[llvm] [NewPM] Remove MergedLoadStoreMotionLegacyPass (PR #72813)

[Aiden Grossman via llvm-commits]

https://github.com/boomanaiden154 created https://github.com/llvm/llvm-project/pull/72813

This pass isn't used anywhere and thus isn't tested anywhere. Because of these reasons, remove it.

>From 54027cf7e4011e72267fc0e894bb5c60f9017175 Mon Sep 17 00:00:00 2001
From: Aiden Grossman <agrossman154 at yahoo.com>
Date: Sun, 19 Nov 2023 16:03:22 -0800
Subject: [PATCH] [NewPM] Remove MergedLoadStoreMotionLegacyPass

This pass isn't used anywhere and thus isn't tested anywhere. Because of
these reasons, remove it.
---
 llvm/include/llvm/InitializePasses.h          |  1 -
 llvm/include/llvm/LinkAllPasses.h             |  1 -
 llvm/include/llvm/Transforms/Scalar.h         |  7 ---
 .../Scalar/MergedLoadStoreMotion.cpp          | 47 -------------------
 llvm/lib/Transforms/Scalar/Scalar.cpp         |  1 -
 5 files changed, 57 deletions(-)

diff --git a/llvm/include/llvm/InitializePasses.h b/llvm/include/llvm/InitializePasses.h
index da38a38b87ebc4d..77632c9486c7dd9 100644
--- a/llvm/include/llvm/InitializePasses.h
+++ b/llvm/include/llvm/InitializePasses.h
@@ -231,7 +231,6 @@ void initializeMachineVerifierPassPass(PassRegistry&);
 void initializeMemoryDependenceWrapperPassPass(PassRegistry&);
 void initializeMemorySSAWrapperPassPass(PassRegistry&);
 void initializeMergeICmpsLegacyPassPass(PassRegistry &);
-void initializeMergedLoadStoreMotionLegacyPassPass(PassRegistry&);
 void initializeModuleSummaryIndexWrapperPassPass(PassRegistry&);
 void initializeModuloScheduleTestPass(PassRegistry&);
 void initializeNaryReassociateLegacyPassPass(PassRegistry&);
diff --git a/llvm/include/llvm/LinkAllPasses.h b/llvm/include/llvm/LinkAllPasses.h
index 3fc90e85c3533e2..3314ab51bb86338 100644
--- a/llvm/include/llvm/LinkAllPasses.h
+++ b/llvm/include/llvm/LinkAllPasses.h
@@ -126,7 +126,6 @@ namespace {
       (void) llvm::createConstantHoistingPass();
       (void) llvm::createCodeGenPreparePass();
       (void) llvm::createEarlyCSEPass();
-      (void) llvm::createMergedLoadStoreMotionPass();
       (void) llvm::createGVNPass();
       (void) llvm::createPostDomTree();
       (void) llvm::createMergeICmpsLegacyPass();
diff --git a/llvm/include/llvm/Transforms/Scalar.h b/llvm/include/llvm/Transforms/Scalar.h
index 0676f485f3fbcf4..a4672c7a184064d 100644
--- a/llvm/include/llvm/Transforms/Scalar.h
+++ b/llvm/include/llvm/Transforms/Scalar.h
@@ -170,13 +170,6 @@ FunctionPass *createTailCallEliminationPass();
 //
 FunctionPass *createEarlyCSEPass(bool UseMemorySSA = false);
 
-//===----------------------------------------------------------------------===//
-//
-// MergedLoadStoreMotion - This pass merges loads and stores in diamonds. Loads
-// are hoisted into the header, while stores sink into the footer.
-//
-FunctionPass *createMergedLoadStoreMotionPass(bool SplitFooterBB = false);
-
 //===----------------------------------------------------------------------===//
 //
 // ConstantHoisting - This pass prepares a function for expensive constants.
diff --git a/llvm/lib/Transforms/Scalar/MergedLoadStoreMotion.cpp b/llvm/lib/Transforms/Scalar/MergedLoadStoreMotion.cpp
index 3c0f2010d1edf4c..d65054a6ff9d5fa 100644
--- a/llvm/lib/Transforms/Scalar/MergedLoadStoreMotion.cpp
+++ b/llvm/lib/Transforms/Scalar/MergedLoadStoreMotion.cpp
@@ -80,7 +80,6 @@
 #include "llvm/Analysis/GlobalsModRef.h"
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/Instructions.h"
-#include "llvm/InitializePasses.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Transforms/Scalar.h"
@@ -378,52 +377,6 @@ bool MergedLoadStoreMotion::run(Function &F, AliasAnalysis &AA) {
   return Changed;
 }
 
-namespace {
-class MergedLoadStoreMotionLegacyPass : public FunctionPass {
-  const bool SplitFooterBB;
-public:
-  static char ID; // Pass identification, replacement for typeid
-  MergedLoadStoreMotionLegacyPass(bool SplitFooterBB = false)
-      : FunctionPass(ID), SplitFooterBB(SplitFooterBB) {
-    initializeMergedLoadStoreMotionLegacyPassPass(
-        *PassRegistry::getPassRegistry());
-  }
-
-  ///
-  /// Run the transformation for each function
-  ///
-  bool runOnFunction(Function &F) override {
-    if (skipFunction(F))
-      return false;
-    MergedLoadStoreMotion Impl(SplitFooterBB);
-    return Impl.run(F, getAnalysis<AAResultsWrapperPass>().getAAResults());
-  }
-
-private:
-  void getAnalysisUsage(AnalysisUsage &AU) const override {
-    if (!SplitFooterBB)
-      AU.setPreservesCFG();
-    AU.addRequired<AAResultsWrapperPass>();
-    AU.addPreserved<GlobalsAAWrapperPass>();
-  }
-};
-
-char MergedLoadStoreMotionLegacyPass::ID = 0;
-} // anonymous namespace
-
-///
-/// createMergedLoadStoreMotionPass - The public interface to this file.
-///
-FunctionPass *llvm::createMergedLoadStoreMotionPass(bool SplitFooterBB) {
-  return new MergedLoadStoreMotionLegacyPass(SplitFooterBB);
-}
-
-INITIALIZE_PASS_BEGIN(MergedLoadStoreMotionLegacyPass, "mldst-motion",
-                      "MergedLoadStoreMotion", false, false)
-INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)
-INITIALIZE_PASS_END(MergedLoadStoreMotionLegacyPass, "mldst-motion",
-                    "MergedLoadStoreMotion", false, false)
-
 PreservedAnalyses
 MergedLoadStoreMotionPass::run(Function &F, FunctionAnalysisManager &AM) {
   MergedLoadStoreMotion Impl(Options.SplitFooterBB);
diff --git a/llvm/lib/Transforms/Scalar/Scalar.cpp b/llvm/lib/Transforms/Scalar/Scalar.cpp
index 11bb8e936b74e7c..cf90488bfe60fc1 100644
--- a/llvm/lib/Transforms/Scalar/Scalar.cpp
+++ b/llvm/lib/Transforms/Scalar/Scalar.cpp
@@ -43,7 +43,6 @@ void llvm::initializeScalarOpts(PassRegistry &Registry) {
   initializeLowerConstantIntrinsicsPass(Registry);
   initializeLowerWidenableConditionLegacyPassPass(Registry);
   initializeMergeICmpsLegacyPassPass(Registry);
-  initializeMergedLoadStoreMotionLegacyPassPass(Registry);
   initializeNaryReassociateLegacyPassPass(Registry);
   initializePartiallyInlineLibCallsLegacyPassPass(Registry);
   initializeReassociateLegacyPassPass(Registry);