.PrepareArtifact":44.191,"Driver.Dispatch":28.25,"Driver.Packet.dispatch":28.208,"Vulkan.GraphicsPipelinePrebuild":17.346,"Vulkan.GraphicsPipeline":17.322,"Vulkan.GraphicsPipelineLibrary":17.162},"trace_dropped":false,"trace":"aps5-trace-5aea65b4b1c3-3620398.json.gz"}
{"commit":"1e7272196389","dirty":false,"env":{"APS5_DRAW_CACHE_ENTRIES":"4096","APS5_HOST_IMPORT_MIB":"16384","APS5_PAD_INPUT_FILE":"<path>","APS5_PIPELINED_DRAWS":"1","APS5_TRACE_SECONDS":"0:60"},"gpu":"AMD Radeon RX 6650 XT (RADV NAVI23)","driver":"radv Mesa 26.2.4-arch1.1","os":"Linux 7.2.9-arch1-1","resolution":"3840x2160","window":{"spec":"seconds 0:60","first_present":0,"ms":62789.392},"presents":91,"frame_ms":{"p50":39.617,"p90":2610.342,"p99":4203.167,"max":4203.167},"gpu_busy_ms_per_present":34.887,"worker_busy_pct":{"queue worker 0x0":7.23,"queue worker 0x40":6.691,"queue worker 0x48":4.982},"top_phases_ms_per_frame":{"Driver.Packet":129.92,"Driver.Packet.memory_wait":71.194,"Shader.PrepareArtifact":44.54,"Driver.Packet.dispatch":34.86,"Driver.Dispatch":34.808,"Vulkan.Dispatch":22.51,"Vulkan.Dispatch.shader_resources":22.246,"Vulkan.GraphicsPipelinePrebuild":19.135},"trace_dropped":false,"trace":"aps5-trace-1e7272196389-4086320.json.gz"}
{"commit":"5aea65b4b1c3","dirty":false,"env":{"APS5_DRAW_CACHE_ENTRIES":"4096","APS5_HOST_IMPORT_MIB":"16384","APS5_PAD_INPUT_FILE":"<path>","APS5_PIPELINED_DRAWS":"1","APS5_TRACE_SECONDS":"0:60"},"gpu":"AMD Radeon RX 6650 XT (RADV NAVI23)","driver":"radv Mesa 26.2.4-arch1.1","os":"Linux 7.2.9-arch1-1","resolution":"3840x2160","window":{"spec":"seconds 0:60","first_present":0,"ms":61633.391},"presents":125,"frame_ms":{"p50":31.313,"p90":1939.731,"p99":3029.308,"max":3053.024},"gpu_busy_ms_per_present":32.66,"worker_busy_pct":{"queue worker 0x0":8.393,"queue worker 0x48":5.481,"queue worker 0x40":7.758},"top_phases_ms_per_frame":{"Driver.Packet":106.213,"Driver.Packet.memory_wait":56.589,"Shader.PrepareArtifact":33.973,"Driver.Packet.dispatch":26.534,"Driver.Dispatch":26.468,"Vulkan.Dispatch":15.256,"Vulkan.GraphicsPipelinePrebuild":15.075,"Vulkan.GraphicsPipeline":15.051},"trace_dropped":false,"trace":"aps5-trace-5aea65b4b1c3-3880445.json.gz"}

Checklist

• Based on recorded main; only this topic's commits above it
• One topic per PR
• No code comments added except technical debt
• No unimplemented paths or silent stubs added
• No investigation files, game assets or images added
• Existing pinned third-party source only
• Generic behavior
• Depends on: none
• Unblocks: none
• GPUs tested: AMD Radeon RX 6650 XT, RADV Mesa 26.2.4, Arch Linux; matched cold-start comparison below
• AI-assisted: yes