[d3d9] Don't set storage buffer usage unless necessary

This actually matters now to some degree.

src/d3d9/d3d9_constant_buffer.cpp

@@ -13,7 +13,7 @@ namespace dxvk {
           DxsoProgramType       ShaderStage,
           DxsoConstantBuffers   BufferType,
           VkDeviceSize          Size)
-  : D3D9ConstantBuffer(pDevice, GetShaderStage(ShaderStage),
+  : D3D9ConstantBuffer(pDevice, getBufferUsage(pDevice, ShaderStage, BufferType), GetShaderStage(ShaderStage),
       computeResourceSlotId(ShaderStage, DxsoBindingType::ConstantBuffer, BufferType),
       Size) {
 
@@ -22,11 +22,13 @@ namespace dxvk {
 
   D3D9ConstantBuffer::D3D9ConstantBuffer(
           D3D9DeviceEx*         pDevice,
+          VkBufferUsageFlags    Usage,
           VkShaderStageFlags    Stages,
           uint32_t              ResourceSlot,
           VkDeviceSize          Size)
   : m_device    (pDevice)
   , m_binding   (ResourceSlot)
+  , m_usage     (Usage)
   , m_stages    (Stages)
   , m_size      (Size)
   , m_align     (getAlignment(pDevice->GetDXVKDevice())) {
@@ -98,12 +100,15 @@ namespace dxvk {
     // in the backend, so set both STORAGE and UNIFORM usage/access.
     DxvkBufferCreateInfo bufferInfo;
     bufferInfo.size   = align(m_size, m_align);
-    bufferInfo.usage  = VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT
+    bufferInfo.usage  = m_usage;
-                      | VK_BUFFER_USAGE_STORAGE_BUFFER_BIT;
+    bufferInfo.access = 0;
-    bufferInfo.access = VK_ACCESS_UNIFORM_READ_BIT
-                      | VK_ACCESS_SHADER_READ_BIT;
     bufferInfo.stages = util::pipelineStages(m_stages);
 
+    if (m_usage & VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT)
+      bufferInfo.access |= VK_ACCESS_UNIFORM_READ_BIT;
+    if (m_usage & VK_BUFFER_USAGE_STORAGE_BUFFER_BIT)
+      bufferInfo.access |= VK_ACCESS_SHADER_READ_BIT;
+
     VkMemoryPropertyFlags memoryFlags
       = VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT
       | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT;
@@ -130,4 +135,21 @@ namespace dxvk {
       device->properties().extRobustness2.robustUniformBufferAccessSizeAlignment);
   }
 
+
+  VkBufferUsageFlags D3D9ConstantBuffer::getBufferUsage(
+          D3D9DeviceEx*         pDevice,
+          DxsoProgramType       ShaderStage,
+          DxsoConstantBuffers   BufferType) {
+    VkBufferUsageFlags result = VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT;
+
+    // We won't always need this, but the only buffer that
+    // this applies to is so large that it will not matter.
+    if (pDevice->CanSWVP()
+     && ShaderStage == DxsoProgramType::VertexShader
+     && BufferType == DxsoConstantBuffers::VSConstantBuffer)
+      result |= VK_BUFFER_USAGE_STORAGE_BUFFER_BIT;
+
+    return result;
+  }
+
 }

src/d3d9/d3d9_constant_buffer.h

@@ -29,6 +29,7 @@ namespace dxvk {
 
     D3D9ConstantBuffer(
             D3D9DeviceEx*         pDevice,
+            VkBufferUsageFlags    Usage,
             VkShaderStageFlags    Stages,
             uint32_t              ResourceSlot,
             VkDeviceSize          Size);
@@ -66,6 +67,7 @@ namespace dxvk {
     D3D9DeviceEx*         m_device  = nullptr;
 
     uint32_t              m_binding = 0u;
+    VkBufferUsageFlags    m_usage   = 0u;
     VkShaderStageFlags    m_stages  = 0u;
     VkDeviceSize          m_size    = 0ull;
     VkDeviceSize          m_align   = 0ull;
@@ -78,6 +80,11 @@ namespace dxvk {
 
     VkDeviceSize getAlignment(const Rc<DxvkDevice>& device) const;
 
+    static VkBufferUsageFlags getBufferUsage(
+            D3D9DeviceEx*         pDevice,
+            DxsoProgramType       ShaderStage,
+            DxsoConstantBuffers   BufferType);
+
   };
 
 }

src/d3d9/d3d9_device.cpp

@@ -5021,6 +5021,7 @@ namespace dxvk {
 
     if (m_usingGraphicsPipelines) {
       m_specBuffer = D3D9ConstantBuffer(this,
+        VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT,
         VK_SHADER_STAGE_VERTEX_BIT | VK_SHADER_STAGE_FRAGMENT_BIT,
         getSpecConstantBufferSlot(),
         sizeof(D3D9SpecializationInfo));