Fixed shader warning on Xbox for ResolveStencilBuffer.compute (#163)

* fix warning

* changelog

Co-authored-by: sebastienlagarde <[email protected]>

Author: FrancescoC-unity

com.unity.render-pipelines.high-definition/CHANGELOG.md

@@ -539,6 +539,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Fixed NaN which can appear with real time reflection and inf value
 - Fixed an issue that was collapsing the volume components in the HDRP default settings
 - Fixed warning about missing bound decal buffer
+- Fixed shader warning on Xbox for ResolveStencilBuffer.compute. 
 
 ### Changed
 - Color buffer pyramid is not allocated anymore if neither refraction nor distortion are enabled

com.unity.render-pipelines.high-definition/Runtime/ShaderLibrary/ResolveStencilBuffer.compute

@@ -79,7 +79,10 @@ void KERNEL_NAME(uint3 groupId          : SV_GroupID,
 
 #else
 
-    bool isFirstThread = WaveIsFirstLane();
+    // Need to workaround a warning incorrectly triggered when on Xbox One, so instead of using WaveIsFirstLane()
+    // we check the groupThreadId as in the non intrinsic version.
+    //bool isFirstThread = WaveIsFirstLane();
+    bool isFirstThread = groupThreadId.x == 0 && groupThreadId.y == 0;
     uint coarseStencilValue = WaveActiveBitOr(resolvedStencil);
 
 #endif