[NPM] port -unify-loop-exits to NPM

[aeubanks]

llvm/lib/Transforms/Utils/UnifyLoopExits.cpp

241

the legacy pass doesn't call getLoopAnalysisUsage(AU), are you sure that this preserves all loop analyses? Or is it just LoopAnalysis?

[TaWeiTu]

Replace PreservedAnalyses::all() with LoopAnalysis and DominatorTreeAnalysis.

[aeubanks]

Could you rebase this on top of master? Using arc patch with a merge conflict doesn't work well.

[TaWeiTu]

Rebase.

llvm/include/llvm/InitializePasses.h

 void initializeTargetLibraryInfoWrapperPassPass(PassRegistry&);
 void initializeTargetPassConfigPass(PassRegistry&);
 void initializeTargetTransformInfoWrapperPassPass(PassRegistry&);
 void initializeThreadSanitizerLegacyPassPass(PassRegistry&);
 void initializeTwoAddressInstructionPassPass(PassRegistry&);
 void initializeTypeBasedAAWrapperPassPass(PassRegistry&);
 void initializeTypePromotionPass(PassRegistry&);
 void initializeUnifyFunctionExitNodesLegacyPassPass(PassRegistry &);
-void initializeUnifyLoopExitsPass(PassRegistry &);
+void initializeUnifyLoopExitsLegacyPassPass(PassRegistry &);
 void initializeUnpackMachineBundlesPass(PassRegistry&);
 void initializeUnreachableBlockElimLegacyPassPass(PassRegistry&);
 void initializeUnreachableMachineBlockElimPass(PassRegistry&);
 void initializeVectorCombineLegacyPassPass(PassRegistry&);
 void initializeVerifierLegacyPassPass(PassRegistry&);
 void initializeVirtRegMapPass(PassRegistry&);
 void initializeVirtRegRewriterPass(PassRegistry&);
 void initializeWarnMissedTransformationsLegacyPass(PassRegistry &);

llvm/include/llvm/Transforms/Utils/UnifyLoopExits.h

+//===- UnifyLoopExits.h - Redirect exiting edges to one block -*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TRANSFORMS_UTILS_UNIFYLOOPEXITS_H
+#define LLVM_TRANSFORMS_UTILS_UNIFYLOOPEXITS_H
+
+#include "llvm/IR/PassManager.h"
+
+namespace llvm {
+
+class UnifyLoopExitsPass : public PassInfoMixin<UnifyLoopExitsPass> {
+public:
+  PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
+};
+} // namespace llvm
+
+#endif // LLVM_TRANSFORMS_UTILS_UNIFYLOOPEXITS_H

llvm/lib/Passes/PassBuilder.cpp

 #include "llvm/Transforms/Utils/LowerSwitch.h"
 #include "llvm/Transforms/Utils/Mem2Reg.h"
 #include "llvm/Transforms/Utils/MetaRenamer.h"
 #include "llvm/Transforms/Utils/NameAnonGlobals.h"
 #include "llvm/Transforms/Utils/StripGCRelocates.h"
 #include "llvm/Transforms/Utils/StripNonLineTableDebugInfo.h"
 #include "llvm/Transforms/Utils/SymbolRewriter.h"
 #include "llvm/Transforms/Utils/UnifyFunctionExitNodes.h"
+#include "llvm/Transforms/Utils/UnifyLoopExits.h"
 #include "llvm/Transforms/Vectorize/LoadStoreVectorizer.h"
 #include "llvm/Transforms/Vectorize/LoopVectorize.h"
 #include "llvm/Transforms/Vectorize/SLPVectorizer.h"
 #include "llvm/Transforms/Vectorize/VectorCombine.h"
 
 using namespace llvm;
 
 static cl::opt<unsigned> MaxDevirtIterations("pm-max-devirt-iterations",

llvm/lib/Passes/PassRegistry.def

 FUNCTION_PASS("simplifycfg", SimplifyCFGPass())
 FUNCTION_PASS("sink", SinkingPass())
 FUNCTION_PASS("slp-vectorizer", SLPVectorizerPass())
 FUNCTION_PASS("speculative-execution", SpeculativeExecutionPass())
 FUNCTION_PASS("spec-phis", SpeculateAroundPHIsPass())
 FUNCTION_PASS("sroa", SROA())
 FUNCTION_PASS("strip-gc-relocates", StripGCRelocates())
 FUNCTION_PASS("tailcallelim", TailCallElimPass())
+FUNCTION_PASS("unify-loop-exits", UnifyLoopExitsPass())
 FUNCTION_PASS("vector-combine", VectorCombinePass())
 FUNCTION_PASS("verify", VerifierPass())
 FUNCTION_PASS("verify<domtree>", DominatorTreeVerifierPass())
 FUNCTION_PASS("verify<loops>", LoopVerifierPass())
 FUNCTION_PASS("verify<memoryssa>", MemorySSAVerifierPass())
 FUNCTION_PASS("verify<regions>", RegionInfoVerifierPass())
 FUNCTION_PASS("verify<safepoint-ir>", SafepointIRVerifierPass())
 FUNCTION_PASS("verify<scalar-evolution>", ScalarEvolutionVerifierPass())

llvm/lib/Transforms/Utils/UnifyLoopExits.cpp

 // is redistributed to all the original exit blocks.
 //
 // Limitation: This assumes that all terminators in the CFG are direct branches
 //             (the "br" instruction). The presence of any other control flow
 //             such as indirectbr, switch or callbr will cause an assert.
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/Transforms/Utils/UnifyLoopExits.h"
 #include "llvm/ADT/MapVector.h"
 #include "llvm/Analysis/LoopInfo.h"
 #include "llvm/IR/Dominators.h"
 #include "llvm/InitializePasses.h"
+#include "llvm/Transforms/Scalar/LoopPassManager.h"
 #include "llvm/Transforms/Utils.h"
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
 
 #define DEBUG_TYPE "unify-loop-exits"
 
 using namespace llvm;
 
 namespace {
-struct UnifyLoopExits : public FunctionPass {
+struct UnifyLoopExitsLegacyPass : public FunctionPass {
   static char ID;
-  UnifyLoopExits() : FunctionPass(ID) {
-    initializeUnifyLoopExitsPass(*PassRegistry::getPassRegistry());
+  UnifyLoopExitsLegacyPass() : FunctionPass(ID) {
+    initializeUnifyLoopExitsLegacyPassPass(*PassRegistry::getPassRegistry());
   }
 
   void getAnalysisUsage(AnalysisUsage &AU) const override {
     AU.addRequiredID(LowerSwitchID);
     AU.addRequired<LoopInfoWrapperPass>();
     AU.addRequired<DominatorTreeWrapperPass>();
     AU.addPreservedID(LowerSwitchID);
     AU.addPreserved<LoopInfoWrapperPass>();
     AU.addPreserved<DominatorTreeWrapperPass>();
   }
 
   bool runOnFunction(Function &F) override;
 };
 } // namespace
 
-char UnifyLoopExits::ID = 0;
+char UnifyLoopExitsLegacyPass::ID = 0;
 
-FunctionPass *llvm::createUnifyLoopExitsPass() { return new UnifyLoopExits(); }
+FunctionPass *llvm::createUnifyLoopExitsPass() {
+  return new UnifyLoopExitsLegacyPass();
+}
 
-INITIALIZE_PASS_BEGIN(UnifyLoopExits, "unify-loop-exits",
+INITIALIZE_PASS_BEGIN(UnifyLoopExitsLegacyPass, "unify-loop-exits",
                       "Fixup each natural loop to have a single exit block",
                       false /* Only looks at CFG */, false /* Analysis Pass */)
 INITIALIZE_PASS_DEPENDENCY(LowerSwitchLegacyPass)
 INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
 INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
-INITIALIZE_PASS_END(UnifyLoopExits, "unify-loop-exits",
+INITIALIZE_PASS_END(UnifyLoopExitsLegacyPass, "unify-loop-exits",
                     "Fixup each natural loop to have a single exit block",
                     false /* Only looks at CFG */, false /* Analysis Pass */)
 
 // The current transform introduces new control flow paths which may break the
 // SSA requirement that every def must dominate all its uses. For example,
 // consider a value D defined inside the loop that is used by some instruction
 // U outside the loop. It follows that D dominates U, since the original
 // program has valid SSA form. After merging the exits, all paths from D to U

 
 #if defined(EXPENSIVE_CHECKS)
   LI.verify(DT);
 #endif // EXPENSIVE_CHECKS
 
   return true;
 }
 
-bool UnifyLoopExits::runOnFunction(Function &F) {
-  LLVM_DEBUG(dbgs() << "===== Unifying loop exits in function " << F.getName()
-                    << "\n");
-  auto &LI = getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
-  auto &DT = getAnalysis<DominatorTreeWrapperPass>().getDomTree();
+static bool runImpl(LoopInfo &LI, DominatorTree &DT) {
 
   bool Changed = false;
   auto Loops = LI.getLoopsInPreorder();
   for (auto L : Loops) {
     LLVM_DEBUG(dbgs() << "Loop: " << L->getHeader()->getName() << " (depth: "
                       << LI.getLoopDepth(L->getHeader()) << ")\n");
     Changed |= unifyLoopExits(DT, LI, L);
   }
   return Changed;
 }
+
+bool UnifyLoopExitsLegacyPass::runOnFunction(Function &F) {
+  LLVM_DEBUG(dbgs() << "===== Unifying loop exits in function " << F.getName()
+                    << "\n");
+  auto &LI = getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
+  auto &DT = getAnalysis<DominatorTreeWrapperPass>().getDomTree();
+
+  return runImpl(LI, DT);
+}
+
+namespace llvm {
+
+PreservedAnalyses UnifyLoopExitsPass::run(Function &F,
+                                          FunctionAnalysisManager &AM) {
+  auto &LI = AM.getResult<LoopAnalysis>(F);
+  auto &DT = AM.getResult<DominatorTreeAnalysis>(F);
+
+  if (!runImpl(LI, DT))
+    return PreservedAnalyses::all();
+  PreservedAnalyses PA;
+  PA.preserve<LoopAnalysis>();
+  PA.preserve<DominatorTreeAnalysis>();
+  return PA;
+}
+} // namespace llvm

llvm/lib/Transforms/Utils/Utils.cpp

void llvm::initializeTransformUtils(PassRegistry &Registry) {
   initializePromoteLegacyPassPass(Registry);
   initializeStripNonLineTableDebugLegacyPassPass(Registry);
   initializeUnifyFunctionExitNodesLegacyPassPass(Registry);
   initializeMetaRenamerPass(Registry);
   initializeStripGCRelocatesLegacyPass(Registry);
   initializePredicateInfoPrinterLegacyPassPass(Registry);
   initializeInjectTLIMappingsLegacyPass(Registry);
   initializeFixIrreduciblePass(Registry);
-  initializeUnifyLoopExitsPass(Registry);
+  initializeUnifyLoopExitsLegacyPassPass(Registry);
   initializeUniqueInternalLinkageNamesLegacyPassPass(Registry);
 }
 
 /// LLVMInitializeTransformUtils - C binding for initializeTransformUtilsPasses.
 void LLVMInitializeTransformUtils(LLVMPassRegistryRef R) {
   initializeTransformUtils(*unwrap(R));
 }
 

llvm/test/Transforms/UnifyLoopExits/basic.ll

 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt < %s -unify-loop-exits -enable-new-pm=0 -S | FileCheck %s
+; RUN: opt < %s -passes='lowerswitch,unify-loop-exits' -S | FileCheck %s
 
 define void @loop_1(i1 %PredEntry, i1 %PredB, i1 %PredC, i1 %PredD) {
 ; CHECK-LABEL: @loop_1(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    br i1 [[PREDENTRY:%.*]], label [[A:%.*]], label [[G:%.*]]
 ; CHECK:       A:
 ; CHECK-NEXT:    br label [[B:%.*]]
 ; CHECK:       B:

llvm/test/Transforms/UnifyLoopExits/nested.ll

 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt < %s -unify-loop-exits -enable-new-pm=0 -S | FileCheck %s
+; RUN: opt < %s -passes='lowerswitch,unify-loop-exits' -S | FileCheck %s
 
 define void @nested(i1 %PredB3, i1 %PredB4, i1 %PredA4, i1 %PredA3, i32 %X, i32 %Y, i32 %Z) {
 ; CHECK-LABEL: @nested(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    br label [[A1:%.*]]
 ; CHECK:       A1:
 ; CHECK-NEXT:    br label [[B1:%.*]]
 ; CHECK:       B1:

llvm/test/Transforms/UnifyLoopExits/restore-ssa.ll

 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt < %s -unify-loop-exits -enable-new-pm=0 -S | FileCheck %s
+; RUN: opt < %s -passes='lowerswitch,unify-loop-exits' -S | FileCheck %s
 
 ; Loop consists of A and B:
 ; - A is the header
 ; - A and B are exiting blocks
 ; - C and return are exit blocks.
 ; Pattern: Value (%mytmp42) defined in exiting block (A) and used in
 ;          exit block (return).
 ;          The relevant code uses DT::dominates(Value,

llvm/test/Transforms/UnifyLoopExits/switch.ll

 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt < %s -unify-loop-exits -enable-new-pm=0 -S | FileCheck %s
+; RUN: opt < %s -passes='lowerswitch,unify-loop-exits' -S | FileCheck %s
 
 define void @loop_1(i32 %Value, i1 %PredEntry, i1 %PredD) {
 ; CHECK-LABEL: @loop_1(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    br i1 [[PREDENTRY:%.*]], label [[A:%.*]], label [[G:%.*]]
 ; CHECK:       A:
 ; CHECK-NEXT:    br label [[B:%.*]]
 ; CHECK:       B: