DbgEntityHistoryCalculator.cpp | Explore in Territory

//===- llvm/CodeGen/AsmPrinter/DbgEntityHistoryCalculator.cpp -------------===//
//
// 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
//
//===----------------------------------------------------------------------===//

#include "llvm/CodeGen/DbgEntityHistoryCalculator.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/CodeGen/LexicalScopes.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineOperand.h"
#include "llvm/CodeGen/TargetLowering.h"
#include "llvm/CodeGen/TargetRegisterInfo.h"
#include "llvm/CodeGen/TargetSubtargetInfo.h"
#include "llvm/IR/DebugInfoMetadata.h"
#include "llvm/IR/DebugLoc.h"
#include "llvm/MC/MCRegisterInfo.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include <cassert>
#include <map>
#include <optional>
#include <utility>

usingnamespacellvm;

#define DEBUG_TYPE …

namespace {
EntryIndex;
}

void InstructionOrdering::initialize(const MachineFunction &MF) { … }

bool InstructionOrdering::isBefore(const MachineInstr *A,
                                   const MachineInstr *B) const { … }

bool DbgValueHistoryMap::startDbgValue(InlinedEntity Var,
                                       const MachineInstr &MI,
                                       EntryIndex &NewIndex) { … }

EntryIndex DbgValueHistoryMap::startClobber(InlinedEntity Var,
                                            const MachineInstr &MI) { … }

void DbgValueHistoryMap::Entry::endEntry(EntryIndex Index) { … }

/// Check if the instruction range [StartMI, EndMI] intersects any instruction
/// range in Ranges. EndMI can be nullptr to indicate that the range is
/// unbounded. Assumes Ranges is ordered and disjoint. Returns true and points
/// to the first intersecting scope range if one exists.
static std::optional<ArrayRef<InsnRange>::iterator>
intersects(const MachineInstr *StartMI, const MachineInstr *EndMI,
           const ArrayRef<InsnRange> &Ranges,
           const InstructionOrdering &Ordering) { … }

void DbgValueHistoryMap::trimLocationRanges(
    const MachineFunction &MF, LexicalScopes &LScopes,
    const InstructionOrdering &Ordering) { … }

bool DbgValueHistoryMap::hasNonEmptyLocation(const Entries &Entries) const { … }

void DbgLabelInstrMap::addInstr(InlinedEntity Label, const MachineInstr &MI) { … }

namespace {

// Maps physreg numbers to the variables they describe.
InlinedEntity;
RegDescribedVarsMap;

// Keeps track of the debug value entries that are currently live for each
// inlined entity. As the history map entries are stored in a SmallVector, they
// may be moved at insertion of new entries, so store indices rather than
// pointers.
DbgValueEntriesMap;

} // end anonymous namespace

// Claim that @Var is not described by @RegNo anymore.
static void dropRegDescribedVar(RegDescribedVarsMap &RegVars, unsigned RegNo,
                                InlinedEntity Var) { … }

// Claim that @Var is now described by @RegNo.
static void addRegDescribedVar(RegDescribedVarsMap &RegVars, unsigned RegNo,
                               InlinedEntity Var) { … }

/// Create a clobbering entry and end all open debug value entries
/// for \p Var that are described by \p RegNo using that entry. Inserts into \p
/// FellowRegisters the set of Registers that were also used to describe \p Var
/// alongside \p RegNo.
static void clobberRegEntries(InlinedEntity Var, unsigned RegNo,
                              const MachineInstr &ClobberingInstr,
                              DbgValueEntriesMap &LiveEntries,
                              DbgValueHistoryMap &HistMap,
                              SmallVectorImpl<Register> &FellowRegisters) { … }

/// Add a new debug value for \p Var. Closes all overlapping debug values.
static void handleNewDebugValue(InlinedEntity Var, const MachineInstr &DV,
                                RegDescribedVarsMap &RegVars,
                                DbgValueEntriesMap &LiveEntries,
                                DbgValueHistoryMap &HistMap) { … }

// Terminate the location range for variables described by register at
// @I by inserting @ClobberingInstr to their history.
static void clobberRegisterUses(RegDescribedVarsMap &RegVars,
                                RegDescribedVarsMap::iterator I,
                                DbgValueHistoryMap &HistMap,
                                DbgValueEntriesMap &LiveEntries,
                                const MachineInstr &ClobberingInstr) { … }

// Terminate the location range for variables described by register
// @RegNo by inserting @ClobberingInstr to their history.
static void clobberRegisterUses(RegDescribedVarsMap &RegVars, unsigned RegNo,
                                DbgValueHistoryMap &HistMap,
                                DbgValueEntriesMap &LiveEntries,
                                const MachineInstr &ClobberingInstr) { … }

void llvm::calculateDbgEntityHistory(const MachineFunction *MF,
                                     const TargetRegisterInfo *TRI,
                                     DbgValueHistoryMap &DbgValues,
                                     DbgLabelInstrMap &DbgLabels) { … }

#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
LLVM_DUMP_METHOD void DbgValueHistoryMap::dump(StringRef FuncName) const {
  dbgs() << "DbgValueHistoryMap('" << FuncName << "'):\n";
  for (const auto &VarRangePair : *this) {
    const InlinedEntity &Var = VarRangePair.first;
    const Entries &Entries = VarRangePair.second;

    const DILocalVariable *LocalVar = cast<DILocalVariable>(Var.first);
    const DILocation *Location = Var.second;

    dbgs() << " - " << LocalVar->getName() << " at ";

    if (Location)
      dbgs() << Location->getFilename() << ":" << Location->getLine() << ":"
             << Location->getColumn();
    else
      dbgs() << "<unknown location>";

    dbgs() << " --\n";

    for (const auto &E : enumerate(Entries)) {
      const auto &Entry = E.value();
      dbgs() << "  Entry[" << E.index() << "]: ";
      if (Entry.isDbgValue())
        dbgs() << "Debug value\n";
      else
        dbgs() << "Clobber\n";
      dbgs() << "   Instr: " << *Entry.getInstr();
      if (Entry.isDbgValue()) {
        if (Entry.getEndIndex() == NoEntry)
          dbgs() << "   - Valid until end of function\n";
        else
          dbgs() << "   - Closed by Entry[" << Entry.getEndIndex() << "]\n";
      }
      dbgs() << "\n";
    }
  }
}
#endif
llvm/llvm/lib/CodeGen/AsmPrinter/DbgEntityHistoryCalculator.cpp
