[LegacyPM] Remove LowerExpectIntrinsicPass

Using the legacy PM for the optimization pipeline was deprecated in 13.0.0.
Many legacy passes have been removed in 2022.

Author: MaskRay

llvm/include/llvm/InitializePasses.h

@@ -188,7 +188,6 @@ void initializeLoopUnrollPass(PassRegistry&);
 void initializeLowerAtomicLegacyPassPass(PassRegistry&);
 void initializeLowerConstantIntrinsicsPass(PassRegistry&);
 void initializeLowerEmuTLSPass(PassRegistry&);
-void initializeLowerExpectIntrinsicPass(PassRegistry&);
 void initializeLowerGlobalDtorsLegacyPassPass(PassRegistry &);
 void initializeLowerWidenableConditionLegacyPassPass(PassRegistry&);
 void initializeLowerIntrinsicsPass(PassRegistry&);

llvm/include/llvm/LinkAllPasses.h

@@ -99,7 +99,6 @@ namespace {
       (void) llvm::createLoopUnrollPass();
       (void) llvm::createLoopRotatePass();
       (void) llvm::createLowerConstantIntrinsicsPass();
-      (void) llvm::createLowerExpectIntrinsicPass();
       (void) llvm::createLowerGlobalDtorsLegacyPass();
       (void) llvm::createLowerInvokePass();
       (void) llvm::createLowerSwitchPass();

llvm/include/llvm/Transforms/Scalar.h

@@ -217,12 +217,6 @@ Pass *createMergeICmpsLegacyPass();
 FunctionPass *createInferAddressSpacesPass(unsigned AddressSpace = ~0u);
 extern char &InferAddressSpacesID;
 
-//===----------------------------------------------------------------------===//
-//
-// LowerExpectIntrinsics - Removes llvm.expect intrinsics and creates
-// "block_weights" metadata.
-FunctionPass *createLowerExpectIntrinsicPass();
-
 //===----------------------------------------------------------------------===//
 //
 // TLSVariableHoist - This pass reduce duplicated TLS address call.

llvm/lib/Transforms/Scalar/LowerExpectIntrinsic.cpp

@@ -415,29 +415,3 @@ PreservedAnalyses LowerExpectIntrinsicPass::run(Function &F,
 
   return PreservedAnalyses::all();
 }
-
-namespace {
-/// Legacy pass for lowering expect intrinsics out of the IR.
-///
-/// When this pass is run over a function it uses expect intrinsics which feed
-/// branches and switches to provide branch weight metadata for those
-/// terminators. It then removes the expect intrinsics from the IR so the rest
-/// of the optimizer can ignore them.
-class LowerExpectIntrinsic : public FunctionPass {
-public:
-  static char ID;
-  LowerExpectIntrinsic() : FunctionPass(ID) {
-    initializeLowerExpectIntrinsicPass(*PassRegistry::getPassRegistry());
-  }
-
-  bool runOnFunction(Function &F) override { return lowerExpectIntrinsic(F); }
-};
-} // namespace
-
-char LowerExpectIntrinsic::ID = 0;
-INITIALIZE_PASS(LowerExpectIntrinsic, "lower-expect",
-                "Lower 'expect' Intrinsics", false, false)
-
-FunctionPass *llvm::createLowerExpectIntrinsicPass() {
-  return new LowerExpectIntrinsic();
-}

llvm/lib/Transforms/Scalar/Scalar.cpp

@@ -41,7 +41,6 @@ void llvm::initializeScalarOpts(PassRegistry &Registry) {
   initializeLoopUnrollPass(Registry);
   initializeLowerAtomicLegacyPassPass(Registry);
   initializeLowerConstantIntrinsicsPass(Registry);
-  initializeLowerExpectIntrinsicPass(Registry);
   initializeLowerWidenableConditionLegacyPassPass(Registry);
   initializeMergeICmpsLegacyPassPass(Registry);
   initializeMergedLoadStoreMotionLegacyPassPass(Registry);