Route oversized compute LDS through a per-workgroup storage buffer.
Retain native shared memory for programs that fit the device limit.
Carry the spill stride through prepared shader results and dispatches.
Preserve the stride in the full-result codec and its round-trip fixture.
Keep the Linux RecompileResult size guard aligned with the added field.
Exercise interleaved workgroups and the device-limit boundary.
This topic contains only the LDS change and its reviewer-requested repair.
The base includes upstream's separately merged NaN result correction.
A compute program with COMPUTE_PGM_RSRC2.SCRATCH_EN takes its per-lane private size from the AGC
shader header (scratch_size_dw_per_thread) instead of being refused. The size travels in
ShaderComputeStageInfo (cache key, request serialization version 10) to the translator, whose
scratch accesses already lower to a per-invocation Function array of that many dwords.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Every VGPR write under EXEC is translated to Select(exec, new, old), so
in SSA each register's previous value stays live until the next write,
even when the guest only used the register as a temporary. In NGG mesh
shaders at 255 registers that keeps dead values alive and the driver
spills them to local memory.
MaskedSelectEliminator (after SSA, folding and the readlane pass)
replaces r = Select(m, new, old) by new when no lane where m is false
can observe r:
- every value derived from r is either a lane-local pure op or a phi,
and their uses are checked the same way;
- or the derived value reaches the true operand of a select, or an
operand of a LogicalAnd, whose condition implies m: m itself, a
LogicalAnd containing m, or a thread bit rebuilt from a ballot of
such a condition (also through ANDs of the mask words);
- anything else (cross-lane ops, ballots, readfirstlane, DPP, swizzle,
permutes, stores, exports, atomics, branch references, implicit-LOD
pixel samples, the false operand of any select) keeps the select.
The select and every value it reaches must be in blocks outside loops,
so each of them runs at most once per invocation and every use sees the
same instance of m. Selects whose condition is the full wave
((0xffffffff >> (lane & 31)) & 1) are replaced in any block.
Exact: in lanes where m is true r equals new, so every derived value is
unchanged there; in lanes where m is false only derived values change,
and each path from them ends in a select or AND that discards those
lanes. The selects are removed latest first and dead code is removed
between rounds, so chains of writes to one register collapse.
The geometry path's merged ES/GS programs (VGT_SHADER_STAGES_EN.GS_EN)
were compiled as mesh-stage programs whose input metadata was never
filled in, so every such draw failed with "mesh shader translation
configuration is not supported".
Recompiler:
- BuildShaderStageInputInfo takes the draw's MeshConfiguration; the mesh
input helpers (primitive size, step and counts) are implemented.
- The prologue emulates one NGG subgroup per workgroup: s2 GS_TG_INFO,
s3 the merged wave info per wave, the GS vertex offsets (ES thread
index times VGT_ESGS_RING_ITEMSIZE, odd strip triangles swapped), the
primitive id, and the ES vertex and instance ids. An indexed draw's
vertex id is read from the index buffer through a raw V# the driver
puts in hidden user words 4..7.
- s_sendmsg GS_ALLOC_REQ becomes MeshAllocate. The epilogue zeroes the
allocation first, clamps it to the output limits, culls primitives no
thread exported and decodes the 9-bit vertex indices.
- The draw parameters live in the last six push dwords. A BDA fault in
a mesh program no longer stops the invocation (as for other programs
with barriers, the fault is recorded and the read returns zero), so
every invocation reaches the subgroup barriers and the epilogue.
- The cache keys cover the mesh configuration; requests serialize its
new esgsItemSize field (version 4).
Driver:
- DecodeShaderStages reads VGT_ESGS_RING_ITEMSIZE (now in the draw key)
and sizes the subgroup for its ES vertices, GS primitives and outputs.
- Stages compile below the mesh draw parameters, which every mesh draw
pushes; the mesh stage always takes part in the push range.
- The index-buffer V# is set per draw (per record on the CPU-resolved
indirect path); the index-buffer alias check spares read-only
elements.
- The workgroup and LocalSize checks count two guest lanes per
invocation on 32-wide subgroups; mesh draws may carry a first vertex
or instance.
agc_driver_mesh_tests (EXCLUDE_FROM_ALL, needs VK_EXT_mesh_shader)
recompiles a hand-assembled merged ES/GS program in the PS5 compiler's
layout and draws indexed and non-indexed triangle lists in one- and
two-wave subgroups and a triangle strip across odd-starting subgroups,
reading the pixels back. agc_shader_replay prints a request's draw and
mesh configuration.
- s_*_saveexec reads its source before writing the old EXEC into the
destination, so the aliased form (vcc, vcc) computes exec & vcc; the
per-lane exec bit comes from the lane's own bit. Every Bink 2 decoder
kernel uses that form; this was the video corruption.
- buffer atomics add/sub/or/xor with a zero operand become an atomic
load or nothing.
- DescriptorBinding carries bufferWritten/bufferAtomic/imageWritten;
results expose a variantId and share SPIR-V copy-on-write; source
keys use a length plus 64-bit hash; captures can be reused.
- wave-LDS ordering barriers, v_movrels/v_movreld lowering, SMEM with a
VCC base, f16 conversion opcode fix, a per-function SPIRV-Tools pass
list, env-gated IR dumps and probes.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0177gthrWEBBfBu5xJDXgBfo
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