Revert "Add a pass to collect dropped var stats for MIR. (#115566)"

This reverts commit 6e2b77d469.

Reverting due to buildbot failure:

unittests/IR/CMakeFiles/IRTests.dir/DroppedVariableStatsIRTest.cpp.o:DroppedVariableStatsIRTest.cpp:function llvm::DroppedVariableStatsIR::runAfterPass(llvm::StringRef, llvm::Any): error: undefined reference to 'llvm::DroppedVariableStatsIR::runOnModule(llvm::Module const*, bool)'

llvm/include/llvm/CodeGen/DroppedVariableStats.h

@@ -7,7 +7,7 @@
 ///===---------------------------------------------------------------------===//
 /// \file
 /// Dropped Variable Statistics for Debug Information. Reports any number
-/// of #dbg_values or DBG_VALUEs that get dropped due to an optimization pass.
+/// of #dbg_value that get dropped due to an optimization pass.
 ///
 ///===---------------------------------------------------------------------===//
 
@@ -221,52 +221,6 @@ private:
   }
 };
 
-/// A class to collect and print dropped debug information due to MIR
-/// optimization passes. After every MIR pass is run, it will print how many
-/// #DBG_VALUEs were dropped due to that pass.
-class DroppedVariableStatsMIR : public DroppedVariableStats {
-public:
-  DroppedVariableStatsMIR() : llvm::DroppedVariableStats(false) {}
-
-  void runBeforePass(StringRef PassID, MachineFunction *MF) {
-    if (PassID == "Debug Variable Analysis")
-      return;
-    setup();
-    return runOnMachineFunction(MF, true);
-  }
-
-  void runAfterPass(StringRef PassID, MachineFunction *MF) {
-    if (PassID == "Debug Variable Analysis")
-      return;
-    runOnMachineFunction(MF, false);
-    calculateDroppedVarStatsOnMachineFunction(MF, PassID, MF->getName().str());
-    cleanup();
-  }
-
-private:
-  const MachineFunction *MFunc;
-  /// Populate DebugVariablesBefore, DebugVariablesAfter, InlinedAts before or
-  /// after a pass has run to facilitate dropped variable calculation for an
-  /// llvm::MachineFunction.
-  void runOnMachineFunction(const MachineFunction *MF, bool Before);
-  /// Iterate over all Instructions in a MachineFunction and report any dropped
-  /// debug information.
-  void calculateDroppedVarStatsOnMachineFunction(const MachineFunction *MF,
-                                                 StringRef PassID,
-                                                 StringRef FuncOrModName);
-  /// Override base class method to run on an llvm::MachineFunction
-  /// specifically.
-  virtual void
-  visitEveryInstruction(unsigned &DroppedCount,
-                        DenseMap<VarID, DILocation *> &InlinedAtsMap,
-                        VarID Var) override;
-  /// Override base class method to run on DBG_VALUEs specifically.
-  virtual void visitEveryDebugRecord(
-      DenseSet<VarID> &VarIDSet,
-      DenseMap<StringRef, DenseMap<VarID, DILocation *>> &InlinedAtsMap,
-      StringRef FuncName, bool Before) override;
-};
-
 } // namespace llvm
 
 #endif

llvm/include/llvm/CodeGen/MachineFunctionPass.h

@@ -18,7 +18,6 @@
 #ifndef LLVM_CODEGEN_MACHINEFUNCTIONPASS_H
 #define LLVM_CODEGEN_MACHINEFUNCTIONPASS_H
 
-#include "llvm/CodeGen/DroppedVariableStats.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/Pass.h"
 
@@ -68,7 +67,6 @@ private:
   MachineFunctionProperties RequiredProperties;
   MachineFunctionProperties SetProperties;
   MachineFunctionProperties ClearedProperties;
-  DroppedVariableStatsMIR DroppedVarStatsMF;
 
   /// createPrinterPass - Get a machine function printer pass.
   Pass *createPrinterPass(raw_ostream &O,

llvm/lib/CodeGen/DroppedVariableStats.cpp

@@ -7,7 +7,7 @@
 ///===---------------------------------------------------------------------===//
 /// \file
 /// Dropped Variable Statistics for Debug Information. Reports any number
-/// of #dbg_values or DBG_VALUEs that get dropped due to an optimization pass.
+/// of #dbg_value that get dropped due to an optimization pass.
 ///
 ///===---------------------------------------------------------------------===//
 
@@ -192,64 +192,3 @@ void DroppedVariableStatsIR::visitEveryDebugRecord(
     }
   }
 }
-
-void DroppedVariableStatsMIR::runOnMachineFunction(const MachineFunction *MF,
-                                                   bool Before) {
-  auto &DebugVariables = DebugVariablesStack.back()[&MF->getFunction()];
-  auto FuncName = MF->getName();
-  MFunc = MF;
-  run(DebugVariables, FuncName, Before);
-}
-
-void DroppedVariableStatsMIR::calculateDroppedVarStatsOnMachineFunction(
-    const MachineFunction *MF, StringRef PassID, StringRef FuncOrModName) {
-  MFunc = MF;
-  StringRef FuncName = MF->getName();
-  const Function *Func = &MF->getFunction();
-  DebugVariables &DbgVariables = DebugVariablesStack.back()[Func];
-  calculateDroppedStatsAndPrint(DbgVariables, FuncName, PassID, FuncOrModName,
-                                "MachineFunction", Func);
-}
-
-void DroppedVariableStatsMIR::visitEveryInstruction(
-    unsigned &DroppedCount, DenseMap<VarID, DILocation *> &InlinedAtsMap,
-    VarID Var) {
-  unsigned PrevDroppedCount = DroppedCount;
-  const DIScope *DbgValScope = std::get<0>(Var);
-  for (const auto &MBB : *MFunc) {
-    for (const auto &MI : MBB) {
-      if (!MI.isDebugInstr()) {
-        auto *DbgLoc = MI.getDebugLoc().get();
-        if (!DbgLoc)
-          continue;
-
-        auto *Scope = DbgLoc->getScope();
-        if (updateDroppedCount(DbgLoc, Scope, DbgValScope, InlinedAtsMap, Var,
-                               DroppedCount))
-          break;
-      }
-    }
-    if (PrevDroppedCount != DroppedCount) {
-      PrevDroppedCount = DroppedCount;
-      break;
-    }
-  }
-}
-
-void DroppedVariableStatsMIR::visitEveryDebugRecord(
-    DenseSet<VarID> &VarIDSet,
-    DenseMap<StringRef, DenseMap<VarID, DILocation *>> &InlinedAtsMap,
-    StringRef FuncName, bool Before) {
-  for (const auto &MBB : *MFunc) {
-    for (const auto &MI : MBB) {
-      if (MI.isDebugValueLike()) {
-        auto *DbgVar = MI.getDebugVariable();
-        if (!DbgVar)
-          continue;
-        auto DbgLoc = MI.getDebugLoc();
-        populateVarIDSetAndInlinedMap(DbgVar, DbgLoc, VarIDSet, InlinedAtsMap,
-                                      FuncName, Before);
-      }
-    }
-  }
-}

llvm/lib/CodeGen/MachineFunctionPass.cpp

@@ -32,11 +32,6 @@
 using namespace llvm;
 using namespace ore;
 
-static cl::opt<bool> DroppedVarStatsMIR(
-    "dropped-variable-stats-mir", cl::Hidden,
-    cl::desc("Dump dropped debug variables stats for MIR passes"),
-    cl::init(false));
-
 Pass *MachineFunctionPass::createPrinterPass(raw_ostream &O,
                                              const std::string &Banner) const {
   return createMachineFunctionPrinterPass(O, Banner);
@@ -96,15 +91,7 @@ bool MachineFunctionPass::runOnFunction(Function &F) {
 
   MFProps.reset(ClearedProperties);
 
-  bool RV;
-  if (DroppedVarStatsMIR) {
-    auto PassName = getPassName();
-    DroppedVarStatsMF.runBeforePass(PassName, &MF);
-    RV = runOnMachineFunction(MF);
-    DroppedVarStatsMF.runAfterPass(PassName, &MF);
-  } else {
-    RV = runOnMachineFunction(MF);
-  }
+  bool RV = runOnMachineFunction(MF);
 
   if (ShouldEmitSizeRemarks) {
     // We wanted size remarks. Check if there was a change to the number of

llvm/unittests/MIR/CMakeLists.txt

@@ -16,7 +16,6 @@ set(LLVM_LINK_COMPONENTS
 add_llvm_unittest(MIRTests
   MachineMetadata.cpp
   MachineStableHashTest.cpp
-  DroppedVariableStatsMIRTest.cpp
   )
 
 target_link_libraries(MIRTests PRIVATE LLVMTestingSupport)