[dxvk] Pull buffer updates out of render passes whenever possible

Instead of ending the render pass and inserting two barriers, we
perform the update and barrier in a dedicated command buffer.

Improves performance in Sekiro by 5-10% depending on resolution and scene.

src/dxvk/dxvk_cmdlist.cpp

@@ -139,16 +139,19 @@ namespace dxvk {
   
   
   void DxvkCommandList::stagedBufferCopy(
+          DxvkCmdBuffer           cmdBuffer,
           VkBuffer                dstBuffer,
           VkDeviceSize            dstOffset,
           VkDeviceSize            dataSize,
     const DxvkStagingBufferSlice& dataSlice) {
+    m_cmdBuffersUsed.set(cmdBuffer);
+    
     VkBufferCopy region;
     region.srcOffset = dataSlice.offset;
     region.dstOffset = dstOffset;
     region.size      = dataSize;
     
-    m_vkd->vkCmdCopyBuffer(m_execBuffer,
+    m_vkd->vkCmdCopyBuffer(getCmdBuffer(cmdBuffer),
       dataSlice.buffer, dstBuffer, 1, &region);
   }
   

src/dxvk/dxvk_cmdlist.h

@@ -620,11 +620,14 @@ namespace dxvk {
     
     
     void cmdUpdateBuffer(
+            DxvkCmdBuffer           cmdBuffer,
             VkBuffer                dstBuffer,
             VkDeviceSize            dstOffset,
             VkDeviceSize            dataSize,
       const void*                   pData) {
-      m_vkd->vkCmdUpdateBuffer(m_execBuffer,
+      m_cmdBuffersUsed.set(cmdBuffer);
+
+      m_vkd->vkCmdUpdateBuffer(getCmdBuffer(cmdBuffer),
         dstBuffer, dstOffset, dataSize, pData);
     }
     
@@ -692,6 +695,7 @@ namespace dxvk {
     
     
     void stagedBufferCopy(
+            DxvkCmdBuffer           cmdBuffer,
             VkBuffer                dstBuffer,
             VkDeviceSize            dstOffset,
             VkDeviceSize            dataSize,

src/dxvk/dxvk_context.cpp

@@ -28,7 +28,7 @@ namespace dxvk {
     m_queryManager(gpuQueryPool) {
 
   }
-    
+  
   
   DxvkContext::~DxvkContext() {
     
@@ -68,6 +68,7 @@ namespace dxvk {
   Rc<DxvkCommandList> DxvkContext::endRecording() {
     this->spillRenderPass();
     
+    m_transfers.recordCommands(m_cmd);
     m_barriers.recordCommands(m_cmd);
 
     m_cmd->endRecording();
@@ -342,6 +343,7 @@ namespace dxvk {
         data[i] = value;
       
       m_cmd->cmdUpdateBuffer(
+        DxvkCmdBuffer::ExecBuffer,
         slice.handle,
         slice.offset,
         slice.length,
@@ -1719,20 +1721,39 @@ namespace dxvk {
           VkDeviceSize              offset,
           VkDeviceSize              size,
     const void*                     data) {
-    this->spillRenderPass();
+    bool replaceBuffer = (size == buffer->info().size)
+                      && (size <= (1 << 20)) /* 1 MB */
+                      && (m_flags.test(DxvkContextFlag::GpRenderPassBound));
     
+    DxvkBufferSliceHandle bufferSlice;
+    DxvkCmdBuffer         cmdBuffer;
+
+    if (replaceBuffer) {
+      // As an optimization, allocate a free slice and perform
+      // the copy in the initialization command buffer instead
+      // interrupting the render pass and stalling the pipeline.
+      bufferSlice = buffer->allocSlice();
+      cmdBuffer   = DxvkCmdBuffer::InitBuffer;
+
+      this->invalidateBuffer(buffer, bufferSlice);
+    } else {
+      this->spillRenderPass();
+    
+      bufferSlice = buffer->getSliceHandle(offset, size);
+      cmdBuffer   = DxvkCmdBuffer::ExecBuffer;
+
+      if (m_barriers.isBufferDirty(bufferSlice, DxvkAccess::Write))
+        m_barriers.recordCommands(m_cmd);
+    }
+
     // Vulkan specifies that small amounts of data (up to 64kB) can
     // be copied to a buffer directly if the size is a multiple of
     // four. Anything else must be copied through a staging buffer.
     // We'll limit the size to 4kB in order to keep command buffers
     // reasonably small, we do not know how much data apps may upload.
-    auto bufferSlice = buffer->getSliceHandle(offset, size);
-
-    if (m_barriers.isBufferDirty(bufferSlice, DxvkAccess::Write))
-      m_barriers.recordCommands(m_cmd);
-    
     if ((size <= 4096) && ((size & 0x3) == 0) && ((offset & 0x3) == 0)) {
       m_cmd->cmdUpdateBuffer(
+        cmdBuffer,
         bufferSlice.handle,
         bufferSlice.offset,
         bufferSlice.length,
@@ -1742,13 +1763,18 @@ namespace dxvk {
       std::memcpy(slice.mapPtr, data, size);
 
       m_cmd->stagedBufferCopy(
+        cmdBuffer,
         bufferSlice.handle,
         bufferSlice.offset,
         bufferSlice.length,
         slice);
     }
 
-    m_barriers.accessBuffer(
+    auto& barriers = replaceBuffer
+      ? m_transfers
+      : m_barriers;
+
+    barriers.accessBuffer(
       bufferSlice,
       VK_PIPELINE_STAGE_TRANSFER_BIT,
       VK_ACCESS_TRANSFER_WRITE_BIT,