[llvm] [RemoveDIs][DebugInfo] Handle DPVAssigns in Assignment Tracking excluding lowering (PR #78982)
Stephen Tozer via llvm-commits
llvm-commits at lists.llvm.org
Mon Jan 22 06:39:06 PST 2024
https://github.com/SLTozer created https://github.com/llvm/llvm-project/pull/78982
This patch adds support for DPVAssigns across all of AssignmentTrackingAnalysis except for AssignmentTrackingLowering, which is implemented in a separate patch. This patch includes handling DPValues in MemLocFragFill, the removal of redundant DPValues as part of AssignmentTrackingAnalysis (which is different to the version in `BasicBlockUtils.cpp`), and preventing the DPVAssigns from being directly emitted in SelectionDAG (just as we don't emit llvm.dbg.assigns directly, but receive a set of locations from AssignmentTrackingAnalysis' output).
>From 00aad95b0faef6726245c4bdf0b8c59596ef7793 Mon Sep 17 00:00:00 2001
From: Stephen Tozer <Stephen.Tozer at Sony.com>
Date: Wed, 3 Jan 2024 16:45:02 +0000
Subject: [PATCH] Handle remaining AT analysis changes, and emit them correctly
in SelDag
---
.../CodeGen/AssignmentTrackingAnalysis.cpp | 280 ++++++++++--------
.../SelectionDAG/SelectionDAGBuilder.cpp | 1 +
2 files changed, 154 insertions(+), 127 deletions(-)
diff --git a/llvm/lib/CodeGen/AssignmentTrackingAnalysis.cpp b/llvm/lib/CodeGen/AssignmentTrackingAnalysis.cpp
index 52b464cc76af4ce..657d47afd1f7168 100644
--- a/llvm/lib/CodeGen/AssignmentTrackingAnalysis.cpp
+++ b/llvm/lib/CodeGen/AssignmentTrackingAnalysis.cpp
@@ -829,6 +829,13 @@ class MemLocFragmentFill {
void process(BasicBlock &BB, VarFragMap &LiveSet) {
BBInsertBeforeMap[&BB].clear();
for (auto &I : BB) {
+ for (auto &DPV : I.getDbgValueRange()) {
+ if (const auto *Locs = FnVarLocs->getWedge(&DPV)) {
+ for (const VarLocInfo &Loc : *Locs) {
+ addDef(Loc, &DPV, *I.getParent(), LiveSet);
+ }
+ }
+ }
if (const auto *Locs = FnVarLocs->getWedge(&I)) {
for (const VarLocInfo &Loc : *Locs) {
addDef(Loc, &I, *I.getParent(), LiveSet);
@@ -2335,73 +2342,78 @@ removeRedundantDbgLocsUsingBackwardScan(const BasicBlock *BB,
VariableDefinedBytes.clear();
}
- // Get the location defs that start just before this instruction.
- const auto *Locs = FnVarLocs.getWedge(&I);
- if (!Locs)
- continue;
+ auto HandleLocsForWedge = [&](auto *WedgePosition) {
+ // Get the location defs that start just before this instruction.
+ const auto *Locs = FnVarLocs.getWedge(WedgePosition);
+ if (!Locs)
+ return;
+
+ NumWedgesScanned++;
+ bool ChangedThisWedge = false;
+ // The new pruned set of defs, reversed because we're scanning backwards.
+ SmallVector<VarLocInfo> NewDefsReversed;
+
+ // Iterate over the existing defs in reverse.
+ for (auto RIt = Locs->rbegin(), REnd = Locs->rend(); RIt != REnd; ++RIt) {
+ NumDefsScanned++;
+ DebugAggregate Aggr =
+ getAggregate(FnVarLocs.getVariable(RIt->VariableID));
+ uint64_t SizeInBits = Aggr.first->getSizeInBits().value_or(0);
+ uint64_t SizeInBytes = divideCeil(SizeInBits, 8);
+
+ // Cutoff for large variables to prevent expensive bitvector operations.
+ const uint64_t MaxSizeBytes = 2048;
+
+ if (SizeInBytes == 0 || SizeInBytes > MaxSizeBytes) {
+ // If the size is unknown (0) then keep this location def to be safe.
+ // Do the same for defs of large variables, which would be expensive
+ // to represent with a BitVector.
+ NewDefsReversed.push_back(*RIt);
+ continue;
+ }
- NumWedgesScanned++;
- bool ChangedThisWedge = false;
- // The new pruned set of defs, reversed because we're scanning backwards.
- SmallVector<VarLocInfo> NewDefsReversed;
-
- // Iterate over the existing defs in reverse.
- for (auto RIt = Locs->rbegin(), REnd = Locs->rend(); RIt != REnd; ++RIt) {
- NumDefsScanned++;
- DebugAggregate Aggr =
- getAggregate(FnVarLocs.getVariable(RIt->VariableID));
- uint64_t SizeInBits = Aggr.first->getSizeInBits().value_or(0);
- uint64_t SizeInBytes = divideCeil(SizeInBits, 8);
-
- // Cutoff for large variables to prevent expensive bitvector operations.
- const uint64_t MaxSizeBytes = 2048;
-
- if (SizeInBytes == 0 || SizeInBytes > MaxSizeBytes) {
- // If the size is unknown (0) then keep this location def to be safe.
- // Do the same for defs of large variables, which would be expensive
- // to represent with a BitVector.
- NewDefsReversed.push_back(*RIt);
- continue;
- }
+ // Only keep this location definition if it is not fully eclipsed by
+ // other definitions in this wedge that come after it
+
+ // Inert the bytes the location definition defines.
+ auto InsertResult =
+ VariableDefinedBytes.try_emplace(Aggr, BitVector(SizeInBytes));
+ bool FirstDefinition = InsertResult.second;
+ BitVector &DefinedBytes = InsertResult.first->second;
+
+ DIExpression::FragmentInfo Fragment =
+ RIt->Expr->getFragmentInfo().value_or(
+ DIExpression::FragmentInfo(SizeInBits, 0));
+ bool InvalidFragment = Fragment.endInBits() > SizeInBits;
+ uint64_t StartInBytes = Fragment.startInBits() / 8;
+ uint64_t EndInBytes = divideCeil(Fragment.endInBits(), 8);
+
+ // If this defines any previously undefined bytes, keep it.
+ if (FirstDefinition || InvalidFragment ||
+ DefinedBytes.find_first_unset_in(StartInBytes, EndInBytes) != -1) {
+ if (!InvalidFragment)
+ DefinedBytes.set(StartInBytes, EndInBytes);
+ NewDefsReversed.push_back(*RIt);
+ continue;
+ }
- // Only keep this location definition if it is not fully eclipsed by
- // other definitions in this wedge that come after it
-
- // Inert the bytes the location definition defines.
- auto InsertResult =
- VariableDefinedBytes.try_emplace(Aggr, BitVector(SizeInBytes));
- bool FirstDefinition = InsertResult.second;
- BitVector &DefinedBytes = InsertResult.first->second;
-
- DIExpression::FragmentInfo Fragment =
- RIt->Expr->getFragmentInfo().value_or(
- DIExpression::FragmentInfo(SizeInBits, 0));
- bool InvalidFragment = Fragment.endInBits() > SizeInBits;
- uint64_t StartInBytes = Fragment.startInBits() / 8;
- uint64_t EndInBytes = divideCeil(Fragment.endInBits(), 8);
-
- // If this defines any previously undefined bytes, keep it.
- if (FirstDefinition || InvalidFragment ||
- DefinedBytes.find_first_unset_in(StartInBytes, EndInBytes) != -1) {
- if (!InvalidFragment)
- DefinedBytes.set(StartInBytes, EndInBytes);
- NewDefsReversed.push_back(*RIt);
- continue;
+ // Redundant def found: throw it away. Since the wedge of defs is being
+ // rebuilt, doing nothing is the same as deleting an entry.
+ ChangedThisWedge = true;
+ NumDefsRemoved++;
}
- // Redundant def found: throw it away. Since the wedge of defs is being
- // rebuilt, doing nothing is the same as deleting an entry.
- ChangedThisWedge = true;
- NumDefsRemoved++;
- }
-
- // Un-reverse the defs and replace the wedge with the pruned version.
- if (ChangedThisWedge) {
- std::reverse(NewDefsReversed.begin(), NewDefsReversed.end());
- FnVarLocs.setWedge(&I, std::move(NewDefsReversed));
- NumWedgesChanged++;
- Changed = true;
- }
+ // Un-reverse the defs and replace the wedge with the pruned version.
+ if (ChangedThisWedge) {
+ std::reverse(NewDefsReversed.begin(), NewDefsReversed.end());
+ FnVarLocs.setWedge(WedgePosition, std::move(NewDefsReversed));
+ NumWedgesChanged++;
+ Changed = true;
+ }
+ };
+ HandleLocsForWedge(&I);
+ for (DPValue &DPV : reverse(I.getDbgValueRange()))
+ HandleLocsForWedge(&DPV);
}
return Changed;
@@ -2426,42 +2438,48 @@ removeRedundantDbgLocsUsingForwardScan(const BasicBlock *BB,
// instructions.
for (const Instruction &I : *BB) {
// Get the defs that come just before this instruction.
- const auto *Locs = FnVarLocs.getWedge(&I);
- if (!Locs)
- continue;
-
- NumWedgesScanned++;
- bool ChangedThisWedge = false;
- // The new pruned set of defs.
- SmallVector<VarLocInfo> NewDefs;
+ auto HandleLocsForWedge = [&](auto *WedgePosition) {
+ const auto *Locs = FnVarLocs.getWedge(WedgePosition);
+ if (!Locs)
+ return;
+
+ NumWedgesScanned++;
+ bool ChangedThisWedge = false;
+ // The new pruned set of defs.
+ SmallVector<VarLocInfo> NewDefs;
+
+ // Iterate over the existing defs.
+ for (const VarLocInfo &Loc : *Locs) {
+ NumDefsScanned++;
+ DebugVariable Key(FnVarLocs.getVariable(Loc.VariableID).getVariable(),
+ std::nullopt, Loc.DL.getInlinedAt());
+ auto VMI = VariableMap.find(Key);
+
+ // Update the map if we found a new value/expression describing the
+ // variable, or if the variable wasn't mapped already.
+ if (VMI == VariableMap.end() || VMI->second.first != Loc.Values ||
+ VMI->second.second != Loc.Expr) {
+ VariableMap[Key] = {Loc.Values, Loc.Expr};
+ NewDefs.push_back(Loc);
+ continue;
+ }
- // Iterate over the existing defs.
- for (const VarLocInfo &Loc : *Locs) {
- NumDefsScanned++;
- DebugVariable Key(FnVarLocs.getVariable(Loc.VariableID).getVariable(),
- std::nullopt, Loc.DL.getInlinedAt());
- auto VMI = VariableMap.find(Key);
-
- // Update the map if we found a new value/expression describing the
- // variable, or if the variable wasn't mapped already.
- if (VMI == VariableMap.end() || VMI->second.first != Loc.Values ||
- VMI->second.second != Loc.Expr) {
- VariableMap[Key] = {Loc.Values, Loc.Expr};
- NewDefs.push_back(Loc);
- continue;
+ // Did not insert this Loc, which is the same as removing it.
+ ChangedThisWedge = true;
+ NumDefsRemoved++;
}
- // Did not insert this Loc, which is the same as removing it.
- ChangedThisWedge = true;
- NumDefsRemoved++;
- }
+ // Replace the existing wedge with the pruned version.
+ if (ChangedThisWedge) {
+ FnVarLocs.setWedge(WedgePosition, std::move(NewDefs));
+ NumWedgesChanged++;
+ Changed = true;
+ }
+ };
- // Replace the existing wedge with the pruned version.
- if (ChangedThisWedge) {
- FnVarLocs.setWedge(&I, std::move(NewDefs));
- NumWedgesChanged++;
- Changed = true;
- }
+ for (DPValue &DPV : I.getDbgValueRange())
+ HandleLocsForWedge(&DPV);
+ HandleLocsForWedge(&I);
}
return Changed;
@@ -2508,41 +2526,46 @@ removeUndefDbgLocsFromEntryBlock(const BasicBlock *BB,
// instructions.
for (const Instruction &I : *BB) {
// Get the defs that come just before this instruction.
- const auto *Locs = FnVarLocs.getWedge(&I);
- if (!Locs)
- continue;
-
- NumWedgesScanned++;
- bool ChangedThisWedge = false;
- // The new pruned set of defs.
- SmallVector<VarLocInfo> NewDefs;
-
- // Iterate over the existing defs.
- for (const VarLocInfo &Loc : *Locs) {
- NumDefsScanned++;
- DebugAggregate Aggr{FnVarLocs.getVariable(Loc.VariableID).getVariable(),
- Loc.DL.getInlinedAt()};
- DebugVariable Var = FnVarLocs.getVariable(Loc.VariableID);
+ auto HandleLocsForWedge = [&](auto *WedgePosition) {
+ const auto *Locs = FnVarLocs.getWedge(WedgePosition);
+ if (!Locs)
+ return;
+
+ NumWedgesScanned++;
+ bool ChangedThisWedge = false;
+ // The new pruned set of defs.
+ SmallVector<VarLocInfo> NewDefs;
+
+ // Iterate over the existing defs.
+ for (const VarLocInfo &Loc : *Locs) {
+ NumDefsScanned++;
+ DebugAggregate Aggr{FnVarLocs.getVariable(Loc.VariableID).getVariable(),
+ Loc.DL.getInlinedAt()};
+ DebugVariable Var = FnVarLocs.getVariable(Loc.VariableID);
+
+ // Remove undef entries that are encountered before any non-undef
+ // intrinsics from the entry block.
+ if (Loc.Values.isKillLocation(Loc.Expr) && !HasDefinedBits(Aggr, Var)) {
+ // Did not insert this Loc, which is the same as removing it.
+ NumDefsRemoved++;
+ ChangedThisWedge = true;
+ continue;
+ }
- // Remove undef entries that are encountered before any non-undef
- // intrinsics from the entry block.
- if (Loc.Values.isKillLocation(Loc.Expr) && !HasDefinedBits(Aggr, Var)) {
- // Did not insert this Loc, which is the same as removing it.
- NumDefsRemoved++;
- ChangedThisWedge = true;
- continue;
+ DefineBits(Aggr, Var);
+ NewDefs.push_back(Loc);
}
- DefineBits(Aggr, Var);
- NewDefs.push_back(Loc);
- }
-
- // Replace the existing wedge with the pruned version.
- if (ChangedThisWedge) {
- FnVarLocs.setWedge(&I, std::move(NewDefs));
- NumWedgesChanged++;
- Changed = true;
- }
+ // Replace the existing wedge with the pruned version.
+ if (ChangedThisWedge) {
+ FnVarLocs.setWedge(WedgePosition, std::move(NewDefs));
+ NumWedgesChanged++;
+ Changed = true;
+ }
+ };
+ for (DPValue &DPV : I.getDbgValueRange())
+ HandleLocsForWedge(&DPV);
+ HandleLocsForWedge(&I);
}
return Changed;
@@ -2574,6 +2597,9 @@ static DenseSet<DebugAggregate> findVarsWithStackSlot(Function &Fn) {
for (DbgAssignIntrinsic *DAI : at::getAssignmentMarkers(&I)) {
Result.insert({DAI->getVariable(), DAI->getDebugLoc().getInlinedAt()});
}
+ for (DPValue *DPV : at::getDPVAssignmentMarkers(&I)) {
+ Result.insert({DPV->getVariable(), DPV->getDebugLoc().getInlinedAt()});
+ }
}
}
return Result;
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 44c78a006656e0e..f4e098d4a876950 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -1241,6 +1241,7 @@ void SelectionDAGBuilder::visitDbgInfo(const Instruction &I) {
It->Expr, Vals.size() > 1, It->DL, SDNodeOrder);
}
}
+ return;
}
// Is there is any debug-info attached to this instruction, in the form of
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