[dxvk] Implement accurate barrier tracking for draws with side effects

Similar to how this is handled for compute shaders, with some caveats:
- The barriers are never actually emitted, only tracked. Spilling the
  render pass will reset the barriers as it acts as a full barrier.
- Doing this for all draws and all resources would be prohibitively
  expensive, so whenever switching between pipelines with side effects
  and pipelines without side effects, we'll spill the render pass.

src/dxvk/dxvk_context.cpp

@@ -14,6 +14,7 @@ namespace dxvk {
     m_initBarriers(DxvkCmdBuffer::InitBuffer),
     m_execAcquires(DxvkCmdBuffer::ExecBuffer),
     m_execBarriers(DxvkCmdBuffer::ExecBuffer),
+    m_gfxBarriers (DxvkCmdBuffer::ExecBuffer),
     m_queryManager(m_common->queryPool()),
     m_staging     (device) {
 
@@ -3280,6 +3281,8 @@ namespace dxvk {
       m_queryManager.endQueries(m_cmd, VK_QUERY_TYPE_OCCLUSION);
       m_queryManager.endQueries(m_cmd, VK_QUERY_TYPE_PIPELINE_STATISTICS);
       
+      m_gfxBarriers.reset();
+
       this->renderPassUnbindFramebuffer();
       this->unbindGraphicsPipeline();
       this->commitPredicateUpdates();
@@ -3601,7 +3604,13 @@ namespace dxvk {
       return false;
     }
 
-    m_state.gp.flags = m_state.gp.pipeline->flags();
+    if (m_state.gp.flags != m_state.gp.pipeline->flags()) {
+      m_state.gp.flags = m_state.gp.pipeline->flags();
+
+      // This is necessary because we'll only do hazard
+      // tracking if the active pipeline has side effects
+      this->spillRenderPass();
+    }
 
     if (m_state.gp.pipeline->layout()->pushConstRange().size)
       m_flags.set(DxvkContextFlag::DirtyPushConstants);
@@ -4158,17 +4167,20 @@ namespace dxvk {
   
   template<bool Indexed>
   bool DxvkContext::commitGraphicsState() {
+    if (m_flags.test(DxvkContextFlag::GpDirtyPipeline)) {
+      if (unlikely(!this->updateGraphicsPipeline()))
+        return false;
+    }
+    
+    if (m_state.gp.flags.test(DxvkGraphicsPipelineFlag::HasStorageDescriptors))
+      this->commitGraphicsBarriers();
+
     if (m_flags.test(DxvkContextFlag::GpDirtyFramebuffer))
       this->updateFramebuffer();
 
     if (!m_flags.test(DxvkContextFlag::GpRenderPassBound))
       this->startRenderPass();
     
-    if (m_flags.test(DxvkContextFlag::GpDirtyPipeline)) {
-      if (unlikely(!this->updateGraphicsPipeline()))
-        return false;
-    }
-    
     if (m_flags.test(DxvkContextFlag::GpDirtyIndexBuffer) && Indexed)
       this->updateIndexBufferBinding();
     
@@ -4343,11 +4355,102 @@ namespace dxvk {
   }
   
   
-  void DxvkContext::commitGraphicsPostBarriers() {
+  void DxvkContext::commitGraphicsBarriers() {
+    auto layout = m_state.gp.pipeline->layout();
+
+    bool requiresBarrier = false;
+
+    for (uint32_t i = 0; i < layout->bindingCount() && !requiresBarrier; i++) {
+      if (m_state.gp.state.bsBindingMask.test(i)) {
+        const DxvkDescriptorSlot binding = layout->binding(i);
+        const DxvkShaderResourceSlot& slot = m_rc[binding.slot];
+
+        DxvkAccessFlags dstAccess = DxvkAccess::Read;
+        DxvkAccessFlags srcAccess = 0;
+        
+        switch (binding.type) {
+          case VK_DESCRIPTOR_TYPE_STORAGE_BUFFER:
+            if (binding.access & VK_ACCESS_SHADER_WRITE_BIT)
+              dstAccess.set(DxvkAccess::Write);
+            /* fall through */
+
+          case VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER:
+          case VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC:
+            if (slot.bufferSlice.bufferInfo().usage & VK_BUFFER_USAGE_STORAGE_BUFFER_BIT) {
+              srcAccess = m_gfxBarriers.getBufferAccess(
+                slot.bufferSlice.getSliceHandle());
+
+              m_gfxBarriers.accessBuffer(
+                slot.bufferSlice.getSliceHandle(),
+                binding.stages, binding.access,
+                slot.bufferSlice.bufferInfo().stages,
+                slot.bufferSlice.bufferInfo().access);
+            }
+            break;
+
+          case VK_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER:
+            if (binding.access & VK_ACCESS_SHADER_WRITE_BIT)
+              dstAccess.set(DxvkAccess::Write);
+            /* fall through */
+
+          case VK_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER:
+            if (slot.bufferView->bufferInfo().usage & VK_BUFFER_USAGE_STORAGE_TEXEL_BUFFER_BIT) {
+              srcAccess = m_gfxBarriers.getBufferAccess(
+                slot.bufferView->getSliceHandle());
+
+              m_gfxBarriers.accessBuffer(
+                slot.bufferView->getSliceHandle(),
+                binding.stages, binding.access,
+                slot.bufferView->bufferInfo().stages,
+                slot.bufferView->bufferInfo().access);
+            }
+            break;
+
+          case VK_DESCRIPTOR_TYPE_STORAGE_IMAGE:
+            if (binding.access & VK_ACCESS_SHADER_WRITE_BIT)
+              dstAccess.set(DxvkAccess::Write);
+            /* fall through */
+
+          case VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE:
+          case VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER:
+            if (slot.imageView->imageInfo().usage & VK_IMAGE_USAGE_STORAGE_BIT) {
+              srcAccess = m_gfxBarriers.getImageAccess(
+                slot.imageView->image(),
+                slot.imageView->imageSubresources());
+
+              m_gfxBarriers.accessImage(
+                slot.imageView->image(),
+                slot.imageView->imageSubresources(),
+                slot.imageView->imageInfo().layout,
+                binding.stages, binding.access,
+                slot.imageView->imageInfo().layout,
+                slot.imageView->imageInfo().stages,
+                slot.imageView->imageInfo().access);
+            }
+            break;
+
+          default:
+            /* nothing to do */;
+        }
+
+        if (srcAccess == 0)
+          continue;
+
+        // Skip write-after-write barriers if explicitly requested
+        if ((m_barrierControl.test(DxvkBarrierControl::IgnoreWriteAfterWrite))
+         && (srcAccess.test(DxvkAccess::Write))
+         && (dstAccess.test(DxvkAccess::Write)))
+          continue;
+
+        requiresBarrier = (srcAccess | dstAccess).test(DxvkAccess::Write);
+      }
+    }
+
     // External subpass dependencies serve as full memory
     // and execution barriers, so we can use this to allow
     // inter-stage synchronization.
-    this->spillRenderPass();
+    if (requiresBarrier)
+      this->spillRenderPass();
   }
 
 
@@ -4355,9 +4458,6 @@ namespace dxvk {
   void DxvkContext::finalizeDraw() {
     if (m_flags.test(DxvkContextFlag::DirtyDrawBuffer) && Indirect)
       this->trackDrawBuffer();
-
-    if (m_state.gp.flags.test(DxvkGraphicsPipelineFlag::HasStorageDescriptors))
-      this->commitGraphicsPostBarriers();
   }
 
 

src/dxvk/dxvk_context.h

@@ -1013,6 +1013,7 @@ namespace dxvk {
     DxvkBarrierSet          m_initBarriers;
     DxvkBarrierSet          m_execAcquires;
     DxvkBarrierSet          m_execBarriers;
+    DxvkBarrierSet          m_gfxBarriers;
     DxvkBarrierControlFlags m_barrierControl;
     
     DxvkGpuQueryManager     m_queryManager;
@@ -1161,7 +1162,7 @@ namespace dxvk {
     void commitComputeInitBarriers();
     void commitComputePostBarriers();
     
-    void commitGraphicsPostBarriers();
+    void commitGraphicsBarriers();
 
     template<bool Indirect>
     void finalizeDraw();