[Autobackout][FunctionalRegression]Revert of change: 5f467c7: Make VRT GRF sizes backward-compatible in VC

If VRT GRF size is not supported for given platform,
    VC will look for closest largest value, e.g. on Xe2:
    64->128, 96->128, 192->256.

Author: sys-igc

IGC/VectorCompiler/include/GenXSubtarget.h

@@ -463,8 +463,6 @@ class GenXSubtarget final : public GenXGenSubtargetInfo {
   PreDefined_Surface stackSurface() const { return StackSurf; }
 
   bool isIntrinsicSupported(unsigned ID) const;
-
-  ArrayRef<unsigned> getSupportedGRFSizes() const;
   bool isValidGRFSize(unsigned Size) const;
 };
 

IGC/VectorCompiler/lib/GenXCodeGen/GenXCisaBuilder.cpp

@@ -960,15 +960,8 @@ static void addKernelAttrsFromMetadata(VISAKernel &Kernel,
   // Set by compile option.
   if (BC->isAutoLargeGRFMode())
     NumGRF = 0;
-  if (BC->getGRFSize()) {
+  if (BC->getGRFSize())
     NumGRF = BC->getGRFSize();
-    if (!Subtarget->isValidGRFSize(NumGRF)) {
-      // looking for closest largest value
-      const auto GrfSizes = Subtarget->getSupportedGRFSizes();
-      auto It = std::upper_bound(GrfSizes.begin(), GrfSizes.end(), NumGRF);
-      NumGRF = It != GrfSizes.end() ? *It : *(It - 1);
-    }
-  }
   // Set by kernel metadata.
   if (KM.getGRFSize()) {
     unsigned NumGRFPerKernel = *KM.getGRFSize();

IGC/VectorCompiler/lib/GenXCodeGen/GenXSubtarget.cpp

@@ -27,7 +27,7 @@ SPDX-License-Identifier: MIT
 #include "Probe/Assertion.h"
 #include "common/StringMacros.hpp"
 
-#include <algorithm>
+#include <unordered_set>
 
 using namespace llvm;
 
@@ -296,30 +296,22 @@ bool GenXSubtarget::isInternalIntrinsicSupported(unsigned ID) const {
   return true;
 }
 
-ArrayRef<unsigned> GenXSubtarget::getSupportedGRFSizes() const {
+bool GenXSubtarget::isValidGRFSize(unsigned Size) const {
   switch (TargetId) {
   case GenXSubtarget::XeHP:
   case GenXSubtarget::XeHPG:
   case GenXSubtarget::XeLPG:
   case GenXSubtarget::XeLPGPlus:
   case GenXSubtarget::XeHPC:
   case GenXSubtarget::XeHPCVG:
-  case GenXSubtarget::Xe2: {
-    static const unsigned Supported[] = {128, 256};
-    return Supported;
-  }
+  case GenXSubtarget::Xe2:
+    return Size == 128 || Size == 256;
   case GenXSubtarget::Xe3: {
-    static const unsigned Supported[] = {32, 64, 96, 128, 160, 192, 256};
-    return Supported;
-  }
-  default: {
-    static const unsigned Supported[] = {128}; // platforms <= TGL
-    return Supported;
+    static const std::unordered_set<unsigned> Supported = {32,  64,  96, 128,
+                                                           160, 192, 256};
+    return Supported.count(Size);
   }
+  default:
+    return Size == 128; // platforms <= TGL
   }
 }
-
-bool GenXSubtarget::isValidGRFSize(unsigned Size) const {
-  const auto GrfSizes = getSupportedGRFSizes();
-  return std::binary_search(GrfSizes.begin(), GrfSizes.end(), Size);
-}