This reapplies r207235 with an additional bugfixes caught by the msan
buildbot - do not insert debug intrinsics before phi nodes.
Debug info for optimized code: Support variables that are on the stack and
described by DBG_VALUEs during their lifetime.
Previously, when a variable was at a FrameIndex for any part of its
lifetime, this would shadow all other DBG_VALUEs and only a single
fbreg location would be emitted, which in fact is only valid for a small
range and not the entire lexical scope of the variable. The included
dbg-value-const-byref testcase demonstrates this.
This patch fixes this by
Local
- emitting dbg.value intrinsics for allocas that are passed by reference
- dropping all dbg.declares (they are now fully lowered to dbg.values)
SelectionDAG
- renamed constructors for SDDbgValue for better readability.
- fix UserValue::match() to handle indirect values correctly
- not inserting an MMI table entries for dbg.values that describe allocas.
- lowering dbg.values that describe allocas into *indirect* DBG_VALUEs.
CodeGenPrepare
- leaving dbg.values for an alloca were they are (see comment)
Other
- regenerated/updated instcombine.ll testcase and included source
rdar://problem/16679879
http://reviews.llvm.org/D3374
llvm-svn: 207269
diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp
index 85734f7..875615c 100644
--- a/llvm/lib/CodeGen/CodeGenPrepare.cpp
+++ b/llvm/lib/CodeGen/CodeGenPrepare.cpp
@@ -3470,7 +3470,12 @@
for (BasicBlock::iterator BI = I->begin(), BE = I->end(); BI != BE;) {
Instruction *Insn = BI; ++BI;
DbgValueInst *DVI = dyn_cast<DbgValueInst>(Insn);
- if (!DVI) {
+ // Leave dbg.values that refer to an alloca alone. These
+ // instrinsics describe the address of a variable (= the alloca)
+ // being taken. They should not be moved next to the alloca
+ // (and to the beginning of the scope), but rather stay close to
+ // where said address is used.
+ if (!DVI || (DVI->getValue() && isa<AllocaInst>(DVI->getValue()))) {
PrevNonDbgInst = Insn;
continue;
}
diff --git a/llvm/lib/CodeGen/LiveDebugVariables.cpp b/llvm/lib/CodeGen/LiveDebugVariables.cpp
index dcd78a2..388f58f 100644
--- a/llvm/lib/CodeGen/LiveDebugVariables.cpp
+++ b/llvm/lib/CodeGen/LiveDebugVariables.cpp
@@ -157,8 +157,8 @@
UserValue *getNext() const { return next; }
/// match - Does this UserValue match the parameters?
- bool match(const MDNode *Var, unsigned Offset) const {
- return Var == variable && Offset == offset;
+ bool match(const MDNode *Var, unsigned Offset, bool indirect) const {
+ return Var == variable && Offset == offset && indirect == IsIndirect;
}
/// merge - Merge equivalence classes.
@@ -427,7 +427,7 @@
UserValue *UV = Leader->getLeader();
Leader = UV;
for (; UV; UV = UV->getNext())
- if (UV->match(Var, Offset))
+ if (UV->match(Var, Offset, IsIndirect))
return UV;
}
diff --git a/llvm/lib/CodeGen/SelectionDAG/InstrEmitter.cpp b/llvm/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
index c134454..7c124b8 100644
--- a/llvm/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
@@ -688,10 +688,13 @@
MIB.addReg(0U);
}
- if (Offset != 0) // Indirect addressing.
+ // Indirect addressing is indicated by an Imm as the second parameter.
+ if (SD->isIndirect())
MIB.addImm(Offset);
- else
+ else {
+ assert(Offset == 0 && "direct value cannot have an offset");
MIB.addReg(0U, RegState::Debug);
+ }
MIB.addMetadata(MDPtr);
diff --git a/llvm/lib/CodeGen/SelectionDAG/SDNodeDbgValue.h b/llvm/lib/CodeGen/SelectionDAG/SDNodeDbgValue.h
index b62bd62..ee54292 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SDNodeDbgValue.h
+++ b/llvm/lib/CodeGen/SelectionDAG/SDNodeDbgValue.h
@@ -45,14 +45,17 @@
unsigned FrameIx; // valid for stack objects
} u;
MDNode *mdPtr;
+ bool IsIndirect;
uint64_t Offset;
DebugLoc DL;
unsigned Order;
bool Invalid;
public:
// Constructor for non-constants.
- SDDbgValue(MDNode *mdP, SDNode *N, unsigned R, uint64_t off, DebugLoc dl,
- unsigned O) : mdPtr(mdP), Offset(off), DL(dl), Order(O),
+ SDDbgValue(MDNode *mdP, SDNode *N, unsigned R,
+ bool indir, uint64_t off, DebugLoc dl,
+ unsigned O) : mdPtr(mdP), IsIndirect(indir),
+ Offset(off), DL(dl), Order(O),
Invalid(false) {
kind = SDNODE;
u.s.Node = N;
@@ -62,14 +65,16 @@
// Constructor for constants.
SDDbgValue(MDNode *mdP, const Value *C, uint64_t off, DebugLoc dl,
unsigned O) :
- mdPtr(mdP), Offset(off), DL(dl), Order(O), Invalid(false) {
+ mdPtr(mdP), IsIndirect(false), Offset(off), DL(dl), Order(O),
+ Invalid(false) {
kind = CONST;
u.Const = C;
}
// Constructor for frame indices.
SDDbgValue(MDNode *mdP, unsigned FI, uint64_t off, DebugLoc dl, unsigned O) :
- mdPtr(mdP), Offset(off), DL(dl), Order(O), Invalid(false) {
+ mdPtr(mdP), IsIndirect(false), Offset(off), DL(dl), Order(O),
+ Invalid(false) {
kind = FRAMEIX;
u.FrameIx = FI;
}
@@ -92,6 +97,9 @@
// Returns the FrameIx for a stack object
unsigned getFrameIx() { assert (kind==FRAMEIX); return u.FrameIx; }
+ // Returns whether this is an indirect value.
+ bool isIndirect() { return IsIndirect; }
+
// Returns the offset.
uint64_t getOffset() { return Offset; }
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index f397446..6ebedfc 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -5646,21 +5646,26 @@
/// getDbgValue - Creates a SDDbgValue node.
///
+/// SDNode
SDDbgValue *
-SelectionDAG::getDbgValue(MDNode *MDPtr, SDNode *N, unsigned R, uint64_t Off,
+SelectionDAG::getDbgValue(MDNode *MDPtr, SDNode *N, unsigned R,
+ bool IsIndirect, uint64_t Off,
DebugLoc DL, unsigned O) {
- return new (Allocator) SDDbgValue(MDPtr, N, R, Off, DL, O);
+ return new (Allocator) SDDbgValue(MDPtr, N, R, IsIndirect, Off, DL, O);
}
+/// Constant
SDDbgValue *
-SelectionDAG::getDbgValue(MDNode *MDPtr, const Value *C, uint64_t Off,
- DebugLoc DL, unsigned O) {
+SelectionDAG::getConstantDbgValue(MDNode *MDPtr, const Value *C,
+ uint64_t Off,
+ DebugLoc DL, unsigned O) {
return new (Allocator) SDDbgValue(MDPtr, C, Off, DL, O);
}
+/// FrameIndex
SDDbgValue *
-SelectionDAG::getDbgValue(MDNode *MDPtr, unsigned FI, uint64_t Off,
- DebugLoc DL, unsigned O) {
+SelectionDAG::getFrameIndexDbgValue(MDNode *MDPtr, unsigned FI, uint64_t Off,
+ DebugLoc DL, unsigned O) {
return new (Allocator) SDDbgValue(MDPtr, FI, Off, DL, O);
}
@@ -6066,6 +6071,7 @@
SDDbgValue *Dbg = *I;
if (Dbg->getKind() == SDDbgValue::SDNODE) {
SDDbgValue *Clone = getDbgValue(Dbg->getMDPtr(), ToNode, To.getResNo(),
+ Dbg->isIndirect(),
Dbg->getOffset(), Dbg->getDebugLoc(),
Dbg->getOrder());
ClonedDVs.push_back(Clone);
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index f20d07a..5f34dd2 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -992,11 +992,14 @@
unsigned DbgSDNodeOrder = DDI.getSDNodeOrder();
MDNode *Variable = DI->getVariable();
uint64_t Offset = DI->getOffset();
+ // A dbg.value for an alloca is always indirect.
+ bool IsIndirect = isa<AllocaInst>(V) || Offset != 0;
SDDbgValue *SDV;
if (Val.getNode()) {
- if (!EmitFuncArgumentDbgValue(V, Variable, Offset, Val)) {
+ if (!EmitFuncArgumentDbgValue(V, Variable, Offset, IsIndirect, Val)) {
SDV = DAG.getDbgValue(Variable, Val.getNode(),
- Val.getResNo(), Offset, dl, DbgSDNodeOrder);
+ Val.getResNo(), IsIndirect,
+ Offset, dl, DbgSDNodeOrder);
DAG.AddDbgValue(SDV, Val.getNode(), false);
}
} else
@@ -4544,7 +4547,7 @@
/// At the end of instruction selection, they will be inserted to the entry BB.
bool
SelectionDAGBuilder::EmitFuncArgumentDbgValue(const Value *V, MDNode *Variable,
- int64_t Offset,
+ int64_t Offset, bool IsIndirect,
const SDValue &N) {
const Argument *Arg = dyn_cast<Argument>(V);
if (!Arg)
@@ -4596,8 +4599,6 @@
if (!Op)
return false;
- // FIXME: This does not handle register-indirect values at offset 0.
- bool IsIndirect = Offset != 0;
if (Op->isReg())
FuncInfo.ArgDbgValues.push_back(BuildMI(MF, getCurDebugLoc(),
TII->get(TargetOpcode::DBG_VALUE),
@@ -4744,17 +4745,17 @@
FrameIndexSDNode *FINode = dyn_cast<FrameIndexSDNode>(N.getNode());
if (FINode)
// Byval parameter. We have a frame index at this point.
- SDV = DAG.getDbgValue(Variable, FINode->getIndex(),
- 0, dl, SDNodeOrder);
+ SDV = DAG.getFrameIndexDbgValue(Variable, FINode->getIndex(),
+ 0, dl, SDNodeOrder);
else {
// Address is an argument, so try to emit its dbg value using
// virtual register info from the FuncInfo.ValueMap.
- EmitFuncArgumentDbgValue(Address, Variable, 0, N);
+ EmitFuncArgumentDbgValue(Address, Variable, 0, false, N);
return nullptr;
}
} else if (AI)
SDV = DAG.getDbgValue(Variable, N.getNode(), N.getResNo(),
- 0, dl, SDNodeOrder);
+ true, 0, dl, SDNodeOrder);
else {
// Can't do anything with other non-AI cases yet.
DEBUG(dbgs() << "Dropping debug info for " << DI << "\n");
@@ -4766,7 +4767,7 @@
} else {
// If Address is an argument then try to emit its dbg value using
// virtual register info from the FuncInfo.ValueMap.
- if (!EmitFuncArgumentDbgValue(Address, Variable, 0, N)) {
+ if (!EmitFuncArgumentDbgValue(Address, Variable, 0, false, N)) {
// If variable is pinned by a alloca in dominating bb then
// use StaticAllocaMap.
if (const AllocaInst *AI = dyn_cast<AllocaInst>(Address)) {
@@ -4774,8 +4775,8 @@
DenseMap<const AllocaInst*, int>::iterator SI =
FuncInfo.StaticAllocaMap.find(AI);
if (SI != FuncInfo.StaticAllocaMap.end()) {
- SDV = DAG.getDbgValue(Variable, SI->second,
- 0, dl, SDNodeOrder);
+ SDV = DAG.getFrameIndexDbgValue(Variable, SI->second,
+ 0, dl, SDNodeOrder);
DAG.AddDbgValue(SDV, nullptr, false);
return nullptr;
}
@@ -4802,7 +4803,7 @@
SDDbgValue *SDV;
if (isa<ConstantInt>(V) || isa<ConstantFP>(V) || isa<UndefValue>(V)) {
- SDV = DAG.getDbgValue(Variable, V, Offset, dl, SDNodeOrder);
+ SDV = DAG.getConstantDbgValue(Variable, V, Offset, dl, SDNodeOrder);
DAG.AddDbgValue(SDV, nullptr, false);
} else {
// Do not use getValue() in here; we don't want to generate code at
@@ -4812,9 +4813,12 @@
// Check unused arguments map.
N = UnusedArgNodeMap[V];
if (N.getNode()) {
- if (!EmitFuncArgumentDbgValue(V, Variable, Offset, N)) {
+ // A dbg.value for an alloca is always indirect.
+ bool IsIndirect = isa<AllocaInst>(V) || Offset != 0;
+ if (!EmitFuncArgumentDbgValue(V, Variable, Offset, IsIndirect, N)) {
SDV = DAG.getDbgValue(Variable, N.getNode(),
- N.getResNo(), Offset, dl, SDNodeOrder);
+ N.getResNo(), IsIndirect,
+ Offset, dl, SDNodeOrder);
DAG.AddDbgValue(SDV, N.getNode(), false);
}
} else if (!V->use_empty() ) {
@@ -4843,11 +4847,6 @@
FuncInfo.StaticAllocaMap.find(AI);
if (SI == FuncInfo.StaticAllocaMap.end())
return nullptr; // VLAs.
- int FI = SI->second;
-
- MachineModuleInfo &MMI = DAG.getMachineFunction().getMMI();
- if (!DI.getDebugLoc().isUnknown() && MMI.hasDebugInfo())
- MMI.setVariableDbgInfo(Variable, FI, DI.getDebugLoc());
return nullptr;
}
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
index a04108d..fb29691 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
@@ -785,7 +785,8 @@
/// corresponding DBG_VALUE machine instruction for it now. At the end of
/// instruction selection, they will be inserted to the entry BB.
bool EmitFuncArgumentDbgValue(const Value *V, MDNode *Variable,
- int64_t Offset, const SDValue &N);
+ int64_t Offset, bool IsIndirect,
+ const SDValue &N);
};
} // end namespace llvm