From 50d223e614ab01332807eaee3446b1e67fc4b3f1 Mon Sep 17 00:00:00 2001
From: Joshua Ashton <joshua@froggi.es>
Date: Sat, 27 Feb 2021 19:29:52 +0000
Subject: [PATCH] [d3d9] Add option to use device local memory for constant
 buffers

Useful for testing performance.
---
 dxvk.conf                 | 12 ++++++++++++
 src/d3d9/d3d9_device.cpp  |  3 +++
 src/d3d9/d3d9_options.cpp |  2 ++
 src/d3d9/d3d9_options.h   |  3 +++
 4 files changed, 20 insertions(+)

diff --git a/dxvk.conf b/dxvk.conf
index 1cd42564..a6c925c3 100644
--- a/dxvk.conf
+++ b/dxvk.conf
@@ -342,3 +342,15 @@
 # - True/False
 
 # d3d9.alphaTestWiggleRoom = False
+
+# Device Local Constant Buffers
+#
+# Enables using device local, host accessible memory for constant buffers in D3D9.
+# This tends to actually be slower for some reason on AMD,
+# and the exact same performance on NVIDIA.
+#
+# Supported values:
+# - True/False
+
+# d3d9.deviceLocalConstantBuffers = False
+
diff --git a/src/d3d9/d3d9_device.cpp b/src/d3d9/d3d9_device.cpp
index d74f01e3..a6b300fe 100644
--- a/src/d3d9/d3d9_device.cpp
+++ b/src/d3d9/d3d9_device.cpp
@@ -4627,6 +4627,9 @@ namespace dxvk {
     VkMemoryPropertyFlags memoryFlags = VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT
                                       | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT;
 
+    if (m_d3d9Options.deviceLocalConstantBuffers)
+      memoryFlags |= VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT;
+
     Rc<DxvkBuffer> buffer = m_dxvkDevice->createBuffer(info, memoryFlags);
 
     const uint32_t slotId = computeResourceSlotId(
diff --git a/src/d3d9/d3d9_options.cpp b/src/d3d9/d3d9_options.cpp
index f49259dc..ac2de14e 100644
--- a/src/d3d9/d3d9_options.cpp
+++ b/src/d3d9/d3d9_options.cpp
@@ -75,6 +75,8 @@ namespace dxvk {
 
     this->apitraceMode = config.getOption<bool>("d3d9.apitraceMode", false);
 
+    this->deviceLocalConstantBuffers = config.getOption<bool>("d3d9.deviceLocalConstantBuffers", false);
+
     // If we are not Nvidia, enable general hazards.
     this->generalHazards = adapter == nullptr || !adapter->matchesDriver(DxvkGpuVendor::Nvidia, VK_DRIVER_ID_NVIDIA_PROPRIETARY_KHR, 0, 0);
     applyTristate(this->generalHazards, config.getOption<Tristate>("d3d9.generalHazards", Tristate::Auto));
diff --git a/src/d3d9/d3d9_options.h b/src/d3d9/d3d9_options.h
index d27fdddd..8ff661da 100644
--- a/src/d3d9/d3d9_options.h
+++ b/src/d3d9/d3d9_options.h
@@ -154,6 +154,9 @@ namespace dxvk {
 
     /// Apitrace mode: Maps all buffers in cached memory.
     bool apitraceMode;
+
+    /// Use device local memory for constant buffers.
+    bool deviceLocalConstantBuffers;
   };
 
 }
\ No newline at end of file