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c362f0a17e
The D35953, D62650 and D73691 introduced trimming of variables locations in LiveDebugVariables pass, since there are some cases where after the virtregrewrite we have exploded number of DBG_VALUEs created for some inlined variables. As it looks, all problematic cases were regarding inlined variables, so it seems reasonable to stop trimming the location ranges for non-inlined variables. It has very good impact on the llvm-locstats report. Differential Revision: https://reviews.llvm.org/D102917
1887 lines
70 KiB
C++
1887 lines
70 KiB
C++
//===- LiveDebugVariables.cpp - Tracking debug info variables -------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements the LiveDebugVariables analysis.
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//
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// Remove all DBG_VALUE instructions referencing virtual registers and replace
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// them with a data structure tracking where live user variables are kept - in a
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// virtual register or in a stack slot.
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//
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// Allow the data structure to be updated during register allocation when values
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// are moved between registers and stack slots. Finally emit new DBG_VALUE
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// instructions after register allocation is complete.
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//
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//===----------------------------------------------------------------------===//
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#include "LiveDebugVariables.h"
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#include "llvm/ADT/ArrayRef.h"
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#include "llvm/ADT/DenseMap.h"
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#include "llvm/ADT/IntervalMap.h"
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#include "llvm/ADT/MapVector.h"
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#include "llvm/ADT/STLExtras.h"
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#include "llvm/ADT/SmallSet.h"
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#include "llvm/ADT/SmallVector.h"
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#include "llvm/ADT/Statistic.h"
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#include "llvm/ADT/StringRef.h"
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#include "llvm/CodeGen/LexicalScopes.h"
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#include "llvm/CodeGen/LiveInterval.h"
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#include "llvm/CodeGen/LiveIntervals.h"
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#include "llvm/CodeGen/MachineBasicBlock.h"
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#include "llvm/CodeGen/MachineDominators.h"
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#include "llvm/CodeGen/MachineFunction.h"
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#include "llvm/CodeGen/MachineInstr.h"
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#include "llvm/CodeGen/MachineInstrBuilder.h"
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#include "llvm/CodeGen/MachineOperand.h"
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#include "llvm/CodeGen/MachineRegisterInfo.h"
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#include "llvm/CodeGen/SlotIndexes.h"
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#include "llvm/CodeGen/TargetInstrInfo.h"
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#include "llvm/CodeGen/TargetOpcodes.h"
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#include "llvm/CodeGen/TargetRegisterInfo.h"
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#include "llvm/CodeGen/TargetSubtargetInfo.h"
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#include "llvm/CodeGen/VirtRegMap.h"
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#include "llvm/Config/llvm-config.h"
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#include "llvm/IR/DebugInfoMetadata.h"
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#include "llvm/IR/DebugLoc.h"
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#include "llvm/IR/Function.h"
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#include "llvm/IR/Metadata.h"
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#include "llvm/InitializePasses.h"
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#include "llvm/MC/MCRegisterInfo.h"
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#include "llvm/Pass.h"
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#include "llvm/Support/Casting.h"
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#include "llvm/Support/CommandLine.h"
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#include "llvm/Support/Debug.h"
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#include "llvm/Support/raw_ostream.h"
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#include <algorithm>
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#include <cassert>
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#include <iterator>
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#include <memory>
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#include <utility>
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using namespace llvm;
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#define DEBUG_TYPE "livedebugvars"
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static cl::opt<bool>
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EnableLDV("live-debug-variables", cl::init(true),
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cl::desc("Enable the live debug variables pass"), cl::Hidden);
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STATISTIC(NumInsertedDebugValues, "Number of DBG_VALUEs inserted");
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STATISTIC(NumInsertedDebugLabels, "Number of DBG_LABELs inserted");
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char LiveDebugVariables::ID = 0;
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INITIALIZE_PASS_BEGIN(LiveDebugVariables, DEBUG_TYPE,
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"Debug Variable Analysis", false, false)
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INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree)
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INITIALIZE_PASS_DEPENDENCY(LiveIntervals)
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INITIALIZE_PASS_END(LiveDebugVariables, DEBUG_TYPE,
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"Debug Variable Analysis", false, false)
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void LiveDebugVariables::getAnalysisUsage(AnalysisUsage &AU) const {
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AU.addRequired<MachineDominatorTree>();
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AU.addRequiredTransitive<LiveIntervals>();
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AU.setPreservesAll();
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MachineFunctionPass::getAnalysisUsage(AU);
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}
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LiveDebugVariables::LiveDebugVariables() : MachineFunctionPass(ID) {
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initializeLiveDebugVariablesPass(*PassRegistry::getPassRegistry());
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}
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enum : unsigned { UndefLocNo = ~0U };
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namespace {
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/// Describes a debug variable value by location number and expression along
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/// with some flags about the original usage of the location.
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class DbgVariableValue {
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public:
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DbgVariableValue(ArrayRef<unsigned> NewLocs, bool WasIndirect, bool WasList,
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const DIExpression &Expr)
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: WasIndirect(WasIndirect), WasList(WasList), Expression(&Expr) {
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assert(!(WasIndirect && WasList) &&
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"DBG_VALUE_LISTs should not be indirect.");
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SmallVector<unsigned> LocNoVec;
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for (unsigned LocNo : NewLocs) {
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auto It = find(LocNoVec, LocNo);
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if (It == LocNoVec.end())
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LocNoVec.push_back(LocNo);
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else {
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// Loc duplicates an element in LocNos; replace references to Op
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// with references to the duplicating element.
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unsigned OpIdx = LocNoVec.size();
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unsigned DuplicatingIdx = std::distance(LocNoVec.begin(), It);
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Expression =
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DIExpression::replaceArg(Expression, OpIdx, DuplicatingIdx);
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}
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}
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// FIXME: Debug values referencing 64+ unique machine locations are rare and
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// currently unsupported for performance reasons. If we can verify that
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// performance is acceptable for such debug values, we can increase the
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// bit-width of LocNoCount to 14 to enable up to 16384 unique machine
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// locations. We will also need to verify that this does not cause issues
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// with LiveDebugVariables' use of IntervalMap.
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if (LocNoVec.size() < 64) {
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LocNoCount = LocNoVec.size();
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if (LocNoCount > 0) {
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LocNos = std::make_unique<unsigned[]>(LocNoCount);
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std::copy(LocNoVec.begin(), LocNoVec.end(), loc_nos_begin());
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}
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} else {
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LLVM_DEBUG(dbgs() << "Found debug value with 64+ unique machine "
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"locations, dropping...\n");
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LocNoCount = 1;
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// Turn this into an undef debug value list; right now, the simplest form
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// of this is an expression with one arg, and an undef debug operand.
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Expression =
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DIExpression::get(Expr.getContext(), {dwarf::DW_OP_LLVM_arg, 0,
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dwarf::DW_OP_stack_value});
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if (auto FragmentInfoOpt = Expr.getFragmentInfo())
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Expression = *DIExpression::createFragmentExpression(
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Expression, FragmentInfoOpt->OffsetInBits,
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FragmentInfoOpt->SizeInBits);
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LocNos = std::make_unique<unsigned[]>(LocNoCount);
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LocNos[0] = UndefLocNo;
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}
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}
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DbgVariableValue() : LocNoCount(0), WasIndirect(0), WasList(0) {}
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DbgVariableValue(const DbgVariableValue &Other)
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: LocNoCount(Other.LocNoCount), WasIndirect(Other.getWasIndirect()),
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WasList(Other.getWasList()), Expression(Other.getExpression()) {
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if (Other.getLocNoCount()) {
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LocNos.reset(new unsigned[Other.getLocNoCount()]);
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std::copy(Other.loc_nos_begin(), Other.loc_nos_end(), loc_nos_begin());
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}
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}
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DbgVariableValue &operator=(const DbgVariableValue &Other) {
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if (this == &Other)
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return *this;
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if (Other.getLocNoCount()) {
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LocNos.reset(new unsigned[Other.getLocNoCount()]);
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std::copy(Other.loc_nos_begin(), Other.loc_nos_end(), loc_nos_begin());
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} else {
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LocNos.release();
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}
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LocNoCount = Other.getLocNoCount();
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WasIndirect = Other.getWasIndirect();
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WasList = Other.getWasList();
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Expression = Other.getExpression();
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return *this;
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}
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const DIExpression *getExpression() const { return Expression; }
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uint8_t getLocNoCount() const { return LocNoCount; }
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bool containsLocNo(unsigned LocNo) const {
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return is_contained(loc_nos(), LocNo);
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}
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bool getWasIndirect() const { return WasIndirect; }
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bool getWasList() const { return WasList; }
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bool isUndef() const { return LocNoCount == 0 || containsLocNo(UndefLocNo); }
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DbgVariableValue decrementLocNosAfterPivot(unsigned Pivot) const {
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SmallVector<unsigned, 4> NewLocNos;
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for (unsigned LocNo : loc_nos())
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NewLocNos.push_back(LocNo != UndefLocNo && LocNo > Pivot ? LocNo - 1
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: LocNo);
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return DbgVariableValue(NewLocNos, WasIndirect, WasList, *Expression);
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}
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DbgVariableValue remapLocNos(ArrayRef<unsigned> LocNoMap) const {
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SmallVector<unsigned> NewLocNos;
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for (unsigned LocNo : loc_nos())
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// Undef values don't exist in locations (and thus not in LocNoMap
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// either) so skip over them. See getLocationNo().
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NewLocNos.push_back(LocNo == UndefLocNo ? UndefLocNo : LocNoMap[LocNo]);
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return DbgVariableValue(NewLocNos, WasIndirect, WasList, *Expression);
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}
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DbgVariableValue changeLocNo(unsigned OldLocNo, unsigned NewLocNo) const {
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SmallVector<unsigned> NewLocNos;
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NewLocNos.assign(loc_nos_begin(), loc_nos_end());
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auto OldLocIt = find(NewLocNos, OldLocNo);
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assert(OldLocIt != NewLocNos.end() && "Old location must be present.");
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*OldLocIt = NewLocNo;
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return DbgVariableValue(NewLocNos, WasIndirect, WasList, *Expression);
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}
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bool hasLocNoGreaterThan(unsigned LocNo) const {
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return any_of(loc_nos(),
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[LocNo](unsigned ThisLocNo) { return ThisLocNo > LocNo; });
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}
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void printLocNos(llvm::raw_ostream &OS) const {
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for (const unsigned &Loc : loc_nos())
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OS << (&Loc == loc_nos_begin() ? " " : ", ") << Loc;
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}
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friend inline bool operator==(const DbgVariableValue &LHS,
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const DbgVariableValue &RHS) {
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if (std::tie(LHS.LocNoCount, LHS.WasIndirect, LHS.WasList,
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LHS.Expression) !=
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std::tie(RHS.LocNoCount, RHS.WasIndirect, RHS.WasList, RHS.Expression))
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return false;
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return std::equal(LHS.loc_nos_begin(), LHS.loc_nos_end(),
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RHS.loc_nos_begin());
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}
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friend inline bool operator!=(const DbgVariableValue &LHS,
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const DbgVariableValue &RHS) {
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return !(LHS == RHS);
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}
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unsigned *loc_nos_begin() { return LocNos.get(); }
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const unsigned *loc_nos_begin() const { return LocNos.get(); }
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unsigned *loc_nos_end() { return LocNos.get() + LocNoCount; }
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const unsigned *loc_nos_end() const { return LocNos.get() + LocNoCount; }
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ArrayRef<unsigned> loc_nos() const {
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return ArrayRef<unsigned>(LocNos.get(), LocNoCount);
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}
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private:
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// IntervalMap requires the value object to be very small, to the extent
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// that we do not have enough room for an std::vector. Using a C-style array
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// (with a unique_ptr wrapper for convenience) allows us to optimize for this
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// specific case by packing the array size into only 6 bits (it is highly
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// unlikely that any debug value will need 64+ locations).
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std::unique_ptr<unsigned[]> LocNos;
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uint8_t LocNoCount : 6;
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bool WasIndirect : 1;
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bool WasList : 1;
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const DIExpression *Expression = nullptr;
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};
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} // namespace
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/// Map of where a user value is live to that value.
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using LocMap = IntervalMap<SlotIndex, DbgVariableValue, 4>;
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/// Map of stack slot offsets for spilled locations.
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/// Non-spilled locations are not added to the map.
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using SpillOffsetMap = DenseMap<unsigned, unsigned>;
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/// Cache to save the location where it can be used as the starting
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/// position as input for calling MachineBasicBlock::SkipPHIsLabelsAndDebug.
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/// This is to prevent MachineBasicBlock::SkipPHIsLabelsAndDebug from
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/// repeatedly searching the same set of PHIs/Labels/Debug instructions
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/// if it is called many times for the same block.
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using BlockSkipInstsMap =
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DenseMap<MachineBasicBlock *, MachineBasicBlock::iterator>;
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namespace {
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class LDVImpl;
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/// A user value is a part of a debug info user variable.
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///
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/// A DBG_VALUE instruction notes that (a sub-register of) a virtual register
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/// holds part of a user variable. The part is identified by a byte offset.
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///
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/// UserValues are grouped into equivalence classes for easier searching. Two
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/// user values are related if they are held by the same virtual register. The
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/// equivalence class is the transitive closure of that relation.
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class UserValue {
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const DILocalVariable *Variable; ///< The debug info variable we are part of.
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/// The part of the variable we describe.
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const Optional<DIExpression::FragmentInfo> Fragment;
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DebugLoc dl; ///< The debug location for the variable. This is
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///< used by dwarf writer to find lexical scope.
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UserValue *leader; ///< Equivalence class leader.
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UserValue *next = nullptr; ///< Next value in equivalence class, or null.
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/// Numbered locations referenced by locmap.
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SmallVector<MachineOperand, 4> locations;
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/// Map of slot indices where this value is live.
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LocMap locInts;
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/// Set of interval start indexes that have been trimmed to the
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/// lexical scope.
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SmallSet<SlotIndex, 2> trimmedDefs;
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/// Insert a DBG_VALUE into MBB at Idx for DbgValue.
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void insertDebugValue(MachineBasicBlock *MBB, SlotIndex StartIdx,
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SlotIndex StopIdx, DbgVariableValue DbgValue,
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ArrayRef<bool> LocSpills,
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ArrayRef<unsigned> SpillOffsets, LiveIntervals &LIS,
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const TargetInstrInfo &TII,
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const TargetRegisterInfo &TRI,
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BlockSkipInstsMap &BBSkipInstsMap);
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/// Replace OldLocNo ranges with NewRegs ranges where NewRegs
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/// is live. Returns true if any changes were made.
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bool splitLocation(unsigned OldLocNo, ArrayRef<Register> NewRegs,
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LiveIntervals &LIS);
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public:
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/// Create a new UserValue.
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UserValue(const DILocalVariable *var,
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Optional<DIExpression::FragmentInfo> Fragment, DebugLoc L,
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LocMap::Allocator &alloc)
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: Variable(var), Fragment(Fragment), dl(std::move(L)), leader(this),
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locInts(alloc) {}
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/// Get the leader of this value's equivalence class.
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UserValue *getLeader() {
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UserValue *l = leader;
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while (l != l->leader)
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l = l->leader;
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return leader = l;
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}
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/// Return the next UserValue in the equivalence class.
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UserValue *getNext() const { return next; }
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/// Merge equivalence classes.
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static UserValue *merge(UserValue *L1, UserValue *L2) {
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L2 = L2->getLeader();
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if (!L1)
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return L2;
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L1 = L1->getLeader();
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if (L1 == L2)
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return L1;
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// Splice L2 before L1's members.
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UserValue *End = L2;
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while (End->next) {
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End->leader = L1;
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End = End->next;
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}
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End->leader = L1;
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End->next = L1->next;
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L1->next = L2;
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return L1;
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}
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/// Return the location number that matches Loc.
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///
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/// For undef values we always return location number UndefLocNo without
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/// inserting anything in locations. Since locations is a vector and the
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/// location number is the position in the vector and UndefLocNo is ~0,
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/// we would need a very big vector to put the value at the right position.
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unsigned getLocationNo(const MachineOperand &LocMO) {
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if (LocMO.isReg()) {
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if (LocMO.getReg() == 0)
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return UndefLocNo;
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// For register locations we dont care about use/def and other flags.
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for (unsigned i = 0, e = locations.size(); i != e; ++i)
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if (locations[i].isReg() &&
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locations[i].getReg() == LocMO.getReg() &&
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locations[i].getSubReg() == LocMO.getSubReg())
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return i;
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} else
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for (unsigned i = 0, e = locations.size(); i != e; ++i)
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if (LocMO.isIdenticalTo(locations[i]))
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return i;
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locations.push_back(LocMO);
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// We are storing a MachineOperand outside a MachineInstr.
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locations.back().clearParent();
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// Don't store def operands.
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if (locations.back().isReg()) {
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if (locations.back().isDef())
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locations.back().setIsDead(false);
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locations.back().setIsUse();
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}
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return locations.size() - 1;
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}
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/// Remove (recycle) a location number. If \p LocNo still is used by the
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/// locInts nothing is done.
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void removeLocationIfUnused(unsigned LocNo) {
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// Bail out if LocNo still is used.
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for (LocMap::const_iterator I = locInts.begin(); I.valid(); ++I) {
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const DbgVariableValue &DbgValue = I.value();
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if (DbgValue.containsLocNo(LocNo))
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return;
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}
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// Remove the entry in the locations vector, and adjust all references to
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// location numbers above the removed entry.
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locations.erase(locations.begin() + LocNo);
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for (LocMap::iterator I = locInts.begin(); I.valid(); ++I) {
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const DbgVariableValue &DbgValue = I.value();
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if (DbgValue.hasLocNoGreaterThan(LocNo))
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I.setValueUnchecked(DbgValue.decrementLocNosAfterPivot(LocNo));
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}
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}
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/// Ensure that all virtual register locations are mapped.
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void mapVirtRegs(LDVImpl *LDV);
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/// Add a definition point to this user value.
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void addDef(SlotIndex Idx, ArrayRef<MachineOperand> LocMOs, bool IsIndirect,
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bool IsList, const DIExpression &Expr) {
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SmallVector<unsigned> Locs;
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for (MachineOperand Op : LocMOs)
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Locs.push_back(getLocationNo(Op));
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DbgVariableValue DbgValue(Locs, IsIndirect, IsList, Expr);
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// Add a singular (Idx,Idx) -> value mapping.
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LocMap::iterator I = locInts.find(Idx);
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if (!I.valid() || I.start() != Idx)
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I.insert(Idx, Idx.getNextSlot(), std::move(DbgValue));
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else
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// A later DBG_VALUE at the same SlotIndex overrides the old location.
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I.setValue(std::move(DbgValue));
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}
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/// Extend the current definition as far as possible down.
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///
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/// Stop when meeting an existing def or when leaving the live
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/// range of VNI. End points where VNI is no longer live are added to Kills.
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///
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/// We only propagate DBG_VALUES locally here. LiveDebugValues performs a
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/// data-flow analysis to propagate them beyond basic block boundaries.
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///
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/// \param Idx Starting point for the definition.
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/// \param DbgValue value to propagate.
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/// \param LiveIntervalInfo For each location number key in this map,
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/// restricts liveness to where the LiveRange has the value equal to the\
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/// VNInfo.
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/// \param [out] Kills Append end points of VNI's live range to Kills.
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/// \param LIS Live intervals analysis.
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void extendDef(SlotIndex Idx, DbgVariableValue DbgValue,
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|
SmallDenseMap<unsigned, std::pair<LiveRange *, const VNInfo *>>
|
|
&LiveIntervalInfo,
|
|
Optional<std::pair<SlotIndex, SmallVector<unsigned>>> &Kills,
|
|
LiveIntervals &LIS);
|
|
|
|
/// The value in LI may be copies to other registers. Determine if
|
|
/// any of the copies are available at the kill points, and add defs if
|
|
/// possible.
|
|
///
|
|
/// \param DbgValue Location number of LI->reg, and DIExpression.
|
|
/// \param LocIntervals Scan for copies of the value for each location in the
|
|
/// corresponding LiveInterval->reg.
|
|
/// \param KilledAt The point where the range of DbgValue could be extended.
|
|
/// \param [in,out] NewDefs Append (Idx, DbgValue) of inserted defs here.
|
|
void addDefsFromCopies(
|
|
DbgVariableValue DbgValue,
|
|
SmallVectorImpl<std::pair<unsigned, LiveInterval *>> &LocIntervals,
|
|
SlotIndex KilledAt,
|
|
SmallVectorImpl<std::pair<SlotIndex, DbgVariableValue>> &NewDefs,
|
|
MachineRegisterInfo &MRI, LiveIntervals &LIS);
|
|
|
|
/// Compute the live intervals of all locations after collecting all their
|
|
/// def points.
|
|
void computeIntervals(MachineRegisterInfo &MRI, const TargetRegisterInfo &TRI,
|
|
LiveIntervals &LIS, LexicalScopes &LS);
|
|
|
|
/// Replace OldReg ranges with NewRegs ranges where NewRegs is
|
|
/// live. Returns true if any changes were made.
|
|
bool splitRegister(Register OldReg, ArrayRef<Register> NewRegs,
|
|
LiveIntervals &LIS);
|
|
|
|
/// Rewrite virtual register locations according to the provided virtual
|
|
/// register map. Record the stack slot offsets for the locations that
|
|
/// were spilled.
|
|
void rewriteLocations(VirtRegMap &VRM, const MachineFunction &MF,
|
|
const TargetInstrInfo &TII,
|
|
const TargetRegisterInfo &TRI,
|
|
SpillOffsetMap &SpillOffsets);
|
|
|
|
/// Recreate DBG_VALUE instruction from data structures.
|
|
void emitDebugValues(VirtRegMap *VRM, LiveIntervals &LIS,
|
|
const TargetInstrInfo &TII,
|
|
const TargetRegisterInfo &TRI,
|
|
const SpillOffsetMap &SpillOffsets,
|
|
BlockSkipInstsMap &BBSkipInstsMap);
|
|
|
|
/// Return DebugLoc of this UserValue.
|
|
const DebugLoc &getDebugLoc() { return dl; }
|
|
|
|
void print(raw_ostream &, const TargetRegisterInfo *);
|
|
};
|
|
|
|
/// A user label is a part of a debug info user label.
|
|
class UserLabel {
|
|
const DILabel *Label; ///< The debug info label we are part of.
|
|
DebugLoc dl; ///< The debug location for the label. This is
|
|
///< used by dwarf writer to find lexical scope.
|
|
SlotIndex loc; ///< Slot used by the debug label.
|
|
|
|
/// Insert a DBG_LABEL into MBB at Idx.
|
|
void insertDebugLabel(MachineBasicBlock *MBB, SlotIndex Idx,
|
|
LiveIntervals &LIS, const TargetInstrInfo &TII,
|
|
BlockSkipInstsMap &BBSkipInstsMap);
|
|
|
|
public:
|
|
/// Create a new UserLabel.
|
|
UserLabel(const DILabel *label, DebugLoc L, SlotIndex Idx)
|
|
: Label(label), dl(std::move(L)), loc(Idx) {}
|
|
|
|
/// Does this UserLabel match the parameters?
|
|
bool matches(const DILabel *L, const DILocation *IA,
|
|
const SlotIndex Index) const {
|
|
return Label == L && dl->getInlinedAt() == IA && loc == Index;
|
|
}
|
|
|
|
/// Recreate DBG_LABEL instruction from data structures.
|
|
void emitDebugLabel(LiveIntervals &LIS, const TargetInstrInfo &TII,
|
|
BlockSkipInstsMap &BBSkipInstsMap);
|
|
|
|
/// Return DebugLoc of this UserLabel.
|
|
const DebugLoc &getDebugLoc() { return dl; }
|
|
|
|
void print(raw_ostream &, const TargetRegisterInfo *);
|
|
};
|
|
|
|
/// Implementation of the LiveDebugVariables pass.
|
|
class LDVImpl {
|
|
LiveDebugVariables &pass;
|
|
LocMap::Allocator allocator;
|
|
MachineFunction *MF = nullptr;
|
|
LiveIntervals *LIS;
|
|
const TargetRegisterInfo *TRI;
|
|
|
|
using StashedInstrRef =
|
|
std::tuple<unsigned, unsigned, const DILocalVariable *,
|
|
const DIExpression *, DebugLoc>;
|
|
|
|
/// Position and VReg of a PHI instruction during register allocation.
|
|
struct PHIValPos {
|
|
SlotIndex SI; /// Slot where this PHI occurs.
|
|
Register Reg; /// VReg this PHI occurs in.
|
|
unsigned SubReg; /// Qualifiying subregister for Reg.
|
|
};
|
|
|
|
/// Map from debug instruction number to PHI position during allocation.
|
|
std::map<unsigned, PHIValPos> PHIValToPos;
|
|
/// Index of, for each VReg, which debug instruction numbers and corresponding
|
|
/// PHIs are sensitive to splitting. Each VReg may have multiple PHI defs,
|
|
/// at different positions.
|
|
DenseMap<Register, std::vector<unsigned>> RegToPHIIdx;
|
|
|
|
std::map<SlotIndex, std::vector<StashedInstrRef>> StashedInstrReferences;
|
|
|
|
/// Whether emitDebugValues is called.
|
|
bool EmitDone = false;
|
|
|
|
/// Whether the machine function is modified during the pass.
|
|
bool ModifiedMF = false;
|
|
|
|
/// All allocated UserValue instances.
|
|
SmallVector<std::unique_ptr<UserValue>, 8> userValues;
|
|
|
|
/// All allocated UserLabel instances.
|
|
SmallVector<std::unique_ptr<UserLabel>, 2> userLabels;
|
|
|
|
/// Map virtual register to eq class leader.
|
|
using VRMap = DenseMap<unsigned, UserValue *>;
|
|
VRMap virtRegToEqClass;
|
|
|
|
/// Map to find existing UserValue instances.
|
|
using UVMap = DenseMap<DebugVariable, UserValue *>;
|
|
UVMap userVarMap;
|
|
|
|
/// Find or create a UserValue.
|
|
UserValue *getUserValue(const DILocalVariable *Var,
|
|
Optional<DIExpression::FragmentInfo> Fragment,
|
|
const DebugLoc &DL);
|
|
|
|
/// Find the EC leader for VirtReg or null.
|
|
UserValue *lookupVirtReg(Register VirtReg);
|
|
|
|
/// Add DBG_VALUE instruction to our maps.
|
|
///
|
|
/// \param MI DBG_VALUE instruction
|
|
/// \param Idx Last valid SLotIndex before instruction.
|
|
///
|
|
/// \returns True if the DBG_VALUE instruction should be deleted.
|
|
bool handleDebugValue(MachineInstr &MI, SlotIndex Idx);
|
|
|
|
/// Track a DBG_INSTR_REF. This needs to be removed from the MachineFunction
|
|
/// during regalloc -- but there's no need to maintain live ranges, as we
|
|
/// refer to a value rather than a location.
|
|
///
|
|
/// \param MI DBG_INSTR_REF instruction
|
|
/// \param Idx Last valid SlotIndex before instruction
|
|
///
|
|
/// \returns True if the DBG_VALUE instruction should be deleted.
|
|
bool handleDebugInstrRef(MachineInstr &MI, SlotIndex Idx);
|
|
|
|
/// Add DBG_LABEL instruction to UserLabel.
|
|
///
|
|
/// \param MI DBG_LABEL instruction
|
|
/// \param Idx Last valid SlotIndex before instruction.
|
|
///
|
|
/// \returns True if the DBG_LABEL instruction should be deleted.
|
|
bool handleDebugLabel(MachineInstr &MI, SlotIndex Idx);
|
|
|
|
/// Collect and erase all DBG_VALUE instructions, adding a UserValue def
|
|
/// for each instruction.
|
|
///
|
|
/// \param mf MachineFunction to be scanned.
|
|
///
|
|
/// \returns True if any debug values were found.
|
|
bool collectDebugValues(MachineFunction &mf);
|
|
|
|
/// Compute the live intervals of all user values after collecting all
|
|
/// their def points.
|
|
void computeIntervals();
|
|
|
|
public:
|
|
LDVImpl(LiveDebugVariables *ps) : pass(*ps) {}
|
|
|
|
bool runOnMachineFunction(MachineFunction &mf);
|
|
|
|
/// Release all memory.
|
|
void clear() {
|
|
MF = nullptr;
|
|
PHIValToPos.clear();
|
|
RegToPHIIdx.clear();
|
|
StashedInstrReferences.clear();
|
|
userValues.clear();
|
|
userLabels.clear();
|
|
virtRegToEqClass.clear();
|
|
userVarMap.clear();
|
|
// Make sure we call emitDebugValues if the machine function was modified.
|
|
assert((!ModifiedMF || EmitDone) &&
|
|
"Dbg values are not emitted in LDV");
|
|
EmitDone = false;
|
|
ModifiedMF = false;
|
|
}
|
|
|
|
/// Map virtual register to an equivalence class.
|
|
void mapVirtReg(Register VirtReg, UserValue *EC);
|
|
|
|
/// Replace any PHI referring to OldReg with its corresponding NewReg, if
|
|
/// present.
|
|
void splitPHIRegister(Register OldReg, ArrayRef<Register> NewRegs);
|
|
|
|
/// Replace all references to OldReg with NewRegs.
|
|
void splitRegister(Register OldReg, ArrayRef<Register> NewRegs);
|
|
|
|
/// Recreate DBG_VALUE instruction from data structures.
|
|
void emitDebugValues(VirtRegMap *VRM);
|
|
|
|
void print(raw_ostream&);
|
|
};
|
|
|
|
} // end anonymous namespace
|
|
|
|
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
|
|
static void printDebugLoc(const DebugLoc &DL, raw_ostream &CommentOS,
|
|
const LLVMContext &Ctx) {
|
|
if (!DL)
|
|
return;
|
|
|
|
auto *Scope = cast<DIScope>(DL.getScope());
|
|
// Omit the directory, because it's likely to be long and uninteresting.
|
|
CommentOS << Scope->getFilename();
|
|
CommentOS << ':' << DL.getLine();
|
|
if (DL.getCol() != 0)
|
|
CommentOS << ':' << DL.getCol();
|
|
|
|
DebugLoc InlinedAtDL = DL.getInlinedAt();
|
|
if (!InlinedAtDL)
|
|
return;
|
|
|
|
CommentOS << " @[ ";
|
|
printDebugLoc(InlinedAtDL, CommentOS, Ctx);
|
|
CommentOS << " ]";
|
|
}
|
|
|
|
static void printExtendedName(raw_ostream &OS, const DINode *Node,
|
|
const DILocation *DL) {
|
|
const LLVMContext &Ctx = Node->getContext();
|
|
StringRef Res;
|
|
unsigned Line = 0;
|
|
if (const auto *V = dyn_cast<const DILocalVariable>(Node)) {
|
|
Res = V->getName();
|
|
Line = V->getLine();
|
|
} else if (const auto *L = dyn_cast<const DILabel>(Node)) {
|
|
Res = L->getName();
|
|
Line = L->getLine();
|
|
}
|
|
|
|
if (!Res.empty())
|
|
OS << Res << "," << Line;
|
|
auto *InlinedAt = DL ? DL->getInlinedAt() : nullptr;
|
|
if (InlinedAt) {
|
|
if (DebugLoc InlinedAtDL = InlinedAt) {
|
|
OS << " @[";
|
|
printDebugLoc(InlinedAtDL, OS, Ctx);
|
|
OS << "]";
|
|
}
|
|
}
|
|
}
|
|
|
|
void UserValue::print(raw_ostream &OS, const TargetRegisterInfo *TRI) {
|
|
OS << "!\"";
|
|
printExtendedName(OS, Variable, dl);
|
|
|
|
OS << "\"\t";
|
|
for (LocMap::const_iterator I = locInts.begin(); I.valid(); ++I) {
|
|
OS << " [" << I.start() << ';' << I.stop() << "):";
|
|
if (I.value().isUndef())
|
|
OS << " undef";
|
|
else {
|
|
I.value().printLocNos(OS);
|
|
if (I.value().getWasIndirect())
|
|
OS << " ind";
|
|
else if (I.value().getWasList())
|
|
OS << " list";
|
|
}
|
|
}
|
|
for (unsigned i = 0, e = locations.size(); i != e; ++i) {
|
|
OS << " Loc" << i << '=';
|
|
locations[i].print(OS, TRI);
|
|
}
|
|
OS << '\n';
|
|
}
|
|
|
|
void UserLabel::print(raw_ostream &OS, const TargetRegisterInfo *TRI) {
|
|
OS << "!\"";
|
|
printExtendedName(OS, Label, dl);
|
|
|
|
OS << "\"\t";
|
|
OS << loc;
|
|
OS << '\n';
|
|
}
|
|
|
|
void LDVImpl::print(raw_ostream &OS) {
|
|
OS << "********** DEBUG VARIABLES **********\n";
|
|
for (auto &userValue : userValues)
|
|
userValue->print(OS, TRI);
|
|
OS << "********** DEBUG LABELS **********\n";
|
|
for (auto &userLabel : userLabels)
|
|
userLabel->print(OS, TRI);
|
|
}
|
|
#endif
|
|
|
|
void UserValue::mapVirtRegs(LDVImpl *LDV) {
|
|
for (unsigned i = 0, e = locations.size(); i != e; ++i)
|
|
if (locations[i].isReg() &&
|
|
Register::isVirtualRegister(locations[i].getReg()))
|
|
LDV->mapVirtReg(locations[i].getReg(), this);
|
|
}
|
|
|
|
UserValue *LDVImpl::getUserValue(const DILocalVariable *Var,
|
|
Optional<DIExpression::FragmentInfo> Fragment,
|
|
const DebugLoc &DL) {
|
|
// FIXME: Handle partially overlapping fragments. See
|
|
// https://reviews.llvm.org/D70121#1849741.
|
|
DebugVariable ID(Var, Fragment, DL->getInlinedAt());
|
|
UserValue *&UV = userVarMap[ID];
|
|
if (!UV) {
|
|
userValues.push_back(
|
|
std::make_unique<UserValue>(Var, Fragment, DL, allocator));
|
|
UV = userValues.back().get();
|
|
}
|
|
return UV;
|
|
}
|
|
|
|
void LDVImpl::mapVirtReg(Register VirtReg, UserValue *EC) {
|
|
assert(Register::isVirtualRegister(VirtReg) && "Only map VirtRegs");
|
|
UserValue *&Leader = virtRegToEqClass[VirtReg];
|
|
Leader = UserValue::merge(Leader, EC);
|
|
}
|
|
|
|
UserValue *LDVImpl::lookupVirtReg(Register VirtReg) {
|
|
if (UserValue *UV = virtRegToEqClass.lookup(VirtReg))
|
|
return UV->getLeader();
|
|
return nullptr;
|
|
}
|
|
|
|
bool LDVImpl::handleDebugValue(MachineInstr &MI, SlotIndex Idx) {
|
|
// DBG_VALUE loc, offset, variable, expr
|
|
// DBG_VALUE_LIST variable, expr, locs...
|
|
if (!MI.isDebugValue()) {
|
|
LLVM_DEBUG(dbgs() << "Can't handle non-DBG_VALUE*: " << MI);
|
|
return false;
|
|
}
|
|
if (!MI.getDebugVariableOp().isMetadata()) {
|
|
LLVM_DEBUG(dbgs() << "Can't handle DBG_VALUE* with invalid variable: "
|
|
<< MI);
|
|
return false;
|
|
}
|
|
if (MI.isNonListDebugValue() &&
|
|
(MI.getNumOperands() != 4 ||
|
|
!(MI.getDebugOffset().isImm() || MI.getDebugOffset().isReg()))) {
|
|
LLVM_DEBUG(dbgs() << "Can't handle malformed DBG_VALUE: " << MI);
|
|
return false;
|
|
}
|
|
|
|
// Detect invalid DBG_VALUE instructions, with a debug-use of a virtual
|
|
// register that hasn't been defined yet. If we do not remove those here, then
|
|
// the re-insertion of the DBG_VALUE instruction after register allocation
|
|
// will be incorrect.
|
|
// TODO: If earlier passes are corrected to generate sane debug information
|
|
// (and if the machine verifier is improved to catch this), then these checks
|
|
// could be removed or replaced by asserts.
|
|
bool Discard = false;
|
|
for (const MachineOperand &Op : MI.debug_operands()) {
|
|
if (Op.isReg() && Register::isVirtualRegister(Op.getReg())) {
|
|
const Register Reg = Op.getReg();
|
|
if (!LIS->hasInterval(Reg)) {
|
|
// The DBG_VALUE is described by a virtual register that does not have a
|
|
// live interval. Discard the DBG_VALUE.
|
|
Discard = true;
|
|
LLVM_DEBUG(dbgs() << "Discarding debug info (no LIS interval): " << Idx
|
|
<< " " << MI);
|
|
} else {
|
|
// The DBG_VALUE is only valid if either Reg is live out from Idx, or
|
|
// Reg is defined dead at Idx (where Idx is the slot index for the
|
|
// instruction preceding the DBG_VALUE).
|
|
const LiveInterval &LI = LIS->getInterval(Reg);
|
|
LiveQueryResult LRQ = LI.Query(Idx);
|
|
if (!LRQ.valueOutOrDead()) {
|
|
// We have found a DBG_VALUE with the value in a virtual register that
|
|
// is not live. Discard the DBG_VALUE.
|
|
Discard = true;
|
|
LLVM_DEBUG(dbgs() << "Discarding debug info (reg not live): " << Idx
|
|
<< " " << MI);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// Get or create the UserValue for (variable,offset) here.
|
|
bool IsIndirect = MI.isDebugOffsetImm();
|
|
if (IsIndirect)
|
|
assert(MI.getDebugOffset().getImm() == 0 &&
|
|
"DBG_VALUE with nonzero offset");
|
|
bool IsList = MI.isDebugValueList();
|
|
const DILocalVariable *Var = MI.getDebugVariable();
|
|
const DIExpression *Expr = MI.getDebugExpression();
|
|
UserValue *UV = getUserValue(Var, Expr->getFragmentInfo(), MI.getDebugLoc());
|
|
if (!Discard)
|
|
UV->addDef(Idx,
|
|
ArrayRef<MachineOperand>(MI.debug_operands().begin(),
|
|
MI.debug_operands().end()),
|
|
IsIndirect, IsList, *Expr);
|
|
else {
|
|
MachineOperand MO = MachineOperand::CreateReg(0U, false);
|
|
MO.setIsDebug();
|
|
// We should still pass a list the same size as MI.debug_operands() even if
|
|
// all MOs are undef, so that DbgVariableValue can correctly adjust the
|
|
// expression while removing the duplicated undefs.
|
|
SmallVector<MachineOperand, 4> UndefMOs(MI.getNumDebugOperands(), MO);
|
|
UV->addDef(Idx, UndefMOs, false, IsList, *Expr);
|
|
}
|
|
return true;
|
|
}
|
|
|
|
bool LDVImpl::handleDebugInstrRef(MachineInstr &MI, SlotIndex Idx) {
|
|
assert(MI.isDebugRef());
|
|
unsigned InstrNum = MI.getOperand(0).getImm();
|
|
unsigned OperandNum = MI.getOperand(1).getImm();
|
|
auto *Var = MI.getDebugVariable();
|
|
auto *Expr = MI.getDebugExpression();
|
|
auto &DL = MI.getDebugLoc();
|
|
StashedInstrRef Stashed =
|
|
std::make_tuple(InstrNum, OperandNum, Var, Expr, DL);
|
|
StashedInstrReferences[Idx].push_back(Stashed);
|
|
return true;
|
|
}
|
|
|
|
bool LDVImpl::handleDebugLabel(MachineInstr &MI, SlotIndex Idx) {
|
|
// DBG_LABEL label
|
|
if (MI.getNumOperands() != 1 || !MI.getOperand(0).isMetadata()) {
|
|
LLVM_DEBUG(dbgs() << "Can't handle " << MI);
|
|
return false;
|
|
}
|
|
|
|
// Get or create the UserLabel for label here.
|
|
const DILabel *Label = MI.getDebugLabel();
|
|
const DebugLoc &DL = MI.getDebugLoc();
|
|
bool Found = false;
|
|
for (auto const &L : userLabels) {
|
|
if (L->matches(Label, DL->getInlinedAt(), Idx)) {
|
|
Found = true;
|
|
break;
|
|
}
|
|
}
|
|
if (!Found)
|
|
userLabels.push_back(std::make_unique<UserLabel>(Label, DL, Idx));
|
|
|
|
return true;
|
|
}
|
|
|
|
bool LDVImpl::collectDebugValues(MachineFunction &mf) {
|
|
bool Changed = false;
|
|
for (MachineBasicBlock &MBB : mf) {
|
|
for (MachineBasicBlock::iterator MBBI = MBB.begin(), MBBE = MBB.end();
|
|
MBBI != MBBE;) {
|
|
// Use the first debug instruction in the sequence to get a SlotIndex
|
|
// for following consecutive debug instructions.
|
|
if (!MBBI->isDebugOrPseudoInstr()) {
|
|
++MBBI;
|
|
continue;
|
|
}
|
|
// Debug instructions has no slot index. Use the previous
|
|
// non-debug instruction's SlotIndex as its SlotIndex.
|
|
SlotIndex Idx =
|
|
MBBI == MBB.begin()
|
|
? LIS->getMBBStartIdx(&MBB)
|
|
: LIS->getInstructionIndex(*std::prev(MBBI)).getRegSlot();
|
|
// Handle consecutive debug instructions with the same slot index.
|
|
do {
|
|
// Only handle DBG_VALUE in handleDebugValue(). Skip all other
|
|
// kinds of debug instructions.
|
|
if ((MBBI->isDebugValue() && handleDebugValue(*MBBI, Idx)) ||
|
|
(MBBI->isDebugRef() && handleDebugInstrRef(*MBBI, Idx)) ||
|
|
(MBBI->isDebugLabel() && handleDebugLabel(*MBBI, Idx))) {
|
|
MBBI = MBB.erase(MBBI);
|
|
Changed = true;
|
|
} else
|
|
++MBBI;
|
|
} while (MBBI != MBBE && MBBI->isDebugOrPseudoInstr());
|
|
}
|
|
}
|
|
return Changed;
|
|
}
|
|
|
|
void UserValue::extendDef(
|
|
SlotIndex Idx, DbgVariableValue DbgValue,
|
|
SmallDenseMap<unsigned, std::pair<LiveRange *, const VNInfo *>>
|
|
&LiveIntervalInfo,
|
|
Optional<std::pair<SlotIndex, SmallVector<unsigned>>> &Kills,
|
|
LiveIntervals &LIS) {
|
|
SlotIndex Start = Idx;
|
|
MachineBasicBlock *MBB = LIS.getMBBFromIndex(Start);
|
|
SlotIndex Stop = LIS.getMBBEndIdx(MBB);
|
|
LocMap::iterator I = locInts.find(Start);
|
|
|
|
// Limit to the intersection of the VNIs' live ranges.
|
|
for (auto &LII : LiveIntervalInfo) {
|
|
LiveRange *LR = LII.second.first;
|
|
assert(LR && LII.second.second && "Missing range info for Idx.");
|
|
LiveInterval::Segment *Segment = LR->getSegmentContaining(Start);
|
|
assert(Segment && Segment->valno == LII.second.second &&
|
|
"Invalid VNInfo for Idx given?");
|
|
if (Segment->end < Stop) {
|
|
Stop = Segment->end;
|
|
Kills = {Stop, {LII.first}};
|
|
} else if (Segment->end == Stop && Kills.hasValue()) {
|
|
// If multiple locations end at the same place, track all of them in
|
|
// Kills.
|
|
Kills->second.push_back(LII.first);
|
|
}
|
|
}
|
|
|
|
// There could already be a short def at Start.
|
|
if (I.valid() && I.start() <= Start) {
|
|
// Stop when meeting a different location or an already extended interval.
|
|
Start = Start.getNextSlot();
|
|
if (I.value() != DbgValue || I.stop() != Start) {
|
|
// Clear `Kills`, as we have a new def available.
|
|
Kills = None;
|
|
return;
|
|
}
|
|
// This is a one-slot placeholder. Just skip it.
|
|
++I;
|
|
}
|
|
|
|
// Limited by the next def.
|
|
if (I.valid() && I.start() < Stop) {
|
|
Stop = I.start();
|
|
// Clear `Kills`, as we have a new def available.
|
|
Kills = None;
|
|
}
|
|
|
|
if (Start < Stop) {
|
|
DbgVariableValue ExtDbgValue(DbgValue);
|
|
I.insert(Start, Stop, std::move(ExtDbgValue));
|
|
}
|
|
}
|
|
|
|
void UserValue::addDefsFromCopies(
|
|
DbgVariableValue DbgValue,
|
|
SmallVectorImpl<std::pair<unsigned, LiveInterval *>> &LocIntervals,
|
|
SlotIndex KilledAt,
|
|
SmallVectorImpl<std::pair<SlotIndex, DbgVariableValue>> &NewDefs,
|
|
MachineRegisterInfo &MRI, LiveIntervals &LIS) {
|
|
// Don't track copies from physregs, there are too many uses.
|
|
if (any_of(LocIntervals, [](auto LocI) {
|
|
return !Register::isVirtualRegister(LocI.second->reg());
|
|
}))
|
|
return;
|
|
|
|
// Collect all the (vreg, valno) pairs that are copies of LI.
|
|
SmallDenseMap<unsigned,
|
|
SmallVector<std::pair<LiveInterval *, const VNInfo *>, 4>>
|
|
CopyValues;
|
|
for (auto &LocInterval : LocIntervals) {
|
|
unsigned LocNo = LocInterval.first;
|
|
LiveInterval *LI = LocInterval.second;
|
|
for (MachineOperand &MO : MRI.use_nodbg_operands(LI->reg())) {
|
|
MachineInstr *MI = MO.getParent();
|
|
// Copies of the full value.
|
|
if (MO.getSubReg() || !MI->isCopy())
|
|
continue;
|
|
Register DstReg = MI->getOperand(0).getReg();
|
|
|
|
// Don't follow copies to physregs. These are usually setting up call
|
|
// arguments, and the argument registers are always call clobbered. We are
|
|
// better off in the source register which could be a callee-saved
|
|
// register, or it could be spilled.
|
|
if (!Register::isVirtualRegister(DstReg))
|
|
continue;
|
|
|
|
// Is the value extended to reach this copy? If not, another def may be
|
|
// blocking it, or we are looking at a wrong value of LI.
|
|
SlotIndex Idx = LIS.getInstructionIndex(*MI);
|
|
LocMap::iterator I = locInts.find(Idx.getRegSlot(true));
|
|
if (!I.valid() || I.value() != DbgValue)
|
|
continue;
|
|
|
|
if (!LIS.hasInterval(DstReg))
|
|
continue;
|
|
LiveInterval *DstLI = &LIS.getInterval(DstReg);
|
|
const VNInfo *DstVNI = DstLI->getVNInfoAt(Idx.getRegSlot());
|
|
assert(DstVNI && DstVNI->def == Idx.getRegSlot() && "Bad copy value");
|
|
CopyValues[LocNo].push_back(std::make_pair(DstLI, DstVNI));
|
|
}
|
|
}
|
|
|
|
if (CopyValues.empty())
|
|
return;
|
|
|
|
#if !defined(NDEBUG)
|
|
for (auto &LocInterval : LocIntervals)
|
|
LLVM_DEBUG(dbgs() << "Got " << CopyValues[LocInterval.first].size()
|
|
<< " copies of " << *LocInterval.second << '\n');
|
|
#endif
|
|
|
|
// Try to add defs of the copied values for the kill point. Check that there
|
|
// isn't already a def at Idx.
|
|
LocMap::iterator I = locInts.find(KilledAt);
|
|
if (I.valid() && I.start() <= KilledAt)
|
|
return;
|
|
DbgVariableValue NewValue(DbgValue);
|
|
for (auto &LocInterval : LocIntervals) {
|
|
unsigned LocNo = LocInterval.first;
|
|
bool FoundCopy = false;
|
|
for (auto &LIAndVNI : CopyValues[LocNo]) {
|
|
LiveInterval *DstLI = LIAndVNI.first;
|
|
const VNInfo *DstVNI = LIAndVNI.second;
|
|
if (DstLI->getVNInfoAt(KilledAt) != DstVNI)
|
|
continue;
|
|
LLVM_DEBUG(dbgs() << "Kill at " << KilledAt << " covered by valno #"
|
|
<< DstVNI->id << " in " << *DstLI << '\n');
|
|
MachineInstr *CopyMI = LIS.getInstructionFromIndex(DstVNI->def);
|
|
assert(CopyMI && CopyMI->isCopy() && "Bad copy value");
|
|
unsigned NewLocNo = getLocationNo(CopyMI->getOperand(0));
|
|
NewValue = NewValue.changeLocNo(LocNo, NewLocNo);
|
|
FoundCopy = true;
|
|
break;
|
|
}
|
|
// If there are any killed locations we can't find a copy for, we can't
|
|
// extend the variable value.
|
|
if (!FoundCopy)
|
|
return;
|
|
}
|
|
I.insert(KilledAt, KilledAt.getNextSlot(), NewValue);
|
|
NewDefs.push_back(std::make_pair(KilledAt, NewValue));
|
|
}
|
|
|
|
void UserValue::computeIntervals(MachineRegisterInfo &MRI,
|
|
const TargetRegisterInfo &TRI,
|
|
LiveIntervals &LIS, LexicalScopes &LS) {
|
|
SmallVector<std::pair<SlotIndex, DbgVariableValue>, 16> Defs;
|
|
|
|
// Collect all defs to be extended (Skipping undefs).
|
|
for (LocMap::const_iterator I = locInts.begin(); I.valid(); ++I)
|
|
if (!I.value().isUndef())
|
|
Defs.push_back(std::make_pair(I.start(), I.value()));
|
|
|
|
// Extend all defs, and possibly add new ones along the way.
|
|
for (unsigned i = 0; i != Defs.size(); ++i) {
|
|
SlotIndex Idx = Defs[i].first;
|
|
DbgVariableValue DbgValue = Defs[i].second;
|
|
SmallDenseMap<unsigned, std::pair<LiveRange *, const VNInfo *>> LIs;
|
|
SmallVector<const VNInfo *, 4> VNIs;
|
|
bool ShouldExtendDef = false;
|
|
for (unsigned LocNo : DbgValue.loc_nos()) {
|
|
const MachineOperand &LocMO = locations[LocNo];
|
|
if (!LocMO.isReg() || !Register::isVirtualRegister(LocMO.getReg())) {
|
|
ShouldExtendDef |= !LocMO.isReg();
|
|
continue;
|
|
}
|
|
ShouldExtendDef = true;
|
|
LiveInterval *LI = nullptr;
|
|
const VNInfo *VNI = nullptr;
|
|
if (LIS.hasInterval(LocMO.getReg())) {
|
|
LI = &LIS.getInterval(LocMO.getReg());
|
|
VNI = LI->getVNInfoAt(Idx);
|
|
}
|
|
if (LI && VNI)
|
|
LIs[LocNo] = {LI, VNI};
|
|
}
|
|
if (ShouldExtendDef) {
|
|
Optional<std::pair<SlotIndex, SmallVector<unsigned>>> Kills;
|
|
extendDef(Idx, DbgValue, LIs, Kills, LIS);
|
|
|
|
if (Kills) {
|
|
SmallVector<std::pair<unsigned, LiveInterval *>, 2> KilledLocIntervals;
|
|
bool AnySubreg = false;
|
|
for (unsigned LocNo : Kills->second) {
|
|
const MachineOperand &LocMO = this->locations[LocNo];
|
|
if (LocMO.getSubReg()) {
|
|
AnySubreg = true;
|
|
break;
|
|
}
|
|
LiveInterval *LI = &LIS.getInterval(LocMO.getReg());
|
|
KilledLocIntervals.push_back({LocNo, LI});
|
|
}
|
|
|
|
// FIXME: Handle sub-registers in addDefsFromCopies. The problem is that
|
|
// if the original location for example is %vreg0:sub_hi, and we find a
|
|
// full register copy in addDefsFromCopies (at the moment it only
|
|
// handles full register copies), then we must add the sub1 sub-register
|
|
// index to the new location. However, that is only possible if the new
|
|
// virtual register is of the same regclass (or if there is an
|
|
// equivalent sub-register in that regclass). For now, simply skip
|
|
// handling copies if a sub-register is involved.
|
|
if (!AnySubreg)
|
|
addDefsFromCopies(DbgValue, KilledLocIntervals, Kills->first, Defs,
|
|
MRI, LIS);
|
|
}
|
|
}
|
|
|
|
// For physregs, we only mark the start slot idx. DwarfDebug will see it
|
|
// as if the DBG_VALUE is valid up until the end of the basic block, or
|
|
// the next def of the physical register. So we do not need to extend the
|
|
// range. It might actually happen that the DBG_VALUE is the last use of
|
|
// the physical register (e.g. if this is an unused input argument to a
|
|
// function).
|
|
}
|
|
|
|
// The computed intervals may extend beyond the range of the debug
|
|
// location's lexical scope. In this case, splitting of an interval
|
|
// can result in an interval outside of the scope being created,
|
|
// causing extra unnecessary DBG_VALUEs to be emitted. To prevent
|
|
// this, trim the intervals to the lexical scope in the case of inlined
|
|
// variables, since heavy inlining may cause production of dramatically big
|
|
// number of DBG_VALUEs to be generated.
|
|
if (!dl.getInlinedAt())
|
|
return;
|
|
|
|
LexicalScope *Scope = LS.findLexicalScope(dl);
|
|
if (!Scope)
|
|
return;
|
|
|
|
SlotIndex PrevEnd;
|
|
LocMap::iterator I = locInts.begin();
|
|
|
|
// Iterate over the lexical scope ranges. Each time round the loop
|
|
// we check the intervals for overlap with the end of the previous
|
|
// range and the start of the next. The first range is handled as
|
|
// a special case where there is no PrevEnd.
|
|
for (const InsnRange &Range : Scope->getRanges()) {
|
|
SlotIndex RStart = LIS.getInstructionIndex(*Range.first);
|
|
SlotIndex REnd = LIS.getInstructionIndex(*Range.second);
|
|
|
|
// Variable locations at the first instruction of a block should be
|
|
// based on the block's SlotIndex, not the first instruction's index.
|
|
if (Range.first == Range.first->getParent()->begin())
|
|
RStart = LIS.getSlotIndexes()->getIndexBefore(*Range.first);
|
|
|
|
// At the start of each iteration I has been advanced so that
|
|
// I.stop() >= PrevEnd. Check for overlap.
|
|
if (PrevEnd && I.start() < PrevEnd) {
|
|
SlotIndex IStop = I.stop();
|
|
DbgVariableValue DbgValue = I.value();
|
|
|
|
// Stop overlaps previous end - trim the end of the interval to
|
|
// the scope range.
|
|
I.setStopUnchecked(PrevEnd);
|
|
++I;
|
|
|
|
// If the interval also overlaps the start of the "next" (i.e.
|
|
// current) range create a new interval for the remainder (which
|
|
// may be further trimmed).
|
|
if (RStart < IStop)
|
|
I.insert(RStart, IStop, DbgValue);
|
|
}
|
|
|
|
// Advance I so that I.stop() >= RStart, and check for overlap.
|
|
I.advanceTo(RStart);
|
|
if (!I.valid())
|
|
return;
|
|
|
|
if (I.start() < RStart) {
|
|
// Interval start overlaps range - trim to the scope range.
|
|
I.setStartUnchecked(RStart);
|
|
// Remember that this interval was trimmed.
|
|
trimmedDefs.insert(RStart);
|
|
}
|
|
|
|
// The end of a lexical scope range is the last instruction in the
|
|
// range. To convert to an interval we need the index of the
|
|
// instruction after it.
|
|
REnd = REnd.getNextIndex();
|
|
|
|
// Advance I to first interval outside current range.
|
|
I.advanceTo(REnd);
|
|
if (!I.valid())
|
|
return;
|
|
|
|
PrevEnd = REnd;
|
|
}
|
|
|
|
// Check for overlap with end of final range.
|
|
if (PrevEnd && I.start() < PrevEnd)
|
|
I.setStopUnchecked(PrevEnd);
|
|
}
|
|
|
|
void LDVImpl::computeIntervals() {
|
|
LexicalScopes LS;
|
|
LS.initialize(*MF);
|
|
|
|
for (unsigned i = 0, e = userValues.size(); i != e; ++i) {
|
|
userValues[i]->computeIntervals(MF->getRegInfo(), *TRI, *LIS, LS);
|
|
userValues[i]->mapVirtRegs(this);
|
|
}
|
|
}
|
|
|
|
bool LDVImpl::runOnMachineFunction(MachineFunction &mf) {
|
|
clear();
|
|
MF = &mf;
|
|
LIS = &pass.getAnalysis<LiveIntervals>();
|
|
TRI = mf.getSubtarget().getRegisterInfo();
|
|
LLVM_DEBUG(dbgs() << "********** COMPUTING LIVE DEBUG VARIABLES: "
|
|
<< mf.getName() << " **********\n");
|
|
|
|
bool Changed = collectDebugValues(mf);
|
|
computeIntervals();
|
|
LLVM_DEBUG(print(dbgs()));
|
|
|
|
// Collect the set of VReg / SlotIndexs where PHIs occur; index the sensitive
|
|
// VRegs too, for when we're notified of a range split.
|
|
SlotIndexes *Slots = LIS->getSlotIndexes();
|
|
for (const auto &PHIIt : MF->DebugPHIPositions) {
|
|
const MachineFunction::DebugPHIRegallocPos &Position = PHIIt.second;
|
|
MachineBasicBlock *MBB = Position.MBB;
|
|
Register Reg = Position.Reg;
|
|
unsigned SubReg = Position.SubReg;
|
|
SlotIndex SI = Slots->getMBBStartIdx(MBB);
|
|
PHIValPos VP = {SI, Reg, SubReg};
|
|
PHIValToPos.insert(std::make_pair(PHIIt.first, VP));
|
|
RegToPHIIdx[Reg].push_back(PHIIt.first);
|
|
}
|
|
|
|
ModifiedMF = Changed;
|
|
return Changed;
|
|
}
|
|
|
|
static void removeDebugInstrs(MachineFunction &mf) {
|
|
for (MachineBasicBlock &MBB : mf) {
|
|
for (auto MBBI = MBB.begin(), MBBE = MBB.end(); MBBI != MBBE; ) {
|
|
if (!MBBI->isDebugInstr()) {
|
|
++MBBI;
|
|
continue;
|
|
}
|
|
MBBI = MBB.erase(MBBI);
|
|
}
|
|
}
|
|
}
|
|
|
|
bool LiveDebugVariables::runOnMachineFunction(MachineFunction &mf) {
|
|
if (!EnableLDV)
|
|
return false;
|
|
if (!mf.getFunction().getSubprogram()) {
|
|
removeDebugInstrs(mf);
|
|
return false;
|
|
}
|
|
if (!pImpl)
|
|
pImpl = new LDVImpl(this);
|
|
return static_cast<LDVImpl*>(pImpl)->runOnMachineFunction(mf);
|
|
}
|
|
|
|
void LiveDebugVariables::releaseMemory() {
|
|
if (pImpl)
|
|
static_cast<LDVImpl*>(pImpl)->clear();
|
|
}
|
|
|
|
LiveDebugVariables::~LiveDebugVariables() {
|
|
if (pImpl)
|
|
delete static_cast<LDVImpl*>(pImpl);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Live Range Splitting
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
bool
|
|
UserValue::splitLocation(unsigned OldLocNo, ArrayRef<Register> NewRegs,
|
|
LiveIntervals& LIS) {
|
|
LLVM_DEBUG({
|
|
dbgs() << "Splitting Loc" << OldLocNo << '\t';
|
|
print(dbgs(), nullptr);
|
|
});
|
|
bool DidChange = false;
|
|
LocMap::iterator LocMapI;
|
|
LocMapI.setMap(locInts);
|
|
for (unsigned i = 0; i != NewRegs.size(); ++i) {
|
|
LiveInterval *LI = &LIS.getInterval(NewRegs[i]);
|
|
if (LI->empty())
|
|
continue;
|
|
|
|
// Don't allocate the new LocNo until it is needed.
|
|
unsigned NewLocNo = UndefLocNo;
|
|
|
|
// Iterate over the overlaps between locInts and LI.
|
|
LocMapI.find(LI->beginIndex());
|
|
if (!LocMapI.valid())
|
|
continue;
|
|
LiveInterval::iterator LII = LI->advanceTo(LI->begin(), LocMapI.start());
|
|
LiveInterval::iterator LIE = LI->end();
|
|
while (LocMapI.valid() && LII != LIE) {
|
|
// At this point, we know that LocMapI.stop() > LII->start.
|
|
LII = LI->advanceTo(LII, LocMapI.start());
|
|
if (LII == LIE)
|
|
break;
|
|
|
|
// Now LII->end > LocMapI.start(). Do we have an overlap?
|
|
if (LocMapI.value().containsLocNo(OldLocNo) &&
|
|
LII->start < LocMapI.stop()) {
|
|
// Overlapping correct location. Allocate NewLocNo now.
|
|
if (NewLocNo == UndefLocNo) {
|
|
MachineOperand MO = MachineOperand::CreateReg(LI->reg(), false);
|
|
MO.setSubReg(locations[OldLocNo].getSubReg());
|
|
NewLocNo = getLocationNo(MO);
|
|
DidChange = true;
|
|
}
|
|
|
|
SlotIndex LStart = LocMapI.start();
|
|
SlotIndex LStop = LocMapI.stop();
|
|
DbgVariableValue OldDbgValue = LocMapI.value();
|
|
|
|
// Trim LocMapI down to the LII overlap.
|
|
if (LStart < LII->start)
|
|
LocMapI.setStartUnchecked(LII->start);
|
|
if (LStop > LII->end)
|
|
LocMapI.setStopUnchecked(LII->end);
|
|
|
|
// Change the value in the overlap. This may trigger coalescing.
|
|
LocMapI.setValue(OldDbgValue.changeLocNo(OldLocNo, NewLocNo));
|
|
|
|
// Re-insert any removed OldDbgValue ranges.
|
|
if (LStart < LocMapI.start()) {
|
|
LocMapI.insert(LStart, LocMapI.start(), OldDbgValue);
|
|
++LocMapI;
|
|
assert(LocMapI.valid() && "Unexpected coalescing");
|
|
}
|
|
if (LStop > LocMapI.stop()) {
|
|
++LocMapI;
|
|
LocMapI.insert(LII->end, LStop, OldDbgValue);
|
|
--LocMapI;
|
|
}
|
|
}
|
|
|
|
// Advance to the next overlap.
|
|
if (LII->end < LocMapI.stop()) {
|
|
if (++LII == LIE)
|
|
break;
|
|
LocMapI.advanceTo(LII->start);
|
|
} else {
|
|
++LocMapI;
|
|
if (!LocMapI.valid())
|
|
break;
|
|
LII = LI->advanceTo(LII, LocMapI.start());
|
|
}
|
|
}
|
|
}
|
|
|
|
// Finally, remove OldLocNo unless it is still used by some interval in the
|
|
// locInts map. One case when OldLocNo still is in use is when the register
|
|
// has been spilled. In such situations the spilled register is kept as a
|
|
// location until rewriteLocations is called (VirtRegMap is mapping the old
|
|
// register to the spill slot). So for a while we can have locations that map
|
|
// to virtual registers that have been removed from both the MachineFunction
|
|
// and from LiveIntervals.
|
|
//
|
|
// We may also just be using the location for a value with a different
|
|
// expression.
|
|
removeLocationIfUnused(OldLocNo);
|
|
|
|
LLVM_DEBUG({
|
|
dbgs() << "Split result: \t";
|
|
print(dbgs(), nullptr);
|
|
});
|
|
return DidChange;
|
|
}
|
|
|
|
bool
|
|
UserValue::splitRegister(Register OldReg, ArrayRef<Register> NewRegs,
|
|
LiveIntervals &LIS) {
|
|
bool DidChange = false;
|
|
// Split locations referring to OldReg. Iterate backwards so splitLocation can
|
|
// safely erase unused locations.
|
|
for (unsigned i = locations.size(); i ; --i) {
|
|
unsigned LocNo = i-1;
|
|
const MachineOperand *Loc = &locations[LocNo];
|
|
if (!Loc->isReg() || Loc->getReg() != OldReg)
|
|
continue;
|
|
DidChange |= splitLocation(LocNo, NewRegs, LIS);
|
|
}
|
|
return DidChange;
|
|
}
|
|
|
|
void LDVImpl::splitPHIRegister(Register OldReg, ArrayRef<Register> NewRegs) {
|
|
auto RegIt = RegToPHIIdx.find(OldReg);
|
|
if (RegIt == RegToPHIIdx.end())
|
|
return;
|
|
|
|
std::vector<std::pair<Register, unsigned>> NewRegIdxes;
|
|
// Iterate over all the debug instruction numbers affected by this split.
|
|
for (unsigned InstrID : RegIt->second) {
|
|
auto PHIIt = PHIValToPos.find(InstrID);
|
|
assert(PHIIt != PHIValToPos.end());
|
|
const SlotIndex &Slot = PHIIt->second.SI;
|
|
assert(OldReg == PHIIt->second.Reg);
|
|
|
|
// Find the new register that covers this position.
|
|
for (auto NewReg : NewRegs) {
|
|
const LiveInterval &LI = LIS->getInterval(NewReg);
|
|
auto LII = LI.find(Slot);
|
|
if (LII != LI.end() && LII->start <= Slot) {
|
|
// This new register covers this PHI position, record this for indexing.
|
|
NewRegIdxes.push_back(std::make_pair(NewReg, InstrID));
|
|
// Record that this value lives in a different VReg now.
|
|
PHIIt->second.Reg = NewReg;
|
|
break;
|
|
}
|
|
}
|
|
|
|
// If we do not find a new register covering this PHI, then register
|
|
// allocation has dropped its location, for example because it's not live.
|
|
// The old VReg will not be mapped to a physreg, and the instruction
|
|
// number will have been optimized out.
|
|
}
|
|
|
|
// Re-create register index using the new register numbers.
|
|
RegToPHIIdx.erase(RegIt);
|
|
for (auto &RegAndInstr : NewRegIdxes)
|
|
RegToPHIIdx[RegAndInstr.first].push_back(RegAndInstr.second);
|
|
}
|
|
|
|
void LDVImpl::splitRegister(Register OldReg, ArrayRef<Register> NewRegs) {
|
|
// Consider whether this split range affects any PHI locations.
|
|
splitPHIRegister(OldReg, NewRegs);
|
|
|
|
// Check whether any intervals mapped by a DBG_VALUE were split and need
|
|
// updating.
|
|
bool DidChange = false;
|
|
for (UserValue *UV = lookupVirtReg(OldReg); UV; UV = UV->getNext())
|
|
DidChange |= UV->splitRegister(OldReg, NewRegs, *LIS);
|
|
|
|
if (!DidChange)
|
|
return;
|
|
|
|
// Map all of the new virtual registers.
|
|
UserValue *UV = lookupVirtReg(OldReg);
|
|
for (unsigned i = 0; i != NewRegs.size(); ++i)
|
|
mapVirtReg(NewRegs[i], UV);
|
|
}
|
|
|
|
void LiveDebugVariables::
|
|
splitRegister(Register OldReg, ArrayRef<Register> NewRegs, LiveIntervals &LIS) {
|
|
if (pImpl)
|
|
static_cast<LDVImpl*>(pImpl)->splitRegister(OldReg, NewRegs);
|
|
}
|
|
|
|
void UserValue::rewriteLocations(VirtRegMap &VRM, const MachineFunction &MF,
|
|
const TargetInstrInfo &TII,
|
|
const TargetRegisterInfo &TRI,
|
|
SpillOffsetMap &SpillOffsets) {
|
|
// Build a set of new locations with new numbers so we can coalesce our
|
|
// IntervalMap if two vreg intervals collapse to the same physical location.
|
|
// Use MapVector instead of SetVector because MapVector::insert returns the
|
|
// position of the previously or newly inserted element. The boolean value
|
|
// tracks if the location was produced by a spill.
|
|
// FIXME: This will be problematic if we ever support direct and indirect
|
|
// frame index locations, i.e. expressing both variables in memory and
|
|
// 'int x, *px = &x'. The "spilled" bit must become part of the location.
|
|
MapVector<MachineOperand, std::pair<bool, unsigned>> NewLocations;
|
|
SmallVector<unsigned, 4> LocNoMap(locations.size());
|
|
for (unsigned I = 0, E = locations.size(); I != E; ++I) {
|
|
bool Spilled = false;
|
|
unsigned SpillOffset = 0;
|
|
MachineOperand Loc = locations[I];
|
|
// Only virtual registers are rewritten.
|
|
if (Loc.isReg() && Loc.getReg() &&
|
|
Register::isVirtualRegister(Loc.getReg())) {
|
|
Register VirtReg = Loc.getReg();
|
|
if (VRM.isAssignedReg(VirtReg) &&
|
|
Register::isPhysicalRegister(VRM.getPhys(VirtReg))) {
|
|
// This can create a %noreg operand in rare cases when the sub-register
|
|
// index is no longer available. That means the user value is in a
|
|
// non-existent sub-register, and %noreg is exactly what we want.
|
|
Loc.substPhysReg(VRM.getPhys(VirtReg), TRI);
|
|
} else if (VRM.getStackSlot(VirtReg) != VirtRegMap::NO_STACK_SLOT) {
|
|
// Retrieve the stack slot offset.
|
|
unsigned SpillSize;
|
|
const MachineRegisterInfo &MRI = MF.getRegInfo();
|
|
const TargetRegisterClass *TRC = MRI.getRegClass(VirtReg);
|
|
bool Success = TII.getStackSlotRange(TRC, Loc.getSubReg(), SpillSize,
|
|
SpillOffset, MF);
|
|
|
|
// FIXME: Invalidate the location if the offset couldn't be calculated.
|
|
(void)Success;
|
|
|
|
Loc = MachineOperand::CreateFI(VRM.getStackSlot(VirtReg));
|
|
Spilled = true;
|
|
} else {
|
|
Loc.setReg(0);
|
|
Loc.setSubReg(0);
|
|
}
|
|
}
|
|
|
|
// Insert this location if it doesn't already exist and record a mapping
|
|
// from the old number to the new number.
|
|
auto InsertResult = NewLocations.insert({Loc, {Spilled, SpillOffset}});
|
|
unsigned NewLocNo = std::distance(NewLocations.begin(), InsertResult.first);
|
|
LocNoMap[I] = NewLocNo;
|
|
}
|
|
|
|
// Rewrite the locations and record the stack slot offsets for spills.
|
|
locations.clear();
|
|
SpillOffsets.clear();
|
|
for (auto &Pair : NewLocations) {
|
|
bool Spilled;
|
|
unsigned SpillOffset;
|
|
std::tie(Spilled, SpillOffset) = Pair.second;
|
|
locations.push_back(Pair.first);
|
|
if (Spilled) {
|
|
unsigned NewLocNo = std::distance(&*NewLocations.begin(), &Pair);
|
|
SpillOffsets[NewLocNo] = SpillOffset;
|
|
}
|
|
}
|
|
|
|
// Update the interval map, but only coalesce left, since intervals to the
|
|
// right use the old location numbers. This should merge two contiguous
|
|
// DBG_VALUE intervals with different vregs that were allocated to the same
|
|
// physical register.
|
|
for (LocMap::iterator I = locInts.begin(); I.valid(); ++I) {
|
|
I.setValueUnchecked(I.value().remapLocNos(LocNoMap));
|
|
I.setStart(I.start());
|
|
}
|
|
}
|
|
|
|
/// Find an iterator for inserting a DBG_VALUE instruction.
|
|
static MachineBasicBlock::iterator
|
|
findInsertLocation(MachineBasicBlock *MBB, SlotIndex Idx, LiveIntervals &LIS,
|
|
BlockSkipInstsMap &BBSkipInstsMap) {
|
|
SlotIndex Start = LIS.getMBBStartIdx(MBB);
|
|
Idx = Idx.getBaseIndex();
|
|
|
|
// Try to find an insert location by going backwards from Idx.
|
|
MachineInstr *MI;
|
|
while (!(MI = LIS.getInstructionFromIndex(Idx))) {
|
|
// We've reached the beginning of MBB.
|
|
if (Idx == Start) {
|
|
// Retrieve the last PHI/Label/Debug location found when calling
|
|
// SkipPHIsLabelsAndDebug last time. Start searching from there.
|
|
//
|
|
// Note the iterator kept in BBSkipInstsMap is one step back based
|
|
// on the iterator returned by SkipPHIsLabelsAndDebug last time.
|
|
// One exception is when SkipPHIsLabelsAndDebug returns MBB->begin(),
|
|
// BBSkipInstsMap won't save it. This is to consider the case that
|
|
// new instructions may be inserted at the beginning of MBB after
|
|
// last call of SkipPHIsLabelsAndDebug. If we save MBB->begin() in
|
|
// BBSkipInstsMap, after new non-phi/non-label/non-debug instructions
|
|
// are inserted at the beginning of the MBB, the iterator in
|
|
// BBSkipInstsMap won't point to the beginning of the MBB anymore.
|
|
// Therefore The next search in SkipPHIsLabelsAndDebug will skip those
|
|
// newly added instructions and that is unwanted.
|
|
MachineBasicBlock::iterator BeginIt;
|
|
auto MapIt = BBSkipInstsMap.find(MBB);
|
|
if (MapIt == BBSkipInstsMap.end())
|
|
BeginIt = MBB->begin();
|
|
else
|
|
BeginIt = std::next(MapIt->second);
|
|
auto I = MBB->SkipPHIsLabelsAndDebug(BeginIt);
|
|
if (I != BeginIt)
|
|
BBSkipInstsMap[MBB] = std::prev(I);
|
|
return I;
|
|
}
|
|
Idx = Idx.getPrevIndex();
|
|
}
|
|
|
|
// Don't insert anything after the first terminator, though.
|
|
return MI->isTerminator() ? MBB->getFirstTerminator() :
|
|
std::next(MachineBasicBlock::iterator(MI));
|
|
}
|
|
|
|
/// Find an iterator for inserting the next DBG_VALUE instruction
|
|
/// (or end if no more insert locations found).
|
|
static MachineBasicBlock::iterator
|
|
findNextInsertLocation(MachineBasicBlock *MBB, MachineBasicBlock::iterator I,
|
|
SlotIndex StopIdx, ArrayRef<MachineOperand> LocMOs,
|
|
LiveIntervals &LIS, const TargetRegisterInfo &TRI) {
|
|
SmallVector<Register, 4> Regs;
|
|
for (const MachineOperand &LocMO : LocMOs)
|
|
if (LocMO.isReg())
|
|
Regs.push_back(LocMO.getReg());
|
|
if (Regs.empty())
|
|
return MBB->instr_end();
|
|
|
|
// Find the next instruction in the MBB that define the register Reg.
|
|
while (I != MBB->end() && !I->isTerminator()) {
|
|
if (!LIS.isNotInMIMap(*I) &&
|
|
SlotIndex::isEarlierEqualInstr(StopIdx, LIS.getInstructionIndex(*I)))
|
|
break;
|
|
if (any_of(Regs, [&I, &TRI](Register &Reg) {
|
|
return I->definesRegister(Reg, &TRI);
|
|
}))
|
|
// The insert location is directly after the instruction/bundle.
|
|
return std::next(I);
|
|
++I;
|
|
}
|
|
return MBB->end();
|
|
}
|
|
|
|
void UserValue::insertDebugValue(MachineBasicBlock *MBB, SlotIndex StartIdx,
|
|
SlotIndex StopIdx, DbgVariableValue DbgValue,
|
|
ArrayRef<bool> LocSpills,
|
|
ArrayRef<unsigned> SpillOffsets,
|
|
LiveIntervals &LIS, const TargetInstrInfo &TII,
|
|
const TargetRegisterInfo &TRI,
|
|
BlockSkipInstsMap &BBSkipInstsMap) {
|
|
SlotIndex MBBEndIdx = LIS.getMBBEndIdx(&*MBB);
|
|
// Only search within the current MBB.
|
|
StopIdx = (MBBEndIdx < StopIdx) ? MBBEndIdx : StopIdx;
|
|
MachineBasicBlock::iterator I =
|
|
findInsertLocation(MBB, StartIdx, LIS, BBSkipInstsMap);
|
|
// Undef values don't exist in locations so create new "noreg" register MOs
|
|
// for them. See getLocationNo().
|
|
SmallVector<MachineOperand, 8> MOs;
|
|
if (DbgValue.isUndef()) {
|
|
MOs.assign(DbgValue.loc_nos().size(),
|
|
MachineOperand::CreateReg(
|
|
/* Reg */ 0, /* isDef */ false, /* isImp */ false,
|
|
/* isKill */ false, /* isDead */ false,
|
|
/* isUndef */ false, /* isEarlyClobber */ false,
|
|
/* SubReg */ 0, /* isDebug */ true));
|
|
} else {
|
|
for (unsigned LocNo : DbgValue.loc_nos())
|
|
MOs.push_back(locations[LocNo]);
|
|
}
|
|
|
|
++NumInsertedDebugValues;
|
|
|
|
assert(cast<DILocalVariable>(Variable)
|
|
->isValidLocationForIntrinsic(getDebugLoc()) &&
|
|
"Expected inlined-at fields to agree");
|
|
|
|
// If the location was spilled, the new DBG_VALUE will be indirect. If the
|
|
// original DBG_VALUE was indirect, we need to add DW_OP_deref to indicate
|
|
// that the original virtual register was a pointer. Also, add the stack slot
|
|
// offset for the spilled register to the expression.
|
|
const DIExpression *Expr = DbgValue.getExpression();
|
|
bool IsIndirect = DbgValue.getWasIndirect();
|
|
bool IsList = DbgValue.getWasList();
|
|
for (unsigned I = 0, E = LocSpills.size(); I != E; ++I) {
|
|
if (LocSpills[I]) {
|
|
if (!IsList) {
|
|
uint8_t DIExprFlags = DIExpression::ApplyOffset;
|
|
if (IsIndirect)
|
|
DIExprFlags |= DIExpression::DerefAfter;
|
|
Expr = DIExpression::prepend(Expr, DIExprFlags, SpillOffsets[I]);
|
|
IsIndirect = true;
|
|
} else {
|
|
SmallVector<uint64_t, 4> Ops;
|
|
DIExpression::appendOffset(Ops, SpillOffsets[I]);
|
|
Ops.push_back(dwarf::DW_OP_deref);
|
|
Expr = DIExpression::appendOpsToArg(Expr, Ops, I);
|
|
}
|
|
}
|
|
|
|
assert((!LocSpills[I] || MOs[I].isFI()) &&
|
|
"a spilled location must be a frame index");
|
|
}
|
|
|
|
unsigned DbgValueOpcode =
|
|
IsList ? TargetOpcode::DBG_VALUE_LIST : TargetOpcode::DBG_VALUE;
|
|
do {
|
|
BuildMI(*MBB, I, getDebugLoc(), TII.get(DbgValueOpcode), IsIndirect, MOs,
|
|
Variable, Expr);
|
|
|
|
// Continue and insert DBG_VALUES after every redefinition of a register
|
|
// associated with the debug value within the range
|
|
I = findNextInsertLocation(MBB, I, StopIdx, MOs, LIS, TRI);
|
|
} while (I != MBB->end());
|
|
}
|
|
|
|
void UserLabel::insertDebugLabel(MachineBasicBlock *MBB, SlotIndex Idx,
|
|
LiveIntervals &LIS, const TargetInstrInfo &TII,
|
|
BlockSkipInstsMap &BBSkipInstsMap) {
|
|
MachineBasicBlock::iterator I =
|
|
findInsertLocation(MBB, Idx, LIS, BBSkipInstsMap);
|
|
++NumInsertedDebugLabels;
|
|
BuildMI(*MBB, I, getDebugLoc(), TII.get(TargetOpcode::DBG_LABEL))
|
|
.addMetadata(Label);
|
|
}
|
|
|
|
void UserValue::emitDebugValues(VirtRegMap *VRM, LiveIntervals &LIS,
|
|
const TargetInstrInfo &TII,
|
|
const TargetRegisterInfo &TRI,
|
|
const SpillOffsetMap &SpillOffsets,
|
|
BlockSkipInstsMap &BBSkipInstsMap) {
|
|
MachineFunction::iterator MFEnd = VRM->getMachineFunction().end();
|
|
|
|
for (LocMap::const_iterator I = locInts.begin(); I.valid();) {
|
|
SlotIndex Start = I.start();
|
|
SlotIndex Stop = I.stop();
|
|
DbgVariableValue DbgValue = I.value();
|
|
|
|
SmallVector<bool> SpilledLocs;
|
|
SmallVector<unsigned> LocSpillOffsets;
|
|
for (unsigned LocNo : DbgValue.loc_nos()) {
|
|
auto SpillIt =
|
|
!DbgValue.isUndef() ? SpillOffsets.find(LocNo) : SpillOffsets.end();
|
|
bool Spilled = SpillIt != SpillOffsets.end();
|
|
SpilledLocs.push_back(Spilled);
|
|
LocSpillOffsets.push_back(Spilled ? SpillIt->second : 0);
|
|
}
|
|
|
|
// If the interval start was trimmed to the lexical scope insert the
|
|
// DBG_VALUE at the previous index (otherwise it appears after the
|
|
// first instruction in the range).
|
|
if (trimmedDefs.count(Start))
|
|
Start = Start.getPrevIndex();
|
|
|
|
LLVM_DEBUG(auto &dbg = dbgs(); dbg << "\t[" << Start << ';' << Stop << "):";
|
|
DbgValue.printLocNos(dbg));
|
|
MachineFunction::iterator MBB = LIS.getMBBFromIndex(Start)->getIterator();
|
|
SlotIndex MBBEnd = LIS.getMBBEndIdx(&*MBB);
|
|
|
|
LLVM_DEBUG(dbgs() << ' ' << printMBBReference(*MBB) << '-' << MBBEnd);
|
|
insertDebugValue(&*MBB, Start, Stop, DbgValue, SpilledLocs, LocSpillOffsets,
|
|
LIS, TII, TRI, BBSkipInstsMap);
|
|
// This interval may span multiple basic blocks.
|
|
// Insert a DBG_VALUE into each one.
|
|
while (Stop > MBBEnd) {
|
|
// Move to the next block.
|
|
Start = MBBEnd;
|
|
if (++MBB == MFEnd)
|
|
break;
|
|
MBBEnd = LIS.getMBBEndIdx(&*MBB);
|
|
LLVM_DEBUG(dbgs() << ' ' << printMBBReference(*MBB) << '-' << MBBEnd);
|
|
insertDebugValue(&*MBB, Start, Stop, DbgValue, SpilledLocs,
|
|
LocSpillOffsets, LIS, TII, TRI, BBSkipInstsMap);
|
|
}
|
|
LLVM_DEBUG(dbgs() << '\n');
|
|
if (MBB == MFEnd)
|
|
break;
|
|
|
|
++I;
|
|
}
|
|
}
|
|
|
|
void UserLabel::emitDebugLabel(LiveIntervals &LIS, const TargetInstrInfo &TII,
|
|
BlockSkipInstsMap &BBSkipInstsMap) {
|
|
LLVM_DEBUG(dbgs() << "\t" << loc);
|
|
MachineFunction::iterator MBB = LIS.getMBBFromIndex(loc)->getIterator();
|
|
|
|
LLVM_DEBUG(dbgs() << ' ' << printMBBReference(*MBB));
|
|
insertDebugLabel(&*MBB, loc, LIS, TII, BBSkipInstsMap);
|
|
|
|
LLVM_DEBUG(dbgs() << '\n');
|
|
}
|
|
|
|
void LDVImpl::emitDebugValues(VirtRegMap *VRM) {
|
|
LLVM_DEBUG(dbgs() << "********** EMITTING LIVE DEBUG VARIABLES **********\n");
|
|
if (!MF)
|
|
return;
|
|
|
|
BlockSkipInstsMap BBSkipInstsMap;
|
|
const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
|
|
SpillOffsetMap SpillOffsets;
|
|
for (auto &userValue : userValues) {
|
|
LLVM_DEBUG(userValue->print(dbgs(), TRI));
|
|
userValue->rewriteLocations(*VRM, *MF, *TII, *TRI, SpillOffsets);
|
|
userValue->emitDebugValues(VRM, *LIS, *TII, *TRI, SpillOffsets,
|
|
BBSkipInstsMap);
|
|
}
|
|
LLVM_DEBUG(dbgs() << "********** EMITTING LIVE DEBUG LABELS **********\n");
|
|
for (auto &userLabel : userLabels) {
|
|
LLVM_DEBUG(userLabel->print(dbgs(), TRI));
|
|
userLabel->emitDebugLabel(*LIS, *TII, BBSkipInstsMap);
|
|
}
|
|
|
|
LLVM_DEBUG(dbgs() << "********** EMITTING DEBUG PHIS **********\n");
|
|
|
|
auto Slots = LIS->getSlotIndexes();
|
|
for (auto &It : PHIValToPos) {
|
|
// For each ex-PHI, identify its physreg location or stack slot, and emit
|
|
// a DBG_PHI for it.
|
|
unsigned InstNum = It.first;
|
|
auto Slot = It.second.SI;
|
|
Register Reg = It.second.Reg;
|
|
unsigned SubReg = It.second.SubReg;
|
|
|
|
MachineBasicBlock *OrigMBB = Slots->getMBBFromIndex(Slot);
|
|
if (VRM->isAssignedReg(Reg) &&
|
|
Register::isPhysicalRegister(VRM->getPhys(Reg))) {
|
|
unsigned PhysReg = VRM->getPhys(Reg);
|
|
if (SubReg != 0)
|
|
PhysReg = TRI->getSubReg(PhysReg, SubReg);
|
|
|
|
auto Builder = BuildMI(*OrigMBB, OrigMBB->begin(), DebugLoc(),
|
|
TII->get(TargetOpcode::DBG_PHI));
|
|
Builder.addReg(PhysReg);
|
|
Builder.addImm(InstNum);
|
|
} else if (VRM->getStackSlot(Reg) != VirtRegMap::NO_STACK_SLOT) {
|
|
const MachineRegisterInfo &MRI = MF->getRegInfo();
|
|
const TargetRegisterClass *TRC = MRI.getRegClass(Reg);
|
|
unsigned SpillSize, SpillOffset;
|
|
|
|
// Test whether this location is legal with the given subreg.
|
|
bool Success =
|
|
TII->getStackSlotRange(TRC, SubReg, SpillSize, SpillOffset, *MF);
|
|
|
|
if (Success) {
|
|
auto Builder = BuildMI(*OrigMBB, OrigMBB->begin(), DebugLoc(),
|
|
TII->get(TargetOpcode::DBG_PHI));
|
|
Builder.addFrameIndex(VRM->getStackSlot(Reg));
|
|
Builder.addImm(InstNum);
|
|
}
|
|
}
|
|
// If there was no mapping for a value ID, it's optimized out. Create no
|
|
// DBG_PHI, and any variables using this value will become optimized out.
|
|
}
|
|
MF->DebugPHIPositions.clear();
|
|
|
|
LLVM_DEBUG(dbgs() << "********** EMITTING INSTR REFERENCES **********\n");
|
|
|
|
// Re-insert any DBG_INSTR_REFs back in the position they were. Ordering
|
|
// is preserved by vector.
|
|
const MCInstrDesc &RefII = TII->get(TargetOpcode::DBG_INSTR_REF);
|
|
for (auto &P : StashedInstrReferences) {
|
|
const SlotIndex &Idx = P.first;
|
|
auto *MBB = Slots->getMBBFromIndex(Idx);
|
|
MachineBasicBlock::iterator insertPos =
|
|
findInsertLocation(MBB, Idx, *LIS, BBSkipInstsMap);
|
|
for (auto &Stashed : P.second) {
|
|
auto MIB = BuildMI(*MF, std::get<4>(Stashed), RefII);
|
|
MIB.addImm(std::get<0>(Stashed));
|
|
MIB.addImm(std::get<1>(Stashed));
|
|
MIB.addMetadata(std::get<2>(Stashed));
|
|
MIB.addMetadata(std::get<3>(Stashed));
|
|
MachineInstr *New = MIB;
|
|
MBB->insert(insertPos, New);
|
|
}
|
|
}
|
|
|
|
EmitDone = true;
|
|
BBSkipInstsMap.clear();
|
|
}
|
|
|
|
void LiveDebugVariables::emitDebugValues(VirtRegMap *VRM) {
|
|
if (pImpl)
|
|
static_cast<LDVImpl*>(pImpl)->emitDebugValues(VRM);
|
|
}
|
|
|
|
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
|
|
LLVM_DUMP_METHOD void LiveDebugVariables::dump() const {
|
|
if (pImpl)
|
|
static_cast<LDVImpl*>(pImpl)->print(dbgs());
|
|
}
|
|
#endif
|