- TOUCHING mv's FILE UNDER ID-136, deliberately and by ruling: MG_Backend/DirectGLES/
MultiDraw.cpp is mv's per ID-113, and the integrator overrode that boundary for this one
change because the two halves must not exist apart on any head. The boundary has not drifted.
- BoundDrawIndirectBufferId (MultiDraw.cpp) gets the handle arm its neighbour
ResolveBoundIndexBuffer already had, in mv's own idiom rather than a second one beside it:
the arm is `MG_Config::Transport != Monolith`, STATED (ID-81) and never inferred from a null
handle (ID-110); a null handle is "this verb bound no indirect buffer", the same 0 the
monolith arm returns for an empty slot; a missing backend resource is the named refusal
Fatal{RoleViolation, "multidraw-indirect-buffer-arm"}, a sibling of mv's
RefuseMissingIndexBufferRecord, never a quiet fall-back to the frontend. The monolith body
below it is unchanged token for token. The function moved down beside BoundIndexBufferId,
which is the same question about the other target.
- WHY A HANDLE ARM AND NOT A MIGRATION: the tier never reads a byte of the client's indirect
buffer. It binds its OWN scratch command buffer and wants to put back the name that was
there - a save/restore. With a transport the only other writer of this process's
GL_DRAW_INDIRECT_BUFFER is DirectGLES.cpp's DrawSyncBit::IndirectBuffer arm, which binds from
MGPipeApplier().VerbIndirectBuffer and nothing else, so "what was bound" IS "what the verb's
record named".
- Escalation (iii) withdrawn in the same commit - MGPipeBarriered's clause, the client's
verb-keyed half in ClientVerbIsBarriered, and the contract row. It was never wrong, it was
the wrong instrument: there is one draw opcode and the tier is chosen server-side per batch,
so the narrowest key both roles could compute charged EVERY plain glMultiDraw* on the
auto -> ext default - a per-batch rendezvous on the arm the phone ships, added to make a lane
green. THE CHECK ON AN ESCALATION IS "WHICH ARM PAYS FOR IT", NOT "WHICH LANE GOES GREEN";
the rule is recorded in PipeApply.h beside the three that remain and in CONTRACT-P5E §2.1.
- Red-once D: `if (false && ...)` on the new arm and the entry dies 3/3, deterministically, on
`Fatal{UnmigratedPipeInput, "GetBufferBindingSlot@DrawArrays"} [BARRIER-PULLED, UNBARRIERED,
the client did not fill it, retires in P8 (indirect), P9 (readback), P13 (transfer)]`.
Its counterpart is this head itself: the escalation is GONE and the lane is green, so nothing
needed it - and the strict census's admitted set drops from nine rows back to ID-128's eight,
because the pull no longer happens at all rather than being legalised.
- Gate on the flipped head: unit 2256/2256, isplit 179/179, gens rc=0, lane counts unchanged
(179 / 1357 / 2 / 2).
- MultiDraw.cpp asked the bound element array buffer three questions (is one bound,
what GL name is bound and how big is its store, give me its bytes on the CPU) and
asked all three of MGB_CTX->GetBoundVertexArray() on the apply thread. That was the
last unguarded read of that field in the backend: package vi retired the ordinary
draw path's copy and this one survived only because these 9 entries used to die
earlier, on the framebuffer row fb has since retired.
- ResolveBoundIndexBuffer(question, entry) answers all three from
MGPipeApplier().IndexBuffer.Res on the record arm - EnsureBufferResourceForHandle
for the driver name, ResourceWidthForHandle for the size, the server's staged
shadow (hostBytes + RequireStagedCoverage) for the CPU bytes - and keeps the
monolith body token for token below it. No wire row was added.
- The arm is STATED, not inferred (ID-81 / ID-110): BufferImpl::VertexInputReadsRecords(),
the family's own selector, which reduces to Transport != Monolith AND the vertex-input
bit. Nothing here decides an arm from a null pointer or a noted handle.
- A missing record on the handle arm is a named refusal:
Fatal{RoleViolation, multidraw-index-buffer-arm}, the shape of
RefuseNullFrontendTextureOffTheHandleArm. The frontend element slot is not a second
opinion on this side - it answers for whatever the client has bound now.
- VertexInputReadsRecords() moved from DirectGLES.cpp to Managers.h, unchanged, so the
two translation units on this draw path share ONE selector rather than a copy each.
- Strict census: GetBoundVertexArray@DrawArrays 9 -> 0. The same 9 entries now stop on
GetProgramForDraw@DrawArrays, which is pa's row; no other row moved, no new row.
- P1 package B (BRIEF-P1 C.2): the four DirectGLES TUs include <MG_Pipe/PipeInputsSwitch.h> right after
their MG_State/GLState/Core.h include (Managers.cpp after its Managers.h include) and spell every
frontend read MGB_CTX->Accessor(...). In the pull build MGB_CTX is MG_State::pGLContext, so the
code is the tree before this commit token for token; in the push build it is &gPipeInputs, the block
the frontend fills at every verb boundary.
- 113 arrow occurrences on 113 lines went through the mechanical sed (DirectGLES.cpp 91, Managers.cpp 15,
MultiDraw.cpp 5, Utils.cpp 2). The 9 non-arrow lines follow D9: Managers.cpp's five bare/compound
guards and three ternary conditions become MGB_CTX_LIVE (UniquePtr::operator bool spelled out, so the
pull build does not move); DirectGLES.cpp's GetFramebufferBindingSlotFast keys its static cache on
MGB_CTX_IDENTITY (a const void* compare) instead of pGLContext.get().
- The cache refill loop dereferences MGB_CTX once into a local reference and reads the slots through it,
instead of &MGB_CTX->GetFramebufferBindingSlot(i) per iteration as D9 spells it: a store into
g_fbSlotCache (a pointer) may alias the unique_ptr's own pointer under clang's TBAA, so the per-iteration
spelling re-reads pGLContext inside the loop and grows the three functions the loop is inlined into
(SyncCurrentProgram +16, ForceBindCurrentFBO +9, BlitNamedFramebuffer +1; .text +32). Hoisting the
dereference restores the single load and a zero .text delta.
- grep -rc pGLContext MobileGL/MG_Backend/DirectGLES reports 0 in every file; symbol_report --threshold 0
against the 087685d1 baseline: 0 added / 0 removed / 0 resized / 0 renamed, .text +0, nm --defined-only
set identical. The only bytes that move are __LINE__ immediates in RecordError sites after the inserted
include line. The 8 SyncPersistentMappedRange and 3 SyncGpuWrites sites and the PipeStats AddCalls
literals are untouched.
- A window with no Present divided by a faked 1 and printed the window TOTALS under
"bytes/f[...]": the *MultiDraw* slice (47 draws, no present) reported 1,404,550 bytes as a
PER-FRAME figure, a 47x overstatement of exactly the SEG_STAGE sizing input plan B section
8.2 / section 11 P0 asks this package to produce. FormatWindowLine now relabels the bracket
to "bytes[...]" and prints draws/f=n/a when the window holds no frame; acc/draw=n/a follows
the same rule, because "0.00" beside a non-zero acc= is the same lie. Pinned by
PipeStatsTest.SummaryLineSurvivesZeroFrames and the reworked SummaryLineSurvivesZeroDraws.
- Every per-frame and per-draw field now goes through one FormatFixed2 helper. draws/f read 1
for 26 draws over 14 frames (1.86) and buf read 97 for 1360 bytes (97.14): a systematic
downward truncation of up to a whole unit on the figures the package exists to produce.
Pinned by PipeStatsTest.PerFrameFieldsKeepTwoDecimals.
- FormatSummaryLine rewrote the window bases as a side effect of formatting, so any second
reader silently zeroed the next window. Split into a pure FormatWindowLine() and an explicit
AdvanceSummaryWindow(); EmitSummaryLine calls both. Pinned by
PipeStatsTest.FormattingTwiceDoesNotConsumeTheWindow.
- Init() called ResetForTesting(), against the header's own "not used by any shipping path".
Both now forward to an internal ResetCounters().
- TracyPlot published only the MISS half of each gate under the gate's unqualified name, so
the headline output channel of section 11 P0 carried no denominator. Two series per gate now
("...-hit" / "...-miss") from static literal arrays. The payload histogram stays unplotted
and says why: it is a run-total distribution over draws (section 4.5.7), not a per-frame
scalar, and it reaches the operator through the JSON dump.
- GetOrCreatePipeline's 15-call tally sat ABOVE the list-topology primitive-restart refusal,
so a declined draw added ten reads it never made - an OVER-count, which breaks the lower
bound contract every other tally keeps. Moved to immediately before the payload build, and
the enumeration reconciled with the constant: the excluded read is the sample-shading
capability, short-circuited by m_sampleRateShadingFeatureEnabled.
- Six real staging paths were uncounted while the inventory claimed coverage. The inventory
claim "DirectVulkan's own buffer staging ... has no second copy to count" was simply false.
Now wired: MultiDraw.cpp's UploadScratch/UploadScratchRing (indirect commands, the compute
tier's draw-info array, the rebased index stream - the class is passed in, so a new tier
cannot forget it); Managers.cpp's pool-recycle reseed and the VBO-backed Float64 narrowing;
VkBufferManager's eight host->device copies of buffer contents plus UploadTransient, the
single chokepoint for Magma's per-draw vertex/index/indirect staging; VkTextureManager's
packed staging slice, with the same box/rect SHAPE split Espryt already reported.
- New byte class stage-indirect-cmd, for draw PARAMETER bytes a backend synthesises and
stages. Kept out of stage-index-client because these are the population that becomes MGPipe
command-record payload (section 4.5.7), not resource bytes. A name addition, not a rename:
no recorded baseline is invalidated.
- stage-ubo-named moved past the zero-copy direct-bind decision in ResolveUniformBufferPayload
(a direct bind repacks nothing, so counting it there reported a copy that never happened),
and Magma's default-uniform-block image now feeds stage-ubo-global the way Espryt's does,
counted after the per-frame slice memo.
- The site inventory in PipeStats.cpp is rewritten to name every unwired path by file and
function. An inventory that overstates coverage is worse than a missing counter, because
the zero is then read as an answer.
- Evidence, lavapipe/llvmpipe, MOBILEGL_PIPE_STATS=1: the MultiDraw slice now prints
"window=0 draws/f=n/a bytes[buf=1404550 ...]"; the indirect tiers
(MOBILEGL_ESPRYT_MULTIDRAW_MODE=indirect|multiindirect) move icmd 0 -> 660; Magma's GuiBatch
line moves from buf=0 tex=0 ubog=0 to buf=685.71 tex=41.14 ubog=157.71 with tex[emit=9
box=9 rect=0 jobs=9]. Off-path A/B against the base tree with the env unset, 9 runs each of
a 40-scenario draw slice, sorted totals in ms: Espryt base 389..794 (median 399) vs branch
384..403 (median 394); Magma base 406..472 (median 410) vs branch 408..761 (median 414) -
the always-compiled guard is below this harness's noise on both backends.
- 1410 unit tests green (15 PipeStatsTest). integration-gpu 860/860, 860/860, 859/860; the one
failure is DirectVulkan.PointSizeDemotion...TheDemotionIsActuallyArmedWhenTheEnvironmentPins-
ItOn, a member of the load-dependent *IsActuallyArmed* flake family already present in the
untouched base tree, and it passes 8/8 standalone here. stdio gate and gen_pipe check green.
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.
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