Support platform specific KeepTileYForFlattened setting

Change KeepTileYForFlattened regkey to allow platform default setting.

Author: iwwu

IGC/Compiler/CISACodeGen/ComputeShaderBase.cpp

@@ -66,7 +66,12 @@ namespace IGC
             MMD->csInfo.neededThreadIdLayout == ThreadIDLayout::X;
         if (m_Platform->supportHWGenerateTID() && m_DriverInfo->SupportHWGenerateTID())
         {
-            if (IGC_IS_FLAG_DISABLED(KeepTileYForFlattened) && useLinearWalk)
+            // If KeepTileYForFlattened == 2, use the platform default value.
+            // Otherwise 0 is forced off, 1 is forced on.
+            bool KeepTileYForFlattenedValue = IGC_GET_FLAG_VALUE(KeepTileYForFlattened) == 2 ?
+                m_Platform->EnableKeepTileYForFlattenedDefault() :
+                IGC_IS_FLAG_ENABLED(KeepTileYForFlattened);
+            if (!KeepTileYForFlattenedValue && useLinearWalk)
             {
                 needsLinearWalk = true;
             }

IGC/Compiler/CISACodeGen/Platform.hpp

@@ -964,6 +964,11 @@ bool EnableNewTileYCheckDefault() const
     return (m_platformInfo.eProductFamily == IGFX_DG2);
 }
 
+bool EnableKeepTileYForFlattenedDefault() const
+{
+    return false;
+}
+
 bool needsWAForThreadsUtilization() const
 {
     return (m_platformInfo.eProductFamily == IGFX_DG2 ||

IGC/common/igc_flags.h

@@ -241,7 +241,7 @@ DECLARE_IGC_REGKEY(bool, ForceAddressArithSinking,      false,   "Force sinking
 DECLARE_IGC_REGKEY(bool, SetDefaultTileYWalk,           true,  "Use TileY walk as default for HW generating threadID", true)
 DECLARE_IGC_REGKEY(bool, ForceTileY,                    false, "Force TileY mode on DG2", false)
 DECLARE_IGC_REGKEY(DWORD, EnableNewTileYCheck,          2,     "Enable new TileY check. 0 - off, 1 - on, 2 - platform default", false)
-DECLARE_IGC_REGKEY(bool, KeepTileYForFlattened,         false, "Keep TileY for FlattenedThreadIdInGroup on DG2", false)
+DECLARE_IGC_REGKEY(DWORD, KeepTileYForFlattened,        2,     "Keep TileY for FlattenedThreadIdInGroup. 0 - off, 1 - on, 2 - platform default", false)
 
 DECLARE_IGC_REGKEY(bool, DisableDynamicTextureFolding,  false,  "Disable Dynamic Texture Folding", false)
 DECLARE_IGC_REGKEY(bool, DisableDynamicResInfoFolding,  true,  "Disable Dynamic ResInfo Instruction Folding", false)