[CodeGen][NewPM] Port LiveIntervals to new pass manager (#98118)

- Add `LiveIntervalsAnalysis`.
- Add `LiveIntervalsPrinterPass`.
- Use `LiveIntervalsWrapperPass` in legacy pass manager.
- Use `std::unique_ptr` instead of raw pointer for `LICalc`, so
destructor and default move constructor can handle it correctly.

This would be the last analysis required by `PHIElimination`.

Author: paperchalice

llvm/include/llvm/CodeGen/LiveIntervals.h

@@ -23,8 +23,10 @@
 #include "llvm/ADT/IndexedMap.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/CodeGen/LiveInterval.h"
+#include "llvm/CodeGen/LiveIntervalCalc.h"
 #include "llvm/CodeGen/MachineBasicBlock.h"
 #include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachinePassManager.h"
 #include "llvm/CodeGen/SlotIndexes.h"
 #include "llvm/CodeGen/TargetRegisterInfo.h"
 #include "llvm/MC/LaneBitmask.h"
@@ -40,7 +42,6 @@ namespace llvm {
 extern cl::opt<bool> UseSegmentSetForPhysRegs;
 
 class BitVector;
-class LiveIntervalCalc;
 class MachineBlockFrequencyInfo;
 class MachineDominatorTree;
 class MachineFunction;
@@ -50,14 +51,17 @@ class raw_ostream;
 class TargetInstrInfo;
 class VirtRegMap;
 
-class LiveIntervals : public MachineFunctionPass {
+class LiveIntervals {
+  friend class LiveIntervalsAnalysis;
+  friend class LiveIntervalsWrapperPass;
+
   MachineFunction *MF = nullptr;
   MachineRegisterInfo *MRI = nullptr;
   const TargetRegisterInfo *TRI = nullptr;
   const TargetInstrInfo *TII = nullptr;
   SlotIndexes *Indexes = nullptr;
   MachineDominatorTree *DomTree = nullptr;
-  LiveIntervalCalc *LICalc = nullptr;
+  std::unique_ptr<LiveIntervalCalc> LICalc;
 
   /// Special pool allocator for VNInfo's (LiveInterval val#).
   VNInfo::Allocator VNInfoAllocator;
@@ -93,11 +97,20 @@ class LiveIntervals : public MachineFunctionPass {
   /// interference.
   SmallVector<LiveRange *, 0> RegUnitRanges;
 
-public:
-  static char ID;
+  // Can only be created from pass manager.
+  LiveIntervals() = default;
+  LiveIntervals(MachineFunction &MF, SlotIndexes &SI, MachineDominatorTree &DT)
+      : Indexes(&SI), DomTree(&DT) {
+    analyze(MF);
+  }
+
+  void analyze(MachineFunction &MF);
 
-  LiveIntervals();
-  ~LiveIntervals() override;
+  void clear();
+
+public:
+  LiveIntervals(LiveIntervals &&) = default;
+  ~LiveIntervals();
 
   /// Calculate the spill weight to assign to a single instruction.
   static float getSpillWeight(bool isDef, bool isUse,
@@ -279,14 +292,17 @@ class LiveIntervals : public MachineFunctionPass {
 
   VNInfo::Allocator &getVNInfoAllocator() { return VNInfoAllocator; }
 
-  void getAnalysisUsage(AnalysisUsage &AU) const override;
-  void releaseMemory() override;
+  /// Implement the dump method.
+  void print(raw_ostream &O) const;
+  void dump() const;
 
-  /// Pass entry point; Calculates LiveIntervals.
-  bool runOnMachineFunction(MachineFunction &) override;
+  // For legacy pass to recompute liveness.
+  void reanalyze(MachineFunction &MF) {
+    clear();
+    analyze(MF);
+  }
 
-  /// Implement the dump method.
-  void print(raw_ostream &O, const Module * = nullptr) const override;
+  MachineDominatorTree &getDomTree() { return *DomTree; }
 
   /// If LI is confined to a single basic block, return a pointer to that
   /// block.  If LI is live in to or out of any block, return NULL.
@@ -480,6 +496,48 @@ class LiveIntervals : public MachineFunctionPass {
   class HMEditor;
 };
 
+class LiveIntervalsAnalysis : public AnalysisInfoMixin<LiveIntervalsAnalysis> {
+  friend AnalysisInfoMixin<LiveIntervalsAnalysis>;
+  static AnalysisKey Key;
+
+public:
+  using Result = LiveIntervals;
+  Result run(MachineFunction &MF, MachineFunctionAnalysisManager &MFAM);
+};
+
+class LiveIntervalsPrinterPass
+    : public PassInfoMixin<LiveIntervalsPrinterPass> {
+  raw_ostream &OS;
+
+public:
+  explicit LiveIntervalsPrinterPass(raw_ostream &OS) : OS(OS) {}
+  PreservedAnalyses run(MachineFunction &MF,
+                        MachineFunctionAnalysisManager &MFAM);
+  static bool isRequired() { return true; }
+};
+
+class LiveIntervalsWrapperPass : public MachineFunctionPass {
+  LiveIntervals LIS;
+
+public:
+  static char ID;
+
+  LiveIntervalsWrapperPass();
+
+  void getAnalysisUsage(AnalysisUsage &AU) const override;
+  void releaseMemory() override { LIS.clear(); }
+
+  /// Pass entry point; Calculates LiveIntervals.
+  bool runOnMachineFunction(MachineFunction &) override;
+
+  /// Implement the dump method.
+  void print(raw_ostream &O, const Module * = nullptr) const override {
+    LIS.print(O);
+  }
+
+  LiveIntervals &getLIS() { return LIS; }
+};
+
 } // end namespace llvm
 
 #endif

llvm/include/llvm/InitializePasses.h

@@ -151,7 +151,7 @@ void initializeGISelCSEAnalysisWrapperPassPass(PassRegistry &);
 void initializeGISelKnownBitsAnalysisPass(PassRegistry &);
 void initializeLiveDebugValuesPass(PassRegistry&);
 void initializeLiveDebugVariablesPass(PassRegistry&);
-void initializeLiveIntervalsPass(PassRegistry&);
+void initializeLiveIntervalsWrapperPassPass(PassRegistry &);
 void initializeLiveRangeShrinkPass(PassRegistry&);
 void initializeLiveRegMatrixPass(PassRegistry&);
 void initializeLiveStacksPass(PassRegistry&);

llvm/include/llvm/Passes/CodeGenPassBuilder.h

@@ -36,6 +36,7 @@
 #include "llvm/CodeGen/InterleavedAccess.h"
 #include "llvm/CodeGen/InterleavedLoadCombine.h"
 #include "llvm/CodeGen/JMCInstrumenter.h"
+#include "llvm/CodeGen/LiveIntervals.h"
 #include "llvm/CodeGen/LocalStackSlotAllocation.h"
 #include "llvm/CodeGen/LowerEmuTLS.h"
 #include "llvm/CodeGen/MIRPrinter.h"
@@ -1106,7 +1107,7 @@ void CodeGenPassBuilder<Derived, TargetMachineT>::addOptimizedRegAlloc(
 
   // Eventually, we want to run LiveIntervals before PHI elimination.
   if (Opt.EarlyLiveIntervals)
-    addPass(LiveIntervalsPass());
+    addPass(RequireAnalysisPass<LiveIntervalsAnalysis, MachineFunction>());
 
   addPass(TwoAddressInstructionPass());
   addPass(RegisterCoalescerPass());

llvm/include/llvm/Passes/MachinePassRegistry.def

@@ -94,6 +94,7 @@ LOOP_PASS("loop-reduce", LoopStrengthReducePass())
 // LiveVariables can be removed completely, and LiveIntervals can be directly
 // computed. (We still either need to regenerate kill flags after regalloc, or
 // preferably fix the scavenger to not depend on them).
+MACHINE_FUNCTION_ANALYSIS("live-intervals", LiveIntervalsAnalysis())
 MACHINE_FUNCTION_ANALYSIS("live-vars", LiveVariablesAnalysis())
 MACHINE_FUNCTION_ANALYSIS("machine-branch-prob",
                           MachineBranchProbabilityAnalysis())
@@ -132,6 +133,7 @@ MACHINE_FUNCTION_PASS("finalize-isel", FinalizeISelPass())
 MACHINE_FUNCTION_PASS("localstackalloc", LocalStackSlotAllocationPass())
 MACHINE_FUNCTION_PASS("no-op-machine-function", NoOpMachineFunctionPass())
 MACHINE_FUNCTION_PASS("print", PrintMIRPass())
+MACHINE_FUNCTION_PASS("print<live-intervals>", LiveIntervalsPrinterPass(dbgs()))
 MACHINE_FUNCTION_PASS("print<live-vars>", LiveVariablesPrinterPass(dbgs()))
 MACHINE_FUNCTION_PASS("print<machine-branch-prob>",
                       MachineBranchProbabilityPrinterPass(dbgs()))
@@ -208,7 +210,6 @@ DUMMY_MACHINE_FUNCTION_PASS("irtranslator", IRTranslatorPass)
 DUMMY_MACHINE_FUNCTION_PASS("kcfi", MachineKCFIPass)
 DUMMY_MACHINE_FUNCTION_PASS("legalizer", LegalizerPass)
 DUMMY_MACHINE_FUNCTION_PASS("livedebugvalues", LiveDebugValuesPass)
-DUMMY_MACHINE_FUNCTION_PASS("liveintervals", LiveIntervalsPass)
 DUMMY_MACHINE_FUNCTION_PASS("lrshrink", LiveRangeShrinkPass)
 DUMMY_MACHINE_FUNCTION_PASS("machine-combiner", MachineCombinerPass)
 DUMMY_MACHINE_FUNCTION_PASS("machine-cp", MachineCopyPropagationPass)

llvm/lib/CodeGen/CodeGen.cpp

@@ -60,7 +60,7 @@ void llvm::initializeCodeGen(PassRegistry &Registry) {
   initializeJMCInstrumenterPass(Registry);
   initializeLiveDebugValuesPass(Registry);
   initializeLiveDebugVariablesPass(Registry);
-  initializeLiveIntervalsPass(Registry);
+  initializeLiveIntervalsWrapperPassPass(Registry);
   initializeLiveRangeShrinkPass(Registry);
   initializeLiveStacksPass(Registry);
   initializeLiveVariablesWrapperPassPass(Registry);

llvm/lib/CodeGen/InlineSpiller.cpp

@@ -131,7 +131,7 @@ class HoistSpillHelper : private LiveRangeEdit::Delegate {
 public:
   HoistSpillHelper(MachineFunctionPass &pass, MachineFunction &mf,
                    VirtRegMap &vrm)
-      : MF(mf), LIS(pass.getAnalysis<LiveIntervals>()),
+      : MF(mf), LIS(pass.getAnalysis<LiveIntervalsWrapperPass>().getLIS()),
         LSS(pass.getAnalysis<LiveStacks>()),
         MDT(pass.getAnalysis<MachineDominatorTreeWrapperPass>().getDomTree()),
         VRM(vrm), MRI(mf.getRegInfo()), TII(*mf.getSubtarget().getInstrInfo()),
@@ -188,7 +188,7 @@ class InlineSpiller : public Spiller {
 public:
   InlineSpiller(MachineFunctionPass &Pass, MachineFunction &MF, VirtRegMap &VRM,
                 VirtRegAuxInfo &VRAI)
-      : MF(MF), LIS(Pass.getAnalysis<LiveIntervals>()),
+      : MF(MF), LIS(Pass.getAnalysis<LiveIntervalsWrapperPass>().getLIS()),
         LSS(Pass.getAnalysis<LiveStacks>()),
         MDT(Pass.getAnalysis<MachineDominatorTreeWrapperPass>().getDomTree()),
         VRM(VRM), MRI(MF.getRegInfo()), TII(*MF.getSubtarget().getInstrInfo()),

llvm/lib/CodeGen/LiveDebugVariables.cpp

@@ -79,13 +79,13 @@ char LiveDebugVariables::ID = 0;
 INITIALIZE_PASS_BEGIN(LiveDebugVariables, DEBUG_TYPE,
                 "Debug Variable Analysis", false, false)
 INITIALIZE_PASS_DEPENDENCY(MachineDominatorTreeWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(LiveIntervals)
+INITIALIZE_PASS_DEPENDENCY(LiveIntervalsWrapperPass)
 INITIALIZE_PASS_END(LiveDebugVariables, DEBUG_TYPE,
                 "Debug Variable Analysis", false, false)
 
 void LiveDebugVariables::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.addRequired<MachineDominatorTreeWrapperPass>();
-  AU.addRequiredTransitive<LiveIntervals>();
+  AU.addRequiredTransitive<LiveIntervalsWrapperPass>();
   AU.setPreservesAll();
   MachineFunctionPass::getAnalysisUsage(AU);
 }
@@ -1263,7 +1263,7 @@ void LDVImpl::computeIntervals() {
 bool LDVImpl::runOnMachineFunction(MachineFunction &mf, bool InstrRef) {
   clear();
   MF = &mf;
-  LIS = &pass.getAnalysis<LiveIntervals>();
+  LIS = &pass.getAnalysis<LiveIntervalsWrapperPass>().getLIS();
   TRI = mf.getSubtarget().getRegisterInfo();
   LLVM_DEBUG(dbgs() << "********** COMPUTING LIVE DEBUG VARIABLES: "
                     << mf.getName() << " **********\n");

llvm/lib/CodeGen/LiveIntervals.cpp

@@ -57,14 +57,39 @@ using namespace llvm;
 
 #define DEBUG_TYPE "regalloc"
 
-char LiveIntervals::ID = 0;
-char &llvm::LiveIntervalsID = LiveIntervals::ID;
-INITIALIZE_PASS_BEGIN(LiveIntervals, "liveintervals", "Live Interval Analysis",
-                      false, false)
+AnalysisKey LiveIntervalsAnalysis::Key;
+
+LiveIntervalsAnalysis::Result
+LiveIntervalsAnalysis::run(MachineFunction &MF,
+                           MachineFunctionAnalysisManager &MFAM) {
+  return Result(MF, MFAM.getResult<SlotIndexesAnalysis>(MF),
+                MFAM.getResult<MachineDominatorTreeAnalysis>(MF));
+}
+
+PreservedAnalyses
+LiveIntervalsPrinterPass::run(MachineFunction &MF,
+                              MachineFunctionAnalysisManager &MFAM) {
+  OS << "Live intervals for machine function: " << MF.getName() << ":\n";
+  MFAM.getResult<LiveIntervalsAnalysis>(MF).print(OS);
+  return PreservedAnalyses::all();
+}
+
+char LiveIntervalsWrapperPass::ID = 0;
+char &llvm::LiveIntervalsID = LiveIntervalsWrapperPass::ID;
+INITIALIZE_PASS_BEGIN(LiveIntervalsWrapperPass, "liveintervals",
+                      "Live Interval Analysis", false, false)
 INITIALIZE_PASS_DEPENDENCY(MachineDominatorTreeWrapperPass)
 INITIALIZE_PASS_DEPENDENCY(SlotIndexesWrapperPass)
-INITIALIZE_PASS_END(LiveIntervals, "liveintervals",
-                "Live Interval Analysis", false, false)
+INITIALIZE_PASS_END(LiveIntervalsWrapperPass, "liveintervals",
+                    "Live Interval Analysis", false, false)
+
+bool LiveIntervalsWrapperPass::runOnMachineFunction(MachineFunction &MF) {
+  LIS.Indexes = &getAnalysis<SlotIndexesWrapperPass>().getSI();
+  LIS.DomTree = &getAnalysis<MachineDominatorTreeWrapperPass>().getDomTree();
+  LIS.analyze(MF);
+  LLVM_DEBUG(dump());
+  return false;
+}
 
 #ifndef NDEBUG
 static cl::opt<bool> EnablePrecomputePhysRegs(
@@ -83,7 +108,7 @@ cl::opt<bool> UseSegmentSetForPhysRegs(
 
 } // end namespace llvm
 
-void LiveIntervals::getAnalysisUsage(AnalysisUsage &AU) const {
+void LiveIntervalsWrapperPass::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.setPreservesCFG();
   AU.addPreserved<LiveVariablesWrapperPass>();
   AU.addPreservedID(MachineLoopInfoID);
@@ -94,13 +119,13 @@ void LiveIntervals::getAnalysisUsage(AnalysisUsage &AU) const {
   MachineFunctionPass::getAnalysisUsage(AU);
 }
 
-LiveIntervals::LiveIntervals() : MachineFunctionPass(ID) {
-  initializeLiveIntervalsPass(*PassRegistry::getPassRegistry());
+LiveIntervalsWrapperPass::LiveIntervalsWrapperPass() : MachineFunctionPass(ID) {
+  initializeLiveIntervalsWrapperPassPass(*PassRegistry::getPassRegistry());
 }
 
-LiveIntervals::~LiveIntervals() { delete LICalc; }
+LiveIntervals::~LiveIntervals() { clear(); }
 
-void LiveIntervals::releaseMemory() {
+void LiveIntervals::clear() {
   // Free the live intervals themselves.
   for (unsigned i = 0, e = VirtRegIntervals.size(); i != e; ++i)
     delete VirtRegIntervals[Register::index2VirtReg(i)];
@@ -117,16 +142,14 @@ void LiveIntervals::releaseMemory() {
   VNInfoAllocator.Reset();
 }
 
-bool LiveIntervals::runOnMachineFunction(MachineFunction &fn) {
+void LiveIntervals::analyze(MachineFunction &fn) {
   MF = &fn;
   MRI = &MF->getRegInfo();
   TRI = MF->getSubtarget().getRegisterInfo();
   TII = MF->getSubtarget().getInstrInfo();
-  Indexes = &getAnalysis<SlotIndexesWrapperPass>().getSI();
-  DomTree = &getAnalysis<MachineDominatorTreeWrapperPass>().getDomTree();
 
   if (!LICalc)
-    LICalc = new LiveIntervalCalc();
+    LICalc = std::make_unique<LiveIntervalCalc>();
 
   // Allocate space for all virtual registers.
   VirtRegIntervals.resize(MRI->getNumVirtRegs());
@@ -141,11 +164,9 @@ bool LiveIntervals::runOnMachineFunction(MachineFunction &fn) {
     for (unsigned i = 0, e = TRI->getNumRegUnits(); i != e; ++i)
       getRegUnit(i);
   }
-  LLVM_DEBUG(dump());
-  return false;
 }
 
-void LiveIntervals::print(raw_ostream &OS, const Module* ) const {
+void LiveIntervals::print(raw_ostream &OS) const {
   OS << "********** INTERVALS **********\n";
 
   // Dump the regunits.
@@ -179,6 +200,10 @@ LLVM_DUMP_METHOD void LiveIntervals::dumpInstrs() const {
 }
 #endif
 
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+LLVM_DUMP_METHOD void LiveIntervals::dump() const { print(dbgs()); }
+#endif
+
 LiveInterval *LiveIntervals::createInterval(Register reg) {
   float Weight = reg.isPhysical() ? huge_valf : 0.0F;
   return new LiveInterval(reg, Weight);

llvm/lib/CodeGen/LiveRegMatrix.cpp

@@ -38,7 +38,7 @@ STATISTIC(NumUnassigned , "Number of registers unassigned");
 char LiveRegMatrix::ID = 0;
 INITIALIZE_PASS_BEGIN(LiveRegMatrix, "liveregmatrix",
                       "Live Register Matrix", false, false)
-INITIALIZE_PASS_DEPENDENCY(LiveIntervals)
+INITIALIZE_PASS_DEPENDENCY(LiveIntervalsWrapperPass)
 INITIALIZE_PASS_DEPENDENCY(VirtRegMap)
 INITIALIZE_PASS_END(LiveRegMatrix, "liveregmatrix",
                     "Live Register Matrix", false, false)
@@ -47,14 +47,14 @@ LiveRegMatrix::LiveRegMatrix() : MachineFunctionPass(ID) {}
 
 void LiveRegMatrix::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.setPreservesAll();
-  AU.addRequiredTransitive<LiveIntervals>();
+  AU.addRequiredTransitive<LiveIntervalsWrapperPass>();
   AU.addRequiredTransitive<VirtRegMap>();
   MachineFunctionPass::getAnalysisUsage(AU);
 }
 
 bool LiveRegMatrix::runOnMachineFunction(MachineFunction &MF) {
   TRI = MF.getSubtarget().getRegisterInfo();
-  LIS = &getAnalysis<LiveIntervals>();
+  LIS = &getAnalysis<LiveIntervalsWrapperPass>().getLIS();
   VRM = &getAnalysis<VirtRegMap>();
 
   unsigned NumRegUnits = TRI->getNumRegUnits();

llvm/lib/CodeGen/MachineBasicBlock.cpp

@@ -1161,7 +1161,8 @@ MachineBasicBlock *MachineBasicBlock::SplitCriticalEdge(
                     << " -- " << printMBBReference(*NMBB) << " -- "
                     << printMBBReference(*Succ) << '\n');
 
-  LiveIntervals *LIS = P.getAnalysisIfAvailable<LiveIntervals>();
+  auto *LISWrapper = P.getAnalysisIfAvailable<LiveIntervalsWrapperPass>();
+  LiveIntervals *LIS = LISWrapper ? &LISWrapper->getLIS() : nullptr;
   auto *SIWrapper = P.getAnalysisIfAvailable<SlotIndexesWrapperPass>();
   SlotIndexes *Indexes = SIWrapper ? &SIWrapper->getSI() : nullptr;
   if (LIS)