[NewPM] Remove ScalarizerLegacyPass (#72814)

This pass isn't used anywhere upstream and thus has no test coverage.
Because of these reasons, remove it.

llvm/include/llvm/InitializePasses.h

@@ -287,7 +287,6 @@ void initializeSafepointIRVerifierPass(PassRegistry&);
 void initializeSelectOptimizePass(PassRegistry &);
 void initializeScalarEvolutionWrapperPassPass(PassRegistry&);
 void initializeScalarizeMaskedMemIntrinLegacyPassPass(PassRegistry &);
-void initializeScalarizerLegacyPassPass(PassRegistry&);
 void initializeScavengerTestPass(PassRegistry&);
 void initializeScopedNoAliasAAWrapperPassPass(PassRegistry&);
 void initializeSeparateConstOffsetFromGEPLegacyPassPass(PassRegistry &);

llvm/include/llvm/LinkAllPasses.h

@@ -136,7 +136,6 @@ namespace {
       (void) llvm::createLowerAtomicPass();
       (void) llvm::createLoadStoreVectorizerPass();
       (void) llvm::createPartiallyInlineLibCallsPass();
-      (void) llvm::createScalarizerPass();
       (void) llvm::createSeparateConstOffsetFromGEPPass();
       (void) llvm::createSpeculativeExecutionPass();
       (void) llvm::createSpeculativeExecutionIfHasBranchDivergencePass();

llvm/include/llvm/Transforms/Scalar/Scalarizer.h

@@ -51,10 +51,6 @@ class ScalarizerPass : public PassInfoMixin<ScalarizerPass> {
   void setScalarizeLoadStore(bool Value) { Options.ScalarizeLoadStore = Value; }
   void setScalarizeMinBits(unsigned Value) { Options.ScalarizeMinBits = Value; }
 };
-
-/// Create a legacy pass manager instance of the Scalarizer pass
-FunctionPass *createScalarizerPass();
-
 }
 
 #endif /* LLVM_TRANSFORMS_SCALAR_SCALARIZER_H */

llvm/lib/Transforms/Scalar/Scalar.cpp

@@ -21,7 +21,6 @@ using namespace llvm;
 void llvm::initializeScalarOpts(PassRegistry &Registry) {
   initializeConstantHoistingLegacyPassPass(Registry);
   initializeDCELegacyPassPass(Registry);
-  initializeScalarizerLegacyPassPass(Registry);
   initializeLoopGuardWideningLegacyPassPass(Registry);
   initializeGVNLegacyPassPass(Registry);
   initializeEarlyCSELegacyPassPass(Registry);

llvm/lib/Transforms/Scalar/Scalarizer.cpp

@@ -36,8 +36,6 @@
 #include "llvm/IR/Module.h"
 #include "llvm/IR/Type.h"
 #include "llvm/IR/Value.h"
-#include "llvm/InitializePasses.h"
-#include "llvm/Pass.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Transforms/Utils/Local.h"
@@ -342,31 +340,8 @@ class ScalarizerVisitor : public InstVisitor<ScalarizerVisitor, bool> {
   const unsigned ScalarizeMinBits;
 };
 
-class ScalarizerLegacyPass : public FunctionPass {
-public:
-  static char ID;
-
-  ScalarizerLegacyPass() : FunctionPass(ID) {
-    initializeScalarizerLegacyPassPass(*PassRegistry::getPassRegistry());
-  }
-
-  bool runOnFunction(Function &F) override;
-
-  void getAnalysisUsage(AnalysisUsage& AU) const override {
-    AU.addRequired<DominatorTreeWrapperPass>();
-    AU.addPreserved<DominatorTreeWrapperPass>();
-  }
-};
-
 } // end anonymous namespace
 
-char ScalarizerLegacyPass::ID = 0;
-INITIALIZE_PASS_BEGIN(ScalarizerLegacyPass, "scalarizer",
-                      "Scalarize vector operations", false, false)
-INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
-INITIALIZE_PASS_END(ScalarizerLegacyPass, "scalarizer",
-                    "Scalarize vector operations", false, false)
-
 Scatterer::Scatterer(BasicBlock *bb, BasicBlock::iterator bbi, Value *v,
                      const VectorSplit &VS, ValueVector *cachePtr)
     : BB(bb), BBI(bbi), V(v), VS(VS), CachePtr(cachePtr) {
@@ -439,19 +414,6 @@ Value *Scatterer::operator[](unsigned Frag) {
   return CV[Frag];
 }
 
-bool ScalarizerLegacyPass::runOnFunction(Function &F) {
-  if (skipFunction(F))
-    return false;
-
-  DominatorTree *DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
-  ScalarizerVisitor Impl(DT, ScalarizerPassOptions());
-  return Impl.visit(F);
-}
-
-FunctionPass *llvm::createScalarizerPass() {
-  return new ScalarizerLegacyPass();
-}
-
 bool ScalarizerVisitor::visit(Function &F) {
   assert(Gathered.empty() && Scattered.empty());