forked from OSchip/llvm-project
1423 lines
50 KiB
C++
1423 lines
50 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/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/Compiler.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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/// Describes a location by number along with some flags about the original
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/// usage of the location.
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class DbgValueLocation {
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public:
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DbgValueLocation(unsigned LocNo)
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: LocNo(LocNo) {
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static_assert(sizeof(*this) == sizeof(unsigned), "bad bitfield packing");
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assert(locNo() == LocNo && "location truncation");
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}
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DbgValueLocation() : LocNo(0) {}
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unsigned locNo() const {
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// Fix up the undef location number, which gets truncated.
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return LocNo == INT_MAX ? UndefLocNo : LocNo;
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}
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bool isUndef() const { return locNo() == UndefLocNo; }
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DbgValueLocation changeLocNo(unsigned NewLocNo) const {
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return DbgValueLocation(NewLocNo);
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}
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friend inline bool operator==(const DbgValueLocation &LHS,
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const DbgValueLocation &RHS) {
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return LHS.LocNo == RHS.LocNo;
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}
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friend inline bool operator!=(const DbgValueLocation &LHS,
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const DbgValueLocation &RHS) {
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return !(LHS == RHS);
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}
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private:
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unsigned LocNo;
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};
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/// Map of where a user value is live, and its location.
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using LocMap = IntervalMap<SlotIndex, DbgValueLocation, 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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namespace {
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class LDVImpl;
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/// A UserValue is uniquely identified by the source variable it refers to
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/// (Variable), the expression describing how to get the value (Expression) and
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/// the specific usage (InlinedAt). InlinedAt differentiates both between
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/// inline and non-inline functions, and multiple inlined instances in the same
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/// scope. FIXME: The only part of the Expression which matters for UserValue
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/// identification is the fragment part.
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class UserValueIdentity {
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private:
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/// The debug info variable we are part of.
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const DILocalVariable *Variable;
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/// Any complex address expression.
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const DIExpression *Expression;
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/// Function usage identification.
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const DILocation *InlinedAt;
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public:
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UserValueIdentity(const DILocalVariable *Var, const DIExpression *Expr,
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const DILocation *IA)
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: Variable(Var), Expression(Expr), InlinedAt(IA) {}
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bool match(const DILocalVariable *Var, const DIExpression *Expr,
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const DILocation *IA) const {
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// FIXME: The fragment should be part of the identity, but not
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// other things in the expression like stack values.
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return Var == Variable && Expr == Expression && IA == InlinedAt;
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}
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bool match(const UserValueIdentity &Other) const {
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return match(Other.Variable, Other.Expression, Other.InlinedAt);
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}
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unsigned hash_value() const {
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return hash_combine(Variable, Expression, InlinedAt);
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}
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};
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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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class UserValue {
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const DILocalVariable *Variable; ///< The debug info variable we are part of.
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const DIExpression *Expression; ///< Any complex address expression.
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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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/// 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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/// Insert a DBG_VALUE into MBB at Idx for LocNo.
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void insertDebugValue(MachineBasicBlock *MBB, SlotIndex StartIdx,
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SlotIndex StopIdx, DbgValueLocation Loc, bool Spilled,
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unsigned SpillOffset, LiveIntervals &LIS,
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const TargetInstrInfo &TII,
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const TargetRegisterInfo &TRI);
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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<unsigned> NewRegs,
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LiveIntervals &LIS);
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public:
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UserValue(const UserValue &) = delete;
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/// Create a new UserValue.
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UserValue(const DILocalVariable *var, const DIExpression *expr, DebugLoc L,
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LocMap::Allocator &alloc)
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: Variable(var), Expression(expr), dl(std::move(L)), locInts(alloc) {}
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UserValueIdentity getId() {
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return UserValueIdentity(Variable, Expression, dl->getInlinedAt());
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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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/// 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 value.
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void addDef(SlotIndex Idx, const MachineOperand &LocMO) {
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DbgValueLocation Loc(getLocationNo(LocMO));
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// Add a singular (Idx,Idx) -> Loc 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(), Loc);
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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(Loc);
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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 Loc Location number to propagate.
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/// \param LR Restrict liveness to where LR has the value VNI. May be null.
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/// \param VNI When LR is not null, this is the value to restrict to.
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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, DbgValueLocation Loc,
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LiveRange *LR, const VNInfo *VNI,
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SmallVectorImpl<SlotIndex> *Kills,
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LiveIntervals &LIS);
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/// The value in LI/LocNo may be copies to other registers. Determine if
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/// any of the copies are available at the kill points, and add defs if
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/// possible.
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///
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/// \param LI Scan for copies of the value in LI->reg.
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/// \param LocNo Location number of LI->reg.
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/// \param Kills Points where the range of LocNo could be extended.
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/// \param [in,out] NewDefs Append (Idx, LocNo) of inserted defs here.
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void addDefsFromCopies(
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LiveInterval *LI, unsigned LocNo,
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const SmallVectorImpl<SlotIndex> &Kills,
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SmallVectorImpl<std::pair<SlotIndex, DbgValueLocation>> &NewDefs,
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MachineRegisterInfo &MRI, LiveIntervals &LIS);
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/// Compute the live intervals of all locations after collecting all their
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/// def points.
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void computeIntervals(MachineRegisterInfo &MRI, const TargetRegisterInfo &TRI,
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LiveIntervals &LIS, LexicalScopes &LS);
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/// Replace OldReg ranges with NewRegs ranges where NewRegs is
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/// live. Returns true if any changes were made.
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bool splitRegister(unsigned OldReg, ArrayRef<unsigned> NewRegs,
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LiveIntervals &LIS);
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/// Rewrite virtual register locations according to the provided virtual
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/// register map. Record the stack slot offsets for the locations that
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/// were spilled.
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void rewriteLocations(VirtRegMap &VRM, const MachineFunction &MF,
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const TargetInstrInfo &TII,
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const TargetRegisterInfo &TRI,
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SpillOffsetMap &SpillOffsets);
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/// Recreate DBG_VALUE instruction from data structures.
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void emitDebugValues(VirtRegMap *VRM, LiveIntervals &LIS,
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const TargetInstrInfo &TII,
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const TargetRegisterInfo &TRI,
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const SpillOffsetMap &SpillOffsets);
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/// Return DebugLoc of this UserValue.
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DebugLoc getDebugLoc() { return dl;}
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void print(raw_ostream &, const TargetRegisterInfo *);
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};
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} // namespace
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namespace llvm {
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template <> struct DenseMapInfo<UserValueIdentity> {
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static UserValueIdentity getEmptyKey() {
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auto Key = DenseMapInfo<DILocalVariable *>::getEmptyKey();
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return UserValueIdentity(Key, nullptr, nullptr);
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}
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static UserValueIdentity getTombstoneKey() {
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auto Key = DenseMapInfo<DILocalVariable *>::getTombstoneKey();
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return UserValueIdentity(Key, nullptr, nullptr);
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}
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static unsigned getHashValue(const UserValueIdentity &Val) {
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return Val.hash_value();
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}
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static bool isEqual(const UserValueIdentity &LHS,
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const UserValueIdentity &RHS) {
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return LHS.match(RHS);
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}
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};
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} // namespace llvm
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namespace {
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/// A user label is a part of a debug info user label.
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class UserLabel {
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const DILabel *Label; ///< The debug info label we are part of.
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DebugLoc dl; ///< The debug location for the label. This is
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///< used by dwarf writer to find lexical scope.
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SlotIndex loc; ///< Slot used by the debug label.
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/// Insert a DBG_LABEL into MBB at Idx.
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void insertDebugLabel(MachineBasicBlock *MBB, SlotIndex Idx,
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LiveIntervals &LIS, const TargetInstrInfo &TII);
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public:
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/// Create a new UserLabel.
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UserLabel(const DILabel *label, DebugLoc L, SlotIndex Idx)
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: Label(label), dl(std::move(L)), loc(Idx) {}
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/// Does this UserLabel match the parameters?
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bool match(const DILabel *L, const DILocation *IA,
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const SlotIndex Index) const {
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return Label == L && dl->getInlinedAt() == IA && loc == Index;
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}
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/// Recreate DBG_LABEL instruction from data structures.
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void emitDebugLabel(LiveIntervals &LIS, const TargetInstrInfo &TII);
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/// Return DebugLoc of this UserLabel.
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DebugLoc getDebugLoc() { return dl; }
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void print(raw_ostream &, const TargetRegisterInfo *);
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};
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/// Implementation of the LiveDebugVariables pass.
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class LDVImpl {
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LiveDebugVariables &pass;
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LocMap::Allocator allocator;
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MachineFunction *MF = nullptr;
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LiveIntervals *LIS;
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const TargetRegisterInfo *TRI;
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/// Whether emitDebugValues is called.
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bool EmitDone = false;
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/// Whether the machine function is modified during the pass.
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bool ModifiedMF = false;
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/// All allocated UserValue instances.
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SmallVector<std::unique_ptr<UserValue>, 8> userValues;
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/// All allocated UserLabel instances.
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SmallVector<std::unique_ptr<UserLabel>, 2> userLabels;
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/// Map virtual register to UserValues which use it.
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using VRMap = DenseMap<unsigned, SmallVector<UserValue *, 4>>;
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VRMap VirtRegToUserVals;
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/// Map unique UserValue identity to UserValue.
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using UVMap = DenseMap<UserValueIdentity, UserValue *>;
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UVMap UserVarMap;
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/// Find or create a UserValue.
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UserValue *getUserValue(const DILocalVariable *Var, const DIExpression *Expr,
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const DebugLoc &DL);
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/// Find the UserValues for VirtReg or null.
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SmallVectorImpl<UserValue *> *lookupVirtReg(unsigned VirtReg);
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/// Add DBG_VALUE instruction to our maps.
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///
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/// \param MI DBG_VALUE instruction
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/// \param Idx Last valid SLotIndex before instruction.
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///
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/// \returns True if the DBG_VALUE instruction should be deleted.
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bool handleDebugValue(MachineInstr &MI, SlotIndex Idx);
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/// Add DBG_LABEL instruction to UserLabel.
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///
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/// \param MI DBG_LABEL instruction
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/// \param Idx Last valid SlotIndex before instruction.
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///
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/// \returns True if the DBG_LABEL instruction should be deleted.
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bool handleDebugLabel(MachineInstr &MI, SlotIndex Idx);
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/// Collect and erase all DBG_VALUE instructions, adding a UserValue def
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/// for each instruction.
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///
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/// \param mf MachineFunction to be scanned.
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///
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/// \returns True if any debug values were found.
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bool collectDebugValues(MachineFunction &mf);
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/// Compute the live intervals of all user values after collecting all
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/// their def points.
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void computeIntervals();
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public:
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LDVImpl(LiveDebugVariables *ps) : pass(*ps) {}
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bool runOnMachineFunction(MachineFunction &mf);
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/// Release all memory.
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void clear() {
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MF = nullptr;
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userValues.clear();
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userLabels.clear();
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VirtRegToUserVals.clear();
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UserVarMap.clear();
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// Make sure we call emitDebugValues if the machine function was modified.
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assert((!ModifiedMF || EmitDone) &&
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"Dbg values are not emitted in LDV");
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EmitDone = false;
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ModifiedMF = false;
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}
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/// Map virtual register to a UserValue.
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void mapVirtReg(unsigned VirtReg, UserValue *UV);
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/// Replace all references to OldReg with NewRegs.
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void splitRegister(unsigned OldReg, ArrayRef<unsigned> NewRegs);
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/// Recreate DBG_VALUE instruction from data structures.
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void emitDebugValues(VirtRegMap *VRM);
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void print(raw_ostream&);
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};
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} // end anonymous namespace
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#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
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static void printDebugLoc(const DebugLoc &DL, raw_ostream &CommentOS,
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const LLVMContext &Ctx) {
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if (!DL)
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return;
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auto *Scope = cast<DIScope>(DL.getScope());
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// Omit the directory, because it's likely to be long and uninteresting.
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CommentOS << Scope->getFilename();
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CommentOS << ':' << DL.getLine();
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if (DL.getCol() != 0)
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CommentOS << ':' << DL.getCol();
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|
|
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;
|
|
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 {
|
|
OS << I.value().locNo();
|
|
}
|
|
}
|
|
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,
|
|
const DIExpression *Expr, const DebugLoc &DL) {
|
|
auto Ident = UserValueIdentity(Var, Expr, DL->getInlinedAt());
|
|
UserValue *&UVEntry = UserVarMap[Ident];
|
|
|
|
if (UVEntry)
|
|
return UVEntry;
|
|
|
|
userValues.push_back(std::make_unique<UserValue>(Var, Expr, DL, allocator));
|
|
return UVEntry = userValues.back().get();
|
|
}
|
|
|
|
void LDVImpl::mapVirtReg(unsigned VirtReg, UserValue *UV) {
|
|
assert(Register::isVirtualRegister(VirtReg) && "Only map VirtRegs");
|
|
assert(UserVarMap.find(UV->getId()) != UserVarMap.end() &&
|
|
"UserValue should exist in UserVarMap");
|
|
VirtRegToUserVals[VirtReg].push_back(UV);
|
|
}
|
|
|
|
SmallVectorImpl<UserValue *> *LDVImpl::lookupVirtReg(unsigned VirtReg) {
|
|
VRMap::iterator Itr = VirtRegToUserVals.find(VirtReg);
|
|
if (Itr != VirtRegToUserVals.end())
|
|
return &Itr->getSecond();
|
|
return nullptr;
|
|
}
|
|
|
|
bool LDVImpl::handleDebugValue(MachineInstr &MI, SlotIndex Idx) {
|
|
// DBG_VALUE loc, offset, variable
|
|
if (MI.getNumOperands() != 4 ||
|
|
!(MI.getOperand(1).isReg() || MI.getOperand(1).isImm()) ||
|
|
!MI.getOperand(2).isMetadata()) {
|
|
LLVM_DEBUG(dbgs() << "Can't handle " << 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;
|
|
if (MI.getOperand(0).isReg() &&
|
|
Register::isVirtualRegister(MI.getOperand(0).getReg())) {
|
|
const Register Reg = MI.getOperand(0).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.
|
|
assert(!MI.getOperand(1).isImm() && "DBG_VALUE with indirect flag before "
|
|
"LiveDebugVariables");
|
|
const DILocalVariable *Var = MI.getDebugVariable();
|
|
const DIExpression *Expr = MI.getDebugExpression();
|
|
UserValue *UV =
|
|
getUserValue(Var, Expr, MI.getDebugLoc());
|
|
if (!Discard)
|
|
UV->addDef(Idx, MI.getOperand(0));
|
|
else {
|
|
MachineOperand MO = MachineOperand::CreateReg(0U, false);
|
|
MO.setIsDebug();
|
|
UV->addDef(Idx, MO);
|
|
}
|
|
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->match(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 (MachineFunction::iterator MFI = mf.begin(), MFE = mf.end(); MFI != MFE;
|
|
++MFI) {
|
|
MachineBasicBlock *MBB = &*MFI;
|
|
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->isDebugInstr()) {
|
|
++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->isDebugLabel() && handleDebugLabel(*MBBI, Idx))) {
|
|
MBBI = MBB->erase(MBBI);
|
|
Changed = true;
|
|
} else
|
|
++MBBI;
|
|
} while (MBBI != MBBE && MBBI->isDebugInstr());
|
|
}
|
|
}
|
|
return Changed;
|
|
}
|
|
|
|
void UserValue::extendDef(SlotIndex Idx, DbgValueLocation Loc, LiveRange *LR,
|
|
const VNInfo *VNI, SmallVectorImpl<SlotIndex> *Kills,
|
|
LiveIntervals &LIS) {
|
|
SlotIndex Start = Idx;
|
|
MachineBasicBlock *MBB = LIS.getMBBFromIndex(Start);
|
|
SlotIndex Stop = LIS.getMBBEndIdx(MBB);
|
|
LocMap::iterator I = locInts.find(Start);
|
|
|
|
// Limit to VNI's live range.
|
|
bool ToEnd = true;
|
|
if (LR && VNI) {
|
|
LiveInterval::Segment *Segment = LR->getSegmentContaining(Start);
|
|
if (!Segment || Segment->valno != VNI) {
|
|
if (Kills)
|
|
Kills->push_back(Start);
|
|
return;
|
|
}
|
|
if (Segment->end < Stop) {
|
|
Stop = Segment->end;
|
|
ToEnd = false;
|
|
}
|
|
}
|
|
|
|
// 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() != Loc || I.stop() != Start)
|
|
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();
|
|
// Limited by VNI's live range.
|
|
else if (!ToEnd && Kills)
|
|
Kills->push_back(Stop);
|
|
|
|
if (Start < Stop)
|
|
I.insert(Start, Stop, Loc);
|
|
}
|
|
|
|
void UserValue::addDefsFromCopies(
|
|
LiveInterval *LI, unsigned LocNo,
|
|
const SmallVectorImpl<SlotIndex> &Kills,
|
|
SmallVectorImpl<std::pair<SlotIndex, DbgValueLocation>> &NewDefs,
|
|
MachineRegisterInfo &MRI, LiveIntervals &LIS) {
|
|
if (Kills.empty())
|
|
return;
|
|
// Don't track copies from physregs, there are too many uses.
|
|
if (!Register::isVirtualRegister(LI->reg))
|
|
return;
|
|
|
|
// Collect all the (vreg, valno) pairs that are copies of LI.
|
|
SmallVector<std::pair<LiveInterval*, const VNInfo*>, 8> CopyValues;
|
|
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 LocNo 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().locNo() != LocNo)
|
|
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.push_back(std::make_pair(DstLI, DstVNI));
|
|
}
|
|
|
|
if (CopyValues.empty())
|
|
return;
|
|
|
|
LLVM_DEBUG(dbgs() << "Got " << CopyValues.size() << " copies of " << *LI
|
|
<< '\n');
|
|
|
|
// Try to add defs of the copied values for each kill point.
|
|
for (unsigned i = 0, e = Kills.size(); i != e; ++i) {
|
|
SlotIndex Idx = Kills[i];
|
|
for (unsigned j = 0, e = CopyValues.size(); j != e; ++j) {
|
|
LiveInterval *DstLI = CopyValues[j].first;
|
|
const VNInfo *DstVNI = CopyValues[j].second;
|
|
if (DstLI->getVNInfoAt(Idx) != DstVNI)
|
|
continue;
|
|
// Check that there isn't already a def at Idx
|
|
LocMap::iterator I = locInts.find(Idx);
|
|
if (I.valid() && I.start() <= Idx)
|
|
continue;
|
|
LLVM_DEBUG(dbgs() << "Kill at " << Idx << " covered by valno #"
|
|
<< DstVNI->id << " in " << *DstLI << '\n');
|
|
MachineInstr *CopyMI = LIS.getInstructionFromIndex(DstVNI->def);
|
|
assert(CopyMI && CopyMI->isCopy() && "Bad copy value");
|
|
unsigned LocNo = getLocationNo(CopyMI->getOperand(0));
|
|
DbgValueLocation NewLoc(LocNo);
|
|
I.insert(Idx, Idx.getNextSlot(), NewLoc);
|
|
NewDefs.push_back(std::make_pair(Idx, NewLoc));
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
void UserValue::computeIntervals(MachineRegisterInfo &MRI,
|
|
const TargetRegisterInfo &TRI,
|
|
LiveIntervals &LIS, LexicalScopes &LS) {
|
|
SmallVector<std::pair<SlotIndex, DbgValueLocation>, 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;
|
|
DbgValueLocation Loc = Defs[i].second;
|
|
const MachineOperand &LocMO = locations[Loc.locNo()];
|
|
|
|
if (!LocMO.isReg()) {
|
|
extendDef(Idx, Loc, nullptr, nullptr, nullptr, LIS);
|
|
continue;
|
|
}
|
|
|
|
// Register locations are constrained to where the register value is live.
|
|
if (Register::isVirtualRegister(LocMO.getReg())) {
|
|
LiveInterval *LI = nullptr;
|
|
const VNInfo *VNI = nullptr;
|
|
if (LIS.hasInterval(LocMO.getReg())) {
|
|
LI = &LIS.getInterval(LocMO.getReg());
|
|
VNI = LI->getVNInfoAt(Idx);
|
|
}
|
|
SmallVector<SlotIndex, 16> Kills;
|
|
extendDef(Idx, Loc, LI, VNI, &Kills, LIS);
|
|
// 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 (LI && !LocMO.getSubReg())
|
|
addDefsFromCopies(LI, Loc.locNo(), Kills, Defs, MRI, LIS);
|
|
continue;
|
|
}
|
|
|
|
// 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.
|
|
|
|
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);
|
|
|
|
// 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();
|
|
DbgValueLocation Loc = 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
|
|
if (RStart < IStop)
|
|
I.insert(RStart, IStop, Loc);
|
|
}
|
|
|
|
// Advance I so that I.stop() >= RStart, and check for overlap.
|
|
I.advanceTo(RStart);
|
|
if (!I.valid())
|
|
return;
|
|
|
|
// 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()));
|
|
ModifiedMF = Changed;
|
|
return Changed;
|
|
}
|
|
|
|
static void removeDebugValues(MachineFunction &mf) {
|
|
for (MachineBasicBlock &MBB : mf) {
|
|
for (auto MBBI = MBB.begin(), MBBE = MBB.end(); MBBI != MBBE; ) {
|
|
if (!MBBI->isDebugValue()) {
|
|
++MBBI;
|
|
continue;
|
|
}
|
|
MBBI = MBB.erase(MBBI);
|
|
}
|
|
}
|
|
}
|
|
|
|
bool LiveDebugVariables::runOnMachineFunction(MachineFunction &mf) {
|
|
if (!EnableLDV)
|
|
return false;
|
|
if (!mf.getFunction().getSubprogram()) {
|
|
removeDebugValues(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<unsigned> 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().locNo() == 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();
|
|
DbgValueLocation OldLoc = 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(OldLoc.changeLocNo(NewLocNo));
|
|
|
|
// Re-insert any removed OldLocNo ranges.
|
|
if (LStart < LocMapI.start()) {
|
|
LocMapI.insert(LStart, LocMapI.start(), OldLoc);
|
|
++LocMapI;
|
|
assert(LocMapI.valid() && "Unexpected coalescing");
|
|
}
|
|
if (LStop > LocMapI.stop()) {
|
|
++LocMapI;
|
|
LocMapI.insert(LII->end, LStop, OldLoc);
|
|
--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 any remaining OldLocNo intervals and OldLocNo itself.
|
|
locations.erase(locations.begin() + OldLocNo);
|
|
LocMapI.goToBegin();
|
|
while (LocMapI.valid()) {
|
|
DbgValueLocation v = LocMapI.value();
|
|
if (v.locNo() == OldLocNo) {
|
|
LLVM_DEBUG(dbgs() << "Erasing [" << LocMapI.start() << ';'
|
|
<< LocMapI.stop() << ")\n");
|
|
LocMapI.erase();
|
|
} else {
|
|
// Undef values always have location number UndefLocNo, so don't change
|
|
// locNo in that case. See getLocationNo().
|
|
if (!v.isUndef() && v.locNo() > OldLocNo)
|
|
LocMapI.setValueUnchecked(v.changeLocNo(v.locNo() - 1));
|
|
++LocMapI;
|
|
}
|
|
}
|
|
|
|
LLVM_DEBUG({
|
|
dbgs() << "Split result: \t";
|
|
print(dbgs(), nullptr);
|
|
});
|
|
return DidChange;
|
|
}
|
|
|
|
bool
|
|
UserValue::splitRegister(unsigned OldReg, ArrayRef<unsigned> 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::splitRegister(unsigned OldReg, ArrayRef<unsigned> NewRegs) {
|
|
bool DidChange = false;
|
|
if (auto *UserVals = lookupVirtReg(OldReg))
|
|
for (auto *UV : *UserVals)
|
|
DidChange |= UV->splitRegister(OldReg, NewRegs, *LIS);
|
|
|
|
if (!DidChange)
|
|
return;
|
|
|
|
// Map all of the new virtual registers.
|
|
if (auto *UserVals = lookupVirtReg(OldReg))
|
|
for (auto *UV : *UserVals)
|
|
for (unsigned i = 0; i != NewRegs.size(); ++i)
|
|
mapVirtReg(NewRegs[i], UV);
|
|
}
|
|
|
|
void LiveDebugVariables::
|
|
splitRegister(unsigned OldReg, ArrayRef<unsigned> 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) {
|
|
DbgValueLocation Loc = I.value();
|
|
// Undef values don't exist in locations (and thus not in LocNoMap either)
|
|
// so skip over them. See getLocationNo().
|
|
if (Loc.isUndef())
|
|
continue;
|
|
unsigned NewLocNo = LocNoMap[Loc.locNo()];
|
|
I.setValueUnchecked(Loc.changeLocNo(NewLocNo));
|
|
I.setStart(I.start());
|
|
}
|
|
}
|
|
|
|
/// Find an iterator for inserting a DBG_VALUE instruction.
|
|
static MachineBasicBlock::iterator
|
|
findInsertLocation(MachineBasicBlock *MBB, SlotIndex Idx,
|
|
LiveIntervals &LIS) {
|
|
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) {
|
|
MachineBasicBlock::iterator I = MBB->SkipPHIsLabelsAndDebug(MBB->begin());
|
|
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, MachineOperand &LocMO,
|
|
LiveIntervals &LIS,
|
|
const TargetRegisterInfo &TRI) {
|
|
if (!LocMO.isReg())
|
|
return MBB->instr_end();
|
|
Register Reg = LocMO.getReg();
|
|
|
|
// 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 (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, DbgValueLocation Loc,
|
|
bool Spilled, unsigned SpillOffset,
|
|
LiveIntervals &LIS, const TargetInstrInfo &TII,
|
|
const TargetRegisterInfo &TRI) {
|
|
SlotIndex MBBEndIdx = LIS.getMBBEndIdx(&*MBB);
|
|
// Only search within the current MBB.
|
|
StopIdx = (MBBEndIdx < StopIdx) ? MBBEndIdx : StopIdx;
|
|
MachineBasicBlock::iterator I = findInsertLocation(MBB, StartIdx, LIS);
|
|
// Undef values don't exist in locations so create new "noreg" register MOs
|
|
// for them. See getLocationNo().
|
|
MachineOperand MO = !Loc.isUndef() ?
|
|
locations[Loc.locNo()] :
|
|
MachineOperand::CreateReg(/* Reg */ 0, /* isDef */ false, /* isImp */ false,
|
|
/* isKill */ false, /* isDead */ false,
|
|
/* isUndef */ false, /* isEarlyClobber */ false,
|
|
/* SubReg */ 0, /* isDebug */ true);
|
|
|
|
++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 = Expression;
|
|
if (Spilled)
|
|
Expr = DIExpression::prepend(Expr, DIExpression::ApplyOffset, SpillOffset);
|
|
|
|
assert((!Spilled || MO.isFI()) && "a spilled location must be a frame index");
|
|
|
|
do {
|
|
BuildMI(*MBB, I, getDebugLoc(), TII.get(TargetOpcode::DBG_VALUE),
|
|
Spilled, MO, Variable, Expr);
|
|
|
|
// Continue and insert DBG_VALUES after every redefinition of register
|
|
// associated with the debug value within the range
|
|
I = findNextInsertLocation(MBB, I, StopIdx, MO, LIS, TRI);
|
|
} while (I != MBB->end());
|
|
}
|
|
|
|
void UserLabel::insertDebugLabel(MachineBasicBlock *MBB, SlotIndex Idx,
|
|
LiveIntervals &LIS,
|
|
const TargetInstrInfo &TII) {
|
|
MachineBasicBlock::iterator I = findInsertLocation(MBB, Idx, LIS);
|
|
++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) {
|
|
MachineFunction::iterator MFEnd = VRM->getMachineFunction().end();
|
|
|
|
for (LocMap::const_iterator I = locInts.begin(); I.valid();) {
|
|
SlotIndex Start = I.start();
|
|
SlotIndex Stop = I.stop();
|
|
DbgValueLocation Loc = I.value();
|
|
auto SpillIt =
|
|
!Loc.isUndef() ? SpillOffsets.find(Loc.locNo()) : SpillOffsets.end();
|
|
bool Spilled = SpillIt != SpillOffsets.end();
|
|
unsigned SpillOffset = Spilled ? SpillIt->second : 0;
|
|
|
|
LLVM_DEBUG(dbgs() << "\t[" << Start << ';' << Stop << "):" << Loc.locNo());
|
|
MachineFunction::iterator MBB = LIS.getMBBFromIndex(Start)->getIterator();
|
|
SlotIndex MBBEnd = LIS.getMBBEndIdx(&*MBB);
|
|
|
|
LLVM_DEBUG(dbgs() << ' ' << printMBBReference(*MBB) << '-' << MBBEnd);
|
|
insertDebugValue(&*MBB, Start, Stop, Loc, Spilled, SpillOffset, LIS, TII,
|
|
TRI);
|
|
// 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, Loc, Spilled, SpillOffset, LIS, TII,
|
|
TRI);
|
|
}
|
|
LLVM_DEBUG(dbgs() << '\n');
|
|
if (MBB == MFEnd)
|
|
break;
|
|
|
|
++I;
|
|
}
|
|
}
|
|
|
|
void UserLabel::emitDebugLabel(LiveIntervals &LIS, const TargetInstrInfo &TII) {
|
|
LLVM_DEBUG(dbgs() << "\t" << loc);
|
|
MachineFunction::iterator MBB = LIS.getMBBFromIndex(loc)->getIterator();
|
|
|
|
LLVM_DEBUG(dbgs() << ' ' << printMBBReference(*MBB));
|
|
insertDebugLabel(&*MBB, loc, LIS, TII);
|
|
|
|
LLVM_DEBUG(dbgs() << '\n');
|
|
}
|
|
|
|
void LDVImpl::emitDebugValues(VirtRegMap *VRM) {
|
|
LLVM_DEBUG(dbgs() << "********** EMITTING LIVE DEBUG VARIABLES **********\n");
|
|
if (!MF)
|
|
return;
|
|
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);
|
|
}
|
|
LLVM_DEBUG(dbgs() << "********** EMITTING LIVE DEBUG LABELS **********\n");
|
|
for (auto &userLabel : userLabels) {
|
|
LLVM_DEBUG(userLabel->print(dbgs(), TRI));
|
|
userLabel->emitDebugLabel(*LIS, *TII);
|
|
}
|
|
EmitDone = true;
|
|
}
|
|
|
|
void LiveDebugVariables::emitDebugValues(VirtRegMap *VRM) {
|
|
if (pImpl)
|
|
static_cast<LDVImpl*>(pImpl)->emitDebugValues(VRM);
|
|
}
|
|
|
|
bool LiveDebugVariables::doInitialization(Module &M) {
|
|
return Pass::doInitialization(M);
|
|
}
|
|
|
|
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
|
|
LLVM_DUMP_METHOD void LiveDebugVariables::dump() const {
|
|
if (pImpl)
|
|
static_cast<LDVImpl*>(pImpl)->print(dbgs());
|
|
}
|
|
#endif
|