Move the complex address expression out of DIVariable and into an extra
argument of the llvm.dbg.declare/llvm.dbg.value intrinsics.
Previously, DIVariable was a variable-length field that has an optional
reference to a Metadata array consisting of a variable number of
complex address expressions. In the case of OpPiece expressions this is
wasting a lot of storage in IR, because when an aggregate type is, e.g.,
SROA'd into all of its n individual members, the IR will contain n copies
of the DIVariable, all alike, only differing in the complex address
reference at the end.
By making the complex address into an extra argument of the
dbg.value/dbg.declare intrinsics, all of the pieces can reference the
same variable and the complex address expressions can be uniqued across
the CU, too.
Down the road, this will allow us to move other flags, such as
"indirection" out of the DIVariable, too.
The new intrinsics look like this:
declare void @llvm.dbg.declare(metadata %storage, metadata %var, metadata %expr)
declare void @llvm.dbg.value(metadata %storage, i64 %offset, metadata %var, metadata %expr)
This patch adds a new LLVM-local tag to DIExpressions, so we can detect
and pretty-print DIExpression metadata nodes.
What this patch doesn't do:
This patch does not touch the "Indirect" field in DIVariable; but moving
that into the expression would be a natural next step.
http://reviews.llvm.org/D4919
rdar://problem/17994491
Thanks to dblaikie and dexonsmith for reviewing this patch!
Note: I accidentally committed a bogus older version of this patch previously.
llvm-svn: 218787
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 6a8cd2e..9bd5dfea 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -993,15 +993,16 @@
DebugLoc dl = DDI.getdl();
unsigned DbgSDNodeOrder = DDI.getSDNodeOrder();
MDNode *Variable = DI->getVariable();
+ MDNode *Expr = DI->getExpression();
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, IsIndirect, Val)) {
- SDV = DAG.getDbgValue(Variable, Val.getNode(),
- Val.getResNo(), IsIndirect,
- Offset, dl, DbgSDNodeOrder);
+ if (!EmitFuncArgumentDbgValue(V, Variable, Expr, Offset, IsIndirect,
+ Val)) {
+ SDV = DAG.getDbgValue(Variable, Expr, Val.getNode(), Val.getResNo(),
+ IsIndirect, Offset, dl, DbgSDNodeOrder);
DAG.AddDbgValue(SDV, Val.getNode(), false);
}
} else
@@ -4603,10 +4604,11 @@
/// EmitFuncArgumentDbgValue - If the DbgValueInst is a dbg_value of a function
/// argument, create the corresponding DBG_VALUE machine instruction for it now.
/// 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, bool IsIndirect,
- const SDValue &N) {
+bool SelectionDAGBuilder::EmitFuncArgumentDbgValue(const Value *V,
+ MDNode *Variable,
+ MDNode *Expr, int64_t Offset,
+ bool IsIndirect,
+ const SDValue &N) {
const Argument *Arg = dyn_cast<Argument>(V);
if (!Arg)
return false;
@@ -4658,14 +4660,16 @@
return false;
if (Op->isReg())
- FuncInfo.ArgDbgValues.push_back(BuildMI(MF, getCurDebugLoc(),
- TII->get(TargetOpcode::DBG_VALUE),
- IsIndirect,
- Op->getReg(), Offset, Variable));
+ FuncInfo.ArgDbgValues.push_back(
+ BuildMI(MF, getCurDebugLoc(), TII->get(TargetOpcode::DBG_VALUE),
+ IsIndirect, Op->getReg(), Offset, Variable, Expr));
else
FuncInfo.ArgDbgValues.push_back(
- BuildMI(MF, getCurDebugLoc(), TII->get(TargetOpcode::DBG_VALUE))
- .addOperand(*Op).addImm(Offset).addMetadata(Variable));
+ BuildMI(MF, getCurDebugLoc(), TII->get(TargetOpcode::DBG_VALUE))
+ .addOperand(*Op)
+ .addImm(Offset)
+ .addMetadata(Variable)
+ .addMetadata(Expr));
return true;
}
@@ -4785,6 +4789,7 @@
case Intrinsic::dbg_declare: {
const DbgDeclareInst &DI = cast<DbgDeclareInst>(I);
MDNode *Variable = DI.getVariable();
+ MDNode *Expression = DI.getExpression();
const Value *Address = DI.getAddress();
DIVariable DIVar(Variable);
assert((!DIVar || DIVar.isVariable()) &&
@@ -4820,16 +4825,16 @@
FrameIndexSDNode *FINode = dyn_cast<FrameIndexSDNode>(N.getNode());
if (FINode)
// Byval parameter. We have a frame index at this point.
- SDV = DAG.getFrameIndexDbgValue(Variable, FINode->getIndex(),
- 0, dl, SDNodeOrder);
+ SDV = DAG.getFrameIndexDbgValue(
+ Variable, Expression, 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, false, N);
+ EmitFuncArgumentDbgValue(Address, Variable, Expression, 0, false, N);
return nullptr;
}
} else if (AI)
- SDV = DAG.getDbgValue(Variable, N.getNode(), N.getResNo(),
+ SDV = DAG.getDbgValue(Variable, Expression, N.getNode(), N.getResNo(),
true, 0, dl, SDNodeOrder);
else {
// Can't do anything with other non-AI cases yet.
@@ -4842,7 +4847,8 @@
} 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, false, N)) {
+ if (!EmitFuncArgumentDbgValue(Address, Variable, Expression, 0, false,
+ N)) {
// If variable is pinned by a alloca in dominating bb then
// use StaticAllocaMap.
if (const AllocaInst *AI = dyn_cast<AllocaInst>(Address)) {
@@ -4850,7 +4856,7 @@
DenseMap<const AllocaInst*, int>::iterator SI =
FuncInfo.StaticAllocaMap.find(AI);
if (SI != FuncInfo.StaticAllocaMap.end()) {
- SDV = DAG.getFrameIndexDbgValue(Variable, SI->second,
+ SDV = DAG.getFrameIndexDbgValue(Variable, Expression, SI->second,
0, dl, SDNodeOrder);
DAG.AddDbgValue(SDV, nullptr, false);
return nullptr;
@@ -4871,6 +4877,7 @@
return nullptr;
MDNode *Variable = DI.getVariable();
+ MDNode *Expression = DI.getExpression();
uint64_t Offset = DI.getOffset();
const Value *V = DI.getValue();
if (!V)
@@ -4878,7 +4885,8 @@
SDDbgValue *SDV;
if (isa<ConstantInt>(V) || isa<ConstantFP>(V) || isa<UndefValue>(V)) {
- SDV = DAG.getConstantDbgValue(Variable, V, Offset, dl, SDNodeOrder);
+ SDV = DAG.getConstantDbgValue(Variable, Expression, V, Offset, dl,
+ SDNodeOrder);
DAG.AddDbgValue(SDV, nullptr, false);
} else {
// Do not use getValue() in here; we don't want to generate code at
@@ -4890,10 +4898,10 @@
if (N.getNode()) {
// 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(), IsIndirect,
- Offset, dl, SDNodeOrder);
+ if (!EmitFuncArgumentDbgValue(V, Variable, Expression, Offset,
+ IsIndirect, N)) {
+ SDV = DAG.getDbgValue(Variable, Expression, N.getNode(), N.getResNo(),
+ IsIndirect, Offset, dl, SDNodeOrder);
DAG.AddDbgValue(SDV, N.getNode(), false);
}
} else if (!V->use_empty() ) {