SPI_PS_INPUT_ENA/ADDR with PERSP_CENTROID (bit 2) or LINEAR_CENTROID
(bit 6) was rejected; PPSA21564 binds 0x326 (perspective center and
centroid, linear center, POS_X/Y).
The PS input VGPR layout now follows the hardware rule: SPI_PS_INPUT_ADDR
places every input it names in SPI order (two VGPRs per I/J pair, three
for the pull model, one otherwise), loaded or not, and ENA & ADDR selects
the loaded ones. ShaderPixelStageInfo carries inputAddr (replacing
perspectiveCenterVgpr) plus perspectiveCentroid and linearCentroid; the
recompiler places each loaded input with PixelInputVgpr. This also fixes
the system inputs, which were always written from v0 (psSystemInputBase
was never set), so POS_X overwrote the center I in any draw with
barycentrics enabled.
Draws are rasterized single-sampled, where the centroid is the pixel
center: with fragment barycentrics the centroid pairs carry the center
barycentrics (BaryCoordKHR for perspective; the linear center and
centroid pairs now get BaryCoordNoPerspKHR).
NoPerspective was decided for every parameter by one flag (LINEAR_CENTER
loaded). v_interp_p2 now records whether it reads the J of a linear or a
perspective pair, and a parameter is NoPerspective when it is read
through a linear pair; parameters read through neither keep the old
rule. A parameter read through both kinds of pair throws. Only pixel
stages consult this.
The request serializer moves to version 5 (older requests read back with
their loaded inputs as the layout); the cache key and the driver's draw
key compare and hash the new fields. The unsupported-input error names
ENA and ADDR.
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.
Only the lines this branch added lose their comments; the commits before
keep them, with the reasoning behind each change, for whoever digs into
that code later.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A dispatch sized in threads (USE_THREAD_DIMENSIONS) launches a partial last
workgroup on RDNA2, but the host rounds it up to whole groups, so the extra
threads ran: past the end of a node list they read past it and wrote over
live records.
Such dispatches now compile a separate variant (ShaderComputeStageInfo::
partialThreads, keyed only on whether it is set) whose entry EXEC excludes
threads at or past the requested size. The size reaches the shader as three
shader data dwords after the memory offsets (StageInputKind::
DispatchThreadLimit), is mixed into the dispatch cache key and the result
memo hash, and serialized in recompile requests (version 3). Whole-group
dispatches keep their variant.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
SamG-Coder