[Statepoints] Fix yet another issue around gc pointer uniqueing
Given that StatepointLowering now uniques derived pointers before
putting them in the per-statepoint spill map, we may end up with missing
entries for derived pointers when we visit a gc.relocate on a pointer
that was de-duplicated away.
Fix this by keeping two maps, one mapping gc pointers to their
de-duplicated values, and one mapping a de-duplicated value to the slot
it is spilled in.
llvm-svn: 264320
diff --git a/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp b/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
index e5c7ade..9a99968 100644
--- a/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
@@ -356,7 +356,7 @@
ByValArgFrameIndexMap.clear();
RegFixups.clear();
StatepointStackSlots.clear();
- StatepointRelocatedValues.clear();
+ StatepointSpillMaps.clear();
PreferredExtendType.clear();
}
diff --git a/llvm/lib/CodeGen/SelectionDAG/StatepointLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/StatepointLowering.cpp
index 56035d4..f50d7d0 100644
--- a/llvm/lib/CodeGen/SelectionDAG/StatepointLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/StatepointLowering.cpp
@@ -124,7 +124,7 @@
// Spill location is known for gc relocates
if (const auto *Relocate = dyn_cast<GCRelocateInst>(Val)) {
const auto &SpillMap =
- Builder.FuncInfo.StatepointRelocatedValues[Relocate->getStatepoint()];
+ Builder.FuncInfo.StatepointSpillMaps[Relocate->getStatepoint()];
auto It = SpillMap.find(Relocate->getDerivedPtr());
if (It == SpillMap.end())
@@ -249,22 +249,26 @@
removeDuplicateGCPtrs(SmallVectorImpl<const Value *> &Bases,
SmallVectorImpl<const Value *> &Ptrs,
SmallVectorImpl<const GCRelocateInst *> &Relocs,
- SelectionDAGBuilder &Builder) {
-
- // This is horribly inefficient, but I don't care right now
- SmallSet<SDValue, 32> Seen;
+ SelectionDAGBuilder &Builder,
+ FunctionLoweringInfo::StatepointSpillMap &SSM) {
+ DenseMap<SDValue, const Value *> Seen;
SmallVector<const Value *, 64> NewBases, NewPtrs;
SmallVector<const GCRelocateInst *, 64> NewRelocs;
for (size_t i = 0, e = Ptrs.size(); i < e; i++) {
SDValue SD = Builder.getValue(Ptrs[i]);
- // Only add non-duplicates
- if (Seen.count(SD) == 0) {
+ auto SeenIt = Seen.find(SD);
+
+ if (SeenIt == Seen.end()) {
+ // Only add non-duplicates
NewBases.push_back(Bases[i]);
NewPtrs.push_back(Ptrs[i]);
NewRelocs.push_back(Relocs[i]);
+ Seen[SD] = Ptrs[i];
+ } else {
+ // Duplicate pointer found, note in SSM and move on:
+ SSM.DuplicateMap[Ptrs[i]] = SeenIt->second;
}
- Seen.insert(SD);
}
assert(Bases.size() >= NewBases.size());
assert(Ptrs.size() >= NewPtrs.size());
@@ -499,7 +503,7 @@
// This can not be embedded in lowering loops as we need to record *all*
// values, while previous loops account only values with unique SDValues.
const Instruction *StatepointInstr = SI.StatepointInstr;
- auto &SpillMap = Builder.FuncInfo.StatepointRelocatedValues[StatepointInstr];
+ auto &SpillMap = Builder.FuncInfo.StatepointSpillMaps[StatepointInstr];
for (const GCRelocateInst *Relocate : SI.GCRelocates) {
const Value *V = Relocate->getDerivedPtr();
@@ -507,7 +511,7 @@
SDValue Loc = Builder.StatepointLowering.getLocation(SDV);
if (Loc.getNode()) {
- SpillMap[V] = cast<FrameIndexSDNode>(Loc)->getIndex();
+ SpillMap.SlotMap[V] = cast<FrameIndexSDNode>(Loc)->getIndex();
} else {
// Record value as visited, but not spilled. This is case for allocas
// and constants. For this values we can avoid emitting spill load while
@@ -515,7 +519,7 @@
// Actually we do not need to record them in this map at all.
// We do this only to check that we are not relocating any unvisited
// value.
- SpillMap[V] = None;
+ SpillMap.SlotMap[V] = None;
// Default llvm mechanisms for exporting values which are used in
// different basic blocks does not work for gc relocates.
@@ -551,7 +555,8 @@
// input. Also has the effect of removing duplicates in the original
// llvm::Value input list as well. This is a useful optimization for
// reducing the size of the StackMap section. It has no other impact.
- removeDuplicateGCPtrs(SI.Bases, SI.Ptrs, SI.GCRelocates, *this);
+ removeDuplicateGCPtrs(SI.Bases, SI.Ptrs, SI.GCRelocates, *this,
+ FuncInfo.StatepointSpillMaps[SI.StatepointInstr]);
assert(SI.Bases.size() == SI.Ptrs.size() &&
SI.Ptrs.size() == SI.GCRelocates.size());
@@ -886,12 +891,10 @@
const Value *DerivedPtr = Relocate.getDerivedPtr();
SDValue SD = getValue(DerivedPtr);
- FunctionLoweringInfo::StatepointSpilledValueMapTy &SpillMap =
- FuncInfo.StatepointRelocatedValues[Relocate.getStatepoint()];
-
- // We should have recorded location for this pointer
- assert(SpillMap.count(DerivedPtr) && "Relocating not lowered gc value");
- Optional<int> DerivedPtrLocation = SpillMap[DerivedPtr];
+ auto &SpillMap = FuncInfo.StatepointSpillMaps[Relocate.getStatepoint()];
+ auto SlotIt = SpillMap.find(DerivedPtr);
+ assert(SlotIt != SpillMap.end() && "Relocating not lowered gc value");
+ Optional<int> DerivedPtrLocation = SlotIt->second;
// We didn't need to spill these special cases (constants and allocas).
// See the handling in spillIncomingValueForStatepoint for detail.