On devices whose default subgroup is 64 lanes (RADV, AMD on Windows) a
wave32 compute program was compiled for a 64-wide host subgroup, so the two
guest waves of a 64-thread workgroup shared one subgroup: ballots, EXEC,
v_mbcnt and lane reads of the second wave saw the first one's lanes.
With VK_EXT_subgroup_size_control, when compute can require 32 lanes, the
dispatch recompiles wave32 programs for a 32-wide host subgroup
(VulkanDevice::ComputeTarget) and the pipeline requires that size. The
result records the width it was compiled for (hostSubgroupSize, also in the
disk cache).
Co-Authored-By: Claude <noreply@anthropic.com>
Explicit v_interp_p1/p2 interpolation (fragment-shader barycentrics) reads every interpolated
parameter per vertex, and the rect-list shaders refused every per-vertex parameter. Their
tessellation stage emits each corner's parameter value, which is what a per-vertex read of the
generated triangles needs. Only custom parameters (custom interpolation or passthrough), whose
fourth vertex has no value of its own, stay refused; FragmentParameter carries that flag.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
decodeResult and decodeAllocation called memcpy with the data() of
empty vectors, which may be null. Passing a null pointer to memcpy is
undefined even for a zero size, and UBSan reports it on every entry
without push constants, including the existing shader disk cache test.
The copy now runs only for a non-empty table, as Reader::Values does.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01R5WJS4ZdQynAJesCZKH5hb
Every run recompiled every shader: the recompiler's variant cache and
the device's VkPipelineCache only lived in memory, and the first frames
of a title spent hundreds of milliseconds per large program in the
front end, the emitter and the optimizer.
Compiled variants (the SPIR-V plus the compiled shader info and binding
allocation that per-snapshot binding population needs) are now stored
on disk, one file per key, written atomically by a background thread,
and a later run loads them instead of compiling. The key holds every
input the in-memory variant cache matches on: the in-memory recompile
key (stage, code hash, stage registers, user data count, target), every
code word, the host subgroup size, the binding layout, the resource
specialization, and the values of the APS5_* switches the recompiler
sources read (found at build time; switches that only report are left
out). Entries live under a directory per source version, a build-time
hash of the recompiler and AGC driver sources and the build
configuration, and carry their key and checksums: an entry whose
format, version, key, size or checksum does not match, or whose payload
does not decode exactly, is ignored and recompiled. Directories no
build used for two weeks and stale temporary files are removed. Requests
under the debug probe bypass the disk cache.
The device's VkPipelineCache is loaded at creation when the file's
checksum and Vulkan header match the device (vendor, device and
pipelineCacheUUID; the driver version is in the file name), saved every
10 s while it grew, and saved at teardown.
Location: a shader_cache folder beside the running executable (not the
working directory), so the relinked game stays a self-contained folder;
ANYPS5_SHADER_CACHE_DIR overrides it. ANYPS5_NO_SHADER_CACHE=1 turns both caches off; the AGC
tests run with it set so they never write to the user's cache.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ButHENCbXXt8h4EZuWUabJ
Dean
Adrià Franch
Michon
Alberto Ruiz
SamG-Coder
boykopovar
Dean Galvin