Keep track of incoming debug value of unused argument.
Radar 7927666.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105285 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 9f8f0c4..833173f 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -698,6 +698,7 @@
/// consumed.
void SelectionDAGBuilder::clear() {
NodeMap.clear();
+ UnusedArgNodeMap.clear();
PendingLoads.clear();
PendingExports.clear();
CurDebugLoc = DebugLoc();
@@ -4063,7 +4064,10 @@
} else {
bool createUndef = false;
// FIXME : Why not use getValue() directly ?
- SDValue &N = NodeMap[V];
+ SDValue N = NodeMap[V];
+ if (!N.getNode() && isa<Argument>(V))
+ // Check unused arguments map.
+ N = UnusedArgNodeMap[V];
if (N.getNode()) {
if (!EmitFuncArgumentDbgValue(DI, V, Variable, Offset, N)) {
SDV = DAG.getDbgValue(Variable, N.getNode(),
@@ -6032,6 +6036,12 @@
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(TLI, I->getType(), ValueVTs);
unsigned NumValues = ValueVTs.size();
+
+ // If this argument is unused then remember its value. It is used to generate
+ // debugging information.
+ if (I->use_empty() && NumValues)
+ SDB->setUnusedArgValue(I, InVals[i]);
+
for (unsigned Value = 0; Value != NumValues; ++Value) {
EVT VT = ValueVTs[Value];
EVT PartVT = TLI.getRegisterType(*CurDAG->getContext(), VT);
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
index 3fcd4b9..86903ca 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
@@ -88,6 +88,10 @@
DebugLoc CurDebugLoc;
DenseMap<const Value*, SDValue> NodeMap;
+
+ /// UnusedArgNodeMap - Maps argument value for unused arguments. This is used
+ /// to preserve debug information for incoming arguments.
+ DenseMap<const Value*, SDValue> UnusedArgNodeMap;
public:
/// PendingLoads - Loads are not emitted to the program immediately. We bunch
@@ -349,6 +353,12 @@
N = NewN;
}
+ void setUnusedArgValue(const Value *V, SDValue NewN) {
+ SDValue &N = UnusedArgNodeMap[V];
+ assert(N.getNode() == 0 && "Already set a value for this node!");
+ N = NewN;
+ }
+
void GetRegistersForValue(SDISelAsmOperandInfo &OpInfo,
std::set<unsigned> &OutputRegs,
std::set<unsigned> &InputRegs);