Add an option to disable scalarizer in GPGPU path

Author: Gang Y Chen

IGC/AdaptorOCL/UnifyIROCL.cpp

@@ -511,7 +511,10 @@ static void CommonOCLBasedPasses(
     mpm.add(createIGCInstructionCombiningPass());
 
     // "false" to createScalarizerPass() means that vector load/stores are NOT scalarized
-    mpm.add(createScalarizerPass(false));
+    if (IGC_IS_FLAG_ENABLED(DisableScalarizerGPGPU) == false)
+    {
+        mpm.add(createScalarizerPass(false));
+    }
 
     // Create a dummy kernel to attach the symbol table if necessary
     // Only needed if function pointers, externally linked functions, or relocatable global variables are present

IGC/common/igc_flags.def

@@ -288,6 +288,7 @@ DECLARE_IGC_REGKEY(bool, DisableMemOpt2,                false, "Disable MemOpt2"
 DECLARE_IGC_REGKEY(bool, DisablePreRAScheduler,         false, "Disable Pre RA Scheduling", false)
 DECLARE_IGC_REGKEY(DWORD,MaxLiveOutThreshold,           0,     "Max LiveOut Threshold in MemOpt2", false)
 DECLARE_IGC_REGKEY(bool, DisableScalarAtomics,          false, "Disable the Scalar Atomics optimization", false)
+DECLARE_IGC_REGKEY(bool, DisableScalarizerGPGPU,        false, "disable scalarizer on GPGPU path", true)
 DECLARE_IGC_REGKEY(bool, HoistPSConstBufferValues,      true,  "Hoists up down converts for contant buffer accesses, so they an be vectorized more easily.", false)
 DECLARE_IGC_REGKEY(bool, EnableSingleVertexDispatch,    false, "Vertex Shader Single Patch Dispatch Regkey", false)
 DECLARE_IGC_REGKEY(bool, allowLICM,                     true,  "Enable LICM in IGC.", false)