Change to make VectorDecomposer use subtarget info

Change-Id: I82476d4e51c1c52e51c35aa44489fdb821dfac64

Author: azabazno

IGC/VectorCompiler/lib/GenXCodeGen/GenXPostLegalization.cpp

@@ -75,7 +75,6 @@ namespace {
 // GenXPostLegalization : post-legalization pass
 class GenXPostLegalization : public FunctionPass {
   DominatorTree *DT = nullptr;
-  VectorDecomposer VD;
   const DataLayout *DL = nullptr;
   const GenXSubtarget *ST = nullptr;
 public:
@@ -122,6 +121,9 @@ bool GenXPostLegalization::runOnFunction(Function &F)
   bool Modified = false;
   Modified |= breakConstantExprs(&F);
 
+  // Create vector decomposer helper
+  auto VD = std::make_unique<VectorDecomposer>(ST, DT);
+
   for (Function::iterator fi = F.begin(), fe = F.end(); fi != fe; ++fi) {
     BasicBlock *BB = &*fi;
     for (BasicBlock::iterator bi = BB->begin(), be = BB->end(); bi != be; ++bi) {
@@ -142,15 +144,15 @@ bool GenXPostLegalization::runOnFunction(Function &F)
       if (!ST->disableVectorDecomposition()) {
         if (GenXIntrinsic::isWrRegion(Inst)) {
           if (isa<Constant>(Inst->getOperand(0)))
-            VD.addStartWrRegion(Inst);
+            VD->addStartWrRegion(Inst);
           else if (isa<PHINode>(Inst->getOperand(0)))
-            VD.addStartWrRegion(Inst);
+            VD->addStartWrRegion(Inst);
         }
       }
     }
   }
   // Run the vector decomposer for this function.
-  Modified |= VD.run(DT);
+  Modified |= VD->run();
   // Cleanup region reads and writes.
   Modified |= simplifyRegionInsts(&F, DL);
   // Cleanup redundant global loads.

IGC/VectorCompiler/lib/GenXCodeGen/GenXVectorDecomposer.cpp

@@ -120,9 +120,7 @@ int DiagnosticVectorDecomposition::KindID = 0;
  *
  * Return:  true if code modified
  */
-bool VectorDecomposer::run(DominatorTree *ArgDT)
-{
-  DT = ArgDT;
+bool VectorDecomposer::run() {
   DL = &DT->
         getRoot()
             ->getModule()
@@ -190,7 +188,10 @@ bool VectorDecomposer::determineDecomposition(Instruction *Inst)
   NotDecomposingReportInst = Inst;
   Web.clear();
   Decomposition.clear();
-  unsigned NumGrfs = alignTo<256>(DL->getTypeSizeInBits(Inst->getType())) / 256;
+  unsigned GRFWidth = ST ? ST->getGRFWidth() : defaultGRFWidth;
+  unsigned NumGrfs = alignTo(DL->getTypeSizeInBits(Inst->getType()),
+                             GRFWidth * genx::ByteBits) /
+                     (GRFWidth * genx::ByteBits);
   if (NumGrfs == 1)
     return false; // Ignore single GRF vector.
   LLVM_DEBUG(dbgs() << "VectorDecomposer::determineDecomposition(" << Inst->getName() << ")\n");

IGC/VectorCompiler/lib/GenXCodeGen/GenXVectorDecomposer.h

@@ -68,6 +68,7 @@ class Region;
 
 // VectorDecomposer : decomposes vectors in a function
 class VectorDecomposer {
+  const GenXSubtarget *ST;
   DominatorTree *DT;
   const DataLayout *DL = nullptr;
   SmallVector<Instruction *, 16> StartWrRegions;
@@ -81,6 +82,9 @@ class VectorDecomposer {
   std::map<PHINode *, SmallVector<Value *, 8>> PhiParts;
   SmallVector<Instruction *, 8> NewInsts;
 public:
+  VectorDecomposer(const GenXSubtarget *Subtarget, DominatorTree *DTree)
+      : ST(Subtarget), DT(DTree) {}
+
   // clear : clear anything stored
   void clear() {
     clearOne();
@@ -91,7 +95,8 @@ class VectorDecomposer {
   // addStartWrRegion : add a wrregion with undef input to the list
   void addStartWrRegion(Instruction *Inst) { StartWrRegions.push_back(Inst); }
   // run : run the vector decomposer on the stored StartWrRegions
-  bool run(DominatorTree *DT);
+  bool run();
+
 private:
   // clearOne : clear from processing one web
   void clearOne() {