WIP: [CodeGen][NPM] Port VirtRegRewriter to NPM

Not sure why this is squished into VirtRegMap.h

Author: optimisan

llvm/include/llvm/CodeGen/VirtRegMap.h

@@ -235,6 +235,19 @@ class VirtRegMapPrinterPass : public PassInfoMixin<VirtRegMapPrinterPass> {
                         MachineFunctionAnalysisManager &MFAM);
   static bool isRequired() { return true; }
 };
+
+class VirtRegRewriterPass : public PassInfoMixin<VirtRegRewriterPass> {
+  bool ClearVirtRegs = true;
+public:
+  VirtRegRewriterPass(bool ClearVirtRegs = true) : ClearVirtRegs(ClearVirtRegs) {}
+  PreservedAnalyses run(MachineFunction &MF,
+                        MachineFunctionAnalysisManager &MFAM);
+
+  static bool isRequired() { return true; }
+
+  void printPipeline(raw_ostream &OS, function_ref<StringRef(StringRef)>) const;
+};
+
 } // end llvm namespace
 
 #endif // LLVM_CODEGEN_VIRTREGMAP_H

llvm/include/llvm/InitializePasses.h

@@ -316,7 +316,7 @@ void initializeUnreachableBlockElimLegacyPassPass(PassRegistry &);
 void initializeUnreachableMachineBlockElimPass(PassRegistry &);
 void initializeVerifierLegacyPassPass(PassRegistry &);
 void initializeVirtRegMapWrapperLegacyPass(PassRegistry &);
-void initializeVirtRegRewriterPass(PassRegistry &);
+void initializeVirtRegRewriterLegacyPass(PassRegistry &);
 void initializeWasmEHPreparePass(PassRegistry &);
 void initializeWinEHPreparePass(PassRegistry &);
 void initializeWriteBitcodePassPass(PassRegistry &);

llvm/include/llvm/Passes/CodeGenPassBuilder.h

@@ -81,6 +81,7 @@
 #include "llvm/CodeGen/TargetPassConfig.h"
 #include "llvm/CodeGen/TwoAddressInstructionPass.h"
 #include "llvm/CodeGen/UnreachableBlockElim.h"
+#include "llvm/CodeGen/VirtRegMap.h"
 #include "llvm/CodeGen/WasmEHPrepare.h"
 #include "llvm/CodeGen/WinEHPrepare.h"
 #include "llvm/IR/PassManager.h"

llvm/include/llvm/Passes/MachinePassRegistry.def

@@ -215,6 +215,12 @@ MACHINE_FUNCTION_PASS_WITH_PARAMS(
       return parseRegAllocGreedyFilterFunc(*PB, Params);
     }, "reg-filter"
 )
+
+MACHINE_FUNCTION_PASS_WITH_PARAMS(
+    "virt-reg-rewriter", "VirtRegRewriterPass",
+    [](bool ClearVirtRegs) { return VirtRegRewriterPass(ClearVirtRegs); },
+    parseVirtRegRewriterPassOptions, "no-clear-vregs;clear-vregs")
+
 #undef MACHINE_FUNCTION_PASS_WITH_PARAMS
 
 // After a pass is converted to new pass manager, its entry should be moved from
@@ -287,6 +293,5 @@ DUMMY_MACHINE_FUNCTION_PASS("shrink-wrap", ShrinkWrapPass)
 DUMMY_MACHINE_FUNCTION_PASS("stack-frame-layout", StackFrameLayoutAnalysisPass)
 DUMMY_MACHINE_FUNCTION_PASS("stackmap-liveness", StackMapLivenessPass)
 DUMMY_MACHINE_FUNCTION_PASS("unpack-mi-bundles", UnpackMachineBundlesPass)
-DUMMY_MACHINE_FUNCTION_PASS("virtregrewriter", VirtRegRewriterPass)
 DUMMY_MACHINE_FUNCTION_PASS("xray-instrumentation", XRayInstrumentationPass)
 #undef DUMMY_MACHINE_FUNCTION_PASS

llvm/lib/CodeGen/CodeGen.cpp

@@ -141,7 +141,7 @@ void llvm::initializeCodeGen(PassRegistry &Registry) {
   initializeUnreachableBlockElimLegacyPassPass(Registry);
   initializeUnreachableMachineBlockElimPass(Registry);
   initializeVirtRegMapWrapperLegacyPass(Registry);
-  initializeVirtRegRewriterPass(Registry);
+  initializeVirtRegRewriterLegacyPass(Registry);
   initializeWasmEHPreparePass(Registry);
   initializeWinEHPreparePass(Registry);
   initializeXRayInstrumentationPass(Registry);

llvm/lib/CodeGen/VirtRegMap.cpp

@@ -29,6 +29,7 @@
 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/CodeGen/MachineInstr.h"
 #include "llvm/CodeGen/MachineOperand.h"
+#include "llvm/CodeGen/MachinePassManager.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/CodeGen/SlotIndexes.h"
 #include "llvm/CodeGen/TargetFrameLowering.h"
@@ -197,7 +198,7 @@ VirtRegMap VirtRegMapAnalysis::run(MachineFunction &MF,
 //
 namespace {
 
-class VirtRegRewriter : public MachineFunctionPass {
+class VirtRegRewriter {
   MachineFunction *MF = nullptr;
   const TargetRegisterInfo *TRI = nullptr;
   const TargetInstrInfo *TII = nullptr;
@@ -223,9 +224,22 @@ class VirtRegRewriter : public MachineFunctionPass {
 
 public:
   static char ID;
-  VirtRegRewriter(bool ClearVirtRegs_ = true) :
-    MachineFunctionPass(ID),
-    ClearVirtRegs(ClearVirtRegs_) {}
+  VirtRegRewriter(bool ClearVirtRegs, SlotIndexes *Indexes, LiveIntervals *LIS,
+                  LiveRegMatrix *LRM, VirtRegMap *VRM,
+                  LiveDebugVariables *DebugVars)
+      : Indexes(Indexes), LIS(LIS), LRM(LRM), VRM(VRM), DebugVars(DebugVars),
+        ClearVirtRegs(ClearVirtRegs) {}
+
+  bool run(MachineFunction&);
+
+};
+
+class VirtRegRewriterLegacy : public MachineFunctionPass {
+public:
+  static char ID;
+  bool ClearVirtRegs;
+  VirtRegRewriterLegacy(bool ClearVirtRegs = true) :
+    MachineFunctionPass(ID), ClearVirtRegs(ClearVirtRegs) {}
 
   void getAnalysisUsage(AnalysisUsage &AU) const override;
 
@@ -243,22 +257,22 @@ class VirtRegRewriter : public MachineFunctionPass {
 
 } // end anonymous namespace
 
-char VirtRegRewriter::ID = 0;
+char VirtRegRewriterLegacy::ID = 0;
 
-char &llvm::VirtRegRewriterID = VirtRegRewriter::ID;
+char &llvm::VirtRegRewriterID = VirtRegRewriterLegacy::ID;
 
-INITIALIZE_PASS_BEGIN(VirtRegRewriter, "virtregrewriter",
+INITIALIZE_PASS_BEGIN(VirtRegRewriterLegacy, "virtregrewriter",
                       "Virtual Register Rewriter", false, false)
 INITIALIZE_PASS_DEPENDENCY(SlotIndexesWrapperPass)
 INITIALIZE_PASS_DEPENDENCY(LiveIntervalsWrapperPass)
 INITIALIZE_PASS_DEPENDENCY(LiveDebugVariablesWrapperLegacy)
 INITIALIZE_PASS_DEPENDENCY(LiveRegMatrixWrapperLegacy)
 INITIALIZE_PASS_DEPENDENCY(LiveStacksWrapperLegacy)
 INITIALIZE_PASS_DEPENDENCY(VirtRegMapWrapperLegacy)
-INITIALIZE_PASS_END(VirtRegRewriter, "virtregrewriter",
+INITIALIZE_PASS_END(VirtRegRewriterLegacy, "virtregrewriter",
                     "Virtual Register Rewriter", false, false)
 
-void VirtRegRewriter::getAnalysisUsage(AnalysisUsage &AU) const {
+void VirtRegRewriterLegacy::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.setPreservesCFG();
   AU.addRequired<LiveIntervalsWrapperPass>();
   AU.addPreserved<LiveIntervalsWrapperPass>();
@@ -276,16 +290,47 @@ void VirtRegRewriter::getAnalysisUsage(AnalysisUsage &AU) const {
   MachineFunctionPass::getAnalysisUsage(AU);
 }
 
-bool VirtRegRewriter::runOnMachineFunction(MachineFunction &fn) {
+bool VirtRegRewriterLegacy::runOnMachineFunction(MachineFunction &MF) {
+  VirtRegMap &VRM = getAnalysis<VirtRegMapWrapperLegacy>().getVRM();
+  LiveIntervals &LIS = getAnalysis<LiveIntervalsWrapperPass>().getLIS();
+  LiveRegMatrix &LRM = getAnalysis<LiveRegMatrixWrapperLegacy>().getLRM();
+  SlotIndexes &Indexes = getAnalysis<SlotIndexesWrapperPass>().getSI();
+  LiveDebugVariables &DebugVars =
+      getAnalysis<LiveDebugVariablesWrapperLegacy>().getLDV();
+
+  VirtRegRewriter R(ClearVirtRegs, &Indexes, &LIS, &LRM, &VRM, &DebugVars);
+  return R.run(MF);
+}
+
+PreservedAnalyses VirtRegRewriterPass::run(MachineFunction &MF,
+  MachineFunctionAnalysisManager &MFAM) {
+  VirtRegMap &VRM = MFAM.getResult<VirtRegMapAnalysis>(MF);
+  LiveIntervals &LIS = MFAM.getResult<LiveIntervalsAnalysis>(MF);
+  LiveRegMatrix &LRM = MFAM.getResult<LiveRegMatrixAnalysis>(MF);
+  SlotIndexes &Indexes = MFAM.getResult<SlotIndexesAnalysis>(MF);
+  LiveDebugVariables &DebugVars = MFAM.getResult<LiveDebugVariablesAnalysis>(MF);
+
+  VirtRegRewriter R(ClearVirtRegs, &Indexes, &LIS, &LRM, &VRM, &DebugVars);
+  if (!R.run(MF))
+    return PreservedAnalyses::all();
+  auto PA = getMachineFunctionPassPreservedAnalyses();
+  PA.preserveSet<CFGAnalyses>();
+  PA.preserve<LiveIntervalsAnalysis>();
+  PA.preserve<SlotIndexesAnalysis>();
+  PA.preserve<LiveStacksAnalysis>();
+  // LiveDebugVariables is preserved by default, so clear it
+  // if this VRegRewriter is the last one in the pipeline.
+  if (ClearVirtRegs)
+    PA.abandon<LiveDebugVariablesAnalysis>();
+  return PA;
+}
+
+bool VirtRegRewriter::run(MachineFunction &fn) {
   MF = &fn;
   TRI = MF->getSubtarget().getRegisterInfo();
   TII = MF->getSubtarget().getInstrInfo();
   MRI = &MF->getRegInfo();
-  Indexes = &getAnalysis<SlotIndexesWrapperPass>().getSI();
-  LIS = &getAnalysis<LiveIntervalsWrapperPass>().getLIS();
-  LRM = &getAnalysis<LiveRegMatrixWrapperLegacy>().getLRM();
-  VRM = &getAnalysis<VirtRegMapWrapperLegacy>().getVRM();
-  DebugVars = &getAnalysis<LiveDebugVariablesWrapperLegacy>().getLDV();
+
   LLVM_DEBUG(dbgs() << "********** REWRITE VIRTUAL REGISTERS **********\n"
                     << "********** Function: " << MF->getName() << '\n');
   LLVM_DEBUG(VRM->dump());
@@ -726,6 +771,13 @@ void VirtRegRewriter::rewrite() {
   RewriteRegs.clear();
 }
 
+void VirtRegRewriterPass::printPipeline(raw_ostream &OS, function_ref<StringRef(StringRef)>) const {
+  OS << "virt-reg-rewriter<";
+  if (!ClearVirtRegs)
+    OS << "no-";
+  OS << "clear-vregs>";
+}
+
 FunctionPass *llvm::createVirtRegRewriter(bool ClearVirtRegs) {
-  return new VirtRegRewriter(ClearVirtRegs);
+  return new VirtRegRewriterLegacy(ClearVirtRegs);
 }

llvm/lib/Passes/PassBuilder.cpp

@@ -1438,6 +1438,19 @@ Expected<bool> parseMachineSinkingPassOptions(StringRef Params) {
                                             "MachineSinkingPass");
 }
 
+Expected<bool> parseVirtRegRewriterPassOptions(StringRef Params) {
+  bool ClearVirtRegs = true;
+  if (!Params.empty()) {
+    ClearVirtRegs = !Params.consume_front("no-");
+    if (Params != "clear-vregs")
+      return make_error<StringError>(
+          formatv("invalid VirtRegRewriter pass parameter '{0}' ", Params)
+              .str(),
+          inconvertibleErrorCode());
+  }
+  return ClearVirtRegs;
+}
+
 } // namespace
 
 /// Tests whether a pass name starts with a valid prefix for a default pipeline

llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp

@@ -2237,7 +2237,7 @@ Error AMDGPUCodeGenPassBuilder::addRegAssignmentOptimized(
   // many things rely on the use lists of the physical registers, such as the
   // verifier. This is only necessary with allocators which use LiveIntervals,
   // since FastRegAlloc does the replacements itself.
-  // TODO: addPass(VirtRegRewriterPass(false));
+  addPass(VirtRegRewriterPass(false));
 
   // At this point, the sgpr-regalloc has been done and it is good to have the
   // stack slot coloring to try to optimize the SGPR spill stack indices before
@@ -2253,7 +2253,7 @@ Error AMDGPUCodeGenPassBuilder::addRegAssignmentOptimized(
   // For allocating other wwm register operands.
   addRegAlloc<RAGreedyPass>(addPass, RegAllocPhase::WWM);
   addPass(SILowerWWMCopiesPass());
-  // TODO: addPass(VirtRegRewriterPass(false));
+  addPass(VirtRegRewriterPass(false));
   // TODO: addPass(AMDGPUReserveWWMRegsPass());
 
   // For allocating per-thread VGPRs.

llvm/test/CodeGen/X86/pr30821.mir

@@ -1,4 +1,5 @@
 # RUN: llc -x mir < %s -run-pass=greedy,virtregrewriter,stack-slot-coloring | FileCheck %s
+# RUN: llc -x mir < %s -passes=greedy,virt-reg-rewriter,stack-slot-coloring | FileCheck %s
 --- |
   target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
   target triple = "x86_64-unknown-linux-gnu"