From 3e686098ccfe2d8260eb10bcfcc1aa1c079cee88 Mon Sep 17 00:00:00 2001
From: Philip Rebohle <philip.rebohle@tu-dortmund.de>
Date: Fri, 23 Nov 2018 12:28:48 +0100
Subject: [PATCH] [dxbc] Disable subgroup early discard on Nvidia GPUs

People report performance regressions up to 5% with it enabled.
---
 src/dxbc/dxbc_options.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/dxbc/dxbc_options.cpp b/src/dxbc/dxbc_options.cpp
index 29360c9d..74a4b5d8 100644
--- a/src/dxbc/dxbc_options.cpp
+++ b/src/dxbc/dxbc_options.cpp
@@ -21,6 +21,12 @@ namespace dxvk {
      && (devInfo.coreSubgroup.supportedOperations & VK_SUBGROUP_FEATURE_ARITHMETIC_BIT);
     useSubgroupOpsClustered = useSubgroupOpsForEarlyDiscard
      && (devInfo.coreSubgroup.supportedOperations & VK_SUBGROUP_FEATURE_CLUSTERED_BIT);
+    
+    // Disable early discard on Nvidia because it may hurt performance
+    if (DxvkGpuVendor(devInfo.core.properties.vendorID) == DxvkGpuVendor::Nvidia) {
+      useSubgroupOpsForEarlyDiscard = false;
+      useSubgroupOpsClustered       = false;
+    }
   }
   
 }
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