[Feat] (DirectVulkan): relax fragment precision where the bound formats allow it

- WIP, parked: measures 80.9 -> 94.8 fps on Adreno 650 / MC 26.2 (same scene,
  device cooled to 38-40C), but is NOT validated. Desktop GLSL carries no
  precision qualifiers, so every fragment value reaches the driver as fp32 while
  Adreno runs fp16 at twice the rate.
- RelaxTextureDerivedPrecisionPass taints the values a fragment shader derives
  from built-in inputs and decorates everything else RelaxedPrecision. The
  taint direction matters: whitelisting outward from texture reads captures
  nothing, because MC multiplies every texel by an interpolated colour and a UBO
  value and one un-relaxed operand vetoes the expression - measured at 80.4 fps,
  i.e. no gain, both with and without varyings seeded. Precision-critical
  sources are few (gl_FragCoord cannot even hold a 3044-pixel x exactly), so
  tainting them and relaxing the rest is what actually pays.
- SPIR-V cannot see the bound formats - sampler2D yields vec4 whether the
  texture is RGBA8 or RGBA32F - so the decision is made per draw and passed in
  as a compile option, the same shape ExplicitLod0Sampling already uses.
  RelaxedFragmentPrecision is only requested when every sampled texture and
  every colour attachment is an 8-bit-or-less normalized format, where fp16's
  11-bit mantissa already carries the value exactly. Shaderpack HDR gbuffers,
  float data textures and 16-bit normalized targets therefore keep full
  precision, as do shaders that write gl_FragDepth or gl_SampleMask.
- LocalMultiStoreElim runs first: glslang emits function-local variables, and a
  load can never be relaxed, so without SSA promotion the analysis dies at the
  first temporary.
- WHY THIS IS PARKED: the retrace correctness gate never ran green. Every
  DirectVulkan retrace on Adreno 650 dies with DEVICE_LOST in
  UploadDirtyMipLevels on unmodified dev (pre-existing, device-gated), and on
  Adreno 830 - where the gate does pass on dev - minecraft-1.21.4-in-world times
  out at 900s with this change, which still needs explaining. Do not merge until
  that is understood and vanilla plus non-Photon shaderpack cases pass.
  (photon-v1.3b is broken on Adreno independently of this work.)
- The /sdcard/MG/exp_relaxed_precision_all and exp_no_relaxed_precision file
  toggles are development scaffolding for A/B measurement; they must go before
  this ships.

MobileGL/MG_Backend/DirectVulkan/Renderer/FrameContext.cpp

@@ -16,19 +16,18 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         m_device = device;
         m_commandPool = commandPool;
 
-        Vector<VkCommandBuffer> commandBuffers(frameCount * 2, VK_NULL_HANDLE);
+        Vector<VkCommandBuffer> commandBuffers(frameCount, VK_NULL_HANDLE);
         VkCommandBufferAllocateInfo allocInfo{};
         allocInfo.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO;
         allocInfo.commandPool = commandPool;
         allocInfo.level = VK_COMMAND_BUFFER_LEVEL_PRIMARY;
-        allocInfo.commandBufferCount = frameCount * 2;
+        allocInfo.commandBufferCount = frameCount;
         VkResult result = vkAllocateCommandBuffers(device, &allocInfo, commandBuffers.data());
         if (result != VK_SUCCESS) {
             return result;
         }
         for (Uint32 i = 0; i < frameCount; ++i) {
             m_frames[i].commandBuffer = commandBuffers[i];
-            m_frames[i].preCommandBuffer = commandBuffers[frameCount + i];
         }
 
         VkSemaphoreCreateInfo semaphoreInfo{VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO};
@@ -48,10 +47,9 @@ namespace MobileGL::MG_Backend::DirectVulkan {
 
     void FrameContext::Destroy(VkDevice device, VkCommandPool commandPool) {
         const Uint32 frameCount = static_cast<Uint32>(m_frames.size());
-        Vector<VkCommandBuffer> commandBuffers(frameCount * 2, VK_NULL_HANDLE);
+        Vector<VkCommandBuffer> commandBuffers(frameCount, VK_NULL_HANDLE);
         for (Uint32 i = 0; i < frameCount; ++i) {
             commandBuffers[i] = m_frames[i].commandBuffer;
-            commandBuffers[frameCount + i] = m_frames[i].preCommandBuffer;
         }
 
         for (Uint32 i = 0; i < frameCount; ++i) {
@@ -62,7 +60,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             for (auto& frame : m_frames) {
                 FreeRetiredCommandBuffers(frame);
             }
-            vkFreeCommandBuffers(device, commandPool, frameCount * 2, commandBuffers.data());
+            vkFreeCommandBuffers(device, commandPool, frameCount, commandBuffers.data());
         }
         m_frames.clear();
         currentFrameIndex = 0;
@@ -89,8 +87,6 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         currentFrameIndex = (currentFrameIndex + 1) % static_cast<Uint32>(m_frames.size());
         GetCurrent().isCommandRecording = false;
         GetCurrent().hasCommandBufferRecorded = false;
-        GetCurrent().isPreCommandRecording = false;
-        GetCurrent().hasPreCommandBufferRecorded = false;
     }
 
     VkCommandBuffer& FrameContext::BeginCommandRecording(VkCommandBufferUsageFlags flags,
@@ -122,41 +118,6 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         frame.hasCommandBufferRecorded = true;
     }
 
-    VkCommandBuffer FrameContext::BeginPreCommandRecording() {
-        auto& frame = GetCurrent();
-        if (frame.isPreCommandRecording) {
-            return frame.preCommandBuffer;
-        }
-        MOBILEGL_ASSERT(!frame.hasPreCommandBufferRecorded,
-                        "BeginPreCommandRecording: a recorded pre stream is still awaiting submission");
-        VK_VERIFY(vkResetCommandBuffer(frame.preCommandBuffer, 0), "BeginPreCommandRecording, vkResetCommandBuffer");
-        VkCommandBufferBeginInfo beginInfo{};
-        beginInfo.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
-        VK_VERIFY(vkBeginCommandBuffer(frame.preCommandBuffer, &beginInfo),
-                  "BeginPreCommandRecording, vkBeginCommandBuffer");
-        frame.isPreCommandRecording = true;
-        return frame.preCommandBuffer;
-    }
-
-    void FrameContext::EndPreCommandRecordingIfOpen() {
-        auto& frame = GetCurrent();
-        if (!frame.isPreCommandRecording) {
-            return;
-        }
-        VK_VERIFY(vkEndCommandBuffer(frame.preCommandBuffer), "EndPreCommandRecordingIfOpen, vkEndCommandBuffer");
-        frame.isPreCommandRecording = false;
-        frame.hasPreCommandBufferRecorded = true;
-    }
-
-    void FrameContext::AbandonPreCommandRecording() {
-        auto& frame = GetCurrent();
-        if (frame.isPreCommandRecording) {
-            VK_VERIFY(vkEndCommandBuffer(frame.preCommandBuffer), "AbandonPreCommandRecording, vkEndCommandBuffer");
-        }
-        frame.isPreCommandRecording = false;
-        frame.hasPreCommandBufferRecorded = false;
-    }
-
     VkResult FrameContext::InitializeSwapchainSemaphores(VkDevice device, Uint32 swapchainImageCount) {
         DestroySwapchainSemaphores(device);
         if (swapchainImageCount == 0) {
@@ -241,27 +202,17 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                                                                Uint32 swapchainImageIndex) const {
         const auto& frame = GetCurrent();
         MOBILEGL_ASSERT(!frame.isCommandRecording, "GetSubmitInfo called while command buffer recording is still active");
-        MOBILEGL_ASSERT(!frame.isPreCommandRecording,
-                        "GetSubmitInfo called while the pre-pass stream is still recording");
         AssertValidSwapchainImageIndex(swapchainImageIndex);
         SubmitInfoPacket packet{};
         packet.waitSemaphore = frame.imageAvailableSemaphore;
         packet.signalSemaphore = m_swapchainImageRenderFinishedSemaphores[swapchainImageIndex];
-
-        Uint32 commandBufferCount = 0;
-        // The pre-pass stream executes strictly before the frame's commands.
-        if (frame.hasPreCommandBufferRecorded) {
-            packet.commandBuffers[commandBufferCount++] = frame.preCommandBuffer;
-        }
-        if (shouldSubmitCommandBuffer) {
-            packet.commandBuffers[commandBufferCount++] = frame.commandBuffer;
-        }
+        packet.commandBuffer = frame.commandBuffer;
 
         packet.submitInfo.waitSemaphoreCount = frame.imageAvailableSemaphoreConsumed ? 0U : 1U;
         packet.submitInfo.pWaitSemaphores = frame.imageAvailableSemaphoreConsumed ? nullptr : &packet.waitSemaphore;
         packet.submitInfo.pWaitDstStageMask = frame.imageAvailableSemaphoreConsumed ? nullptr : &packet.waitDstStageMask;
-        packet.submitInfo.commandBufferCount = commandBufferCount;
-        packet.submitInfo.pCommandBuffers = commandBufferCount > 0 ? packet.commandBuffers : nullptr;
+        packet.submitInfo.commandBufferCount = shouldSubmitCommandBuffer ? 1U : 0U;
+        packet.submitInfo.pCommandBuffers = shouldSubmitCommandBuffer ? &packet.commandBuffer : nullptr;
         packet.submitInfo.signalSemaphoreCount = 1;
         packet.submitInfo.pSignalSemaphores = &packet.signalSemaphore;
         return packet;
@@ -325,14 +276,12 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         m_recordingObserver = observer;
     }
 
-    VkResult FrameContext::RetireCurrentCommandBuffer(Bool retirePreCommandBuffer) {
+    VkResult FrameContext::RetireCurrentCommandBuffer() {
         MOBILEGL_ASSERT(m_device != VK_NULL_HANDLE && m_commandPool != VK_NULL_HANDLE,
                         "RetireCurrentCommandBuffer requires an initialized FrameContext");
         auto& frame = GetCurrent();
         MOBILEGL_ASSERT(!frame.isCommandRecording,
                         "RetireCurrentCommandBuffer called while the command buffer is still recording");
-        MOBILEGL_ASSERT(!frame.isPreCommandRecording,
-                        "RetireCurrentCommandBuffer called while the pre-pass stream is still recording");
 
         VkCommandBufferAllocateInfo allocInfo{};
         allocInfo.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO;
@@ -340,20 +289,10 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         allocInfo.level = VK_COMMAND_BUFFER_LEVEL_PRIMARY;
         allocInfo.commandBufferCount = 1;
         VkCommandBuffer replacement = VK_NULL_HANDLE;
-        VkResult result = vkAllocateCommandBuffers(m_device, &allocInfo, &replacement);
+        const VkResult result = vkAllocateCommandBuffers(m_device, &allocInfo, &replacement);
         if (result != VK_SUCCESS) {
             return result;
         }
-        if (retirePreCommandBuffer) {
-            VkCommandBuffer preReplacement = VK_NULL_HANDLE;
-            result = vkAllocateCommandBuffers(m_device, &allocInfo, &preReplacement);
-            if (result != VK_SUCCESS) {
-                vkFreeCommandBuffers(m_device, m_commandPool, 1, &replacement);
-                return result;
-            }
-            frame.retiredCommandBuffers.push_back({frame.preCommandBuffer, frame.lastSubmitIndex});
-            frame.preCommandBuffer = preReplacement;
-        }
         // lastSubmitIndex was just written by the renderer for the submission
         // that carried this command buffer.
         frame.retiredCommandBuffers.push_back({frame.commandBuffer, frame.lastSubmitIndex});

MobileGL/MG_Backend/DirectVulkan/Renderer/FrameContext.h

@@ -29,9 +29,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             VkPipelineStageFlags waitDstStageMask = VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT;
             VkSemaphore waitSemaphore = VK_NULL_HANDLE;
             VkSemaphore signalSemaphore = VK_NULL_HANDLE;
-            // [0] = pre-pass command buffer (when recorded), then the frame
-            // command buffer; submitInfo.pCommandBuffers points here.
-            VkCommandBuffer commandBuffers[2] = {VK_NULL_HANDLE, VK_NULL_HANDLE};
+            VkCommandBuffer commandBuffer = VK_NULL_HANDLE;
             VkSubmitInfo submitInfo{VK_STRUCTURE_TYPE_SUBMIT_INFO};
         };
 
@@ -54,18 +52,10 @@ namespace MobileGL::MG_Backend::DirectVulkan {
 
         struct FrameData {
             VkCommandBuffer commandBuffer = VK_NULL_HANDLE;
-            // Pre-pass work stream: out-of-pass commands (deferred clear
-            // materialization, sampled-layout transitions) for resources the
-            // frame's recording has not touched yet. Submitted immediately
-            // BEFORE commandBuffer in the same vkQueueSubmit, so recording
-            // into it never has to split the frame's active render pass.
-            VkCommandBuffer preCommandBuffer = VK_NULL_HANDLE;
             VkSemaphore imageAvailableSemaphore = VK_NULL_HANDLE;
             VkFence imageInFlightFence = VK_NULL_HANDLE;
             Bool isCommandRecording = false;
             Bool hasCommandBufferRecorded = false;
-            Bool isPreCommandRecording = false;
-            Bool hasPreCommandBufferRecorded = false;
             Bool imageAvailableSemaphoreConsumed = false;
             // Command buffers submitted mid-frame (FlushPendingCommands),
             // appended in submit order; freed once their submission is known
@@ -87,14 +77,6 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         VkCommandBuffer& BeginCommandRecording(VkCommandBufferUsageFlags flags = 0,
                                                const VkCommandBufferInheritanceInfo* pInheritanceInfo = nullptr);
         void EndCommandRecording();
-        // Lazily opens the pre-pass work stream (see FrameData::preCommandBuffer).
-        VkCommandBuffer BeginPreCommandRecording();
-        // Closes the pre stream if open, marking it for submission ahead of the
-        // frame command buffer. Safe to call when it never opened.
-        void EndPreCommandRecordingIfOpen();
-        // Drops an in-progress or recorded-but-unsubmitted pre stream (dropped
-        // frame recordings, swapchain recreation).
-        void AbandonPreCommandRecording();
         VkResult InitializeSwapchainSemaphores(VkDevice device, Uint32 swapchainImageCount);
         void DestroySwapchainSemaphores(VkDevice device);
         Bool TransitionToPresent(VkImage image, VkImageLayout oldLayout,
@@ -109,7 +91,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // can restart while the submitted buffer is still executing. Retired
         // buffers are freed after the slot's fence is next waited, or as soon
         // as their submission is observed complete.
-        VkResult RetireCurrentCommandBuffer(Bool retirePreCommandBuffer = false);
+        VkResult RetireCurrentCommandBuffer();
 
         // Frees every retired command buffer whose tagged submission index is
         // known complete. Driven by the renderer's submit tracker on completion

MobileGL/MG_Backend/DirectVulkan/Renderer/ProgramFactory.cpp

@@ -12,7 +12,10 @@
 #include "MG_Util/ShaderTranspiler/ShaderCompiler.h"
 #include "MG_Util/ShaderTranspiler/SpvcSession.h"
 #include "MG_Util/ShaderTranspiler/Types.h"
+#include <cmath>
+#include <cstdio>
 #include <cstring>
+#include <unordered_set>
 #include <spirv-tools/libspirv.h>
 #include <spirv-tools/optimizer.hpp>
 #include <source/opt/build_module.h>
@@ -1099,6 +1102,374 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             return spvtools::Optimizer::PassToken(MakeUnique<ForceExplicitLod0SamplePass>());
         }
 
+        // TEMP-PERFDIAG: measure what fragment-stage fp32 costs on this GPU. Desktop GLSL carries
+        // no precision qualifiers, so everything reaches the driver as full fp32 while Adreno runs
+        // fp16 at twice the rate. Decorating every float-typed result in a fragment entry point
+        // with RelaxedPrecision is the blunt "all mediump" upper bound - it changes results, so it
+        // is a probe, not a shipping transform. Toggled by /sdcard/MG/exp_relaxed_precision.
+        class RelaxedPrecisionProbePass final : public spvtools::opt::Pass {
+        public:
+            const char* name() const override { return "relaxed-precision-probe"; }
+
+            Status Process() override {
+                Bool isFragment = false;
+                for (auto& entryPoint : get_module()->entry_points()) {
+                    if (entryPoint.opcode() != spv::Op::OpEntryPoint) continue;
+                    if (static_cast<spv::ExecutionModel>(entryPoint.GetSingleWordInOperand(0)) ==
+                        spv::ExecutionModel::Fragment) {
+                        isFragment = true;
+                        break;
+                    }
+                }
+                if (!isFragment) return Status::SuccessWithoutChange;
+
+                // Every 32-bit-float scalar/vector/matrix type in the module. Anything wider (f64)
+                // or narrower is left alone: RelaxedPrecision only has meaning for 32-bit floats.
+                std::unordered_set<Uint32> relaxableTypes;
+                for (auto& type : get_module()->types_values()) {
+                    const Uint32 typeId = type.result_id();
+                    if (typeId == 0) continue;
+                    switch (type.opcode()) {
+                    case spv::Op::OpTypeFloat:
+                        if (type.GetSingleWordInOperand(0) == 32) relaxableTypes.insert(typeId);
+                        break;
+                    case spv::Op::OpTypeVector:
+                    case spv::Op::OpTypeMatrix:
+                        if (relaxableTypes.count(type.GetSingleWordInOperand(0)) != 0) {
+                            relaxableTypes.insert(typeId);
+                        }
+                        break;
+                    default:
+                        break;
+                    }
+                }
+                if (relaxableTypes.empty()) return Status::SuccessWithoutChange;
+
+                Vector<Uint32> targets;
+                for (auto& function : *get_module()) {
+                    for (auto& block : function) {
+                        for (auto& inst : block) {
+                            const Uint32 resultId = inst.result_id();
+                            if (resultId == 0) continue;
+                            if (relaxableTypes.count(inst.type_id()) == 0) continue;
+                            targets.push_back(resultId);
+                        }
+                    }
+                }
+                if (targets.empty()) return Status::SuccessWithoutChange;
+
+                for (const Uint32 id : targets) {
+                    context()->get_decoration_mgr()->AddDecoration(
+                        id, static_cast<Uint32>(spv::Decoration::RelaxedPrecision));
+                }
+                context()->InvalidateAnalysesExceptFor(spvtools::opt::IRContext::kAnalysisNone);
+                return Status::SuccessWithChange;
+            }
+        };
+
+        // Relax fragment-stage arithmetic that provably came out of a texture read. Desktop GLSL
+        // has no precision qualifiers, so every fragment value reaches the driver as fp32 while
+        // Adreno runs fp16 at twice the rate - and a texel is at most 8 bits per channel, which
+        // fp16's 11-bit mantissa carries exactly. Seeding at image reads and propagating only
+        // through operations whose every input is already relaxed keeps everything the shader
+        // computes from other sources (screen coordinates, depth, wide-range uniforms) at full
+        // precision, which is where fp16 would actually go wrong: fp16 cannot even represent a
+        // 3044-pixel gl_FragCoord.x exactly.
+        class RelaxTextureDerivedPrecisionPass final : public spvtools::opt::Pass {
+        public:
+            const char* name() const override { return "relax-texture-derived-precision"; }
+
+            Status Process() override {
+                if (!IsFragmentEntryPoint()) return Status::SuccessWithoutChange;
+                // A shader that drives depth or coverage itself is out of scope: those values must
+                // stay exact, and proving which computations feed them is not worth it here.
+                if (WritesDepthOrSampleMask()) return Status::SuccessWithoutChange;
+
+                CollectRelaxableFloatTypes();
+                if (m_relaxableTypes.empty()) return Status::SuccessWithoutChange;
+
+                // Whitelisting from texture reads captures nothing in practice: MC's fragment
+                // shaders multiply every texel by an interpolated colour and a UBO value, so one
+                // un-relaxed operand vetoes the whole expression (measured: no fps change).
+                // Taint the few genuinely precision-critical sources instead and relax the rest.
+                std::unordered_set<Uint32> tainted;
+                CollectPrecisionCriticalSeeds(tainted);
+                Bool grew = true;
+                while (grew) {
+                    grew = false;
+                    for (auto& function : *get_module()) {
+                        for (auto& block : function) {
+                            for (auto& inst : block) {
+                                const Uint32 resultId = inst.result_id();
+                                if (resultId == 0 || tainted.count(resultId) != 0) continue;
+                                if (!AnyOperandTainted(inst, tainted)) continue;
+                                tainted.insert(resultId);
+                                grew = true;
+                            }
+                        }
+                    }
+                }
+
+                std::unordered_set<Uint32> relaxed;
+                for (auto& function : *get_module()) {
+                    for (auto& block : function) {
+                        for (auto& inst : block) {
+                            const Uint32 resultId = inst.result_id();
+                            if (resultId == 0 || tainted.count(resultId) != 0) continue;
+                            if (m_relaxableTypes.count(inst.type_id()) == 0) continue;
+                            relaxed.insert(resultId);
+                        }
+                    }
+                }
+                if (relaxed.empty()) return Status::SuccessWithoutChange;
+
+                for (const Uint32 id : relaxed) {
+                    context()->get_decoration_mgr()->AddDecoration(
+                        id, static_cast<Uint32>(spv::Decoration::RelaxedPrecision));
+                }
+                context()->InvalidateAnalysesExceptFor(spvtools::opt::IRContext::kAnalysisNone);
+                return Status::SuccessWithChange;
+            }
+
+        private:
+            std::unordered_set<Uint32> m_relaxableTypes;
+
+            Bool IsFragmentEntryPoint() const {
+                for (auto& entryPoint : get_module()->entry_points()) {
+                    if (entryPoint.opcode() != spv::Op::OpEntryPoint) continue;
+                    if (static_cast<spv::ExecutionModel>(entryPoint.GetSingleWordInOperand(0)) ==
+                        spv::ExecutionModel::Fragment) {
+                        return true;
+                    }
+                }
+                return false;
+            }
+
+            Bool WritesDepthOrSampleMask() const {
+                for (auto& annotation : get_module()->annotations()) {
+                    if (annotation.opcode() != spv::Op::OpDecorate) continue;
+                    if (static_cast<spv::Decoration>(annotation.GetSingleWordInOperand(1)) !=
+                        spv::Decoration::BuiltIn) {
+                        continue;
+                    }
+                    const auto builtIn = static_cast<spv::BuiltIn>(annotation.GetSingleWordInOperand(2));
+                    if (builtIn == spv::BuiltIn::FragDepth || builtIn == spv::BuiltIn::SampleMask) {
+                        return true;
+                    }
+                }
+                return false;
+            }
+
+            void CollectRelaxableFloatTypes() {
+                m_relaxableTypes.clear();
+                for (auto& type : get_module()->types_values()) {
+                    const Uint32 typeId = type.result_id();
+                    if (typeId == 0) continue;
+                    switch (type.opcode()) {
+                    case spv::Op::OpTypeFloat:
+                        if (type.GetSingleWordInOperand(0) == 32) m_relaxableTypes.insert(typeId);
+                        break;
+                    case spv::Op::OpTypeVector:
+                        if (m_relaxableTypes.count(type.GetSingleWordInOperand(0)) != 0) {
+                            m_relaxableTypes.insert(typeId);
+                        }
+                        break;
+                    default:
+                        break;
+                    }
+                }
+            }
+
+            void CollectImageReadSeeds(std::unordered_set<Uint32>& relaxed) const {
+                for (auto& function : *get_module()) {
+                    for (auto& block : function) {
+                        for (auto& inst : block) {
+                            const Uint32 resultId = inst.result_id();
+                            if (resultId == 0 || m_relaxableTypes.count(inst.type_id()) == 0) continue;
+                            // Interpolated user varyings seed too, or propagation dies at the
+                            // first `texel * vertexColour`: the load of an Input can never be
+                            // relaxed by the rule below (its operand is a pointer), so a single
+                            // varying vetoes every downstream operation. This is what ESSL's
+                            // mediump varyings already mean. Built-ins are excluded - gl_FragCoord
+                            // carries pixel coordinates that fp16 cannot represent exactly.
+                            if (inst.opcode() == spv::Op::OpLoad && IsNonBuiltInFragmentInput(inst)) {
+                                relaxed.insert(resultId);
+                                continue;
+                            }
+                            switch (inst.opcode()) {
+                            case spv::Op::OpImageSampleImplicitLod:
+                            case spv::Op::OpImageSampleExplicitLod:
+                            case spv::Op::OpImageSampleProjImplicitLod:
+                            case spv::Op::OpImageSampleProjExplicitLod:
+                            case spv::Op::OpImageSampleDrefImplicitLod:
+                            case spv::Op::OpImageSampleDrefExplicitLod:
+                            case spv::Op::OpImageFetch:
+                            case spv::Op::OpImageRead:
+                            case spv::Op::OpImageGather:
+                                relaxed.insert(resultId);
+                                break;
+                            default:
+                                break;
+                            }
+                        }
+                    }
+                }
+            }
+
+            // OpLoad straight out of a fragment Input variable that carries no BuiltIn decoration.
+            // Only a direct load counts: a load through an access chain could be indexing a
+            // structure whose other members are not interpolated colour data.
+            Bool IsNonBuiltInFragmentInput(const spvtools::opt::Instruction& load) const {
+                const Uint32 pointerId = load.GetSingleWordInOperand(0);
+                const auto* pointer = context()->get_def_use_mgr()->GetDef(pointerId);
+                if (pointer == nullptr || pointer->opcode() != spv::Op::OpVariable) return false;
+                if (static_cast<spv::StorageClass>(pointer->GetSingleWordInOperand(0)) !=
+                    spv::StorageClass::Input) {
+                    return false;
+                }
+                Bool isBuiltIn = false;
+                context()->get_decoration_mgr()->ForEachDecoration(
+                    pointerId, static_cast<Uint32>(spv::Decoration::BuiltIn),
+                    [&isBuiltIn](const spvtools::opt::Instruction&) { isBuiltIn = true; });
+                return !isBuiltIn;
+            }
+
+            // A float constant small enough that fp16 represents it without surprise. Colour math
+            // constants (0, 1, 0.5, 255, gamma exponents) all live here; anything larger is
+            // treated as unknown so it stops propagation.
+            Bool IsBoundedFloatConstant(Uint32 id) const {
+                const auto* constant = context()->get_constant_mgr()->FindDeclaredConstant(id);
+                if (constant == nullptr) return false;
+                if (const auto* scalar = constant->AsFloatConstant()) {
+                    const float value = scalar->GetFloat();
+                    return std::isfinite(value) && std::fabs(value) <= 1024.0f;
+                }
+                if (const auto* composite = constant->AsVectorConstant()) {
+                    for (const auto* component : composite->GetComponents()) {
+                        const auto* scalar = component->AsFloatConstant();
+                        if (scalar == nullptr) return false;
+                        const float value = scalar->GetFloat();
+                        if (!std::isfinite(value) || std::fabs(value) > 1024.0f) return false;
+                    }
+                    return true;
+                }
+                return false;
+            }
+
+            // Precision-critical sources: a built-in fragment input. gl_FragCoord is the one that
+            // matters - fp16 cannot represent a 3044-pixel x coordinate exactly, and anything
+            // derived from it (screen-space effects, manual depth reconstruction) would visibly
+            // quantise. Everything else a fragment shader reads is colour-range data.
+            void CollectPrecisionCriticalSeeds(std::unordered_set<Uint32>& tainted) const {
+                for (auto& function : *get_module()) {
+                    for (auto& block : function) {
+                        for (auto& inst : block) {
+                            if (inst.opcode() != spv::Op::OpLoad || inst.result_id() == 0) continue;
+                            if (IsBuiltInInputLoad(inst)) tainted.insert(inst.result_id());
+                        }
+                    }
+                }
+            }
+
+            Bool IsBuiltInInputLoad(const spvtools::opt::Instruction& load) const {
+                const Uint32 pointerId = load.GetSingleWordInOperand(0);
+                const auto* pointer = context()->get_def_use_mgr()->GetDef(pointerId);
+                if (pointer == nullptr || pointer->opcode() != spv::Op::OpVariable) return false;
+                if (static_cast<spv::StorageClass>(pointer->GetSingleWordInOperand(0)) !=
+                    spv::StorageClass::Input) {
+                    return false;
+                }
+                Bool isBuiltIn = false;
+                context()->get_decoration_mgr()->ForEachDecoration(
+                    pointerId, static_cast<Uint32>(spv::Decoration::BuiltIn),
+                    [&isBuiltIn](const spvtools::opt::Instruction&) { isBuiltIn = true; });
+                return isBuiltIn;
+            }
+
+            Bool AnyOperandTainted(const spvtools::opt::Instruction& inst,
+                                   const std::unordered_set<Uint32>& tainted) const {
+                const Uint32 operandCount = inst.NumInOperands();
+                for (Uint32 i = 0; i < operandCount; ++i) {
+                    const auto& operand = inst.GetInOperand(i);
+                    if (!spvIsIdType(operand.type)) continue;
+                    if (IsNonNumericOperand(inst, i)) continue;
+                    if (tainted.count(operand.words[0]) != 0) return true;
+                }
+                return false;
+            }
+
+            Bool AllValueOperandsRelaxed(const spvtools::opt::Instruction& inst,
+                                         const std::unordered_set<Uint32>& relaxed) const {
+                switch (inst.opcode()) {
+                // Pointer-typed plumbing: relaxing the loaded value would say nothing about the
+                // memory it came from, and the pointer operand can never be in the set.
+                case spv::Op::OpLoad:
+                case spv::Op::OpStore:
+                case spv::Op::OpAccessChain:
+                case spv::Op::OpInBoundsAccessChain:
+                case spv::Op::OpFunctionCall:
+                    return false;
+                default:
+                    break;
+                }
+
+                Bool sawValueOperand = false;
+                Bool allRelaxed = true;
+                const Uint32 operandCount = inst.NumInOperands();
+                for (Uint32 i = 0; i < operandCount; ++i) {
+                    const auto& operand = inst.GetInOperand(i);
+                    if (!spvIsIdType(operand.type)) continue; // literals: selectors, swizzle indices
+                    const Uint32 id = operand.words[0];
+                    // OpPhi's block labels, OpSelect's condition and OpExtInst's instruction-set id
+                    // are ids that carry no numeric precision; skip them rather than let them veto.
+                    if (IsNonNumericOperand(inst, i)) continue;
+                    sawValueOperand = true;
+                    if (relaxed.count(id) != 0) continue;
+                    if (IsBoundedFloatConstant(id)) continue;
+                    allRelaxed = false;
+                    break;
+                }
+                return sawValueOperand && allRelaxed;
+            }
+
+            static Bool IsNonNumericOperand(const spvtools::opt::Instruction& inst, Uint32 index) {
+                switch (inst.opcode()) {
+                case spv::Op::OpPhi:
+                    return (index % 2) == 1; // parent block labels
+                case spv::Op::OpSelect:
+                    return index == 0; // condition
+                case spv::Op::OpExtInst:
+                    return index == 0; // extended instruction set
+                default:
+                    return false;
+                }
+            }
+        };
+
+        // TEMP-PERFDIAG: A/B switch between the scoped transform and the all-float upper bound.
+        Bool PerfDiagRelaxAllPrecision() {
+            static const Bool enabled = [] {
+                std::FILE* probe = std::fopen("/sdcard/MG/exp_relaxed_precision_all", "rb");
+                if (probe == nullptr) return false;
+                std::fclose(probe);
+                MGLOG_I("[PERFDIAG] fragment RelaxedPrecision: ALL floats (upper-bound probe)");
+                return true;
+            }();
+            return enabled;
+        }
+
+        // TEMP-PERFDIAG: lets a run turn the transform off entirely for an A/B baseline.
+        Bool PerfDiagRelaxedPrecisionEnabled() {
+            static const Bool disabled = [] {
+                std::FILE* probe = std::fopen("/sdcard/MG/exp_no_relaxed_precision", "rb");
+                if (probe == nullptr) return false;
+                std::fclose(probe);
+                MGLOG_I("[PERFDIAG] fragment RelaxedPrecision DISABLED");
+                return true;
+            }();
+            return !disabled;
+        }
+
         Bool TransformSpirvForExplicitLod0Sampling(const Vector<Uint>& input, Vector<Uint>& output) {
             if (input.empty()) {
                 output.clear();
@@ -1128,6 +1499,37 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             return spvtools::Optimizer::PassToken(MakeUnique<GlToVulkanPositionFixPass>(transformFlags));
         }
 
+        // TEMP-PERFDIAG
+        Bool TransformSpirvForRelaxedPrecisionProbe(const Vector<Uint>& input, Vector<Uint>& output) {
+            if (input.empty()) {
+                output.clear();
+                return true;
+            }
+            spvtools::Optimizer optimizer(SPV_ENV_VULKAN_1_3);
+            spvtools::OptimizerOptions options;
+            options.set_run_validator(false);
+            optimizer.SetMessageConsumer([](spv_message_level_t, const char*, const spv_position_t&,
+                                            const char* message) {
+                MGLOG_E("Vulkan: relaxed-precision probe: %s", message != nullptr ? message : "");
+            });
+            // SSA promotion first: glslang emits function-local variables with stores and loads,
+            // and a load can never be relaxed (its operand is a pointer), so without this the
+            // propagation below dies at the first temporary.
+            optimizer.RegisterPass(spvtools::CreateLocalMultiStoreElimPass());
+            if (PerfDiagRelaxAllPrecision()) {
+                optimizer.RegisterPass(spvtools::Optimizer::PassToken(MakeUnique<RelaxedPrecisionProbePass>()));
+            } else {
+                optimizer.RegisterPass(
+                    spvtools::Optimizer::PassToken(MakeUnique<RelaxTextureDerivedPrecisionPass>()));
+            }
+            const Bool success = optimizer.Run(input.data(), input.size(), &output, options);
+            if (!success) {
+                MGLOG_E("Vulkan: relaxed-precision probe failed; keeping the original module");
+                output = input;
+            }
+            return success;
+        }
+
         Bool TransformSpirvForVulkanPositionFix(const Vector<Uint>& input, Vector<Uint>& output,
                                                 ProgramFactory::CompileOptionFlags transformFlags) {
             if (input.empty()) {
@@ -2186,6 +2588,15 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 }
             }
 
+            if ((flags & ProgramFactory::CompileOptionBit::RelaxedFragmentPrecision) &&
+                PerfDiagRelaxedPrecisionEnabled() && shaders[i] &&
+                shaders[i]->GetShaderStage() == ShaderStage::Fragment) {
+                Vector<Uint> relaxedSpirv;
+                if (TransformSpirvForRelaxedPrecisionProbe(moduleSpirvs[i], relaxedSpirv)) {
+                    moduleSpirvs[i] = Move(relaxedSpirv);
+                }
+            }
+
             // GL apps depend on cross-program position invariance for multi-pass equality
             // depth tests (MC 26.3's OIT re-draws the cloud geometry with GEQUAL against the
             // depth its own first pass wrote); decorate Position outputs Invariant so

MobileGL/MG_Backend/DirectVulkan/Renderer/ProgramFactory.h

@@ -47,6 +47,11 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             // level, which makes the two forms produce identical texels (the implicit lambda is
             // clamped into [minLod, maxLod] = [0, 0] regardless of derivatives or bias).
             ExplicitLod0Sampling = 1 << 5,
+            // Fragment arithmetic may run at relaxed (fp16) precision. Only requested for draws
+            // where every sampled texture and every colour attachment is an 8-bit-or-less
+            // normalized format, so nothing the shader reads or writes carries more precision
+            // than fp16 already represents exactly.
+            RelaxedFragmentPrecision = 1 << 6,
         };
         using CompileOptionFlags = Flags<CompileOptionBit>;
         using HashType = Uint64;

MobileGL/MG_Backend/DirectVulkan/Renderer/SwapchainObject.cpp

@@ -262,9 +262,6 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         m_images.resize(imageCount, VK_NULL_HANDLE);
         VK_VERIFY(vkGetSwapchainImagesKHR(device, m_swapchain, &imageCount, m_images.data()));
         m_imageLayouts.assign(imageCount, VK_IMAGE_LAYOUT_UNDEFINED);
-        // Fresh swapchain images hold garbage until a render pass stores into them.
-        m_imageContentDefined.assign(imageCount, false);
-        m_depthStencilContentDefined.assign(imageCount, false);
 
         CreateImageViews(device);
         CreateDepthStencilResources(device, physicalDevice);
@@ -436,39 +433,9 @@ namespace MobileGL::MG_Backend::DirectVulkan {
 
         m_images.clear();
         m_imageLayouts.clear();
-        m_imageContentDefined.clear();
-        m_depthStencilContentDefined.clear();
         m_preTransform = VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHR;
     }
 
-    Bool SwapchainObject::IsImageContentDefined(Uint32 index) const {
-        MOBILEGL_ASSERT(index < m_imageContentDefined.size(), "Swapchain image content index out of range");
-        return m_imageContentDefined[index];
-    }
-
-    void SwapchainObject::SetImageContentDefined(Uint32 index, Bool defined) {
-        MOBILEGL_ASSERT(index < m_imageContentDefined.size(), "Swapchain image content index out of range");
-        m_imageContentDefined[index] = defined;
-    }
-
-    Bool SwapchainObject::IsDepthStencilContentDefined(Uint32 index) const {
-        MOBILEGL_ASSERT(index < m_depthStencilContentDefined.size(),
-                        "Swapchain depth/stencil content index out of range");
-        return m_depthStencilContentDefined[index];
-    }
-
-    void SwapchainObject::SetDepthStencilContentDefined(Uint32 index, Bool defined) {
-        MOBILEGL_ASSERT(index < m_depthStencilContentDefined.size(),
-                        "Swapchain depth/stencil content index out of range");
-        m_depthStencilContentDefined[index] = defined;
-    }
-
-    void SwapchainObject::SetAllDepthStencilContentUndefined() {
-        for (SizeT i = 0; i < m_depthStencilContentDefined.size(); ++i) {
-            m_depthStencilContentDefined[i] = false;
-        }
-    }
-
     VkImage SwapchainObject::GetImage(Uint32 index) const {
         MOBILEGL_ASSERT(index < m_images.size(), "Swapchain image index out of range");
         return m_images[index];

MobileGL/MG_Backend/DirectVulkan/Renderer/SwapchainObject.h

@@ -52,21 +52,6 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         void SetImageLayout(Uint32 index, VkImageLayout layout);
         SizeT GetImageCount() const { return m_images.size(); }
 
-        // EGL content-validity tracking for the default framebuffer. A color
-        // buffer's content is undefined once its image has been presented
-        // (EGL_BUFFER_DESTROYED swap behaviour, the implementation default),
-        // and every ancillary (depth/stencil) buffer's content is undefined
-        // after ANY swap regardless of swap behaviour (EGL 1.5 §3.10.1). The
-        // render-pass manager turns an undefined attachment's tile load into
-        // LOAD_OP_DONT_CARE. Flags start false (a fresh swapchain image holds
-        // garbage) and a render pass storing into an attachment sets it back
-        // to defined.
-        Bool IsImageContentDefined(Uint32 index) const;
-        void SetImageContentDefined(Uint32 index, Bool defined);
-        Bool IsDepthStencilContentDefined(Uint32 index) const;
-        void SetDepthStencilContentDefined(Uint32 index, Bool defined);
-        void SetAllDepthStencilContentUndefined();
-
     private:
         void CreateImageViews(VkDevice device);
         void CreateDepthStencilResources(VkDevice device, VkPhysicalDevice physicalDevice);
@@ -92,7 +77,5 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         Vector<VkDeviceMemory> m_depthStencilImageMemories;
         Vector<VkImageView> m_depthStencilImageViews;
         Vector<VkImageLayout> m_depthStencilImageLayouts;
-        Vector<Bool> m_imageContentDefined;
-        Vector<Bool> m_depthStencilContentDefined;
     };
 } // namespace MobileGL::MG_Backend::DirectVulkan

MobileGL/MG_Backend/DirectVulkan/Renderer/UniformManager.cpp

@@ -16,6 +16,7 @@
 #include "MG_Util/Converters/GLToMG/TextureEnumConverter.h"
 #include "MG_Util/Converters/MGToStr/FramebufferEnumConverter.h"
 #include "MG_Util/Converters/MGToVk/TextureEnumConverter.h"
+#include <vulkan/utility/vk_format_utils.h>
 #include "MG_Util/Metrics/TextureMetrics.h"
 #include <Config.h>
 #include <cstdio>
@@ -446,6 +447,64 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         return outImageInfo.sampler != VK_NULL_HANDLE;
     }
 
+    namespace {
+        // fp16 carries an 11-bit mantissa, so an 8-bit normalized channel round-trips exactly.
+        // Anything wider - 16-bit normalized, half float, full float, and every packed HDR
+        // encoding - holds precision or range that relaxing the arithmetic would throw away.
+        Bool IsLowPrecisionNormalizedFormat(VkFormat format) {
+            if (format == VK_FORMAT_UNDEFINED) return false;
+            if (!vkuFormatIsUNORM(format) && !vkuFormatIsSNORM(format) && !vkuFormatIsSRGB(format)) {
+                return false;
+            }
+            const struct VKU_FORMAT_INFO info = vkuGetFormatInfo(format);
+            for (Uint32 i = 0; i < info.component_count; ++i) {
+                if (info.components[i].size > 8) return false;
+            }
+            return info.component_count > 0;
+        }
+    } // namespace
+
+    Bool UniformManager::DrawTargetIsLowPrecision(const MG_State::GLState::FramebufferObject* drawFramebuffer) {
+        // Default framebuffer: the swapchain is an 8-bit normalized surface.
+        if (drawFramebuffer == nullptr) return true;
+
+        Bool sawColour = false;
+        for (Int i = static_cast<Int>(FramebufferAttachmentType::Color0);
+             i < static_cast<Int>(FramebufferAttachmentType::FramebufferAttachmentTypeCount);
+             ++i) {
+            const auto& attachment =
+                drawFramebuffer->GetAttachment(static_cast<FramebufferAttachmentType>(i));
+            VkFormat format = VK_FORMAT_UNDEFINED;
+            if (const auto& texture = attachment.GetTexture()) {
+                format = MG_Util::ConvertTextureInternalFormatToVkEnum(texture->GetFormat());
+            } else if (const auto& renderbuffer = attachment.GetRenderbuffer()) {
+                format = MG_Util::ConvertTextureInternalFormatToVkEnum(
+                    renderbuffer->GetInternalFormat());
+            } else {
+                continue;
+            }
+            if (!IsLowPrecisionNormalizedFormat(format)) return false;
+            sawColour = true;
+        }
+        return sawColour;
+    }
+
+    Bool UniformManager::ProgramSamplesOnlyLowPrecisionTextures(
+        const MG_State::GLState::ProgramObject& program, const ProgramFactory::VkProgramObject& programObj) {
+        for (Uint32 binding = 0; binding < programObj.bindingKinds.size(); ++binding) {
+            if (programObj.bindingKinds[binding] != ProgramFactory::DescriptorBindingKind::CombinedImageSampler) {
+                continue;
+            }
+            const auto* texture = ResolveSamplerTextureRaw(program, programObj, binding);
+            // An unresolvable binding is unknown territory, not licence to relax.
+            if (texture == nullptr) return false;
+            const VkFormat format =
+                MG_Util::ConvertTextureInternalFormatToVkEnum(texture->GetFormat());
+            if (!IsLowPrecisionNormalizedFormat(format)) return false;
+        }
+        return true;
+    }
+
     Bool UniformManager::ProgramSamplesOnlySingleLevelTextures(
         const MG_State::GLState::ProgramObject& program, const ProgramFactory::VkProgramObject& programObj) {
         Bool sawSampler = false;

MobileGL/MG_Backend/DirectVulkan/Renderer/UniformManager.h

@@ -76,6 +76,15 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // ExplicitLod0Sampling SPIR-V rewrite safe to request. Deliberately conservative: it reads
         // only GL state, so a texture that ends up single-level for another reason (one uploaded
         // level under a wide level range) merely misses the rewrite.
+        // True when every texture this program samples is an 8-bit-or-less normalized format, so
+        // relaxing the fragment stage to fp16 cannot lose a bit the texel ever carried. Says
+        // nothing about the render target - the caller must check that too.
+        static Bool ProgramSamplesOnlyLowPrecisionTextures(const MG_State::GLState::ProgramObject& program,
+                                                          const ProgramFactory::VkProgramObject& programObj);
+        // True when every colour attachment the draw writes is an 8-bit-or-less normalized
+        // format (nullptr = default framebuffer, which is). Blending happens at attachment
+        // precision, so a wider target must keep the fragment stage at full precision.
+        static Bool DrawTargetIsLowPrecision(const MG_State::GLState::FramebufferObject* drawFramebuffer);
         static Bool ProgramSamplesOnlySingleLevelTextures(const MG_State::GLState::ProgramObject& program,
                                                           const ProgramFactory::VkProgramObject& programObj);
 

MobileGL/MG_Backend/DirectVulkan/Renderer/VkRenderPassManager.cpp

@@ -481,8 +481,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
     }
 
     VkRenderPassManager::HashType VkRenderPassManager::ComputeHash(
-        const MG_State::GLState::FramebufferObject& fbo, Uint32 swapchainImageIndex, Bool includePendingClear,
-        Bool includeDefaultFboDepthStencil) {
+        const MG_State::GLState::FramebufferObject& fbo, Uint32 swapchainImageIndex, Bool includePendingClear) {
         XXHASH_VERIFY(XXH64_reset(m_hashState, m_config.CacheVersion));
         const Bool isDefaultFbo = fbo.IsDefaultFramebuffer();
         if (isDefaultFbo) {
@@ -561,17 +560,9 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                          attachment <= FramebufferAttachmentType::BackRight);
                     if (isDefaultColorAttachment) {
                         currentLayout = m_swapchainObject.GetImageLayout(swapchainImageIndex);
-                        // Content validity feeds the attachment's loadOp (see the
-                        // creation path), so it must key the cache as well.
-                        if (!m_swapchainObject.IsImageContentDefined(swapchainImageIndex)) {
-                            currentLayout = VK_IMAGE_LAYOUT_UNDEFINED;
-                        }
                     } else if (attachment == FramebufferAttachmentType::Depth ||
                                attachment == FramebufferAttachmentType::Stencil) {
                         currentLayout = m_swapchainObject.GetDepthStencilImageLayout(swapchainImageIndex);
-                        if (!m_swapchainObject.IsDepthStencilContentDefined(swapchainImageIndex)) {
-                            currentLayout = VK_IMAGE_LAYOUT_UNDEFINED;
-                        }
                     }
                 } else {
                     auto* textureResource = m_textureManager.SyncTextureAndGetDescriptor(*texture);
@@ -626,49 +617,14 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             combineFramebufferAttachmentObjHash(drawbuf);
         }
 
-        // The depth-less default-FBO flavor omits the depth/stencil attachment
-        // entirely, so it must hash differently from the depth-full flavor.
-        const Bool depthStencilIncluded = !isDefaultFbo || includeDefaultFboDepthStencil;
-        XXHASH_VERIFY(XXH64_update(m_hashState, &depthStencilIncluded, sizeof(depthStencilIncluded)));
-        if (depthStencilIncluded) {
-            combineFramebufferAttachmentObjHash(FramebufferAttachmentType::Depth);
-            combineFramebufferAttachmentObjHash(FramebufferAttachmentType::Stencil);
-        }
+        combineFramebufferAttachmentObjHash(FramebufferAttachmentType::Depth);
+        combineFramebufferAttachmentObjHash(FramebufferAttachmentType::Stencil);
 
         return XXH64_digest(m_hashState);
     }
 
     RenderPassEntry& VkRenderPassManager::GetOrCreateRenderPass(const MG_State::GLState::FramebufferObject& fbo,
-                                                                Uint32 swapchainImageIndex,
-                                                                Bool drawUsesDepthStencil) {
-        // Resolve the default-FBO depth flavor (see the header comment): keep the
-        // depth attachment when the caller needs it, when a depth/stencil clear is
-        // pending, or when the active pass already carries it (escalate-only, so
-        // alternating depth-less draws never split an established depth pass).
-        Bool includeDefaultFboDepthStencil = true;
-        if (fbo.IsDefaultFramebuffer()) {
-            Bool activeDefaultHasDepthStencil = false;
-            if (const auto* active = GetActiveRenderPass()) {
-                Bool activeIsSwapchainPass = false;
-                Bool activeHasSwapchainDepthStencil = false;
-                for (const auto& tracked : active->trackedAttachmentLayouts) {
-                    activeIsSwapchainPass |= tracked.target == TrackedAttachmentTarget::SwapchainColor;
-                    activeHasSwapchainDepthStencil |=
-                        tracked.target == TrackedAttachmentTarget::SwapchainDepthStencil;
-                }
-                activeDefaultHasDepthStencil = activeIsSwapchainPass && activeHasSwapchainDepthStencil;
-            }
-            const auto& defaultDepthAtt = fbo.GetAttachment(FramebufferAttachmentType::Depth);
-            const auto& defaultStencilAtt = fbo.GetAttachment(FramebufferAttachmentType::Stencil);
-            const Bool pendingDepthStencilClear =
-                (defaultDepthAtt.IsTexture() && m_clearManager.HasPendingClear(defaultDepthAtt)) ||
-                HasPendingRenderbufferClear(defaultDepthAtt) ||
-                (defaultStencilAtt.IsTexture() && m_clearManager.HasPendingClear(defaultStencilAtt)) ||
-                HasPendingRenderbufferClear(defaultStencilAtt);
-            includeDefaultFboDepthStencil =
-                drawUsesDepthStencil || activeDefaultHasDepthStencil || pendingDepthStencilClear;
-        }
-
+                                                                Uint32 swapchainImageIndex) {
         auto hasPendingClearOnFramebuffer = [&]() -> Bool {
             const auto& drawBuffers = fbo.GetDrawBuffers();
             for (auto attachment : drawBuffers) {
@@ -718,7 +674,6 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             m_rpFastFboVersion == fbo.GetObjectVersion() && m_rpFastSwapchainIndex == swapchainImageIndex &&
             m_rpFastTexEpoch == m_textureManager.GetTextureImageEpoch() &&
             m_rpFastRbEpoch == m_renderbufferImageEpoch &&
-            (!fbo.IsDefaultFramebuffer() || m_rpFastHadDepthStencil == includeDefaultFboDepthStencil) &&
             m_rpFastRenderPassHash == activeRenderPass->hash && !hasPendingClearOnFramebuffer()) {
             auto activeIt = m_renderPasses.find(activeRenderPass->hash);
             if (activeIt != m_renderPasses.end()) {
@@ -727,7 +682,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             }
         }
 
-        auto compatibilityHash = ComputeHash(fbo, swapchainImageIndex, false, includeDefaultFboDepthStencil);
+        auto compatibilityHash = ComputeHash(fbo, swapchainImageIndex, false);
         if (activeRenderPass != nullptr &&
             activeRenderPass->CompatibleWith(compatibilityHash) &&
             !hasPendingClearOnFramebuffer()) {
@@ -744,11 +699,10 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             m_rpFastTexEpoch = m_textureManager.GetTextureImageEpoch();
             m_rpFastRbEpoch = m_renderbufferImageEpoch;
             m_rpFastRenderPassHash = activeRenderPass->hash;
-            m_rpFastHadDepthStencil = activeIt->second.hasDepthStencilAttachment;
             activeIt->second.lastUsedFrame = m_frameCounter;
             return activeIt->second;
         }
-        auto hash = ComputeHash(fbo, swapchainImageIndex, true, includeDefaultFboDepthStencil);
+        auto hash = ComputeHash(fbo, swapchainImageIndex, true);
         auto it = m_renderPasses.find(hash);
         if (it != m_renderPasses.end()) {
             it->second.lastUsedFrame = m_frameCounter;
@@ -940,13 +894,6 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                         MOBILEGL_ASSERT(swapchainImageIndex < swapchainViews.size(),
                                         "GetOrCreateRenderPass: swapchain image index out of range");
                         trackedColorLayout = m_swapchainObject.GetImageLayout(swapchainImageIndex);
-                        // EGL: a presented color buffer's content is undefined when its
-                        // image comes back around (EGL_BUFFER_DESTROYED, the default
-                        // swap behaviour) - skip the tile load instead of reloading
-                        // stale pixels nobody may rely on.
-                        if (!hasClear && !m_swapchainObject.IsImageContentDefined(swapchainImageIndex)) {
-                            trackedColorLayout = VK_IMAGE_LAYOUT_UNDEFINED;
-                        }
                         trackedAttachmentLayouts.emplace_back(TrackedAttachmentLayoutInfo {
                             .target = TrackedAttachmentTarget::SwapchainColor,
                             .swapchainImageIndex = swapchainImageIndex,
@@ -1029,12 +976,6 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         };
         const auto* selectedDepthStencilAttachment = isUsableDepthStencilAttachment(depthAtt) ? &depthAtt :
                                                      (isUsableDepthStencilAttachment(stencilAtt) ? &stencilAtt : nullptr);
-        // Depth-less default-FBO flavor: nothing in this pass touches depth/stencil
-        // and their content is undefined anyway (EGL swap), so drop the attachment
-        // and its whole tile load + store.
-        if (isDefaultFbo && !includeDefaultFboDepthStencil) {
-            selectedDepthStencilAttachment = nullptr;
-        }
         const Bool hasDistinctDepthAndStencilAttachments =
             isUsableDepthStencilAttachment(depthAtt) && isUsableDepthStencilAttachment(stencilAtt) &&
             !sameDepthStencilAttachmentObject(depthAtt, stencilAtt);
@@ -1053,12 +994,6 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             VkImageLayout trackedDepthLayout = isDefaultFbo ?
                 m_swapchainObject.GetDepthStencilImageLayout(swapchainImageIndex) :
                 VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;
-            // EGL 1.5 §3.10.1: every ancillary (depth/stencil) buffer's content is
-            // undefined after a swap, so the first default-FBO pass of a frame can
-            // skip the depth/stencil tile load outright.
-            if (isDefaultFbo && !m_swapchainObject.IsDepthStencilContentDefined(swapchainImageIndex)) {
-                trackedDepthLayout = VK_IMAGE_LAYOUT_UNDEFINED;
-            }
             depthAttachmentDescription.flags = 0;
             VkSampleCountFlagBits depthAttachmentSampleCount = VK_SAMPLE_COUNT_1_BIT;
             Int depthAttachmentId = 0;
@@ -1187,22 +1122,6 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         }
         const Bool hasDepthStencilAttachment = depthAttachmentRef.attachment != VK_ATTACHMENT_UNUSED;
 
-        // Declare only the used colour-reference span. The GL draw-buffer array
-        // always spans 8 slots, so passes used to declare colorAttachmentCount=8
-        // with trailing VK_ATTACHMENT_UNUSED holes - and Adreno configures its
-        // per-pixel render-backend/export path from the DECLARED count, so every
-        // fragment of every pass paid the 8-target export cost (measured on
-        // Adreno 650 / MC 26.2: 11.9 -> 7.5 ms of GPU time per frame, with the
-        // single-quad swapchain blit pass alone dropping 1.26 -> 0.40 ms).
-        // Interior GL_NONE holes keep their slots so fragment-output locations
-        // still line up; a fragment output at a location past the trimmed count
-        // is discarded, which is exactly GL's semantic for writing to a draw
-        // buffer set to GL_NONE.
-        while (!colorAttachmentRefs.empty() &&
-               colorAttachmentRefs.back().attachment == VK_ATTACHMENT_UNUSED) {
-            colorAttachmentRefs.pop_back();
-        }
-
         // Subpass
         VkSubpassDescription subpassDesc;
         subpassDesc.flags = 0;
@@ -1411,17 +1330,6 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         renderPassBeginInfo.pClearValues = clearValues.data();
 
         vkCmdBeginRenderPass(commandBuffer, &renderPassBeginInfo, VK_SUBPASS_CONTENTS_INLINE);
-        // Pre-pass stream bookkeeping: this pass's attachment images are now
-        // referenced by the open frame recording.
-        if (s_textureManager != nullptr) {
-            for (const auto& tracked : renderPassEntry.trackedAttachmentLayouts) {
-                if (tracked.target == TrackedAttachmentTarget::Texture) {
-                    if (const auto texture = tracked.texture.lock()) {
-                        s_textureManager->StampTextureRecordingUse(texture.get());
-                    }
-                }
-            }
-        }
         for (const auto& pending: renderPassEntry.pendingClearAttachments) {
             if (pending.hasInlinePayload) {
                 if (s_renderPassManager != nullptr) {
@@ -1474,15 +1382,11 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                     case TrackedAttachmentTarget::SwapchainColor:
                         MOBILEGL_ASSERT(s_swapchainObject != nullptr, "EndRenderPass: swapchain object is null");
                         s_swapchainObject->SetImageLayout(trackedAttachment.swapchainImageIndex, trackedAttachment.finalLayout);
-                        // The pass stored into the attachment: its content is defined
-                        // until the image is next presented.
-                        s_swapchainObject->SetImageContentDefined(trackedAttachment.swapchainImageIndex, true);
                         break;
                     case TrackedAttachmentTarget::SwapchainDepthStencil:
                         MOBILEGL_ASSERT(s_swapchainObject != nullptr, "EndRenderPass: swapchain object is null");
                         s_swapchainObject->SetDepthStencilImageLayout(trackedAttachment.swapchainImageIndex,
                                                                       trackedAttachment.finalLayout);
-                        s_swapchainObject->SetDepthStencilContentDefined(trackedAttachment.swapchainImageIndex, true);
                         break;
                     default:
                         MOBILEGL_ASSERT(false, "EndRenderPass: unsupported tracked attachment target=%d",

MobileGL/MG_Backend/DirectVulkan/Renderer/VkRenderPassManager.h

@@ -188,22 +188,8 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         HashType ComputeHash(
             const MG_State::GLState::FramebufferObject& fbo,
             Uint32 swapchainImageIndex,
-            Bool includePendingClear = true,
-            Bool includeDefaultFboDepthStencil = true);
-        // drawUsesDepthStencil: whether the operation about to run inside the pass
-        // reads or writes the depth/stencil buffer (depth test or stencil test
-        // enabled, or a depth/stencil clear). Only consulted for the DEFAULT
-        // framebuffer: EGL undefines its ancillary buffers at every swap, so a
-        // default-FBO pass whose draws provably never touch depth/stencil is
-        // created WITHOUT the depth attachment - on a tiler that skips the whole
-        // depth tile load AND store. The flavor only escalates: once a pass with
-        // depth is active, later depth-less draws keep using it, and a depth-using
-        // draw against a depth-less active pass resolves to a new (incompatible)
-        // entry, which the caller's compatibility check turns into a pass split;
-        // the new pass's depth loads DONT_CARE (content was undefined all along).
-        RenderPassEntry& GetOrCreateRenderPass(const MG_State::GLState::FramebufferObject& fbo,
-                                               Uint32 swapchainImageIndex,
-                                               Bool drawUsesDepthStencil = true);
+            Bool includePendingClear = true);
+        RenderPassEntry& GetOrCreateRenderPass(const MG_State::GLState::FramebufferObject& fbo, Uint32 swapchainImageIndex);
         void QueueRenderbufferClear(GLbitfield mask, const ClearFramebufferPayload& clearPayload,
                                     const MG_State::GLState::FramebufferObject& drawFbo);
         void QueueRenderbufferClear(const ClearAttachmentPayload& clearPayload,
@@ -245,10 +231,6 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         Uint64 m_rpFastTexEpoch = 0;
         Uint64 m_rpFastRbEpoch = 0;
         Uint64 m_rpFastRenderPassHash = 0;
-        // Whether the memoized entry carries a depth/stencil attachment; a
-        // default-FBO resolution whose effective depth request differs must
-        // miss the memo (the depth-less/depth-full flavors hash differently).
-        Bool m_rpFastHadDepthStencil = false;
 
     public:
         struct RenderbufferResource {

MobileGL/MG_Backend/DirectVulkan/Renderer/VkTextureManager.cpp

@@ -1049,16 +1049,6 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         return view;
     }
 
-    void VkTextureManager::StampTextureRecordingUse(MG_State::GLState::ITextureObject* texture) {
-        if (texture == nullptr) {
-            return;
-        }
-        auto it = m_textureResources.find(MakeTextureIdentity(texture));
-        if (it != m_textureResources.end()) {
-            it->second.lastRecordingGeneration = m_recordingGeneration;
-        }
-    }
-
     void VkTextureManager::UpdateTrackedImageLayout(MG_State::GLState::ITextureObject* texture, VkImageLayout newLayout) {
         MOBILEGL_ASSERT(texture != nullptr, "UpdateTrackedImageLayout: texture is null");
         auto it = m_textureResources.find(MakeTextureIdentity(texture));
@@ -1086,8 +1076,6 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         MOBILEGL_ASSERT(writtenMipLevel < resource.mipLevels,
                         "UpdateTrackedImageLayoutAfterAttachmentWrite: textureId=%d mipLevel=%u out of range %u",
                         texture->GetExternalIndex(), writtenMipLevel, resource.mipLevels);
-        // Pre-pass stream bookkeeping: the render pass that just ended wrote this image.
-        StampResourceRecordingUse(resource);
 
         if (resource.layout != newLayout && resource.mipLevels > 1) {
             VkPipelineStageFlags srcStageMask = VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT;
@@ -1172,8 +1160,6 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                                               VK_ACCESS_SHADER_READ_BIT, resource->aspect, 0, resource->mipLevels,
                                               resource->arrayLayers);
         MOBILEGL_ASSERT(ok, "TransitionTextureForSampling: transition failed for textureId=%d", texture.GetExternalIndex());
-        // Pre-pass stream bookkeeping: a command referencing the image was recorded.
-        StampResourceRecordingUse(*resource);
         return ok;
     }
 
@@ -1203,8 +1189,6 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                                               resource->aspect, 0, resource->mipLevels, resource->arrayLayers);
         MOBILEGL_ASSERT(ok, "TransitionTextureForStorageImage: transition failed for textureId=%d",
                         texture.GetExternalIndex());
-        // Pre-pass stream bookkeeping: a command referencing the image was recorded.
-        StampResourceRecordingUse(*resource);
         return ok;
     }
 
@@ -1436,17 +1420,8 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             return false;
         }
         const Bool isMultisampleTexture = IsMultisampleTextureUploadTarget(uploadTarget);
-        // A texture that has only ever defined level 0 gets a single-level backing
-        // (ANGLE's model). Preallocating the full chain put every render target
-        // onto Adreno's multi-mip image layout and grew each texture by a third
-        // for levels most textures never define. Once a second level is defined
-        // the backing is recreated ONE time with the full chain (the
-        // preserve-copy path below carries the pixels over), so sequentially-
-        // defined atlas mips do not recreate per level, and glGenerateMipmap -
-        // which defines every level before syncing - works unchanged.
         const Uint32 backingMipLevels =
-            isMultisampleTexture ? 1u
-            : (mipLevels > 1 ? std::max(mipLevels, ComputeFullMipLevelCount(texelSize)) : 1u);
+            isMultisampleTexture ? 1u : std::max(mipLevels, ComputeFullMipLevelCount(texelSize));
         TextureShapeInfo shapeInfo{};
         const Bool supportedShape = TryResolveTextureShapeInfo(texture, uploadTarget, texelSize, shapeInfo);
         MOBILEGL_ASSERT(supportedShape,

MobileGL/MG_Backend/DirectVulkan/Renderer/VkTextureManager.h

@@ -172,13 +172,6 @@ public:
         // NeedsStorageImagePreparation cannot ask for a recreate that will never happen.
         Bool storageUsageResolved = false;
         Uint16 syncedTextureParamsVersion = 0;
-        // Recording generation (VkTextureManager::GetRecordingGeneration) of the last
-        // command referencing this image that was recorded into the CURRENT frame
-        // command buffer. An image untouched by the open recording may have its
-        // out-of-pass work (deferred clears, sampled-layout transitions) recorded
-        // into the frame's PRE command buffer - which executes strictly before the
-        // frame's commands - instead of splitting the active render pass.
-        Uint64 lastRecordingGeneration = 0;
         // Snapshot of ITextureObject::GetContentVersion() at the last successful sync;
         // lets SyncTexture skip the whole re-check/re-upload when content is unchanged.
         Uint64 syncedContentVersion = 0;
@@ -214,7 +207,6 @@ public:
             std::swap(this->usageFlags, that.usageFlags);
             std::swap(this->storageUsageResolved, that.storageUsageResolved);
             std::swap(this->syncedTextureParamsVersion, that.syncedTextureParamsVersion);
-            std::swap(this->lastRecordingGeneration, that.lastRecordingGeneration);
             std::swap(this->syncedContentVersion, that.syncedContentVersion);
             std::swap(this->syncedMipLevelCount, that.syncedMipLevelCount);
         }
@@ -315,21 +307,6 @@ public:
                                                       VkImageLayout newLayout);
     Bool TransitionTextureForSampling(VkCommandBuffer commandBuffer, MG_State::GLState::ITextureObject& texture);
     Bool TransitionTextureForStorageImage(VkCommandBuffer commandBuffer, MG_State::GLState::ITextureObject& texture);
-
-    // Recording-generation bookkeeping for the pre-pass command stream. The
-    // generation advances every time the frame command buffer (re)begins
-    // recording; a resource whose stamp does not match was not referenced by
-    // any command in the open recording, so its out-of-pass work may safely
-    // execute ahead of the whole recording (in the pre command buffer).
-    void AdvanceRecordingGeneration() { ++m_recordingGeneration; }
-    void StampResourceRecordingUse(TextureResource& resource) const {
-        resource.lastRecordingGeneration = m_recordingGeneration;
-    }
-    // Map-lookup variant for callers that only hold the GL texture object.
-    void StampTextureRecordingUse(MG_State::GLState::ITextureObject* texture);
-    Bool WasTouchedThisRecording(const TextureResource& resource) const {
-        return resource.lastRecordingGeneration == m_recordingGeneration;
-    }
     // Records that this texture is bound to a GL image unit, so its image must carry
     // VK_IMAGE_USAGE_STORAGE_BIT. Must be called before NeedsStorageImagePreparation, and
     // therefore before the render pass is committed: an image that has to be upgraded is
@@ -387,9 +364,6 @@ public:
 private:
     // Bumped in SyncTextureResource right after vmaCreateImage(texture). See GetTextureImageEpoch().
     Uint64 m_textureImageEpoch = 1;
-    // See AdvanceRecordingGeneration. Starts above every resource's default
-    // stamp of 0 so a fresh resource counts as untouched.
-    Uint64 m_recordingGeneration = 1;
 
     Bool SyncTexture(MG_State::GLState::ITextureObject &texture,
                      TextureResource &outResource);

MobileGL/MG_Backend/DirectVulkan/Renderer/VulkanRenderer.cpp

@@ -217,53 +217,6 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         return static_cast<Int>((static_cast<Int64>(value) * toExtent + fromExtent / 2) / fromExtent);
     }
 
-    // Redundant dynamic-state elimination for the per-draw hot path: within one
-    // command-buffer recording, a vkCmdSet* whose values already match what the
-    // command buffer holds is skipped. Valid because every PipelineFactory
-    // pipeline declares the same eight dynamic states, so the values persist
-    // across those pipeline binds; the shadow resets whenever a recording
-    // (re)begins, and whenever an auxiliary pipeline with a narrower dynamic
-    // set (blit, depth-mipmap) binds - their static state makes the
-    // corresponding dynamic values undefined per the spec.
-    struct DynamicStateShadow {
-        Bool viewportValid = false;
-        VkViewport viewport{};
-        Bool scissorValid = false;
-        VkRect2D scissor{};
-        Bool blendConstantsValid = false;
-        Float blendConstants[4] = {0.0f, 0.0f, 0.0f, 0.0f};
-        Bool depthBiasValid = false;
-        Float depthBiasConstantFactor = 0.0f;
-        Float depthBiasSlopeFactor = 0.0f;
-        Bool lineWidthValid = false;
-        Float lineWidth = 0.0f;
-        Bool stencilValid = false;
-        Uint32 stencilFrontCompareMask = 0;
-        Uint32 stencilBackCompareMask = 0;
-        Uint32 stencilFrontWriteMask = 0;
-        Uint32 stencilBackWriteMask = 0;
-        Uint32 stencilFrontReference = 0;
-        Uint32 stencilBackReference = 0;
-    };
-    static DynamicStateShadow g_dynamicStateShadow;
-
-    static void ResetDynamicStateShadow() {
-        g_dynamicStateShadow = {};
-    }
-
-    static void ShadowedSetScissor(VkCommandBuffer commandBuffer, const VkRect2D& scissor) {
-        auto& shadow = g_dynamicStateShadow;
-        if (shadow.scissorValid && shadow.scissor.offset.x == scissor.offset.x &&
-            shadow.scissor.offset.y == scissor.offset.y &&
-            shadow.scissor.extent.width == scissor.extent.width &&
-            shadow.scissor.extent.height == scissor.extent.height) {
-            return;
-        }
-        shadow.scissorValid = true;
-        shadow.scissor = scissor;
-        vkCmdSetScissor(commandBuffer, 0, 1, &scissor);
-    }
-
     static void ApplyGLViewportState(VkCommandBuffer commandBuffer,
                                      const IntVec2& framebufferExtent,
                                      VkSurfaceTransformFlagBitsKHR preTransform,
@@ -293,14 +246,6 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         viewport.height = static_cast<float>(viewportHeight);
         viewport.minDepth = depthRange.x();
         viewport.maxDepth = depthRange.y();
-        auto& shadow = g_dynamicStateShadow;
-        if (shadow.viewportValid && shadow.viewport.x == viewport.x && shadow.viewport.y == viewport.y &&
-            shadow.viewport.width == viewport.width && shadow.viewport.height == viewport.height &&
-            shadow.viewport.minDepth == viewport.minDepth && shadow.viewport.maxDepth == viewport.maxDepth) {
-            return;
-        }
-        shadow.viewportValid = true;
-        shadow.viewport = viewport;
         vkCmdSetViewport(commandBuffer, 0, 1, &viewport);
     }
 
@@ -312,17 +257,6 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             blendColor.z(),
             blendColor.w(),
         };
-        auto& shadow = g_dynamicStateShadow;
-        if (shadow.blendConstantsValid && shadow.blendConstants[0] == blendConstants[0] &&
-            shadow.blendConstants[1] == blendConstants[1] && shadow.blendConstants[2] == blendConstants[2] &&
-            shadow.blendConstants[3] == blendConstants[3]) {
-            return;
-        }
-        shadow.blendConstantsValid = true;
-        shadow.blendConstants[0] = blendConstants[0];
-        shadow.blendConstants[1] = blendConstants[1];
-        shadow.blendConstants[2] = blendConstants[2];
-        shadow.blendConstants[3] = blendConstants[3];
         vkCmdSetBlendConstants(commandBuffer, blendConstants);
     }
 
@@ -338,17 +272,8 @@ namespace MobileGL::MG_Backend::DirectVulkan {
     }
 
     static void ApplyPolygonOffsetState(VkCommandBuffer commandBuffer) {
-        const Float constantFactor = MG_State::pGLContext->GetPolygonOffsetUnits();
-        const Float slopeFactor = MG_State::pGLContext->GetPolygonOffsetFactor();
-        auto& shadow = g_dynamicStateShadow;
-        if (shadow.depthBiasValid && shadow.depthBiasConstantFactor == constantFactor &&
-            shadow.depthBiasSlopeFactor == slopeFactor) {
-            return;
-        }
-        shadow.depthBiasValid = true;
-        shadow.depthBiasConstantFactor = constantFactor;
-        shadow.depthBiasSlopeFactor = slopeFactor;
-        vkCmdSetDepthBias(commandBuffer, constantFactor, 0.0f, slopeFactor);
+        vkCmdSetDepthBias(commandBuffer, MG_State::pGLContext->GetPolygonOffsetUnits(), 0.0f,
+                          MG_State::pGLContext->GetPolygonOffsetFactor());
     }
 
     static void ApplyLineWidthState(VkCommandBuffer commandBuffer) {
@@ -363,12 +288,6 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 lineWidth = maxLineWidth;
             }
         }
-        auto& shadow = g_dynamicStateShadow;
-        if (shadow.lineWidthValid && shadow.lineWidth == lineWidth) {
-            return;
-        }
-        shadow.lineWidthValid = true;
-        shadow.lineWidth = lineWidth;
         vkCmdSetLineWidth(commandBuffer, lineWidth);
     }
 
@@ -417,31 +336,15 @@ namespace MobileGL::MG_Backend::DirectVulkan {
     static void ApplyStencilState(VkCommandBuffer commandBuffer) {
         const StencilFaceState& frontStencil = MG_State::pGLContext->GetStencilState(StencilFace::Front);
         const StencilFaceState& backStencil = MG_State::pGLContext->GetStencilState(StencilFace::Back);
-        const Uint32 frontReference = static_cast<Uint32>(std::max(frontStencil.Ref, 0));
-        const Uint32 backReference = static_cast<Uint32>(std::max(backStencil.Ref, 0));
-
-        auto& shadow = g_dynamicStateShadow;
-        if (shadow.stencilValid && shadow.stencilFrontCompareMask == frontStencil.ValueMask &&
-            shadow.stencilBackCompareMask == backStencil.ValueMask &&
-            shadow.stencilFrontWriteMask == frontStencil.WriteMask &&
-            shadow.stencilBackWriteMask == backStencil.WriteMask &&
-            shadow.stencilFrontReference == frontReference && shadow.stencilBackReference == backReference) {
-            return;
-        }
-        shadow.stencilValid = true;
-        shadow.stencilFrontCompareMask = frontStencil.ValueMask;
-        shadow.stencilBackCompareMask = backStencil.ValueMask;
-        shadow.stencilFrontWriteMask = frontStencil.WriteMask;
-        shadow.stencilBackWriteMask = backStencil.WriteMask;
-        shadow.stencilFrontReference = frontReference;
-        shadow.stencilBackReference = backReference;
 
         vkCmdSetStencilCompareMask(commandBuffer, VK_STENCIL_FACE_FRONT_BIT, frontStencil.ValueMask);
         vkCmdSetStencilCompareMask(commandBuffer, VK_STENCIL_FACE_BACK_BIT, backStencil.ValueMask);
         vkCmdSetStencilWriteMask(commandBuffer, VK_STENCIL_FACE_FRONT_BIT, frontStencil.WriteMask);
         vkCmdSetStencilWriteMask(commandBuffer, VK_STENCIL_FACE_BACK_BIT, backStencil.WriteMask);
-        vkCmdSetStencilReference(commandBuffer, VK_STENCIL_FACE_FRONT_BIT, frontReference);
-        vkCmdSetStencilReference(commandBuffer, VK_STENCIL_FACE_BACK_BIT, backReference);
+        vkCmdSetStencilReference(commandBuffer, VK_STENCIL_FACE_FRONT_BIT,
+                                 static_cast<Uint32>(std::max(frontStencil.Ref, 0)));
+        vkCmdSetStencilReference(commandBuffer, VK_STENCIL_FACE_BACK_BIT,
+                                 static_cast<Uint32>(std::max(backStencil.Ref, 0)));
     }
 
     enum class NumericDomain {
@@ -3750,10 +3653,6 @@ void main() {
             vkCmdSetScissor(frame.commandBuffer, 0, 1, &scissor);
 
             vkCmdBindPipeline(frame.commandBuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, pipeline);
-            // The depth-mipmap pipeline's narrower dynamic set (viewport/scissor
-            // only) leaves the other dynamic states undefined; its raw scissor
-            // and viewport writes also bypass the shadow.
-            ResetDynamicStateShadow();
 
             std::fill(depthProgramData,
                       depthProgramData + m_depthMipmapResources.program->GetUBOSize(),
@@ -4041,15 +3940,12 @@ void main() {
             payload.backStencilCompareOp = VK_COMPARE_OP_ALWAYS;
         }
         const Uint32 fragmentOutputMask = programObj.activeFragmentOutputLocationMask;
-        // Outputs at locations past the render pass's trimmed colour span are
-        // simply discarded - GL's semantic for a fragment output whose draw
-        // buffer is GL_NONE (the trailing UNUSED slots no longer occupy
-        // references, see GetOrCreateRenderPass).
-        if ((fragmentOutputMask >> payload.colorAttachmentCount) != 0) {
-            MGLOG_D("GetOrCreatePipeline: fragmentOutputMask=0x%x exceeds colorAttachmentCount=%u for program=%u; "
-                    "outputs past the span are discarded",
-                    fragmentOutputMask, payload.colorAttachmentCount, program.GetExternalIndex());
-        }
+        MOBILEGL_ASSERT(
+            (fragmentOutputMask >> payload.colorAttachmentCount) == 0,
+            "GetOrCreatePipeline: fragmentOutputMask=0x%x exceeds colorAttachmentCount=%u for program=%u",
+            fragmentOutputMask,
+            payload.colorAttachmentCount,
+            program.GetExternalIndex());
         MOBILEGL_ASSERT(payload.colorAttachmentCount <= PipelineFactory::PipelineCreatePayload::kMaxColorAttachments,
                         "GetOrCreatePipeline: colorAttachmentCount=%u exceeds payload capacity",
                         payload.colorAttachmentCount);
@@ -4419,6 +4315,15 @@ void main() {
             transformFlags |= ProgramFactory::CompileOptionBit::ExplicitLod0Sampling;
             programObjPtr = &m_programFactory->GetOrCreateProgram(program, transformFlags);
         }
+        // fp16 fragment arithmetic is only sound when nothing this draw reads or writes carries
+        // more than 8 normalized bits per channel. A shaderpack's HDR gbuffer, or a data texture
+        // holding positions, must keep full precision - and SPIR-V cannot tell, since sampler2D
+        // yields vec4 whatever the bound format is, so the decision has to be made here.
+        if (UniformManager::ProgramSamplesOnlyLowPrecisionTextures(program, *programObjPtr) &&
+            UniformManager::DrawTargetIsLowPrecision(drawFbo.get())) {
+            transformFlags |= ProgramFactory::CompileOptionBit::RelaxedFragmentPrecision;
+            programObjPtr = &m_programFactory->GetOrCreateProgram(program, transformFlags);
+        }
         const auto& programObj = *programObjPtr;
 
         // Begin command recording if not yet
@@ -4501,30 +4406,8 @@ void main() {
                     static_cast<Int>(textureResource->layout));
             if (m_clearManager->HasPendingClear(sampledTexture) ||
                 !IsValidSampledImageLayout(textureResource->layout)) {
-                // Out-of-pass work is needed (deferred clear materialization or
-                // a sampled-layout transition). When the open frame recording
-                // has not referenced this image yet, that work can execute
-                // ahead of the WHOLE recording - record it into the pre-pass
-                // stream instead of splitting the active render pass (ANGLE's
-                // outside-render-pass command stream, restricted to the
-                // provably reorderable case).
-                if (activeRenderPass != nullptr &&
-                    !m_frameContext.GetCurrent().hasPreCommandBufferRecorded &&
-                    !m_textureManager->WasTouchedThisRecording(*textureResource)) {
-                    VkCommandBuffer preCommandBuffer = m_frameContext.BeginPreCommandRecording();
-                    const Bool preClearReady =
-                        MaterializePendingClearForTexture(preCommandBuffer, *sampledTexture);
-                    MOBILEGL_ASSERT(preClearReady,
-                                    "%s: pre-pass MaterializePendingClearForTexture failed for textureId=%d",
-                                    __func__, sampledTexture->GetExternalIndex());
-                    const Bool preTransitionReady =
-                        m_textureManager->TransitionTextureForSampling(preCommandBuffer, *sampledTexture);
-                    MOBILEGL_ASSERT(preTransitionReady,
-                                    "%s: pre-pass TransitionTextureForSampling failed for textureId=%d",
-                                    __func__, sampledTexture->GetExternalIndex());
-                    continue;
-                }
                 needSampledTextureTransitions = true;
+                break;
             }
         }
 
@@ -4548,28 +4431,16 @@ void main() {
             MOBILEGL_ASSERT(transitionedResource != nullptr,
                             "%s: post-transition SyncTextureAndGetDescriptor failed for textureId=%d",
                             __func__, sampledTexture->GetExternalIndex());
-            // Pre-pass stream bookkeeping: the draw about to be recorded reads
-            // this image, so later out-of-pass work on it can no longer jump
-            // ahead of the recording.
-            m_textureManager->StampResourceRecordingUse(*transitionedResource);
             MGLOG_D("SetupDraw: sampled textureId=%d layout(after)=%s(%d)",
                     sampledTexture->GetExternalIndex(), VkImageLayoutToString(transitionedResource->layout),
                     static_cast<Int>(transitionedResource->layout));
         }
 
-        // Depth/stencil participation of THIS draw, for the default-FBO depth-less
-        // pass flavor (GL: a disabled depth/stencil test neither reads nor writes
-        // its buffer).
-        const Bool drawUsesDepthStencil =
-            MG_State::pGLContext->IsCapabilityEnabled(CapabilityInput::DepthTest) ||
-            MG_State::pGLContext->IsCapabilityEnabled(CapabilityInput::StencilTest);
-        auto* renderPassEntry =
-            &m_renderPassManager->GetOrCreateRenderPass(*drawFbo, m_imageIndexAcquired, drawUsesDepthStencil);
+        auto* renderPassEntry = &m_renderPassManager->GetOrCreateRenderPass(*drawFbo, m_imageIndexAcquired);
         if (activeRenderPass && !activeRenderPass->CompatibleWith(*renderPassEntry)) {
             VkRenderPassManager::EndRenderPass(frame.commandBuffer);
             activeRenderPass = nullptr;
-            renderPassEntry =
-                &m_renderPassManager->GetOrCreateRenderPass(*drawFbo, m_imageIndexAcquired, drawUsesDepthStencil);
+            renderPassEntry = &m_renderPassManager->GetOrCreateRenderPass(*drawFbo, m_imageIndexAcquired);
         }
         if (renderPassEntry->attachmentCount == 0 || renderPassEntry->extent.x() <= 0 || renderPassEntry->extent.y() <= 0) {
             MGLOG_D("SetupDraw skipped: drawFbo=%u resolved to an empty render pass (attachmentCount=%u extent=%dx%d)",
@@ -4669,7 +4540,7 @@ void main() {
             scissor.offset = {0, 0};
             scissor.extent = { (Uint)renderPassEntry->extent.x(), (Uint)renderPassEntry->extent.y() };
         }
-        ShadowedSetScissor(frame.commandBuffer, scissor);
+        vkCmdSetScissor(frame.commandBuffer, 0, 1, &scissor);
         return true;
     }
 
@@ -5360,12 +5231,8 @@ void main() {
         if (!m_clearManager->GetPendingClears(&texture, pendingClears)) {
             return true;
         }
-        // A pass may stay open on the FRAME command buffer while this clear is
-        // recorded into the pre-pass stream (a different command buffer that
-        // executes strictly before the frame's commands).
-        MOBILEGL_ASSERT(VkRenderPassManager::GetActiveRenderPass() == nullptr ||
-                            commandBuffer != m_frameContext.GetCurrent().commandBuffer,
-                        "MaterializePendingClearForTexture requires no active render pass on the target buffer");
+        MOBILEGL_ASSERT(VkRenderPassManager::GetActiveRenderPass() == nullptr,
+                        "MaterializePendingClearForTexture requires no active render pass");
 
         auto* resource = m_textureManager->SyncTextureAndGetDescriptor(texture);
         MOBILEGL_ASSERT(resource != nullptr,
@@ -5595,10 +5462,7 @@ void main() {
                         "TryBlitToDefaultFramebufferWithShader: failed to create sampled view for textureId=%d mip=%u",
                         sourceTexture->GetExternalIndex(), srcBinding.mipLevel);
 
-        // A color-only blit never touches depth/stencil: let the default-FBO pass
-        // it opens skip the depth attachment (depth-less flavor).
-        auto& renderPassEntry =
-            m_renderPassManager->GetOrCreateRenderPass(drawFbo, m_imageIndexAcquired, /*drawUsesDepthStencil=*/false);
+        auto& renderPassEntry = m_renderPassManager->GetOrCreateRenderPass(drawFbo, m_imageIndexAcquired);
         const Bool ok = VkRenderPassManager::BeginRenderPass(frame.commandBuffer, renderPassEntry);
         MOBILEGL_ASSERT(ok, "%s: BeginRenderPass failed", __func__);
 
@@ -5614,10 +5478,6 @@ void main() {
         const VkPipeline pipeline = GetOrCreateBlitPipeline(renderPassEntry);
         MOBILEGL_ASSERT(pipeline != VK_NULL_HANDLE, "TryBlitToDefaultFramebufferWithShader: blit pipeline is null");
         vkCmdBindPipeline(frame.commandBuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, pipeline);
-        // The blit pipeline's narrower dynamic set (viewport/scissor only)
-        // leaves the other dynamic states undefined; its raw viewport/scissor
-        // writes also bypass the shadow.
-        ResetDynamicStateShadow();
 
         auto* blitProgramData = static_cast<Uint8*>(m_blitResources.program->MapUBO());
         MOBILEGL_ASSERT(blitProgramData != nullptr, "TryBlitToDefaultFramebufferWithShader: blit UBO is null");
@@ -6414,11 +6274,7 @@ void main() {
             frame.hasCommandBufferRecorded = true;
             m_lastPipelineValid = false; // command-buffer boundary: drop the pipeline memo
         }
-        // The pre-pass stream must never be submitted later than the recording
-        // it was paired with (frame commands recorded after a pre-pass move
-        // rely on the moved work having executed first).
-        m_frameContext.EndPreCommandRecordingIfOpen();
-        if (!frame.hasCommandBufferRecorded && !frame.hasPreCommandBufferRecorded) {
+        if (!frame.hasCommandBufferRecorded) {
             return true;
         }
 
@@ -7553,18 +7409,8 @@ void main() {
             submitInfo.pWaitSemaphores = &waitSemaphore;
             submitInfo.pWaitDstStageMask = &waitDstStageMask;
         }
-        // The pre-pass stream, when recorded, executes strictly before the
-        // frame's commands within the same submission.
-        VkCommandBuffer commandBuffers[2] = {VK_NULL_HANDLE, VK_NULL_HANDLE};
-        Uint32 commandBufferCount = 0;
-        if (frame.hasPreCommandBufferRecorded) {
-            commandBuffers[commandBufferCount++] = frame.preCommandBuffer;
-        }
-        if (frame.hasCommandBufferRecorded) {
-            commandBuffers[commandBufferCount++] = frame.commandBuffer;
-        }
-        submitInfo.commandBufferCount = commandBufferCount;
-        submitInfo.pCommandBuffers = commandBuffers;
+        submitInfo.commandBufferCount = 1;
+        submitInfo.pCommandBuffers = &frame.commandBuffer;
         const VkResult result = vkQueueSubmit(m_graphicsQueue, 1, &submitInfo, fence);
         if (result != VK_SUCCESS) {
             MGLOG_E("SubmitPendingCommandBuffer: vkQueueSubmit returned %d", result);
@@ -7572,7 +7418,6 @@ void main() {
         }
         frame.imageAvailableSemaphoreConsumed = true;
         frame.hasCommandBufferRecorded = false;
-        frame.hasPreCommandBufferRecorded = false;
         RegisterSubmit(fence, pooledFence);
         frame.lastSubmitIndex = m_submitCounter;
         return true;
@@ -7603,8 +7448,6 @@ void main() {
             }
             m_frameContext.EndCommandRecording();
         }
-        m_frameContext.EndPreCommandRecordingIfOpen();
-        const Bool submittingPreCommandBuffer = frame.hasPreCommandBufferRecorded;
         if (!SubmitPendingCommandBuffer(frame, fence, /*pooledFence=*/true)) {
             // Submit failure (device loss regime): the ended command buffer
             // stays marked recorded so Present can still try to submit it.
@@ -7623,7 +7466,7 @@ void main() {
         // The submitted command buffer may still be executing; recording must
         // restart on a fresh one. If none can be allocated, fall back to
         // draining this submission so reusing the buffer stays legal.
-        const VkResult retireResult = m_frameContext.RetireCurrentCommandBuffer(submittingPreCommandBuffer);
+        const VkResult retireResult = m_frameContext.RetireCurrentCommandBuffer();
         if (retireResult != VK_SUCCESS) {
             MGLOG_E("FlushPendingCommands: RetireCurrentCommandBuffer returned %d; draining submission", retireResult);
             if (vkWaitForFences(m_device, 1, &fence, VK_TRUE, UINT64_MAX) == VK_SUCCESS) {
@@ -7689,13 +7532,6 @@ void main() {
     }
 
     void VulkanRenderer::OnFrameCommandRecordingBegan(VkCommandBuffer commandBuffer) {
-        // Dynamic state does not survive a command-buffer boundary.
-        ResetDynamicStateShadow();
-        // Pre-pass stream bookkeeping: a fresh frame recording references no
-        // textures yet.
-        if (m_textureManager) {
-            m_textureManager->AdvanceRecordingGeneration();
-        }
         if (m_timerQueryManager) {
             m_timerQueryManager->OnFrameCommandRecordingBegan(commandBuffer, m_frameContext.GetCurrentFrameIndex(),
                                                               m_bufferManager.GetFrameSerial());
@@ -7768,7 +7604,6 @@ void main() {
                 if (suspendedFrame.isCommandRecording) {
                     m_frameContext.EndCommandRecording();
                 }
-                m_frameContext.AbandonPreCommandRecording();
                 suspendedFrame.isCommandRecording = false;
                 suspendedFrame.hasCommandBufferRecorded = false;
                 m_lastPipelineValid = false;
@@ -7833,19 +7668,16 @@ void main() {
             frame.hasCommandBufferRecorded = true;
             m_lastPipelineValid = false; // command-buffer boundary: drop the pipeline memo
         }
-        m_frameContext.EndPreCommandRecordingIfOpen();
 
         const Bool shouldSubmitCommandBuffer = frame.hasCommandBufferRecorded;
 
-        // 1) Submit current frame work (the pre-pass stream, when recorded,
-        //    rides the same submission strictly ahead of the frame commands).
+        // 1) Submit current frame work.
         auto submitPacket = m_frameContext.GetSubmitInfo(shouldSubmitCommandBuffer, m_imageIndexAcquired);
         VK_VERIFY(vkQueueSubmit(m_graphicsQueue, 1, &submitPacket.submitInfo, frame.imageInFlightFence));
         RegisterSubmit(frame.imageInFlightFence, /*pooledFence=*/false);
         frame.lastSubmitIndex = m_submitCounter;
         frame.isCommandRecording = false;
         frame.hasCommandBufferRecorded = false;
-        frame.hasPreCommandBufferRecorded = false;
         m_swapchainObject.SetImageLayout(m_imageIndexAcquired, VK_IMAGE_LAYOUT_PRESENT_SRC_KHR);
 
         // 2) Present current frame.
@@ -7873,13 +7705,6 @@ void main() {
             result = VK_SUCCESS;
         }
         VK_VERIFY(result, "Present, vkQueuePresentKHR");
-        // EGL swap semantics: the presented color buffer's content is undefined the
-        // next time this image is acquired (EGL_BUFFER_DESTROYED, the default swap
-        // behaviour), and EVERY ancillary depth/stencil buffer's content is
-        // undefined after any swap. The render-pass manager turns the undefined
-        // attachments' next tile loads into LOAD_OP_DONT_CARE.
-        m_swapchainObject.SetImageContentDefined(m_imageIndexAcquired, false);
-        m_swapchainObject.SetAllDepthStencilContentUndefined();
         // The authoritative check, done here - after the frame is presented, before the next
         // acquire. This is what makes a launcher-side resolution change take effect: shrinking
         // the window's buffer (SurfaceHolder.setFixedSize) moves currentExtent, the swapchain
@@ -8839,10 +8664,6 @@ void main() {
         if (m_frameContext.GetFrameCount() > 0) {
             m_frameContext.GetCurrent().isCommandRecording = false;
             m_frameContext.GetCurrent().hasCommandBufferRecorded = false;
-            // The pre-pass stream paired with the abandoned recording is
-            // dropped with it (its next Begin resets the buffer).
-            m_frameContext.GetCurrent().isPreCommandRecording = false;
-            m_frameContext.GetCurrent().hasPreCommandBufferRecorded = false;
         }
         const Bool okArena = m_bufferManager.RecreateTransientArenas(m_frameContext.GetFrameCount());
         MOBILEGL_ASSERT(okArena, "RecreateSwapchain: buffer manager transient arena initialization failed");