Pipe: per-framebuffer state memo, object-held handle hints, per-buffer handle reuse and a cached per-verb gate (ValidateForVerb 0.328 -> 0.282 ms/frame; FCL GL CPU Magma 2.68 -> 2.62, Espryt 3.03 -> 3.00; red-once per piece in its unit case).

MobileGL/Config.h

@@ -148,6 +148,9 @@ namespace MobileGL::MG_Config {
         // record is byte-identical to the one its handle last published (a glBindVertexBuffer
         // that only changed the buffer) re-publishes nothing. Auto is ON; ForceOff re-creates.
         QuirkOverride PipeVertexElementsDedup = QuirkOverride::Auto;
+        // P15: the client reuses a bound framebuffer's built set_framebuffer_state while nothing it
+        // reads has moved (MGPipeFramebufferEmitter::BuildBoundFramebufferState).
+        QuirkOverride PipeFramebufferStateMemo = QuirkOverride::Auto;
         // MOBILEGL_ADVERTISE_FP64: add GL_ARB_gpu_shader_fp64 to the advertised extension
         // string. `double` in a shader always WORKS - it is narrowed to 32 bits before any
         // module reaches a backend (ShaderTranspiler::DemoteFloat64Pass) - but the extension

MobileGL/ConfigLoader.cpp

@@ -374,6 +374,7 @@ namespace MobileGL::MG_ConfigLoader {
         features.MagmaWriteRename = QueryEnvQuirkOverride("MOBILEGL_MAGMA_WRITE_RENAME");
         features.EsprytVaoShadow = QueryEnvQuirkOverride("MOBILEGL_ESPRYT_VAO_SHADOW");
         features.PipeVertexElementsDedup = QueryEnvQuirkOverride("MOBILEGL_PIPE_VERTEX_ELEMENTS_DEDUP");
+        features.PipeFramebufferStateMemo = QueryEnvQuirkOverride("MOBILEGL_PIPE_FRAMEBUFFER_STATE_MEMO");
         features.AdvertiseFp64 = QueryEnvFlag("MOBILEGL_ADVERTISE_FP64");
         features.MagmaR11G11B10FFallback = QueryEnvFlag("MOBILEGL_MAGMA_R11G11B10F_FALLBACK");
         features.MagmaAllowInvalidSpirv = QueryEnvFlag("MOBILEGL_MAGMA_ALLOW_INVALID_SPIRV");

MobileGL/MG_Impl/Pipe/FramebufferEmit.h

@@ -275,13 +275,13 @@ namespace MobileGL::MG_Pipe {
             Bool drawOk = false;
             Bool readOk = false;
             if (shared) {
-                drawOk = BuildFramebufferState(*drawFbo, MGPipeFramebufferTarget::Both, drawState);
+                drawOk = BuildBoundFramebufferState(*drawFbo, MGPipeFramebufferTarget::Both, drawState);
             } else {
                 if (drawFbo) {
-                    drawOk = BuildFramebufferState(*drawFbo, MGPipeFramebufferTarget::Draw, drawState);
+                    drawOk = BuildBoundFramebufferState(*drawFbo, MGPipeFramebufferTarget::Draw, drawState);
                 }
                 if (readFbo) {
-                    readOk = BuildFramebufferState(*readFbo, MGPipeFramebufferTarget::Read, readState);
+                    readOk = BuildBoundFramebufferState(*readFbo, MGPipeFramebufferTarget::Read, readState);
                 }
             }
             if (!drawOk && !readOk) return 0;
@@ -414,6 +414,8 @@ namespace MobileGL::MG_Pipe {
         const MGPFramebufferState& LastNamed() const { return m_lastNamed; }
         Uint64 EmissionCount() const { return m_emissions; }
         Uint64 RefusedCount() const { return m_refusals; }
+        // P15: bound-target builds answered from the memo (BuildBoundFramebufferState).
+        Uint64 MemoHitCount() const { return m_memoHits; }
 
         // A fresh context: what the server has is no longer what this emitter last sent. Only
         // LATCHES reset here - MGPipeApplierReset clears the applier's DrawFramebuffer and
@@ -438,6 +440,7 @@ namespace MobileGL::MG_Pipe {
         void ResetForTest() {
             Reset();
             ResetCounters();
+            for (auto& memo : m_buildMemo) memo.Valid = false;
             m_lastDraw = MGPFramebufferState{};
             m_lastRead = MGPFramebufferState{};
             m_lastNamed = MGPFramebufferState{};
@@ -563,6 +566,40 @@ namespace MobileGL::MG_Pipe {
             return true;
         }
 
+        // BuildFramebufferState for a BOUND target, reusing the last record built for the same
+        // framebuffer and target while nothing the build reads has moved. The build runs per draw
+        // and its answer is a function of:
+        //   - the framebuffer: lifetime id (identity) and object version (attachments, draw and
+        //     read buffers, no-attachment defaults all move it);
+        //   - each attached texture: lifetime id, shape version (sizes, level set, internal
+        //     format: completeness and geometry) and its samples / fixed-locations pair, which
+        //     move the params version rather than the shape;
+        //   - each attached renderbuffer: lifetime id plus its size, format and samples, read
+        //     directly (its storage has no version);
+        //   - the handles it minted: the slot allocator's reset epoch, and the texture emitter's
+        //     table epoch for the sticky bind bits SurfaceOf notes (a dropped table must be
+        //     re-noted).
+        // Not for the default framebuffer, whose geometry follows the current surface.
+        // Kill switch MOBILEGL_PIPE_FRAMEBUFFER_STATE_MEMO=0.
+        Bool BuildBoundFramebufferState(const FramebufferObject& fbo, MGPipeFramebufferTarget target,
+                                        MGPFramebufferState& out) {
+            const Bool memoOn = MG_Config::Features.PipeFramebufferStateMemo != MG_Config::QuirkOverride::ForceOff &&
+                                !fbo.IsDefaultFramebuffer();
+            // Direct-mapped on (framebuffer, target): the build only runs when the bound framebuffer
+            // changed, so a per-target single entry would miss on every A/B/A switch between targets.
+            const Uint64 key = fbo.GetLifetimeId() * 4u + static_cast<Uint64>(target);
+            BuildMemo& memo = m_buildMemo[static_cast<SizeT>((key * 0x9E3779B97F4A7C15ull) >> 60) % m_buildMemo.size()];
+            if (memoOn && memo.Valid && MemoHolds(memo, fbo, target)) {
+                out = memo.State;
+                ++m_memoHits;
+                return true;
+            }
+            memo.Valid = false;
+            if (!BuildFramebufferState(fbo, target, out)) return false;
+            if (memoOn) FillMemo(memo, fbo, target, out);
+            return true;
+        }
+
         static Bool IsBoundTo(const FramebufferObject& fbo, MobileGL::FramebufferTarget target) {
             if (MG_State::pGLContext == nullptr) return false;
             const auto& bound = MG_State::pGLContext->GetFramebufferBindingSlot(target).GetBoundObject();
@@ -642,6 +679,96 @@ namespace MobileGL::MG_Pipe {
             out.FixedSampleLocations = fbo.GetDefaultFixedSampleLocations() ? 1 : 0;
         }
 
+        struct MemoAttachment {
+            Uint32 Point = 0;
+            Bool IsTexture = false;
+            Uint64 LifetimeId = 0;
+            Uint64 ShapeVersion = 0;
+            Int Width = 0, Height = 0, Samples = 0;
+            Uint32 Format = 0;
+            Bool FixedSampleLocations = false;
+        };
+        struct BuildMemo {
+            Bool Valid = false;
+            Uint8 Target = 0;
+            Uint16 ObjectVersion = 0;
+            Uint64 FboLifetimeId = 0;
+            Uint64 AllocatorEpoch = 0;
+            Uint64 TextureTableEpoch = 0;
+            Uint32 AttachmentCount = 0;
+            Array<MemoAttachment, static_cast<SizeT>(FramebufferAttachmentType::FramebufferAttachmentTypeCount)>
+                Attachments{};
+            MGPFramebufferState State{};
+        };
+
+        static Bool AttachmentMatches(const MemoAttachment& entry,
+                                      const MG_State::GLState::FramebufferAttachmentObject& attachment) {
+            if (attachment.IsEmpty() || attachment.IsTexture() != entry.IsTexture) return false;
+            if (entry.IsTexture) {
+                const auto& texture = attachment.GetTexture();
+                return texture->GetLifetimeId() == entry.LifetimeId &&
+                       texture->GetShapeVersion() == entry.ShapeVersion &&
+                       texture->GetSamples() == entry.Samples &&
+                       texture->HasFixedSampleLocations() == entry.FixedSampleLocations;
+            }
+            const auto& renderbuffer = attachment.GetRenderbuffer();
+            return renderbuffer->GetLifetimeId() == entry.LifetimeId && renderbuffer->GetWidth() == entry.Width &&
+                   renderbuffer->GetHeight() == entry.Height && renderbuffer->GetSamples() == entry.Samples &&
+                   static_cast<Uint32>(renderbuffer->GetInternalFormat()) == entry.Format;
+        }
+
+        Bool MemoHolds(const BuildMemo& memo, const FramebufferObject& fbo, MGPipeFramebufferTarget target) const {
+            if (memo.Target != static_cast<Uint8>(target) || memo.FboLifetimeId != fbo.GetLifetimeId() ||
+                memo.ObjectVersion != fbo.GetObjectVersion() || memo.AllocatorEpoch != MGPipeSlots().ResetEpoch() ||
+                memo.TextureTableEpoch != MGPipeTextureEmitterInstance().TableEpoch()) {
+                return false;
+            }
+            const auto& all = fbo.GetAllAttachmentObjects();
+            for (Uint32 i = 0; i < memo.AttachmentCount; ++i) {
+                const MemoAttachment& entry = memo.Attachments[i];
+                if (!AttachmentMatches(entry, all[entry.Point])) return false;
+            }
+            return true;
+        }
+
+        void FillMemo(BuildMemo& memo, const FramebufferObject& fbo, MGPipeFramebufferTarget target,
+                      const MGPFramebufferState& state) {
+            memo.Target = static_cast<Uint8>(target);
+            memo.FboLifetimeId = fbo.GetLifetimeId();
+            memo.ObjectVersion = fbo.GetObjectVersion();
+            memo.AllocatorEpoch = MGPipeSlots().ResetEpoch();
+            memo.TextureTableEpoch = MGPipeTextureEmitterInstance().TableEpoch();
+            memo.AttachmentCount = 0;
+            const auto& all = fbo.GetAllAttachmentObjects();
+            for (SizeT point = 0; point < all.size(); ++point) {
+                const auto& attachment = all[point];
+                if (attachment.IsEmpty()) continue;
+                MemoAttachment& entry = memo.Attachments[memo.AttachmentCount++];
+                entry = MemoAttachment{};
+                entry.Point = static_cast<Uint32>(point);
+                entry.IsTexture = attachment.IsTexture();
+                if (entry.IsTexture) {
+                    const auto& texture = attachment.GetTexture();
+                    entry.LifetimeId = texture->GetLifetimeId();
+                    entry.ShapeVersion = texture->GetShapeVersion();
+                    entry.Samples = texture->GetSamples();
+                    entry.FixedSampleLocations = texture->HasFixedSampleLocations();
+                } else {
+                    const auto& renderbuffer = attachment.GetRenderbuffer();
+                    entry.LifetimeId = renderbuffer->GetLifetimeId();
+                    entry.Width = renderbuffer->GetWidth();
+                    entry.Height = renderbuffer->GetHeight();
+                    entry.Samples = renderbuffer->GetSamples();
+                    entry.Format = static_cast<Uint32>(renderbuffer->GetInternalFormat());
+                }
+            }
+            memo.State = state;
+            memo.Valid = true;
+        }
+
+        // Direct-mapped on (framebuffer lifetime id, target); Named never reaches it.
+        Array<BuildMemo, 16> m_buildMemo{};
+        Uint64 m_memoHits = 0;
         Array<Uint64, 2> m_lastEmitted{};
         // The per-FRAMEBUFFER suppressor for Named records, slot-indexed with the generation
         // checked, exactly as the applier's own table is. A framebuffer has no wire lifetime

MobileGL/MG_Impl/Pipe/PipeFill.cpp

@@ -2640,6 +2640,44 @@ namespace MobileGL::MG_Pipe {
                                                   // consumer mask gains bit 13 in the same
                                                   // commit, or R-8 withholds the whole family.
                                                   kMGPipeWiredBufferBindingSubsystem;
+
+        // P15: the dirty bits whose family this build, push mask and consumer emit - every
+        // condition of the per-bit gate in MGPipeValidateForVerb except the dirty bit itself.
+        Uint32 ComputeLiveDirtyBits(Uint64 pushMask) {
+            Uint32 live = 0;
+            for (Uint32 b = 0; b < kMGPipeDirtyCount; ++b) {
+                const Uint64 subsystem = MGPipeSubsystemForDirty(static_cast<MGPipeDirty>(b));
+                if (subsystem != 0 && (pushMask & subsystem) != 0 && (kMGPipeWiredSubsystems & subsystem) != 0 &&
+                    P4aFamilyHasItsConsumer(subsystem) && P4aFamilyDependenciesAreSet(subsystem, pushMask) &&
+                    P5eFamilyIsLive(subsystem, pushMask)) {
+                    live |= MGPipeDirtyBit(static_cast<MGPipeDirty>(b));
+                }
+            }
+            return live;
+        }
+
+        // Per verb, these conditions used to be re-asked for every bit (~15 consumer-registration
+        // and dependency-table walks per draw). In monolith their only inputs are the push mask and
+        // the registered consumer, so the answer is kept until either moves. Under a transport the
+        // caps mirror answers and can move with a new session, so it is recomputed every verb.
+        Uint32 LiveDirtyBits(Uint64 pushMask) {
+#if MOBILEGL_BUILD_DISAGGREGATED
+            if (MG_Config::Transport != MG_Config::TransportMode::Monolith) return ComputeLiveDirtyBits(pushMask);
+#endif
+            static Bool valid = false;
+            static Uint64 cachedPushMask = 0;
+            static const MGPipeResourceOps* cachedConsumer = nullptr;
+            static Uint32 cachedLive = 0;
+            const MGPipeResourceOps* consumer = MGPipeGetResourceOps();
+            if (!valid || cachedPushMask != pushMask || cachedConsumer != consumer) {
+                cachedLive = ComputeLiveDirtyBits(pushMask);
+                cachedPushMask = pushMask;
+                cachedConsumer = consumer;
+                valid = true;
+            }
+            return cachedLive;
+        }
+
         // Each family constant is either 0 or its own subsystem bit and nothing else. Without
         // this a header that set the wrong constant - the sampler bit in the program header,
         // say - would switch the wrong family on and every gate would still pass.
@@ -3621,15 +3659,8 @@ namespace MobileGL::MG_Pipe {
         // binding-point family and asks bit 13's OWN consumer bit rather than the resource
         // family's. It answers true for every subsystem but bit 13, so nothing that emitted
         // before P5e changes.
-        const auto wants = [&](MGPipeDirty bit) {
-            const Uint64 subsystem = MGPipeSubsystemForDirty(bit);
-            return subsystem != 0 && (pushMask & subsystem) != 0 &&
-                   (kMGPipeWiredSubsystems & subsystem) != 0 &&
-                   P4aFamilyHasItsConsumer(subsystem) &&
-                   P4aFamilyDependenciesAreSet(subsystem, pushMask) &&
-                   P5eFamilyIsLive(subsystem, pushMask) &&
-                   (dirty & MGPipeDirtyBit(bit)) != 0;
-        };
+        const Uint32 liveDirty = LiveDirtyBits(pushMask) & dirty;
+        const auto wants = [&](MGPipeDirty bit) { return (liveDirty & MGPipeDirtyBit(bit)) != 0; };
         Uint64 payloadBytes = 0;
 
         // A fresh context is a fresh server, and that is true of EVERY subsystem, so it is

MobileGL/MG_Impl/Pipe/ProgramEmit.h

@@ -663,7 +663,8 @@ namespace MobileGL::MG_Pipe {
         // composite.
         MGPipeHandle AcquireShaderCsoHandle(const ProgramObject& program) {
             const Uint64 lifetimeId = program.GetLifetimeId();
-            const MGPipeHandle existing = MGPipeSlots().FindByLifetimeId(MGPipeKind::ShaderCso, lifetimeId);
+            const MGPipeHandle existing =
+                MGPipeSlots().FindByLifetimeIdHinted(MGPipeKind::ShaderCso, lifetimeId, program.PipeHandleHint());
             if (!MGPipeHandleIsNull(existing)) return existing;
             // A composite is minted off ITS OWN lifetime id, out of the reserved band, and is
             // an ordinary ShaderCso handle in every other respect - the same kind, the same

MobileGL/MG_Impl/Pipe/ResourceTracker.h

@@ -281,7 +281,8 @@ namespace MobileGL::MG_Pipe {
         // gating it would make the vertex-input subsystem emit null handles whenever the
         // resource subsystem is off. Only the CALLS are gated (D-A1).
         MGPipeHandle Acquire(BufferObject& buffer) {
-            const MGPipeHandle handle = MGPipeSlots().Acquire(MGPipeKind::Buffer, buffer.GetLifetimeId());
+            const MGPipeHandle handle =
+                MGPipeSlots().AcquireHinted(MGPipeKind::Buffer, buffer.GetLifetimeId(), buffer.PipeHandleHint());
             const SizeT slot = handle.Slot;
             if (slot >= m_bySlot.size()) m_bySlot.resize(slot + 1);
             m_bySlot[slot].Object = &buffer;
@@ -292,7 +293,8 @@ namespace MobileGL::MG_Pipe {
         // The handle a buffer already has, or the null handle. Never mints - the emission
         // path calls Acquire, the query paths call this.
         MGPipeHandle Find(const BufferObject& buffer) const {
-            return MGPipeSlots().FindByLifetimeId(MGPipeKind::Buffer, buffer.GetLifetimeId());
+            return MGPipeSlots().FindByLifetimeIdHinted(MGPipeKind::Buffer, buffer.GetLifetimeId(),
+                                                        buffer.PipeHandleHint());
         }
 
         // D-D's inverse, and a RAW pointer is exact here: the entry exists only between the

MobileGL/MG_Impl/Pipe/SamplerEmit.h

@@ -859,7 +859,9 @@ namespace MobileGL::MG_Pipe {
                     unitSampler ? unitSampler.get() : texture->GetSamplerObject().get();
                 if (MG_State::GLState::SamplesAsIncompleteTexture(texture.get(), effective)) continue;
 
-                entry.Texture = MGPipeSlots().Acquire(MGPipeKind::Texture, texture->GetLifetimeId());
+                entry.Texture = MGPipeSlots().AcquireHinted(
+                    MGPipeKind::Texture, texture->GetLifetimeId(),
+                    texture->PipeHandleHint(ITextureObject::PipeHintKind::Texture));
                 // D-A4: a texture the sampler-view resolution names in an emitted MGPBoundView
                 // is SAMPLER-bound from then on (sticky; the texture emitter's contract door,
                 // since this header is included BY TextureEmit.h). One early-out per unit per
@@ -976,7 +978,8 @@ namespace MobileGL::MG_Pipe {
         MGPipeHandle AcquireSamplerView(const ITextureObject& texture, MGPipeHandle textureHandle,
                                         Uint64& payloadBytes) {
             const MGPipeHandle handle =
-                MGPipeSlots().Acquire(MGPipeKind::SamplerViewCso, texture.GetLifetimeId());
+                MGPipeSlots().AcquireHinted(MGPipeKind::SamplerViewCso, texture.GetLifetimeId(),
+                                            texture.PipeHandleHint(ITextureObject::PipeHintKind::SamplerView));
             const SizeT slot = handle.Slot;
             if (slot >= m_viewLatch.size()) m_viewLatch.resize(slot + 1);
             ViewLatch& latch = m_viewLatch[slot];

MobileGL/MG_Impl/Pipe/SlotAllocator.cpp

@@ -223,6 +223,31 @@ namespace MobileGL::MG_Pipe {
         return MGPipeHandle{it->second, entry->Gen};
     }
 
+    MGPipeHandle MGPipeSlotAllocator::FindByLifetimeIdHinted(MGPipeKind kind, Uint64 lifetimeId,
+                                                             Uint64& hint) const {
+        if (hint != 0 && lifetimeId != 0) {
+#if MOBILEGL_BUILD_DISAGGREGATED
+            MGPipeRefuseAllocatorFromApplyThread("FindByLifetimeIdHinted");
+#endif
+            const Uint32 slot = static_cast<Uint32>(hint);
+            const Uint32 gen = static_cast<Uint32>(hint >> 32);
+            const SlotState* entry = EntryOf(StateOf(kind), kind, slot);
+            if (entry != nullptr && entry->Live && entry->Gen == gen && entry->LifetimeId == lifetimeId)
+                return MGPipeHandle{slot, gen};
+        }
+        const MGPipeHandle found = FindByLifetimeId(kind, lifetimeId);
+        hint = MGPipeHandleIsNull(found) ? 0 : MGPipePackHandleHint(found);
+        return found;
+    }
+
+    MGPipeHandle MGPipeSlotAllocator::AcquireHinted(MGPipeKind kind, Uint64 lifetimeId, Uint64& hint) {
+        const MGPipeHandle existing = FindByLifetimeIdHinted(kind, lifetimeId, hint);
+        if (!MGPipeHandleIsNull(existing)) return existing;
+        const MGPipeHandle minted = Acquire(kind, lifetimeId);
+        hint = MGPipeHandleIsNull(minted) ? 0 : MGPipePackHandleHint(minted);
+        return minted;
+    }
+
     MGPipeHandle MGPipeSlotAllocator::Acquire(MGPipeKind kind, Uint64 lifetimeId) {
 #if MOBILEGL_BUILD_DISAGGREGATED
         MGPipeRefuseAllocatorFromApplyThread("Acquire");

MobileGL/MG_Impl/Pipe/SlotAllocator.h

@@ -72,6 +72,12 @@ namespace MobileGL::MG_Pipe {
         MGPipeHandle FindByLifetimeId(MGPipeKind kind, Uint64 lifetimeId) const;
         // FindByLifetimeId, then AllocateFor when it misses. The ordinary client path.
         MGPipeHandle Acquire(MGPipeKind kind, Uint64 lifetimeId);
+        // P15: the same two answers, first trying `hint` - the handle this object was last given,
+        // kept on the frontend object itself (MGPipePackHandleHint). The hint is believed only when
+        // the slot it names is live, at that generation, and owned by this very lifetime id, so a
+        // reset, a free or a recycle can only make it miss; the hint is refreshed on every miss.
+        MGPipeHandle FindByLifetimeIdHinted(MGPipeKind kind, Uint64 lifetimeId, Uint64& hint) const;
+        MGPipeHandle AcquireHinted(MGPipeKind kind, Uint64 lifetimeId, Uint64& hint);
 
         // Returns the slot to the free list. The Gen bump happens on the NEXT handout of that
         // slot, not here, so a handle that is freed twice cannot skip a generation and the
@@ -179,6 +185,12 @@ namespace MobileGL::MG_Pipe {
     // The monolith's one client allocator. Under split there is one per client context.
     MGPipeSlotAllocator& MGPipeSlots();
 
+    // A handle packed into the Uint64 a frontend object keeps as its hint (0 = none; slot 0 is
+    // never handed out).
+    inline Uint64 MGPipePackHandleHint(MGPipeHandle handle) {
+        return static_cast<Uint64>(handle.Slot) | (static_cast<Uint64>(handle.Gen) << 32);
+    }
+
 #if MOBILEGL_BUILD_DISAGGREGATED
     // P5c (hd, CONTRACT-P5C §3.1 / §6 layer 1): with an active transport this allocator is a
     // CLIENT-only surface. Its singleton accessor and original three method guards reject apply -

MobileGL/MG_Impl/Pipe/TextureEmit.h

@@ -590,7 +590,11 @@ namespace MobileGL::MG_Pipe {
         // gating the mint would make the other subsystems emit null handles in exactly the
         // A/B arm that exists to isolate them. Only the CALLS are gated.
         MGPipeHandle AcquireTexture(Uint64 lifetimeId, ITextureObject* object) {
-            const MGPipeHandle handle = MGPipeSlots().Acquire(MGPipeKind::Texture, lifetimeId);
+            const MGPipeHandle handle =
+                object != nullptr
+                    ? MGPipeSlots().AcquireHinted(MGPipeKind::Texture, lifetimeId,
+                                                  object->PipeHandleHint(ITextureObject::PipeHintKind::Texture))
+                    : MGPipeSlots().Acquire(MGPipeKind::Texture, lifetimeId);
             Entry& entry = EntryFor(m_textures, handle);
             RetireIfRecycled(entry, handle);
             entry.Texture = object;
@@ -1287,7 +1291,12 @@ namespace MobileGL::MG_Pipe {
         // MGPipeResourceTracker::ResetForTest for the rule this restates: a texture handle and
         // the applier record it names are SHARE-GROUP OBJECT STATE, so nothing here is
         // per-context and no re-publication path exists or may exist.
+        // Moves whenever the handle table below is dropped (ResetForTest), so a memo that skipped
+        // NoteTextureBoundAs / AcquireTexture for handles it already noted knows to note again.
+        Uint64 TableEpoch() const { return m_tableEpoch; }
+
         void ResetForTest() {
+            ++m_tableEpoch;
             // EVERY REFERENCE THIS EMITTER OWES IS GIVEN BACK FIRST. A case that dropped the
             // table without releasing would pin cache entries for the rest of the process and
             // the next case's LRU would mint over capacity for reasons it cannot see.
@@ -1689,6 +1698,7 @@ namespace MobileGL::MG_Pipe {
         MGPTextureParams m_lastParams{};
         MGPSubData m_lastSubData{};
 
+        Uint64 m_tableEpoch = 0;
         Uint64 m_creates = 0;
         Uint64 m_respecifies = 0;
         Uint64 m_paramSets = 0;

MobileGL/MG_Impl/Pipe/VertexInputEmit.h

@@ -256,13 +256,29 @@ namespace MobileGL::MG_Pipe {
                 for (SizeT i = 0; i < kAttribs; ++i) {
                     if (vao->GetAttribute(static_cast<Uint>(i)).Enabled) count = static_cast<Uint32>(i) + 1;
                 }
+                // P15: interleaved attributes share one buffer (FCL MC 1.21.5: every chunk draw
+                // re-points ~4 attributes at the next chunk's buffer), so the previous attribute's
+                // answer is reused for the same object - one lookup and one sticky-bit note per
+                // buffer instead of per attribute. Scoped to this loop: same object, same handle.
+                const MG_State::GLState::BufferObject* lastBuffer = nullptr;
+                MGPipeHandle lastHandle = kMGPipeNullHandle;
                 for (SizeT i = 0; i < count; ++i) {
                     const auto& attrib = vao->GetAttribute(static_cast<Uint>(i));
                     MGPVertexBuffer& entry = m_entries[i];
                     entry = MGPVertexBuffer{};
-                    entry.Res = attrib.Buffer ? MGPipeSlots().Acquire(MGPipeKind::Buffer,
-                                                                     attrib.Buffer->GetLifetimeId())
-                                              : kMGPipeNullHandle;
+                    const Bool sameBuffer = attrib.Buffer && attrib.Buffer.get() == lastBuffer;
+                    if (sameBuffer) {
+                        entry.Res = lastHandle;
+                    } else {
+                        entry.Res = attrib.Buffer ? MGPipeSlots().AcquireHinted(MGPipeKind::Buffer,
+                                                                               attrib.Buffer->GetLifetimeId(),
+                                                                               attrib.Buffer->PipeHandleHint())
+                                                  : kMGPipeNullHandle;
+                        if (attrib.Buffer) {
+                            lastBuffer = attrib.Buffer.get();
+                            lastHandle = entry.Res;
+                        }
+                    }
                     if (ownedClientBuffers != nullptr && attrib.Enabled && !attrib.Buffer) {
                         entry.Res = (*ownedClientBuffers)[i];
                     }
@@ -271,7 +287,7 @@ namespace MobileGL::MG_Pipe {
                     // glNamedBuffer* may never be bound at any resource emission, but a draw
                     // that fetches from it resolves it right here, on the GL thread, at every
                     // draw. Sticky, so one draw is enough for the rest of its life.
-                    MGPipeResourceTrackerInstance().NoteBoundAs(entry.Res, BufferTarget::Vertex);
+                    if (!sameBuffer) MGPipeResourceTrackerInstance().NoteBoundAs(entry.Res, BufferTarget::Vertex);
                     // The attribute's own byte offset lives in MGPVertexAttribWire::Offset,
                     // so the entry's is the BINDING's, which the frontend already folded in.
                     entry.Offset = 0;

MobileGL/MG_State/GLState/BufferState/BufferObject.h

@@ -202,6 +202,9 @@ namespace MobileGL {
             // glGenBuffers) and never the heap address (recycled by the allocator): both
             // let a deleted-and-recreated buffer answer to a dead one's cache entry.
             Uint64 GetLifetimeId() const { return m_lifetimeId; }
+            // P15: the pipe client's last Buffer handle for this object (MGPipeSlotAllocator::
+            // AcquireHinted). Only a hint: it is checked against the allocator on every use.
+            Uint64& PipeHandleHint() const { return m_pipeHandleHint; }
             // Monotonic counter bumped on every shadow mutation; backends use it to
             // validate cached transient slices.
             Uint64 GetChangeSerial() const;
@@ -238,6 +241,7 @@ namespace MobileGL {
 
             const Uint m_externalIndex = 0;
             const Uint64 m_lifetimeId = AllocateLifetimeId();
+            mutable Uint64 m_pipeHandleHint = 0;
             SizeT m_size = 0;
             BufferUsage m_usage = BufferUsage::StaticDraw;
             // Owns the buffer's bytes (CPU shadow or backend persistent GPU map) and

MobileGL/MG_State/GLState/ProgramState/ProgramObject.h

@@ -1281,6 +1281,9 @@ namespace MobileGL::MG_State::GLState {
         // the next glCreateProgram, this distinguishes a deleted-and-recreated program from the
         // original, so an identity cache can't false-hit on name recycling.
         Uint64 GetLifetimeId() const { return m_lifetimeId; }
+        // P15: the pipe client's last ShaderCso handle for this program (MGPipeSlotAllocator::
+        // FindByLifetimeIdHinted). Only a hint: it is checked against the allocator on every use.
+        Uint64& PipeHandleHint() const { return m_pipeHandleHint; }
 
     private:
         // ---- The one and only join gate for link output (P1 invariant I5) ----
@@ -1372,6 +1375,7 @@ namespace MobileGL::MG_State::GLState {
         // writes them.
         const Uint m_externalIndex = 0;
         const Uint64 m_lifetimeId = 0;
+        mutable Uint64 m_pipeHandleHint = 0;
         // The attach lists are mutated only in Link()'s GL-thread prologue, which is why
         // glGetAttachedShaders / GL_ATTACHED_SHADERS / the orphan-shader sweep need no join.
         Vector<SharedPtr<ShaderObject>> m_shaders;

MobileGL/MG_State/GLState/TextureState/TextureObject.h

@@ -82,6 +82,10 @@ namespace MobileGL::MG_State::GLState {
         virtual Bool HasFixedSampleLocations() const = 0;
         virtual void SetFixedSampleLocations(Bool fixedSampleLocations) = 0;
         virtual Uint64 GetLifetimeId() const = 0;
+        // P15: the pipe client's last handles for this texture, one per kind it is looked up under
+        // (MGPipeSlotAllocator::AcquireHinted). Only hints: checked against the allocator on use.
+        enum class PipeHintKind : Uint8 { Texture = 0, SamplerView = 1, Count = 2 };
+        virtual Uint64& PipeHandleHint(PipeHintKind kind) const = 0;
         // Which aspect of a packed depth/stencil texture a sampler reads (GL 4.6 core 8.10).
         // DEPTH_COMPONENT until set, and meaningless for every other format.
         virtual GLenum GetDepthStencilTextureMode() const = 0;
@@ -164,6 +168,7 @@ namespace MobileGL::MG_State::GLState {
         Bool HasFixedSampleLocations() const override;
         void SetFixedSampleLocations(Bool fixedSampleLocations) override;
         Uint64 GetLifetimeId() const override;
+        Uint64& PipeHandleHint(PipeHintKind kind) const override { return m_pipeHandleHints[static_cast<SizeT>(kind)]; }
         // A plain texture owns its storage; TextureObjectView overrides this.
         const SharedPtr<ITextureObject>& GetViewStorageOwner() const override;
         Uint GetViewMinLevel() const override { return m_viewMinLevel; }
@@ -241,6 +246,7 @@ namespace MobileGL::MG_State::GLState {
 
         const Uint m_externalIndex;
         const Uint64 m_lifetimeId;
+        mutable Uint64 m_pipeHandleHints[static_cast<SizeT>(PipeHintKind::Count)] = {};
         const TextureTarget m_target = TextureTarget::Unknown;
         TextureInternalFormat m_internalFormat = TextureInternalFormat::Unknown;
         SharedPtr<SamplerObject> m_sampler = nullptr;

MobileGL/MG_Test/Pipe/FramebufferEmitTest.cpp

@@ -1264,6 +1264,111 @@ TEST(FramebufferEmit, AFramebufferRecordThatNamesNoUsableHandleIsRefusedRatherTh
         << "an out-of-range slot resized the table instead of being refused";
 }
 
+// ============================ P15: the bound-target build memo ============================
+//
+// EmitFramebufferState reuses the record it built for the same framebuffer and target while
+// nothing the build reads has moved (MGPipeFramebufferEmitter::BuildBoundFramebufferState). Each
+// case first proves the memo ENGAGED (an unchanged second emission is a hit), then moves one input
+// the framebuffer's own version does not see and expects the record to follow it, by field name.
+namespace {
+    MGPipeHandle HandleOfTexture(const SharedPtr<TextureObject2D>& texture) {
+        return MGPipeSlots().FindByLifetimeId(MGPipeKind::Texture, texture->GetLifetimeId());
+    }
+} // namespace
+
+TEST(FramebufferEmit, TheBuildMemoEngagesAndFollowsAnAttachedTexturesRespecify) {
+    FramebufferScope scope;
+    const auto color = MakeColorTexture(80, 32);
+    const auto fbo = MakeShared<FramebufferObject>(20);
+    fbo->AttachTexture(FramebufferAttachmentType::Color0, color, TextureUploadTarget::Texture2D);
+    BindDrawAndRead(fbo, fbo);
+    Framebuffers().EmitFramebufferState(Ctx());
+    const Uint64 hits = Framebuffers().MemoHitCount();
+    EXPECT_EQ(Framebuffers().EmitFramebufferState(Ctx()), 0u);
+    ASSERT_EQ(Framebuffers().MemoHitCount(), hits + 1) << "an unchanged framebuffer did not reuse its built record";
+
+    // The texture's level 0 grows; the framebuffer's object version does not move.
+    color->AllocateStorage(TextureUploadTarget::Texture2D, 0, MipmapInput{IntVec3{64, 64, 1}, 64u * 64u * 4u});
+    EXPECT_EQ(Framebuffers().EmitFramebufferState(Ctx()), sizeof(MGPFramebufferState));
+    EXPECT_EQ(Framebuffers().LastDraw().Width, 64u) << "MGPFramebufferState::Width";
+    EXPECT_EQ(Framebuffers().LastDraw().Height, 64u) << "MGPFramebufferState::Height";
+}
+
+// The build runs when the bound framebuffer changes, so the memo has to hold more than the last
+// framebuffer: an A/B/A switch must find A's record again.
+TEST(FramebufferEmit, TheBuildMemoKeepsEachFramebufferAcrossABindingSwitch) {
+    FramebufferScope scope;
+    const auto colorA = MakeColorTexture(83, 32);
+    const auto colorB = MakeColorTexture(84, 16);
+    const auto a = MakeShared<FramebufferObject>(24);
+    const auto b = MakeShared<FramebufferObject>(25);
+    a->AttachTexture(FramebufferAttachmentType::Color0, colorA, TextureUploadTarget::Texture2D);
+    b->AttachTexture(FramebufferAttachmentType::Color0, colorB, TextureUploadTarget::Texture2D);
+    BindDrawAndRead(a, a);
+    Framebuffers().EmitFramebufferState(Ctx());
+    BindDrawAndRead(b, b);
+    Framebuffers().EmitFramebufferState(Ctx());
+    const Uint64 hits = Framebuffers().MemoHitCount();
+    BindDrawAndRead(a, a);
+    Framebuffers().EmitFramebufferState(Ctx());
+    EXPECT_EQ(Framebuffers().MemoHitCount(), hits + 1) << "switching back to a framebuffer rebuilt its record";
+    EXPECT_EQ(Framebuffers().LastDraw().Width, 32u) << "MGPFramebufferState::Width";
+}
+
+TEST(FramebufferEmit, TheBuildMemoFollowsARestoragedAttachedRenderbuffer) {
+    FramebufferScope scope;
+    const auto renderbuffer = MakeShared<RenderbufferObject>(4);
+    renderbuffer->SetInternalFormat(TextureInternalFormat::RGBA8);
+    renderbuffer->AllocateStorage(IntVec2{32, 32});
+    const auto fbo = MakeShared<FramebufferObject>(21);
+    fbo->AttachRenderbuffer(FramebufferAttachmentType::Color0, renderbuffer);
+    BindDrawAndRead(fbo, fbo);
+    Framebuffers().EmitFramebufferState(Ctx());
+    const Uint64 hits = Framebuffers().MemoHitCount();
+    Framebuffers().EmitFramebufferState(Ctx());
+    ASSERT_EQ(Framebuffers().MemoHitCount(), hits + 1) << "an unchanged framebuffer did not reuse its built record";
+
+    renderbuffer->AllocateStorage(IntVec2{48, 40});
+    Framebuffers().EmitFramebufferState(Ctx());
+    EXPECT_EQ(Framebuffers().LastDraw().Width, 48u) << "MGPFramebufferState::Width";
+    EXPECT_EQ(Framebuffers().LastDraw().Height, 40u) << "MGPFramebufferState::Height";
+}
+
+TEST(FramebufferEmit, TheBuildMemoFollowsAnAttachedTexturesSampleCount) {
+    FramebufferScope scope;
+    const auto color = MakeColorTexture(81, 32);
+    const auto fbo = MakeShared<FramebufferObject>(22);
+    fbo->AttachTexture(FramebufferAttachmentType::Color0, color, TextureUploadTarget::Texture2D);
+    BindDrawAndRead(fbo, fbo);
+    Framebuffers().EmitFramebufferState(Ctx());
+    Framebuffers().EmitFramebufferState(Ctx());
+
+    // Samples move the params version, not the shape.
+    color->SetSamples(4);
+    Framebuffers().EmitFramebufferState(Ctx());
+    EXPECT_EQ(Framebuffers().LastDraw().Samples, 4u) << "MGPFramebufferState::Samples";
+}
+
+TEST(FramebufferEmit, TheBuildMemoReNotesBindBitsAfterTheTextureTableIsDropped) {
+    FramebufferScope scope;
+    const auto color = MakeColorTexture(82, 32);
+    const auto fbo = MakeShared<FramebufferObject>(23);
+    fbo->AttachTexture(FramebufferAttachmentType::Color0, color, TextureUploadTarget::Texture2D);
+    BindDrawAndRead(fbo, fbo);
+    Framebuffers().EmitFramebufferState(Ctx());
+    const MGPipeHandle handle = HandleOfTexture(color);
+    ASSERT_FALSE(MGPipeHandleIsNull(handle));
+    ASSERT_NE(MGPipeTextureEmitterInstance().TextureBindMask(handle) & kMGPipeBindRenderTarget, 0)
+        << "the attachment's RENDER_TARGET bit was never noted";
+
+    // A dropped table (a replaced session) forgets the sticky bits; the next build must note them again.
+    MGPipeTextureEmitterInstance().ResetForTest();
+    MGPipeSetHashSuppressorInstance().InvalidateAll();
+    Framebuffers().EmitFramebufferState(Ctx());
+    EXPECT_NE(MGPipeTextureEmitterInstance().TextureBindMask(handle) & kMGPipeBindRenderTarget, 0)
+        << "MGPResourceDesc::BindMask lost RENDER_TARGET after the texture table was dropped";
+}
+
 int main(int argc, char** argv) {
     // Before anything logs: the logger reads this variable once, on its first write, and
     // caches the handle. The name carries this process's pid, and the file is removed on the

MobileGL/MG_Test/Pipe/SlotAllocatorTest.cpp

@@ -97,6 +97,38 @@ namespace {
         EXPECT_TRUE(allocator.IsLive(MGPipeKind::Buffer, reused));
     }
 
+    // P15: a hint (the handle a frontend object was last given, kept on the object) is a shortcut
+    // and never an answer of its own. It must give the live handle back, and it must miss - never
+    // name another object's handle - after a free, a recycle of its slot, or a reset.
+    TEST(SlotAllocator, AHandleHintIsOnlyBelievedWhileItsSlotStillBelongsToTheObject) {
+        MGPipeSlotAllocator allocator;
+        constexpr Uint64 kFirst = 1001, kSecond = 1002;
+
+        Uint64 hint = 0;
+        const MGPipeHandle minted = allocator.AcquireHinted(MGPipeKind::Buffer, kFirst, hint);
+        ASSERT_FALSE(MGPipeHandleIsNull(minted));
+        EXPECT_EQ(hint, MGPipePackHandleHint(minted)) << "a mint must leave the hint naming the new handle";
+        EXPECT_TRUE(allocator.FindByLifetimeIdHinted(MGPipeKind::Buffer, kFirst, hint) == minted);
+
+        // The slot is freed and handed to another object. The dead object's hint must miss, even
+        // when it is forged to carry the successor's exact slot and generation: the owner moved.
+        allocator.Free(MGPipeKind::Buffer, minted);
+        EXPECT_TRUE(MGPipeHandleIsNull(allocator.FindByLifetimeIdHinted(MGPipeKind::Buffer, kFirst, hint)))
+            << "a freed object's hint still answered";
+        Uint64 staleHint = MGPipePackHandleHint(minted);
+        const MGPipeHandle successor = allocator.AcquireHinted(MGPipeKind::Buffer, kSecond, staleHint);
+        EXPECT_EQ(successor.Slot, minted.Slot) << "the free list did not hand the slot back";
+        Uint64 forged = MGPipePackHandleHint(successor);  // the successor's exact slot and generation
+        EXPECT_TRUE(MGPipeHandleIsNull(allocator.FindByLifetimeIdHinted(MGPipeKind::Buffer, kFirst, forged)))
+            << "a hint naming another object's live slot answered for the dead object";
+
+        // A reset forgets every handle; a hint from before it can only miss.
+        Uint64 beforeReset = MGPipePackHandleHint(successor);
+        allocator.Reset();
+        EXPECT_TRUE(MGPipeHandleIsNull(allocator.FindByLifetimeIdHinted(MGPipeKind::Buffer, kSecond, beforeReset)))
+            << "a hint survived the allocator's reset";
+    }
+
     TEST(SlotAllocator, FreedSlotComesBackBeforeHighWaterGrows) {
         MGPipeSlotAllocator allocator;
 

MobileGL/MG_Test/Pipe/VertexInputEmitTest.cpp

@@ -277,6 +277,34 @@ namespace {
         }
     }
 
+    // P15: the rebuild reuses the previous attribute's handle when it names the SAME buffer object
+    // (interleaved attributes), and only then. Two buffers interleaved A, A, B, A: every entry must
+    // carry its own buffer's handle, including the A after the B.
+    TEST(VertexInputEmit, InterleavedAttributesOnTwoBuffersEachCarryTheirOwnBuffersHandle) {
+        EmitterScope scope;
+        const SharedPtr<VertexArrayObject> vao = MakeVao(1);
+        const SharedPtr<BufferObject> a = Ctx().CreateBufferObject(1);
+        const SharedPtr<BufferObject> b = Ctx().CreateBufferObject(2);
+        a->Respecify(256, nullptr);
+        b->Respecify(256, nullptr);
+        const SharedPtr<BufferObject>* owners[] = {&a, &a, &b, &a};
+        for (Uint i = 0; i < 4; ++i) {
+            vao->SetAttributeFormat(i, 4, DataType::Float32, false, 16, static_cast<SizeT>(4 * i), false, false, 16);
+            vao->MirrorPointerIntoBinding(i, *owners[i], static_cast<SizeT>(4 * i), 16);
+            vao->BindAttributeBuffer(i, *owners[i]);
+            vao->EnableAttribute(i);
+        }
+        Emitter().EmitVertexBuffers(Ctx(), 0);
+        ASSERT_EQ(Emitter().LastVertexBuffers().Count, 4u);
+        for (Uint i = 0; i < 4; ++i) {
+            const MGPipeHandle expected =
+                MGPipeSlots().FindByLifetimeId(MGPipeKind::Buffer, (*owners[i])->GetLifetimeId());
+            ASSERT_FALSE(MGPipeHandleIsNull(expected));
+            EXPECT_TRUE(Emitter().LastEntries()[i].Res == expected)
+                << "MGPVertexBuffer::Res of entry " << i << " is not its own buffer's handle";
+        }
+    }
+
     // KHR-GL43.vertex_attrib_binding.basic-input-case7/8: a pointer call's stride 0 means
     // "tightly packed" and the frontend already resolved it to the element size, so a zero
     // that reaches the wire can only have come from the binding model - where it means every