From 8d1d3d66e0ab810a3dabf69936cf69454011c923 Mon Sep 17 00:00:00 2001
From: Philip Rebohle <philip.rebohle@tu-dortmund.de>
Date: Sat, 25 Jun 2022 16:02:22 +0200
Subject: [PATCH] [dxvk] Optimize descriptor set binding further

---
 src/dxvk/dxvk_context.cpp  | 46 ++++++++++++++++++--------------------
 src/dxvk/dxvk_pipelayout.h | 17 --------------
 2 files changed, 22 insertions(+), 41 deletions(-)

diff --git a/src/dxvk/dxvk_context.cpp b/src/dxvk/dxvk_context.cpp
index ff69d2e6f..428503a07 100644
--- a/src/dxvk/dxvk_context.cpp
+++ b/src/dxvk/dxvk_context.cpp
@@ -85,8 +85,6 @@ namespace dxvk {
       VK_SHADER_STAGE_ALL_GRAPHICS |
       VK_SHADER_STAGE_COMPUTE_BIT);
 
-    m_descriptorState.clearSets();
-
     m_state.gp.pipeline = nullptr;
     m_state.cp.pipeline = nullptr;
 
@@ -4113,10 +4111,10 @@ namespace dxvk {
       : m_descriptorState.getDirtyComputeSets();
     dirtySetMask &= layoutSetMask;
 
-    uint32_t firstUpdated = bit::tzcnt(dirtySetMask);
+    uint32_t bindCount = 0;
     uint32_t k = 0;
 
-    std::array<VkDescriptorSet, DxvkDescriptorSets::SetCount> sets = { };
+    std::array<VkDescriptorSet, DxvkDescriptorSets::SetCount> sets;
     m_descriptorPool->alloc(layout, dirtySetMask, sets.data());
 
     while (dirtySetMask) {
@@ -4130,7 +4128,6 @@ namespace dxvk {
       newBindMask.setRange(bindingIndex, bindingCount);
 
       VkDescriptorSet set = sets[setIndex];
-      m_descriptorState.getSet<BindPoint>(setIndex) = set;
 
       for (uint32_t j = 0; j < bindingCount; j++) {
         const auto& binding = bindings.getBinding(setIndex, j);
@@ -4287,28 +4284,29 @@ namespace dxvk {
           &m_descriptors[k - bindingCount]);
       }
 
+      bindCount += 1;
+
+      // If the next set is not dirty, update and bind all previously
+      // updated sets in one go in order to reduce api call overhead.
+      if (!(dirtySetMask & (1u << (setIndex + 1)))) {
+        if (!useDescriptorTemplates) {
+          m_cmd->updateDescriptorSets(k, m_descriptorWrites.data());
+          k = 0;
+        }
+
+        uint32_t firstSet = setIndex + 1 - bindCount;
+
+        m_cmd->cmdBindDescriptorSets(BindPoint,
+          layout->getPipelineLayout(),
+          firstSet, bindCount, &sets[firstSet],
+          0, nullptr);
+
+        bindCount = 0;
+      }
+
       dirtySetMask &= dirtySetMask - 1;
     }
 
-    if (!useDescriptorTemplates && k)
-      m_cmd->updateDescriptorSets(k, m_descriptorWrites.data());
-
-    // Bind all descriptor sets that need updating
-    uint32_t bindSetMask = layoutSetMask & ((~0u) << firstUpdated);
-
-    while (bindSetMask) {
-      uint32_t setIndex = bit::tzcnt(bindSetMask);
-      uint32_t setCount = bit::tzcnt(~(bindSetMask >> setIndex));
-
-      VkDescriptorSet* sets = &m_descriptorState.getSet<BindPoint>(setIndex);
-
-      m_cmd->cmdBindDescriptorSets(BindPoint,
-        layout->getPipelineLayout(),
-        setIndex, setCount, sets, 0, nullptr);
-
-      bindSetMask &= (~0u) << (setIndex + setCount);
-    }
-
     // Update pipeline if there are unbound resources
     if (refBindMask != newBindMask) {
       refBindMask = newBindMask;
diff --git a/src/dxvk/dxvk_pipelayout.h b/src/dxvk/dxvk_pipelayout.h
index 152af61a7..223652e90 100644
--- a/src/dxvk/dxvk_pipelayout.h
+++ b/src/dxvk/dxvk_pipelayout.h
@@ -523,28 +523,11 @@ namespace dxvk {
       return result;
     }
 
-    void clearSets() {
-      for (size_t i = 0; i < m_sets.size(); i++)
-        m_sets[i] = VK_NULL_HANDLE;
-    }
-
-    template<VkPipelineBindPoint BindPoint>
-    VkDescriptorSet& getSet(uint32_t index) {
-      return m_sets[BindPoint * DxvkDescriptorSets::SetCount + index];
-    }
-
-    template<VkPipelineBindPoint BindPoint>
-    const VkDescriptorSet& getSet(uint32_t index) const {
-      return m_sets[BindPoint * DxvkDescriptorSets::SetCount + index];
-    }
-
   private:
 
     VkShaderStageFlags m_dirtyBuffers   = 0;
     VkShaderStageFlags m_dirtyViews     = 0;
 
-    std::array<VkDescriptorSet, 2 * DxvkDescriptorSets::SetCount> m_sets;
-
   };
   
 }
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