From 2f5c7562c2aa6d889b5439439ef74e085943938a Mon Sep 17 00:00:00 2001
From: Philip Rebohle <philip.rebohle@tu-dortmund.de>
Date: Mon, 23 Aug 2021 16:36:39 +0200
Subject: [PATCH] [dxvk] Track transform feedback counter hazards properly

If we avoid needlessly pausing and resuming transform feedback with the
same counters, we can use existing barrier tracking to insert counter
barriers without requiring an invalid render pass self-dependency.
---
 src/dxvk/dxvk_context.cpp     | 31 ++++++++++++-------------------
 src/dxvk/dxvk_context_state.h |  1 -
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/dxvk/dxvk_context.cpp b/src/dxvk/dxvk_context.cpp
index 526ab3083..ce21a242b 100644
--- a/src/dxvk/dxvk_context.cpp
+++ b/src/dxvk/dxvk_context.cpp
@@ -2146,10 +2146,10 @@ namespace dxvk {
     DxvkCmdBuffer         cmdBuffer;
 
     if (replaceBuffer) {
-      // Pause transform feedback so that we don't mess
-      // with the currently bound counter buffers
+      // Suspend render pass so that we don't mess with the
+      // currently bound transform feedback counter buffers
       if (m_flags.test(DxvkContextFlag::GpXfbActive))
-        this->pauseTransformFeedback();
+        this->spillRenderPass(true);
 
       // As an optimization, allocate a free slice and perform
       // the copy in the initialization command buffer instead
@@ -3925,8 +3925,6 @@ namespace dxvk {
       m_gfxBarriers.recordCommands(m_cmd);
 
       this->unbindGraphicsPipeline();
-
-      m_flags.clr(DxvkContextFlag::GpDirtyXfbCounters);
     } else if (!suspend) {
       // We may end a previously suspended render pass
       if (m_flags.test(DxvkContextFlag::GpRenderPassSuspended)) {
@@ -4023,16 +4021,6 @@ namespace dxvk {
     if (!m_flags.test(DxvkContextFlag::GpXfbActive)) {
       m_flags.set(DxvkContextFlag::GpXfbActive);
 
-      if (m_flags.test(DxvkContextFlag::GpDirtyXfbCounters)) {
-        m_flags.clr(DxvkContextFlag::GpDirtyXfbCounters);
-
-        this->emitMemoryBarrier(0,
-          VK_PIPELINE_STAGE_TRANSFORM_FEEDBACK_BIT_EXT,
-          VK_ACCESS_TRANSFORM_FEEDBACK_COUNTER_WRITE_BIT_EXT,
-          VK_PIPELINE_STAGE_DRAW_INDIRECT_BIT, /* XXX */
-          VK_ACCESS_TRANSFORM_FEEDBACK_COUNTER_READ_BIT_EXT);
-      }
-
       VkBuffer     ctrBuffers[MaxNumXfbBuffers];
       VkDeviceSize ctrOffsets[MaxNumXfbBuffers];
 
@@ -4077,8 +4065,6 @@ namespace dxvk {
       
       m_cmd->cmdEndTransformFeedback(
         0, MaxNumXfbBuffers, ctrBuffers, ctrOffsets);
-      
-      m_flags.set(DxvkContextFlag::GpDirtyXfbCounters);
     }
   }
 
@@ -4171,8 +4157,6 @@ namespace dxvk {
   
   
   bool DxvkContext::updateGraphicsPipelineState() {
-    this->pauseTransformFeedback();
-
     // Set up vertex buffer strides for active bindings
     for (uint32_t i = 0; i < m_state.gp.state.il.bindingCount(); i++) {
       const uint32_t binding = m_state.gp.state.ilBindings[i].binding();
@@ -5105,11 +5089,20 @@ namespace dxvk {
      && m_state.gp.flags.test(DxvkGraphicsPipelineFlag::HasTransformFeedback)) {
       for (uint32_t i = 0; i < MaxNumXfbBuffers && !requiresBarrier; i++) {
         const auto& xfbBufferSlice = m_state.xfb.buffers[i];
+        const auto& xfbCounterSlice = m_state.xfb.counters[i];
 
         if (xfbBufferSlice.defined()) {
           requiresBarrier = this->checkGfxBufferBarrier<DoEmit>(xfbBufferSlice,
             VK_PIPELINE_STAGE_TRANSFORM_FEEDBACK_BIT_EXT,
             VK_ACCESS_TRANSFORM_FEEDBACK_WRITE_BIT_EXT) != 0;
+
+          if (xfbCounterSlice.defined()) {
+            requiresBarrier |= this->checkGfxBufferBarrier<DoEmit>(xfbCounterSlice,
+              VK_PIPELINE_STAGE_DRAW_INDIRECT_BIT |
+              VK_PIPELINE_STAGE_TRANSFORM_FEEDBACK_BIT_EXT,
+              VK_ACCESS_TRANSFORM_FEEDBACK_COUNTER_READ_BIT_EXT |
+              VK_ACCESS_TRANSFORM_FEEDBACK_COUNTER_WRITE_BIT_EXT) != 0;
+          }
         }
       }
     }
diff --git a/src/dxvk/dxvk_context_state.h b/src/dxvk/dxvk_context_state.h
index f3fb1bf68..9252c4334 100644
--- a/src/dxvk/dxvk_context_state.h
+++ b/src/dxvk/dxvk_context_state.h
@@ -32,7 +32,6 @@ namespace dxvk {
     GpDirtyVertexBuffers,       ///< Vertex buffer bindings are out of date
     GpDirtyIndexBuffer,         ///< Index buffer binding are out of date
     GpDirtyXfbBuffers,          ///< Transform feedback buffer bindings are out of date
-    GpDirtyXfbCounters,         ///< Counter buffer values are dirty
     GpDirtyBlendConstants,      ///< Blend constants have changed
     GpDirtyDepthBias,           ///< Depth bias has changed
     GpDirtyDepthBounds,         ///< Depth bounds have changed