MoltenVK has no VK_EXT_image_view_min_lod, so since #130 the first T#
with a MIN_LOD clamp above its base level threw. ASTRO BOT (PPSA21564
01.007.000) hits it on the title screen, about four minutes after boot.
MoltenVK does offer shaderResourceMinLod, which maps the SPIR-V MinLod
operand to Metal's min_lod_clamp.
On a device with shaderResourceMinLod, without the extension and
without graphics pipeline libraries, the new target flag
shaderImageMinLod moves the clamp into the shader:
- DescriptorBindingBuilder writes each direct image's clamp, relative
to the view's base level and bounded by its last level and MAX_MIP,
as a float specialization constant at MinLodBase + image.
- Samples of direct images take it as the MinLod operand, or as an FMax
on an explicit LOD when the clamp is above 0, combined with an
instruction's _cl clamp.
- The image view no longer chains the clamp there; image table entries
with a clamp are still rejected, and devices with the extension are
unaffected. APS5_NO_IMAGE_VIEW_MIN_LOD forces the shader lane.
- It throws when the clamp sits above a paired S#'s MAX_LOD or has no
mip filter, follows an explicit LOD or gradient with a nonzero S# LOD
bias, pairs with a run-time S# or different min and mag filters, or
meets image_get_lod, gathers at a clamp of a level or more, or the
emulated depth-compare or 11:11:10 sample.
- ValidateShaders accepts CapabilityMinLod when the device enables
shaderResourceMinLod.
- The flag is written after hostInterpolationFirst as request
serialization version 53; older versions read it as false.
The gaps, including llvmpipe applying the S# bias after the clamp, are
recorded in docs/dev/debt/shader.md.
Tested on an M-series Mac (MoltenVK 1.4.2, x86_64 under Rosetta):
image_sample_lod_clamp samples a T# with fractional and level clamps
over BASE_LEVEL 0 and 1 in both lanes, and fails without the shader
clamp or with an absolute one; graphics, shader disk cache, shader
memory and request serializer tests pass. PPSA21564 renders the title
and reaches the warp sequence after it.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
RADV gives the second triangle of a full-screen quad PerVertexKHR values
in an order that does not match gl_BaryCoordKHR, so passes whose pixel
shader uses plain v_interp_p1/p2 show a diagonal seam (Silksong final
pass on a Radeon 780M). On RADV, pixel shaders are now first translated
with host interpolation; only shaders the host interpolation checker
rejects keep native VK_KHR_fragment_shader_barycentric.
APS5_NO_HOST_INTERPOLATION_FIRST=1 restores the old behaviour.
AI-assisted. Tested by me on my own machine.
The recompile cache key mixed every supported capability and every byte
of every supported extension name each time it was built, which is once
per draw stage. The shader device profile fixes its capability and
extension lists in its constructor and never changes them, so it now
seals their digest into its target there. A key uses the sealed digest
while the target's feature spans are the ones it was computed from, and
digests them as before otherwise. Key values are unchanged.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_015W3M6NbYpmwWkzkL8YNLaF
MoltenVK and lavapipe leave the tessellation evaluation stage out of
subgroupSupportedStages, so the driver's shader validation refuses every
domain program that declares GroupNonUniform ("subgroup capability 61 is
unsupported for shader stage 4"). Gran Turismo 7 stops there on macOS at
the Used Car dealership.
The device target now records whether the tessellation evaluation stage
has subgroups. When it does not, tessellation evaluation programs outside
the mesh path get a host subgroup width of 1 and the one-lane rules that
vertex programs already use without vertex subgroups: the lane id is 0,
a ballot is the invocation's own bit, a shuffle returns the invocation's
value and an elect is true. Reads of other lanes still throw. Devices
with tessellation evaluation subgroups emit the same SPIR-V as before.
The request serialization moves to version 51.
A draw that blends into several targets with BLEND_CLAMP clear now carries
one merge entry per target. Each entry gets its own storage image and
pixel-shader blend, and every pending entry is stored inside the draw's one
pixel interlock region. Partial writes of packed targets still merge alone.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
On NVIDIA's proprietary driver, function arrays that live in local memory
and are read under a data-dependent branch return wrong values in
subgroups 1-3 of a mesh workgroup; subgroup 0 is correct. A wave64
geometry program whose relative addressing keeps its VGPRs in the vector
window therefore loses register writes in every wave but the first. In
the clipping geometry program of Sony's PS5 PSP emulator (PPSA07550) the
empty waves never cleared their candidate primitive slots and wrote
degenerate triangles over wave 0's, so the 3D menu drew spikes.
On that driver a mesh program's window now lives in a device-local
storage buffer of 256 workgroup slots of 65536 dwords, claimed through a
per-slot lock and released after the final barrier. The pool is created
before the first draw that uses it records anything, and its header is
zeroed in a batch of its own that is submitted and waited for; the pool
is published only after that wait, and a failure releases it. Direct
register accesses keep one function variable per register; a direct
store also writes the buffer when a buffer read can see it, relative
reads load the buffer, relative writes store only to it, and a direct
read that may follow a relative write loads the buffer and refreshes the
variable. A buffer entry is zeroed only when a buffer read can see it
before a write. APS5_NO_MESH_WINDOW_BUFFER=1 keeps the arrays.
A 1D-array resource sampled only by image_sample_lz/image_sample_l no longer
gets the layerRows runtime mode up front. The capture throws
LayerRowSamplesRequired when a view of more than maxImageArrayLayers slices
reaches a shader prepared without it, and the shader is prepared again with
GuestContext::layerRowSamples, as converted samples are. Shaders that never
see such a view keep the interface they have without this path.
Test views of exactly maxImageArrayLayers and maxImageArrayLayers + 1 slices,
with image_sample_lz and image_sample_l, and report each layer-row texture
built under APS5_PROFILE_DRAW.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
A sampled 1D array view with at least maxImageArrayLayers slices, read
only by image_sample_lz or image_sample_l, gets a runtime image mode that
binds a 2D image holding each viewed slice in two adjacent rows. The
shader rounds and clamps the layer as Vulkan array layer selection does
and samples on the boundary between the two copies, so filtering never
reaches another slice. Other uses keep throwing.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
SPIRV-Cross emits the lock's acquire compare-exchange and release
exchange as relaxed Metal atomics, so the plain LDS loads and stores of
a locked 64-bit update were not ordered against the lock and contended
ds_add_u64 lost updates on an Apple M5 Pro. On MoltenVK the driver now sets
SpirvTarget::ldsLockFences, and the lock brackets its critical section
with workgroup-scope acquire and release OpMemoryBarriers, which become
threadgroup atomic_thread_fence with no execution barrier.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Main took request serialization version 48 for the fragment barycentric
built-ins flag (#9193). The depth export clamp bounds are now written at
version 49 and read only for versions from 49, so a version 48 request as main
writes it still decodes, with default bounds. Tests: version 49 is the
emitted prefix, 50 the first unsupported one, a depth exporting request
without its bounds decodes at 48, 47 and 46 (the last two without main's
barycentric byte), and a version 48 two-sample dithered request decodes as
written.
Main took request serialization version 47 for the two-sample dithered
alpha-to-coverage value. The depth export clamp bounds are now written at
version 48 and read only for versions from 48, so a version 47 request as main
writes it still decodes, with default bounds. Tests: version 48 is the
emitted prefix, 49 the first unsupported one, and a version 47 two-sample
dithered request (with and without depth export) decodes as written.
MoltenVK exposes VK_KHR_fragment_shader_barycentric but its MSL step
rejects PerVertexKHR, so the extension is disabled there and a pixel
shader whose I/J VGPRs outlive their v_interp_p1/p2 pairs takes the
generated barycentric stages, which accept only triangle lists without
primitive restart on a device without geometry shaders.
A new target flag, fragmentBarycentricBuiltins, enables the extension
for its built-ins only. The host interpolation check then keeps the
leftover I/J reads (all perspective or all linear, at the fragment's
default position) and reads them from BaryCoordKHR or
BaryCoordNoPerspKHR, while the interpolated attributes stay hardware
varyings. Raw vertex parameters and I/J at an offset or a sample
position still take the generated stages. Apple GPUs return
unnormalized perspective weights unless the fragment function reads
[[position]], so each perspective read keeps a neutral use of
gl_FragCoord.w, loaded as a float. Devices with the full extension are
unaffected; the request serialization moves to version 45.
Co-authored-by: yripper <[email protected]>
TargetMerge gains a TargetBlend (factors, operations, write mask, constants, signedness) that the request serializer, the cache key and the variant hash take only when it is enabled, so every request without it keeps its bytes, key and hash.
Crimson Desert (PPSA25286) draws with VGT_SHADER_STAGES_EN 0x60212d:
local, hull, domain and NGG geometry stages, the hull halves merged in one
registered type-3 program, the domain and geometry halves in one type-2
program. The domain half runs as the tessellation evaluation stage and
captures each vertex's ESGS item, and a mesh shader runs the geometry half
on the captured items.
Registered type-3 merged hulls come from #6679; this adds 16-bit LDS
reads and writes in tessellation stages, which Crimson Desert's merged
hull uses.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Bugsnax (PPSA01503) draws with DB_ALPHA_TO_MASK 0xe701 (quad offsets
3, 1, 2, 3 without OFFSET_ROUND) on a two-sample target and stopped on
the refusal of every dither but the eight-sample 0x18701. The pixel
shader now applies an eight-level per-quad table for it, measured
natively on gfx1032, and the request's dither byte selects that table
(serialization version 47). It is accepted only for two matched raster
and DB_EQAA samples, the two measured location pairs and FP16_ABGR or
32_ABGR exports.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Every recompile cache key appended the target's capability list and
each SPIR-V extension name one byte per 64-bit word, so on a device that
enables a few dozen extensions most of every key was the same device
description: built and compared on every dispatch and draw, and kept in
every in-memory key and disk cache entry. The two lists now enter the key
as a 128-bit digest over the capabilities and the length and bytes of
each extension name, eight bytes per step.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
The recompiler orders an LDS atomic, and the compare-exchange loop that
writes a byte or a halfword of LDS (ds_write_b8/b16), with a
workgroup-scope OpMemoryBarrier after the update. AMD's proprietary
Windows driver 32.0.21042.62 (Radeon 0x13c0, RDNA 2) compiles that
memory barrier to s_barrier, as the code objects in its pipeline cache
show. Such updates usually sit in branches that only some waves of a
workgroup take, so those waves execute extra s_barriers, which pair
with the other waves' barriers, and the other waves read LDS before it
is written. An OpMemoryBarrier is not an execution barrier and SPIR-V
allows it in non-uniform control flow, so the SPIR-V is valid; a
device-scope OpMemoryBarrier compiles to GL0 and GL1 cache
invalidations without s_barrier there.
PS5LM Plus (PPSA99581, llama.cpp's Vulkan backend) drifted into
garbage on that driver with flash attention on. Its flash-attention
shader stores two halfwords to LDS in a branch that two of its four
waves take, inside the KV loop. The driver's code had 23 s_barrier for
the guest's 21; a replay of the dispatch differed from NVIDIA in 159
words, up to 1.7e38, and now has 21 and differs only in the last bit
of 9 words.
On that driver the fence is now device scope, which orders everything
the workgroup-scope fence did. Other drivers keep the workgroup scope.
The flag is part of the shader cache key, and agc_shader_replay takes
--device-scope-lds-memory-barriers to replay a request the way that
driver compiles it. The LDS update helper already fences, so the
second, identical fence after it in ds_min/max_f32 and the other
read-modify-write LDS operations is dropped.
agc_driver_lds_subword_store_branch stores a halfword to LDS in a
branch that waves 0-1 of four take, delays those waves and then
exchanges LDS slots across one s_barrier. Before, thread 64 read a
stale slot on the AMD driver; it passes on AMD and NVIDIA now.
agc_subgroup_barrier checks the driver quirk and that ds_write_b16,
ds_add_u32 and ds_max_f32 each emit one fence of the expected scope.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01BM2kfDbr6MydxsfTckZJDR
The slot counter is reset only after earlier fragment writes, and the overflow flag stays until WaitIdle. The storage buffer is limited to NVIDIA's proprietary driver, which is where the large function array does not finish.
The DB clamps a pixel shader's exported depth to PA_SC_VPORT_ZMIN_0 and
ZMAX_0 unless DB_RENDER_OVERRIDE.DISABLE_VIEWPORT_CLAMP is set. Vulkan only
clamps with depthClamp, which also drops clipping, so the exported value
reached the depth attachment unclamped.
The pixel stage info now carries the two bounds when the shader exports
depth (0 and 1 otherwise), and the exported value is NClamped to them
before it is stored to gl_FragDepth. With
DISABLE_VIEWPORT_CLAMP the value is stored as exported; non-finite or
inverted bounds are rejected. DB_RENDER_OVERRIDE joins the draw key
registers. The bounds
are part of the recompile cache key (only for depth-exporting shaders, so
other keys do not change), the draw key and its register check, and
recompile requests (serialization version 47).
Tests: the pixel stage decode reads the bounds, passes the disable flag through
and rejects bad bounds, and leaves a draw without depth export at 0 and 1; a
recompiled depth export stores the NClamped value, and its bounds survive
serialization and key the cache.
Request version 47: main is at 44 (#8612) and open PRs also claim 44 to 46 (#8564, #7888, #9193 and the #9020, #9335, #9748 stack). Whichever of these lands second renumbers.
The recompiler marks every guest f32 add, subtract and multiply
NoContraction, because the guest rounds each one separately.
SPIRV-Cross turns each of them into a call to a helper that Metal
compiles without optimization, which dominates fragment time on
MoltenVK, and its multiply helper, fma(a, b, +0.0), turns a -0.0
product into +0.0.
On MoltenVK they are now GLSL Fma whose second step is exact, which
gives the separately rounded result: a * b is fma(a, b, -0.0), a + b
is fma(1.0, a, b) and a - b is fma(-1.0, b, a). The sin, cos and log2
series and the offset image coordinates and gather texel scale use the
same forms. The choice is a SpirvTarget flag set for
VK_DRIVER_ID_MOLTENVK, part of the shader cache key and of the request
serialization (version 44); other drivers are unchanged.
agc_driver_f32_separate_rounding checks a multiply feeding an add or a
subtract on rows where fusing them changes the result. It,
agc_driver_f32_arithmetic_nan and agc_driver_f32_denormal_flush also
run the fused forms on devices that do not use them, so lavapipe checks
them against the same rows.
Co-authored-by: Ycaro Gabriel <[email protected]>
A point list routed through the vertex path was refused, and so was
PA_CL_VS_OUT_CNTL.USE_VTX_POINT_SIZE on it. OliSe Player (PPSA01153)
stops on the latter with two of its MilkDrop presets.
The vertex path now draws point lists as Vulkan points. The vertex stage
writes PointSize: the misc export's X clamped to PA_SU_POINT_MINMAX when
USE_VTX_POINT_SIZE is set, and the PA_SU_POINT_SIZE height otherwise.
The point state travels in the recompile request (version 31) and the
cache and draw keys. Non-square register sizes, inverted clamps, point
sprite texture coordinates and, without largePoints, sizes other than
one pixel throw.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
main 7ce3b1df3e took disk-cache format 43 (#8295) for its own layout, so this
branch's format moves to 44. The request serializer stays at 42: main
still writes 41.
The recompiler asked for DenormPreserve only for 16-bit and 64-bit floats,
so a device that flushes 32-bit denormals by default (RADV, MoltenVK) flushed
them whatever the guest's float mode said. target.float32DenormPreserve is set
from shaderDenormPreserveFloat32 when denormBehaviorIndependence allows a 32-bit
mode, is part of the cache key and of the request serialization (version 41),
and makes the module declare DenormPreserve 32 unless the 32-bit flush is
already taken in hardware. APS5_NO_HW_F32_PRESERVE=1 turns it off.
The refusal of a merging shader that writes guest memory under late
tests fired in two cases where the early tests change nothing.
The first was a draw with no depth, stencil or depth-bounds test. Early
tests reject no pixel there, so every write the console makes still
happens. The target merge now carries whether the draw has such a
test, and the refusal applies only then. This adds one byte to the
version 40 merge fields of the recompile request.
The second was any GDS binding, including a shader that only reads GDS.
The refusal now looks for GDS writes, atomics, appends and consumes.
Tests: the depth and stencil decode checks the new flag, and the
static shader key depends on it. A counter-adding shader under late
tests compiles without a test and throws with one. A late-test merge
that reads GDS compiles, and one that adds to GDS throws.
Co-Authored-By: Claude Sonnet 5.5 <[email protected]>
A packed 4_4_4_4 partial write merges inside the pixel shader after early
depth and stencil tests. Moving the tests ahead of a pixel kill only changes
the result when the draw writes depth or stencil, so the target merge now
carries whether the draw does (depth write, or stencil with a write mask and
a non-keep operation), and the late-test kill refusal applies only then.
The flag is part of the static shader key, the serialized request (now
version 40) and the pixel input info.
Co-Authored-By: Claude Sonnet 5.5 <[email protected]>
Dean