Address review comments

Author: madhur13490

llvm/include/llvm/Transforms/Scalar/GVN.h

@@ -139,12 +139,7 @@ class GVNPass : public PassInfoMixin<GVNPass> {
 
   /// This removes the specified instruction from
   /// our various maps and marks it for deletion.
-  void doInstructionDeletion(Instruction *I) {
-    salvageKnowledge(I, AC);
-    salvageDebugInfo(*I);
-    VN.erase(I);
-    removeInstruction(I);
-  }
+  void doInstructionDeletion(Instruction *I);
 
   DominatorTree &getDominatorTree() const { return *DT; }
   AAResults *getAliasAnalysis() const { return VN.getAliasAnalysis(); }

llvm/lib/Transforms/Scalar/GVN.cpp

@@ -728,7 +728,6 @@ void GVNPass::ValueTable::erase(Value *V) {
 /// verifyRemoved - Verify that the value is removed from all internal data
 /// structures.
 void GVNPass::ValueTable::verifyRemoved(const Value *V) const {
-  if (V != nullptr)
     assert(!ValueNumbering.contains(V) &&
            "Inst still occurs in value numbering map!");
 }
@@ -877,6 +876,12 @@ void GVNPass::printPipeline(
   OS << '>';
 }
 
+void GVNPass::doInstructionDeletion(Instruction *I) {
+  salvageKnowledge(I, AC);
+  salvageDebugInfo(*I);
+  removeInstruction(I);
+}
+
 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
 LLVM_DUMP_METHOD void GVNPass::dump(DenseMap<uint32_t, Value *> &Map) const {
   errs() << "{\n";
@@ -1556,7 +1561,6 @@ void GVNPass::eliminatePartiallyRedundantLoad(
         replaceValuesPerBlockEntry(ValuesPerBlock, OldLoad, NewLoad);
         if (uint32_t ValNo = VN.lookup(OldLoad, false))
           LeaderTable.erase(ValNo, OldLoad, OldLoad->getParent());
-        VN.erase(OldLoad);
         removeInstruction(OldLoad);
       }
     }
@@ -1995,9 +1999,9 @@ bool GVNPass::processNonLocalLoad(LoadInst *Load) {
         I->setDebugLoc(Load->getDebugLoc());
     if (V->getType()->isPtrOrPtrVectorTy())
       MD->invalidateCachedPointerInfo(V);
-    doInstructionDeletion(Load);
     ++NumGVNLoad;
     reportLoadElim(Load, V, ORE);
+    doInstructionDeletion(Load);
     return true;
   }
 
@@ -2809,7 +2813,6 @@ bool GVNPass::processBlock(BasicBlock *BB) {
   SmallPtrSet<PHINode *, 8> PHINodesToRemove;
   ChangedFunction |= EliminateDuplicatePHINodes(BB, PHINodesToRemove);
   for (PHINode *PN : PHINodesToRemove) {
-    VN.erase(PN);
     removeInstruction(PN);
   }
   for (Instruction &Inst : make_early_inc_range(*BB)) {
@@ -3022,7 +3025,6 @@ bool GVNPass::performScalarPRE(Instruction *CurInst) {
   CurInst->replaceAllUsesWith(Phi);
   if (MD && Phi->getType()->isPtrOrPtrVectorTy())
     MD->invalidateCachedPointerInfo(Phi);
-  VN.erase(CurInst);
   LeaderTable.erase(ValNo, CurInst, CurrentBlock);
 
   LLVM_DEBUG(dbgs() << "GVN PRE removed: " << *CurInst << '\n');
@@ -3122,6 +3124,7 @@ void GVNPass::cleanupGlobalSets() {
 }
 
 void GVNPass::removeInstruction(Instruction *I) {
+  VN.erase(I);
   if (MD) MD->removeInstruction(I);
   if (MSSAU)
     MSSAU->removeMemoryAccess(I);