Program 203 reuses prefixSumCache for a second subgroup reduction before every workgroup invocation has consumed the first result. Add a fingerprint-gated SPIR-V pass that inserts the missing Workgroup acquire-release barrier while preserving native subgroup operations.
Keep the repair opt-in behind MOBILEGL_ITERATIONRP_FIX_BARRIER, cover insertion, pass-through, and idempotence, and enable it together with the existing iterationRP subgroup repairs for the matching Linux and Android CI retraces.
Add a deterministic iterationRP Program 203 fixture that dispatches the original shader and compares every RG16F texel against fixed half-float golden bits. This catches both a wrong exposure result and collateral writes without retaining a serial reference shader.
Make MobileGLIntegrationTest runnable as a standalone Android executable by linking the shared MobileGL library and backing EGL with an AImageReader window; desktop keeps its static-library pbuffer path.
Validation: Adreno 830 passes with 0/262656 mismatches; lavapipe reproduces the current reduction defect with 1/262656 mismatches at the exposure texel.
iterationRP's Program 203 declares shared vec2 prefixSumCache[32] for a
512-invocation workgroup indexed by gl_SubgroupID; any device narrower
than 16 lanes partitions into more than 32 subgroups and the pack writes
shared memory out of bounds (heap corruption on lavapipe's CPU
rasterizer, ssim 0.028 on the CI retrace). Fix it where the fault lies -
in the fixture - and keep the GL contract sound everywhere else:
- FixIterationRPSubgroupScratchPass: fingerprint-gated SPIR-V pass that
grows exactly that array to ceil(invocations/width) entries on sub-16-lane devices; every other module passes through byte-identical.
- DeriveNumSubgroupsPass stays default-on for the Adreno topology bug
and is made spec-sound: pipelines request REQUIRE_FULL_SUBGROUPS
whenever the workgroup shape makes the flag legal (computeFullSubgroups
enabled, local_size_x a multiple of the native width, subgroup count
within maxComputeWorkgroupSubgroups).
- EmulateSubgroupsPass: 32-lane virtual-subgroup lowering kept in-tree
as a last resort, enabled only by MOBILEGL_MAGMA_EMULATE_SUBGROUP=1 on
devices with no native subgroup support; fails closed on extended
subgroup instructions and on modules whose added scratch would exceed
maxComputeSharedMemorySize.
- IterationRPFirstReductionScenario skips gracefully outside the pack's
16..256-lane source domain; the new IterationRPScratchFixScenario runs
the fixture-shaped reduction on any width and asserts the exact
width-independent total. DriverPost keeps reporting FAIL on
out-of-domain devices.
- Program203 -> IterationRP rename throughout; the per-trace
num_subgroups_quirk plumbing is removed from the trace replayer, JNI
chain, and CI workflows.
Wave 2 of the advertised-extension conformance campaign.
PROGRAM INTERFACE QUERIES (the load-bearing piece). glGetProgramInterfaceiv
and the five glGetProgramResource* entry points were answered by the
BACKENDS - Espryt asked the real driver about SPIRV-Cross-generated ESSL
whose namespace is not the GL one (default-block uniforms live in
MGL_GLOBAL_UBO there), and Magma kept a second, partial reflection that
hardcoded types and diverged from the frontend. Both are now deleted; a new
frontend resource-model layer (ProgramInterface.{h,cpp}) answers every
interface - uniforms, uniform blocks, atomic-counter buffers (recovered
from glslang's synthesized gl_AtomicCounterBlock_<binding> lowering),
buffer variables, shader-storage blocks (classified by TType storage
qualifier since glslang reflects them as uniform blocks), program inputs/
outputs (built-ins' layoutLocationEnd sentinel mapped to -1), and
transform-feedback varyings including the gl_NextBuffer/gl_SkipComponentsN
pseudo-varyings - from the glslang reflection the frontend already trusts
for glGetActiveUniform. Name/index round-tripping, the "[0]" array
spelling, and the GL 4.6 table 7.2 prop/error matrix live in the new layer
only; GetActiveUniform*/GetActiveAttrib* are untouched.
glShaderStorageBlockBinding now takes the interface-layer index (the one
GetProgramResourceIndex returns, with a range check it never had), records
the binding on the program keyed by block NAME - the one coordinate all
three index spaces agree on - and delegates by name across the backend
boundary. Both backends reseed the recorded bindings on their own program
rebuilds, so an unrelated resync can no longer silently revert a rebound
block, and GL_BUFFER_BINDING reports the live binding, not the declared
one. The Espryt delegate applies only to an already-synced twin and can no
longer trigger SyncToBackend from a getter; the sync path's GL query
out-params are initialized and clamped (a load-dependent stack-garbage
Vector size crash caught by the gate, reproduced 3/50 pre-fix, 100/100
post-fix under saturating load).
ESPRYT RENDER-STATE SHADOW RESET (rides along because it shares
DirectGLES.cpp): the render-state shadow is file-static and survives
MobileGL context switches, so GL_FRAMEBUFFER_SRGB (and the whole synced-cap
class) leaked between contexts - the cross-test leakage class the CTS maps
have carried for a week. MakeCurrent now invalidates the shadow like it
already invalidates the program/FBO/buffer caches, and the resync resolves
a never-set scissor box to the current surface instead of pushing the
(0,0,0,0) sentinel verbatim (which scissored everything away - caught by
the retrace gate, bisected to the exact field via a bitmask probe, and
fixed by resolving like the viewport path rather than reverting).
Frontend riders exposed by the layer: glGetUniformLocation resolves
arrays-of-arrays element addressing ("a[2][1]"); transform-feedback capture
accepts element-addressed varying names ("b[1]") and snapshots the request
verbatim for the interface (Magma's decorate pass logs loudly that element
capture is unimplemented there - follow-up).
KNOWN GAPS, documented in code and tests: the 6 subroutines-* cases
(glslang refuses subroutine for SPIR-V; wave 3), the 5 separate-programs-*
cases (glslang's pipe-I/O reflection cannot see a separable non-vertex
stage's own inputs; needs stage-aware output validation first), and
uniform-block-types' per-instance stage masks (not derivable from the
reflection).
Gate: 593/593 unit at default and kill-switch, x10 each, plus the SSB race
case 100/100 under 20-way CPU load; ext caselist Espryt 77.87% -> 80.42%,
Magma 77.58% -> 79.39% (+212 fixed, 0 newly broken); program_interface_query
2/43 -> 31/43 unique on Espryt, 9/43 -> 31/43 on Magma, backends now
byte-identical; KHR-GL45.direct_state_access 370/371 + 371/371 with the 4
sRGB leak victims recovered in cross-test ordering; KHR-GL33 held at
9884/9886; full 39x2 CI retrace with zero wave-attributable failures (the
3 failing newly-added fixtures are bit-identical on the pristine baseline).
~21% of a shaderpack's glCompileShader calls hand different shader objects
byte-identical source; the P0b cache only helps after one finishes, so under
async two workers would run the whole pipeline twice. Now the GL thread
consults a per-context (stage, hash, length, envFingerprint) -> weak-node
map at enqueue and ADOPTS the in-flight (or completed) node instead of
posting a duplicate - a hit is honored only after a full byte comparison
(the hash never decides), a cancel-requested or settled-cancelled node is
never adopted, and no worker ever waits.
Sharing a node makes the unconditional cancel wrong, so release is now
adopter-counted: a plain GL-thread Int (every mutation site is a GL entry
point; the single-threadedness argument and the terminal-early-out that
keeps the count exact are in the header), and the cancel fires only at
count zero AND with no pending link pinning the node (the stage-4
MarkLinkReferenced precedence). Adoption also re-points the object's source
at the node's snapshot so the layer-1 memo's pointer compare stays armed -
without that, an adopter's next glCompileShader would re-enqueue the very
duplicate this stage removes. Both guards are negative-control-proven: each
removed guard fails exactly its own tests. Count discipline was proven with
a temporary hard-abort on underflow/leak across the full suite and retrace
corpus - zero hits.
18 new tests (13 GL-surface incl. shared-node re-source/delete/orphan-sweep
isolation, shared failure logs, 48-over-6 stress with a deterministic
adoption count, flag-off and KHR-suspended zero-adoption guards; 5 direct
map cases incl. fingerprint mismatch and cancelled/expired pruning).
Gates: 538/538 unit both flag states, async suites x5 no flakes, NVIDIA
DirectGLES retrace identical sets both states. Timing: 2-worker
(Android-shaped) 1-3% faster consistently on complementary and BSL;
4-worker unchanged - the win this stage exists for lands where CPU is
scarce.
glLinkProgram with the flag on snapshots its inputs in a GL-thread prologue
(stage-sorted shaders with their compile nodes taken without joining, env,
explicit locations/fragdata/xfb, draw-buffer count), then runs the whole
link body - glslang link/mapIO, SPIR-V, reflection, routing tables - as a
ProgramLinkTask that auto-posts when its last compile dependency settles
(+1-guarded countdown; no worker ever waits on another job). The publish is
one move of the LinkArtifacts block at the join, with the second version
bump so nothing memoized during the pending window survives.
The consume-once TShader claim moved onto the shared compile node as a CAS:
two link jobs racing for one shader resolve to winner-takes-the-parse,
loser re-parses the preprocessed source against the node's own env -
identical SPIR-V pinned by test for 2 and for 12 sharing programs.
Two deliberate corrections to the design's cancel matrix, both test-proven:
attach/detach do NOT cancel a pending link (the snapshot isolates it, and
glCreateShaderProgramv's link-then-detach would otherwise discard its own
result before anyone read it); and a compile node a pending link depends on
is pinned against the orphan-name sweep - the ordinary LWJGL teardown
compile/attach/link/detach/delete used to cancel the dependency and turn a
must-pass link into GL_FALSE.
Continuations are now throw-contained per-item (a stage-3 leftover made
load-bearing by the first real continuation), and the review's deadlock
find is fixed: the dispatch loop no longer cancels a node while holding the
pool mutex, since that cancel can run OnDepSettled -> Post -> same mutex.
Explicit joins: the draw path (GetProgramForDraw, both the pipeline stage
loop and the plain-UseProgram half) and the composite-link site; destroy
paths cancel-not-join; COMPLETION_STATUS readers stay non-joining.
Gates: 506/506 unit both flag states; AsyncCompile/AsyncLink/AsyncTeardown
suites x10 repeats clean both states (teardown with 128 jobs in flight,
then re-Initialize); full NVIDIA DirectGLES retrace flag on twice - result
sets identical to flag off, zero new deltas. Compile-phase prefix-diff,
flag on vs off: complementary-reimagined 5.21s -> 2.16s, BSL 1.72s ->
0.90s - past the design's final acceptance targets before the KHR
extension is even advertised. Default remains OFF until stage 5+7.
glCompileShader with MOBILEGL_ASYNC_SHADER_COMPILE=1 snapshots its inputs on
the GL thread (source SharedPtr, CompileEnv, cache handle) and runs the whole
pure pipeline - preprocess, validators, extractors, glslang parse - as a
ShaderCompileTask on the worker pool, returning immediately. Every read of
compile-produced state joins through the single Compiled() gate; links stay
synchronous this stage and join their attached shaders at the top of the
body. Flag off, the path is the same code run inline.
Mechanics: the job node owns all its inputs (no back-pointer, no lifetime
tie to the shader object), so re-sourcing or deleting a pending shader is
cancel-and-drop, never a wait; glslang worker hygiene is a TLS-allocator
scope guard plus GL-thread builtin prewarm (gated on the flag, latch reset
on Destroy so re-initialization re-warms); worker-side diagnostics defer
through the job and replay on the GL thread at the join, enforced by
IsPoolThread asserts in RecordError and an empty-deferred-errors tripwire.
A body that throws publishes a COMPLETE failed compile (status false, real
info log) rather than an abandoned node, and never memoizes away the retry;
a failed enqueue (OOM) cancels the node instead of stranding the joiner -
including inside the dispatch loop, where the in-flight slot is repaid.
The pool StopAndDrains from an atexit sentinel too: workers still inside
glslang parse while exit() ran static destructors was a real 2-in-5 SIGSEGV,
reproduced and fixed (15/15 clean after).
Backend-internal shader objects (default FS, DirectVulkan blit/mipmap) are
cache-less and always compile inline - compile-and-read-in-one-breath needs
no round trip.
Gates: unit suite 488/488 with the flag off AND on (x5); AsyncCompileTest
(12 e2e cases: pending re-source/delete/recompile, byte-identical failure
logs across modes, 48-compile cache stress) x10 repeats clean both modes;
full NVIDIA DirectGLES retrace identical result sets flag off/on (zero new
deltas); compile-phase timing flat as designed (links still serial - the
parallel win arrives with stage 4's async link + stage 5's
KHR_parallel_shader_compile).
Still fully synchronous - EnsureLinkJoined()/EnsureCompileJoined() are empty
inline no-ops (verified to fold away at every one of the ~1200 call sites;
this project builds without LTO) - but every read of link- or compile-produced
state now goes through a private accessor the compiler enforces, so when
stage 4 moves the bodies onto pool workers, 'which reads must join' is a
type-system fact instead of a 400-line audit.
- ProgramObject: the 31 fields ResetLinkArtifacts clears plus the 5 link
outputs it forgot (infoLog, linkedFragData{Location,Index}, the geometry
strip-capture pair) move into a nested LinkArtifacts behind Artifacts().
ResetLinkArtifacts is now a worker-safe pure clear; the link-observable
version bumps (backendState/link/uboContent) move to a GL-thread-only
BumpLinkObservableVersions() called once from Link()'s prologue and from
glProgramBinary's mandated failure - the link body never writes them, so
a stage-4 worker cannot lose an invalidation against the draw path.
- ShaderObject: compile artifacts (TShader, preprocessed source, side-channel
maps, status/log, consume-once flag) behind Compiled(); the P0b layer-1
memo trio deliberately stays outside as the future non-joining
COMPLETION_STATUS_KHR fast path.
- CompileEnv (new): a GL-thread snapshot of everything the compile pipeline
used to read live from the backend mid-parse - compute limits (the
GetIntegeri_v reach-back is gone from the worker path), advertised
extensions, device quirks, TBuiltInResource inputs. Captured lazily per
backend activation; the consume-once re-parse now runs against the same
env as the original parse.
- The GL-thread prologue / worker-body boundary is marked in Link() where
the stage sort ends; everything below is a pure function of the snapshot.
Public getter signatures unchanged - MG_Impl and both backends compile
untouched. Unit 476/476, Program suites 117/117, DirectGLES retrace 38/39 on
llvmpipe (the one failure is the known pre-existing non-CI iterationrp case;
the NVIDIA userspace driver was updated out from under the running kernel
module mid-session, so GLX there is down until a reboot).
Standalone Asio (submodule, asio-1-38-2 @ 8806a680, ASIO_STANDALONE +
ASIO_NO_DEPRECATED, header-only - no linked artifact) and the job machinery
the async shader pipeline will run on: JobNode (state machine with deferred
errors, continuations firing exactly once, dependency counters, cancel
semantics split into request vs outcome) and ShaderCompilePool
(asio::thread_pool behind a pimpl so no header leaks asio; big-core count
via cpufreq at >=85% of peak clamped to [1,4]; lazily constructed, so with
the flag off no worker thread ever exists; StopAndDrain leads DestroyImpl).
MOBILEGL_ASYNC_SHADER_COMPILE / _THREADS config knobs, default OFF. Nothing
in the GL pipeline references the pool yet - grep-verified; the full
DirectGLES retrace and compile benches are byte- and time-identical. 25
threaded unit tests, clean across 20x gtest_repeat.
Iris-style packs hand MobileGL the same source text repeatedly: probed across
three shaderpack traces, 28-32% of all glCompileShader work was redundant -
~9% same-object recompiles with byte-identical source, ~21% distinct shader
objects sharing identical source (the same common GLSL chunk glued into many
program stages). Two layers, both keyed by XXH64 + length with a full byte
compare on every hit (correctness never rides on the hash):
- Per-object: a successful (or failed) compile remembers its source hash;
glShaderSource with byte-identical text keeps the compiled state and
glCompileShader on unchanged source returns immediately. Deterministic
(stage, source) pipeline makes the memo observationally identical to
recompiling; the consume-once TakeShaderForLink re-parse path is untouched.
- Cross-object: a per-context bounded cache (ProgramState-owned, declared to
outlive every shader object) shares the preprocessed source, both explicit
side-channel maps, and the validation verdicts between objects with equal
source; only the glslang parse stays per-object. Single-GL-thread today;
flagged for a mutex when compiles go async (P1).
Interleaved A/B on the iterationrp trace (the recompile-heavy pack):
5.65s -> 5.46s median total replay, every round faster; BSL/complementary
stay flat (their duplicate sources are the small common shaders, so calls
drop but wall time is parse-bound on unique sources). Full DirectGLES
retrace, 445-test unit suite, and dedupe-semantics tests (no-op recompile,
invalidation on new source, failed-compile memo, cache bounds) all green.
RenameBuiltinShadowingFunction probed the whole source ten times per compile
(5 names x mask + scan, each a full-text pass) and still had two blind spots:
a 5-name list and single-line-definition-only detection. On Complementary-scale
packs (4.5MB of sources) that was ~68% of the compile phase.
The rename is now split by FAILURE LAYER, both halves sharing one name table
header so they cannot drift:
- A SPIR-V OpName pass in SanitizeAndOptimizeBinary covers the full ESSL 3.20
builtin set (~146 names). Renaming a function id is safe by construction:
builtin calls are GLSL.std.450 instructions and can never resolve to a user
OpFunction, overloads are distinct ids (a helper overload delegating to the
real builtin keeps working), dead preprocessor branches never reach SPIR-V,
and macro-expanded definitions are covered. ESSL 3.x is the only consumer
that forbids the redefinitions, and this pass runs before its transpile.
- A lexical pass covers only the 5 names whose exact-signature redefinitions
glslang's relaxed parse rejects outright (never producing SPIR-V for the
backstop): the historical fma/max3/min3/round/tanh. One TokenizeCode pass;
definition detection requires brace depth 0, a type-identifier previous
token that is neither a statement keyword nor a directive tail, and skips
files whose token-level braces do not balance (preprocessor-asymmetric
arms) - over-detection is unrecoverable, so every ambiguity falls through
to the backstop.
Measured on the compile phase (prefix-diff, 3-run medians, Espryt/NVIDIA):
complementary-reimagined 20.0s -> 5.5s, BSL 2.14s -> 1.85s. bliss (the pack
that ships from-scratch fma/tanh helpers) stays at SSIM 0.999962.
Tests: end-to-end ESSL assertions for the multiline-definition and
new-overload shapes, the three adversarial-review reproductions (statement-
keyword call under asymmetric braces, dead-#if compat shim, overload
delegating to the shadowed builtin), and a source-level assertion pinning
the lexical half specifically.
ES has neither glMultiDrawElements nor glMultiDrawElementsBaseVertex, so
both are emulated. DirectGLES had two ways of doing it - one
glMultiDrawElementsBaseVertexEXT where the driver has the extension
interaction, otherwise a per-draw loop. This adds the five MobileGlues
uses (gl/multidraw.cpp), so the ladder is now: one
glMultiDrawElementsBaseVertexEXT; one glMultiDrawElementsIndirectEXT
over a synthesized command buffer; one glDrawElementsIndirect per
command over that same buffer; the base-vertex replay; plain
glDrawElements over a CPU-rewritten index stream, for drivers with no
base-vertex draw at all; and a compute shader that flattens the whole
batch into one rebased index buffer drawn by a single glDrawElements.
They live in their own translation unit that owns the entry point
outright, preparation included - the compute tier has to dispatch BEFORE
PrepareForDraw, or it would have to unpick the program, storage-block
and index bindings the preparation just made, and a dispatch inside an
open transform-feedback span is not legal at all.
The auto ladder is ext -> basevertex -> multiindirect -> indirect ->
drawelements, which is NOT MobileGlues' order (it puts the indirect
tiers first). Measured on mc_sodium_multidraw, ns/op, median of three:
NVIDIA ES 3.2 basevertex 2500 vs multiindirect 5700 and indirect 5800;
Mesa llvmpipe ext 19300, basevertex 25200, multiindirect 27600,
drawelements 28700, indirect 31000. Ring-allocating the command staging
instead of respecifying per batch was tried first and moved the indirect
tiers by less than noise, so the cost is the indirect draw path itself,
not the upload; only a real multi-draw entry point beats replaying the
sub-draws. auto therefore resolves to basevertex on this box - byte for
byte the behaviour that shipped - and the new tiers are what a driver
with the ext interaction, or without base vertex at all, now gets.
compute is never chosen by auto (nor by MobileGlues'): it rewrites the
primitive stream rather than replaying it, and it measured slowest here.
Four places this deliberately does not follow MobileGlues, each a
correctness bug there. A rewritten stream is emitted as GL_UNSIGNED_INT
whatever came in, because GL adds baseVertex at full precision and
folding it into ushort indices wraps. The restart sentinel is carried
across a rebase unrebased, or an enabled primitive restart is lost. The
flattening tier declines strip/loop/fan modes, any sub-draw whose count
is not a whole number of primitives, and any batch at all while
primitive restart is enabled - a restart ends a primitive, so leftover
vertices would find a third vertex in the next sub-draw and become a
triangle GL never draws. And the indirect tiers decline client-memory
index arrays, which have no buffer to address.
gl_DrawID gets better rather than worse: the unrolled tiers now feed
each sub-draw its index (the spec's value, where the old loop left the
uniform untouched), and a program that actually reads it demotes the
batched tiers, which can only hold one value for the whole batch. The
per-batch cost is nil for the programs that do not read it.
Verified: the five DirectGLES retraces are byte-identical (md5) across
all six tiers on NVIDIA and on Mesa, each tier proven to have really
executed rather than silently demoted, via a per-tier announcement in
the log. Unit suite 421/421. The full retrace suite's five failures all
reproduce unchanged on a stashed tree, so none are new.
Both d7976326 bugs passed every unit test while corrupting real frames -
state-level assertions cannot see them. This module renders and reads
back.
A headless EGL-pbuffer harness (no window, no GLFW) linking MobileGL_s
directly, registered once per backend under the ctest label
integration-gpu, behind the default-OFF option
MOBILEGL_BUILD_INTEGRATION_TEST. The platform pre-flight runs the ENTIRE
bring-up in a forked child first - MobileGL aborts rather than returning
errors on an unusable platform, and the child dying on any signal turns
into a clean GTEST_SKIP instead of taking the test binary down.
MOBILEGL_ITEST_REQUIRE_GPU makes the label falsifiable: with it set, an
unusable harness (or a context that lands on a software rasterizer) is a
FAILURE - without it, a CI runner whose driver pinning silently broke
reports the same green as one that rendered every frame. Configure-time
detection pins the EGL vendor and Vulkan ICD jsons, preferring hardware
vendors and never selecting llvmpipe/lavapipe.
Scenarios assert on glReadPixels with whole-region pixel counts (a
2x2 quadrant pattern whose signature distinguishes all eight square
symmetries; every region predicate reports the first offending pixel):
- OrientationScenario: default -> FBO -> default, pinning the
transform-flags memo key. Keying GetBaseTransformFlagsRaw on the
pre-transform alone fails exactly 3 entries.
- StreamedArenaScenario: an untouched streamed vertex buffer must
survive transient-arena recycling. Re-enabling only the cross-frame
vertex revalidation fails exactly this entry.
- CrossFrameBufferScenario + ResidentIndexScenario: cross-frame
mutation matrix (SubData, map/unmap, persistent+flush, coherent
persistent, orphan, CopyBufferSubData; vertex and index) plus six
adversarial resident-EBO constructions. Instrumentation showed the
cross-frame EBO memo cannot be made to serve wrong bytes from GL
level on this stack (89 entries, 81 accepts, zero divergent slices) -
these cases are freshness tripwires, documented as such in-file; the
EBO half of d7976326 remains unpinned by a failing test.
At the buggy commit 72ee7c43 the suite fails 4 entries (3 orientation +
1 streamed-arena); at d7976326 all 52 pass, 5 consecutive runs, zero
flakes, and the default build is bit-for-bit unaffected (unit suite
unchanged). Adversarially verified twice, including hostile-platform
sweeps (26 configurations, all clean skips) and hand-edits of each
production hole in isolation.
The Minecraft-shaped driver benchmark could only be run from a desktop shell
against a desktop driver, which is the wrong machine: MobileGL exists to run on
mobile GPUs, and nothing said what its translation costs there. This puts the
same cases on an Android device, both in the plugin's POST screen and from a
shell, and adds the native-driver baseline they have to be read against.
The cases move into DriverBenchCases.inc so both harnesses run byte-identical
bodies - the desktop program resolving entry points from one EGL provider, and
DriverBenchJni.cpp calling MobileGL's frontend in-process. The JNI file binds
every gl*/egl* name to MG_Impl by macro rather than by linkage: this library
legitimately has the platform libEGL and libGLESv3 in its own lookup scope, and
a benchmark that quietly measured the device driver instead of the translation
layer would have looked like very good news.
Frames are now closed with a fence wait instead of glFinish. MobileGL implements
glFinish and glFlush as no-ops, so the old loop timed submit-plus-GPU on a native
driver and submit-only on a MobileGL backend, and the two numbers did not
describe the same work.
To measure a device's own driver the cases needed to be expressible in GLES:
ESSL 3.20 twins of the four shaders (chosen at runtime from GL_VERSION, since
MobileGL is deliberately still fed desktop GLSL - translating it is the thing
under test), a multi-draw hook that loops DrawElementsBaseVertex where the
multi-draw entry point does not exist, and an EGL bootstrap that falls back from
desktop GL to GLES 3. The binary cross-compiles for arm64 unchanged.
BenchService hosts each run in its own process and exits afterwards. That is not
caution: the backend is latched from MOBILEGL_BACKEND_TYPE at initialization, so
Espryt and Magma can never share a process, and Espryt's teardown terminates the
process-default EGL display, which would take the POST activity's own EGL
objects with it.
Running it found that Magma could not create a windowless context on Mali at
all - CreateInstance required VK_EXT_headless_surface, which no mobile driver
here exposes, and aborted the process. The Xlib path already probes and falls
back to a hidden window for the same reason on NVIDIA; Android now probes too
and hands the WSI an AImageReader's ANativeWindow, a real producer surface
attached to no display whose images are never acquired. DriverPost reports the
extension's absence as a WARN so the fallback is visible rather than silent.
Measured on a Mali-G77 MC9 (native / Espryt / Magma, ns per operation):
5495 chunk draws 14397 / 36934 / 33763, the 26.2 per-draw uniform-range pattern
13710 / 31205 / 21252, sodium-style multi-draw 256956 / 238389 / 209527. The
translation costs about 2.4x per draw here against 5-9x on the desktop, because
the mobile driver's own per-call cost dwarfs it - and both backends beat the
native driver on multi-draw, which it has to emulate.
Desktop unit tests 421/421; the POST screen and both Run Bench buttons verified
on the device.
Desktop Linux GL apps (GLFW/LWJGL, glxgears, anything X11) create contexts
through GLX, and MobileGL only spoke EGL - the two exported glX symbols were
proc-address stubs that could resolve GL entry points but never produce a
context. GLXImpl is the missing sibling of WGLImpl/CGLImpl: the same
window-system-binding pattern, calling the internal MG_Impl::EGLImpl namespace
directly.
The surface covers exactly what GLFW 3.4 resolves via dlsym plus the legacy
visual API: FBConfig enumeration mirrors the two EGLState configs (stencil-8
first so stencil-wanting choosers land on it), glXGetVisualFromFBConfig answers
with the screen's default visual (falling back to any 24-bit TrueColor one),
and glXCreateContextAttribsARB maps the ARB attribs onto EGL context attribs
the way WGL's Ext_CreateContextAttribsARB does - profile mask only emitted for
3.2+ or an explicit profile request, since that bit is what keys MobileGL's
relaxed-semantics compatibility mode. Legacy glXCreateContext/CreateNewContext
hand out 3.3 compatibility contexts, matching wglCreateContext.
Drawables follow the WGL HWND model: the GLXWindow is the X window itself, the
EGL window surface is created lazily on first MakeCurrent and cached per XID,
and the GLX layer owns size discovery per the platform-layer contract - it
pushes changes through EGLImpl::ResizePlatformWindowSurface, polling
XGetGeometry on MakeCurrent and on swaps throttled to 250ms so a fast-swapping
app is not paying a server round trip per frame. libX11 is dlopen'd at runtime
like everywhere else in the tree; Xlib.h is already in every TU via the vulkan
include, so XVisualInfo gets an ABI mirror struct (Xutil.h needs the Bool and
Status macros that Includes.h deliberately pops) and the caller's XFree pairs
with our malloc.
glXGetProcAddress now resolves glX names from the export table before falling
through to the shared GL resolver, which previously returned nullptr for every
glX extension entry point - GLFW requires glXCreateContextAttribsARB and
glXSwapIntervalEXT to arrive that way.
Verified with a smoke test replaying GLFW's exact call sequence (dlsym-only
resolution, manual FBConfig filtering, 3.2 core forward-compatible context,
glXCreateWindow, 60 swapped frames, clean glGetError) on both backends against
the real NVIDIA driver, then with Minecraft 1.21.1, 1.21.4+Fabric+Sodium and
26.2-snapshot-6 reaching in-world rendering on both Espryt and Magma.
glVertexAttribLFormat validated its arguments and then refused unconditionally
with "64-bit vertex attributes are not supported", so
direct_state_access.vertex_arrays_attribute_format failed every GL_DOUBLE
subcase on both backends - the format never landed, the draw fetched whatever
the attribute held before, and the captured values came back as reinterpreted
garbage.
The attribute is now real state. IsLong is its own bit rather than being
inferred from Float64, because glVertexAttribFormat(GL_DOUBLE) also reads
doubles - it just asks for them converted to float - so the type alone cannot
tell the two apart. It participates in the format comparison, so an L-format
call over a plain one still bumps the version, and glVertexAttribPointer clears
it inside the mutation block so the clear and the bump stay atomic.
GL_VERTEX_ATTRIB_ARRAY_LONG stops being hardcoded false, and the pname is now
accepted by the attribute queries at all.
Support is detected, never assumed. SupportsFloat64VertexAttributes comes from
VkPhysicalDeviceFeatures::shaderFloat64 on DirectVulkan and is false on
DirectGLES - not a driver question there and never will be, since ES has no
GL_DOUBLE vertex format and ESSL has no fp64 type to consume one with. A backend
without it declines in the entry point, with the GL error and a log line naming
the reason, rather than accepting state no draw could honour. Both cases get a
DriverPost row so the loss is named at startup instead of at draw setup.
On DirectVulkan the attribute deliberately does not use VK_FORMAT_R64*_SFLOAT:
those are optional and lavapipe advertises zero features for all four of them.
It is fetched as its 32-bit word pair (R32G32_UINT / R32G32B32A32_UINT) and
bitcast back to double in the shader by a new SPIR-V pass, which is bit-exact
and needs no format capability at all. The pass re-declares the input as uvec2 /
uvec4, demotes the original variable to a Private global and seeds it once at
the top of the entry point, so every existing load keeps its id and its double
type and no other instruction is rewritten. Both halves branch on nothing but
"is this attribute long", so they cannot disagree - and if the pass ever fails,
the assertion fires rather than letting a UINT format sit under a double input.
The pointer types are all created before any variable that names them and the
demoted variable is moved after them, since the types-and-variables section may
not forward-reference a type.
dvec3/dvec4 are declined rather than fetched wrong: six or eight uint32
components have no single VkFormat, and GL spreads such an input over two
attribute locations, which the location-per-index model here does not express.
Fixes vertex_arrays_attribute_format on Magma (369/371). On Espryt it stays
failing, now as a detected and explained decline rather than a blanket refusal.
Every program pipeline entry point was an export stub, and the stub macro's
`return (type)1` made glIsProgramPipeline answer GL_TRUE for anything - including
the names glGenProgramPipelines had never written. All four
direct_state_access.program_pipelines cases failed.
ProgramPipelineObject holds what GL 4.6 core 7.4 says a pipeline is: a program
reference per shader stage, the active program glProgramUniform* addresses, a
validate status and an info log. Its validate status starts false, unlike
ProgramObject's, because a pipeline that has never been validated must report
GL_VALIDATE_STATUS as 0.
The name rules follow the shape queries and transform feedbacks already use, and
which the CTS checks first: glGenProgramPipelines only RESERVES a name and
glIsProgramPipeline answers GL_FALSE for it; the object appears on first bind, or
immediately from glCreateProgramPipelines. Map membership is object existence -
a pipeline, unlike a transform feedback, has no stateful default object zero, so
no everBound flag is needed.
glGet(GL_PROGRAM_PIPELINE_BINDING) reports the real binding now instead of a
hardcoded zero whose comment said the entry points were stubbed.
This is the state half only. program_pipelines_functional needs mixed-stage
rendering - a vertex-only and a fragment-only program drawn together - and stays
failing; glCreateShaderProgramv is deliberately left stubbed until that lands, so
nothing can half-work in between.
Takes program_pipelines_creation, _defaults and _errors from failing to passing
on both backends.
Neither target API has GL_TEXTURE_RECTANGLE: ESSL has no rectangle sampler, and
Vulkan's SPIR-V environment does not allow Dim::Rect. Both emulate it on a plain 2D
texture, and the two differ in exactly one way - a rectangle lookup addresses texels
where a 2D one addresses [0,1].
That one difference now lives in one SPIR-V pass, so neither backend has to know about
it: every lookup taking normalized coordinates gets its coordinate divided by the size
the texture reports, and the image type is then rewritten to 2D. Magma had no rectangle
handling at all - it fed Dim::Rect straight to Vulkan, which read the texel coordinates
as normalized and sampled the edge, so all fifteen KHR-GL40.texture_gather.*-2drect
cases came back holding the clear colour.
This replaces the ESSL text rewrite that did the same divide for DirectGLES only. Doing
it in the module instead is both shorter and stricter: the pass resolves an operation's
image type through the sampled-image and pointer wrappers rather than matching a
sampler name in generated source, so it cannot be fooled by an expression where it
expected an identifier, and it needs no help from the frontend reflection to know which
samplers were rectangles.
Still declined, as before: the Dref *sample* forms, whose coordinate carries the compare
value in its last component, and the projective ones, where the divide would have to
happen after the perspective divide. texelFetch is deliberately untouched - integer
texel coordinates mean the same thing on both targets.
KHR-GL40.texture_gather: Magma 66 failures -> 2, Espryt stays at 75/75.
swung0x48
Swung0x48