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-rw-r--r--llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp6
-rw-r--r--llvm/lib/CodeGen/LiveDebugValues.cpp137
-rw-r--r--llvm/lib/CodeGen/MachineVerifier.cpp2
3 files changed, 127 insertions, 18 deletions
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index f0ceba50f14..4163fdbb177 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -1128,6 +1128,12 @@ void DwarfCompileUnit::addComplexAddress(const DbgVariable &DV, DIE &Die,
DwarfExpr.setMemoryLocationKind();
DIExpressionCursor Cursor(DIExpr);
+
+ if (DIExpr->isEntryValue()) {
+ DwarfExpr.setEntryValueFlag();
+ DwarfExpr.addEntryValueExpression(Cursor);
+ }
+
const TargetRegisterInfo &TRI = *Asm->MF->getSubtarget().getRegisterInfo();
if (!DwarfExpr.addMachineRegExpression(TRI, Cursor, Location.getReg()))
return;
diff --git a/llvm/lib/CodeGen/LiveDebugValues.cpp b/llvm/lib/CodeGen/LiveDebugValues.cpp
index 19bd354e611..a669e64692b 100644
--- a/llvm/lib/CodeGen/LiveDebugValues.cpp
+++ b/llvm/lib/CodeGen/LiveDebugValues.cpp
@@ -39,6 +39,7 @@
#include "llvm/CodeGen/TargetFrameLowering.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/CodeGen/TargetLowering.h"
+#include "llvm/CodeGen/TargetPassConfig.h"
#include "llvm/CodeGen/TargetRegisterInfo.h"
#include "llvm/CodeGen/TargetSubtargetInfo.h"
#include "llvm/Config/llvm-config.h"
@@ -185,7 +186,8 @@ private:
InvalidKind = 0,
RegisterKind,
SpillLocKind,
- ImmediateKind
+ ImmediateKind,
+ EntryValueKind
} Kind = InvalidKind;
/// The value location. Stored separately to avoid repeatedly
@@ -199,14 +201,15 @@ private:
const ConstantInt *CImm;
} Loc;
- VarLoc(const MachineInstr &MI, LexicalScopes &LS)
- : Var(MI), MI(MI), UVS(MI.getDebugLoc(), LS) {
+ VarLoc(const MachineInstr &MI, LexicalScopes &LS,
+ VarLocKind K = InvalidKind)
+ : Var(MI), MI(MI), UVS(MI.getDebugLoc(), LS){
static_assert((sizeof(Loc) == sizeof(uint64_t)),
"hash does not cover all members of Loc");
assert(MI.isDebugValue() && "not a DBG_VALUE");
assert(MI.getNumOperands() == 4 && "malformed DBG_VALUE");
if (int RegNo = isDbgValueDescribedByReg(MI)) {
- Kind = RegisterKind;
+ Kind = MI.isDebugEntryValue() ? EntryValueKind : RegisterKind;
Loc.RegNo = RegNo;
} else if (MI.getOperand(0).isImm()) {
Kind = ImmediateKind;
@@ -218,6 +221,8 @@ private:
Kind = ImmediateKind;
Loc.CImm = MI.getOperand(0).getCImm();
}
+ assert((Kind != ImmediateKind || !MI.isDebugEntryValue()) &&
+ "entry values must be register locations");
}
/// The constructor for spill locations.
@@ -256,12 +261,12 @@ private:
/// This operator guarantees that VarLocs are sorted by Variable first.
bool operator<(const VarLoc &Other) const {
- if (Var == Other.Var)
- return Loc.Hash < Other.Loc.Hash;
- return Var < Other.Var;
+ return std::tie(Var, Kind, Loc.Hash) <
+ std::tie(Other.Var, Other.Kind, Other.Loc.Hash);
}
};
+ using DebugParamMap = SmallDenseMap<const DILocalVariable *, MachineInstr *>;
using VarLocMap = UniqueVector<VarLoc>;
using VarLocSet = SparseBitVector<>;
using VarLocInMBB = SmallDenseMap<const MachineBasicBlock *, VarLocSet>;
@@ -347,17 +352,23 @@ private:
VarLocMap &VarLocIDs);
void transferSpillOrRestoreInst(MachineInstr &MI, OpenRangesSet &OpenRanges,
VarLocMap &VarLocIDs, TransferMap &Transfers);
+ void emitEntryValues(MachineInstr &MI, OpenRangesSet &OpenRanges,
+ VarLocMap &VarLocIDs, TransferMap &Transfers,
+ DebugParamMap &DebugEntryVals,
+ SparseBitVector<> &KillSet);
void transferRegisterCopy(MachineInstr &MI, OpenRangesSet &OpenRanges,
VarLocMap &VarLocIDs, TransferMap &Transfers);
void transferRegisterDef(MachineInstr &MI, OpenRangesSet &OpenRanges,
- const VarLocMap &VarLocIDs);
+ VarLocMap &VarLocIDs, TransferMap &Transfers,
+ DebugParamMap &DebugEntryVals);
bool transferTerminatorInst(MachineInstr &MI, OpenRangesSet &OpenRanges,
VarLocInMBB &OutLocs, const VarLocMap &VarLocIDs);
bool process(MachineInstr &MI, OpenRangesSet &OpenRanges,
VarLocInMBB &OutLocs, VarLocMap &VarLocIDs,
- TransferMap &Transfers, bool transferChanges,
- OverlapMap &OverlapFragments, VarToFragments &SeenFragments);
+ TransferMap &Transfers, DebugParamMap &DebugEntryVals,
+ bool transferChanges, OverlapMap &OverlapFragments,
+ VarToFragments &SeenFragments);
void accumulateFragmentMap(MachineInstr &MI, VarToFragments &SeenFragments,
OverlapMap &OLapMap);
@@ -568,6 +579,44 @@ void LiveDebugValues::transferDebugValue(const MachineInstr &MI,
}
}
+void LiveDebugValues::emitEntryValues(MachineInstr &MI,
+ OpenRangesSet &OpenRanges,
+ VarLocMap &VarLocIDs,
+ TransferMap &Transfers,
+ DebugParamMap &DebugEntryVals,
+ SparseBitVector<> &KillSet) {
+ MachineFunction *MF = MI.getParent()->getParent();
+ for (unsigned ID : KillSet) {
+ if (!VarLocIDs[ID].Var.getVar()->isParameter())
+ continue;
+
+ const MachineInstr *CurrDebugInstr = &VarLocIDs[ID].MI;
+
+ // If parameter's DBG_VALUE is not in the map that means we can't
+ // generate parameter's entry value.
+ if (!DebugEntryVals.count(CurrDebugInstr->getDebugVariable()))
+ continue;
+
+ auto ParamDebugInstr = DebugEntryVals[CurrDebugInstr->getDebugVariable()];
+ DIExpression *NewExpr = DIExpression::prepend(
+ ParamDebugInstr->getDebugExpression(), DIExpression::EntryValue);
+ MachineInstr *EntryValDbgMI =
+ BuildMI(*MF, ParamDebugInstr->getDebugLoc(), ParamDebugInstr->getDesc(),
+ ParamDebugInstr->isIndirectDebugValue(),
+ ParamDebugInstr->getOperand(0).getReg(),
+ ParamDebugInstr->getDebugVariable(), NewExpr);
+
+ if (ParamDebugInstr->isIndirectDebugValue())
+ EntryValDbgMI->getOperand(1).setImm(
+ ParamDebugInstr->getOperand(1).getImm());
+
+ Transfers.push_back({&MI, EntryValDbgMI});
+ VarLoc VL(*EntryValDbgMI, LS);
+ unsigned EntryValLocID = VarLocIDs.insert(VL);
+ OpenRanges.insert(EntryValLocID, VL.Var);
+ }
+}
+
/// Create new TransferDebugPair and insert it in \p Transfers. The VarLoc
/// with \p OldVarID should be deleted form \p OpenRanges and replaced with
/// new VarLoc. If \p NewReg is different than default zero value then the
@@ -658,9 +707,9 @@ void LiveDebugValues::insertTransferDebugPair(
}
/// A definition of a register may mark the end of a range.
-void LiveDebugValues::transferRegisterDef(MachineInstr &MI,
- OpenRangesSet &OpenRanges,
- const VarLocMap &VarLocIDs) {
+void LiveDebugValues::transferRegisterDef(
+ MachineInstr &MI, OpenRangesSet &OpenRanges, VarLocMap &VarLocIDs,
+ TransferMap &Transfers, DebugParamMap &DebugEntryVals) {
MachineFunction *MF = MI.getMF();
const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
unsigned SP = TLI->getStackPointerRegisterToSaveRestore();
@@ -690,6 +739,13 @@ void LiveDebugValues::transferRegisterDef(MachineInstr &MI,
}
}
OpenRanges.erase(KillSet, VarLocIDs);
+
+ if (auto *TPC = getAnalysisIfAvailable<TargetPassConfig>()) {
+ auto &TM = TPC->getTM<TargetMachine>();
+ if (TM.Options.EnableDebugEntryValues)
+ emitEntryValues(MI, OpenRanges, VarLocIDs, Transfers, DebugEntryVals,
+ KillSet);
+ }
}
/// Decide if @MI is a spill instruction and return true if it is. We use 2
@@ -941,12 +997,14 @@ void LiveDebugValues::accumulateFragmentMap(MachineInstr &MI,
/// This routine creates OpenRanges and OutLocs.
bool LiveDebugValues::process(MachineInstr &MI, OpenRangesSet &OpenRanges,
VarLocInMBB &OutLocs, VarLocMap &VarLocIDs,
- TransferMap &Transfers, bool transferChanges,
+ TransferMap &Transfers, DebugParamMap &DebugEntryVals,
+ bool transferChanges,
OverlapMap &OverlapFragments,
VarToFragments &SeenFragments) {
bool Changed = false;
transferDebugValue(MI, OpenRanges, VarLocIDs);
- transferRegisterDef(MI, OpenRanges, VarLocIDs);
+ transferRegisterDef(MI, OpenRanges, VarLocIDs, Transfers,
+ DebugEntryVals);
if (transferChanges) {
transferRegisterCopy(MI, OpenRanges, VarLocIDs, Transfers);
transferSpillOrRestoreInst(MI, OpenRanges, VarLocIDs, Transfers);
@@ -1100,6 +1158,43 @@ bool LiveDebugValues::ExtendRanges(MachineFunction &MF) {
enum : bool { dontTransferChanges = false, transferChanges = true };
+ // Besides parameter's modification, check whether a DBG_VALUE is inlined
+ // in order to deduce whether the variable that it tracks comes from
+ // a different function. If that is the case we can't track its entry value.
+ auto IsUnmodifiedFuncParam = [&](const MachineInstr &MI) {
+ auto *DIVar = MI.getDebugVariable();
+ return DIVar->isParameter() && DIVar->isNotModified() &&
+ !MI.getDebugLoc()->getInlinedAt();
+ };
+
+ const TargetLowering *TLI = MF.getSubtarget().getTargetLowering();
+ unsigned SP = TLI->getStackPointerRegisterToSaveRestore();
+ unsigned FP = TRI->getFrameRegister(MF);
+ auto IsRegOtherThanSPAndFP = [&](const MachineOperand &Op) -> bool {
+ return Op.isReg() && Op.getReg() != SP && Op.getReg() != FP;
+ };
+
+ // Working set of currently collected debug variables mapped to DBG_VALUEs
+ // representing candidates for production of debug entry values.
+ DebugParamMap DebugEntryVals;
+
+ MachineBasicBlock &First_MBB = *(MF.begin());
+ // Only in the case of entry MBB collect DBG_VALUEs representing
+ // function parameters in order to generate debug entry values for them.
+ // Currently, we generate debug entry values only for parameters that are
+ // unmodified throughout the function and located in a register.
+ // TODO: Add support for parameters that are described as fragments.
+ // TODO: Add support for modified arguments that can be expressed
+ // by using its entry value.
+ // TODO: Add support for local variables that are expressed in terms of
+ // parameters entry values.
+ for (auto &MI : First_MBB)
+ if (MI.isDebugValue() && IsUnmodifiedFuncParam(MI) &&
+ !MI.isIndirectDebugValue() && IsRegOtherThanSPAndFP(MI.getOperand(0)) &&
+ !DebugEntryVals.count(MI.getDebugVariable()) &&
+ !MI.getDebugExpression()->isFragment())
+ DebugEntryVals[MI.getDebugVariable()] = &MI;
+
// Initialize every mbb with OutLocs.
// We are not looking at any spill instructions during the initial pass
// over the BBs. The LiveDebugVariables pass has already created DBG_VALUE
@@ -1107,9 +1202,16 @@ bool LiveDebugValues::ExtendRanges(MachineFunction &MF) {
// within the BB in which the spill occurs.
for (auto &MBB : MF) {
for (auto &MI : MBB) {
- process(MI, OpenRanges, OutLocs, VarLocIDs, Transfers,
+ process(MI, OpenRanges, OutLocs, VarLocIDs, Transfers, DebugEntryVals,
dontTransferChanges, OverlapFragments, SeenFragments);
}
+ // Add any entry DBG_VALUE instructions necessitated by parameter
+ // clobbering.
+ for (auto &TR : Transfers) {
+ MBB.insertAfter(MachineBasicBlock::iterator(*TR.TransferInst),
+ TR.DebugInst);
+ }
+ Transfers.clear();
}
auto hasNonArtificialLocation = [](const MachineInstr &MI) -> bool {
@@ -1158,7 +1260,8 @@ bool LiveDebugValues::ExtendRanges(MachineFunction &MF) {
for (auto &MI : *MBB)
OLChanged |=
process(MI, OpenRanges, OutLocs, VarLocIDs, Transfers,
- transferChanges, OverlapFragments, SeenFragments);
+ DebugEntryVals, transferChanges, OverlapFragments,
+ SeenFragments);
// Add any DBG_VALUE instructions necessitated by spills.
for (auto &TR : Transfers)
diff --git a/llvm/lib/CodeGen/MachineVerifier.cpp b/llvm/lib/CodeGen/MachineVerifier.cpp
index f9b548653cf..0ad792ac62c 100644
--- a/llvm/lib/CodeGen/MachineVerifier.cpp
+++ b/llvm/lib/CodeGen/MachineVerifier.cpp
@@ -840,7 +840,7 @@ void MachineVerifier::visitMachineBundleBefore(const MachineInstr *MI) {
if (MI->isTerminator() && !TII->isPredicated(*MI)) {
if (!FirstTerminator)
FirstTerminator = MI;
- } else if (FirstTerminator) {
+ } else if (FirstTerminator && !MI->isDebugEntryValue()) {
report("Non-terminator instruction after the first terminator", MI);
errs() << "First terminator was:\t" << *FirstTerminator;
}
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