[llvm] r365659 - [CodeExtractor] Simplify findAllocas, NFC
Vedant Kumar via llvm-commits
llvm-commits at lists.llvm.org
Wed Jul 10 09:32:16 PDT 2019
Author: vedantk
Date: Wed Jul 10 09:32:16 2019
New Revision: 365659
URL: http://llvm.org/viewvc/llvm-project?rev=365659&view=rev
Log:
[CodeExtractor] Simplify findAllocas, NFC
Split getLifetimeMarkers out into its own method and have it return a
struct.
Differential Revision: https://reviews.llvm.org/D64467
Modified:
llvm/trunk/include/llvm/Transforms/Utils/CodeExtractor.h
llvm/trunk/lib/Transforms/Utils/CodeExtractor.cpp
Modified: llvm/trunk/include/llvm/Transforms/Utils/CodeExtractor.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/Utils/CodeExtractor.h?rev=365659&r1=365658&r2=365659&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Transforms/Utils/CodeExtractor.h (original)
+++ llvm/trunk/include/llvm/Transforms/Utils/CodeExtractor.h Wed Jul 10 09:32:16 2019
@@ -151,6 +151,16 @@ class Value;
BasicBlock *findOrCreateBlockForHoisting(BasicBlock *CommonExitBlock);
private:
+ struct LifetimeMarkerInfo {
+ bool SinkLifeStart = false;
+ bool HoistLifeEnd = false;
+ Instruction *LifeStart = nullptr;
+ Instruction *LifeEnd = nullptr;
+ };
+
+ LifetimeMarkerInfo getLifetimeMarkers(Instruction *Addr,
+ BasicBlock *ExitBlock) const;
+
void severSplitPHINodesOfEntry(BasicBlock *&Header);
void severSplitPHINodesOfExits(const SmallPtrSetImpl<BasicBlock *> &Exits);
void splitReturnBlocks();
Modified: llvm/trunk/lib/Transforms/Utils/CodeExtractor.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/CodeExtractor.cpp?rev=365659&r1=365658&r2=365659&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/CodeExtractor.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/CodeExtractor.cpp Wed Jul 10 09:32:16 2019
@@ -410,11 +410,74 @@ CodeExtractor::findOrCreateBlockForHoist
return CommonExitBlock;
}
+// Find the pair of life time markers for address 'Addr' that are either
+// defined inside the outline region or can legally be shrinkwrapped into the
+// outline region. If there are not other untracked uses of the address, return
+// the pair of markers if found; otherwise return a pair of nullptr.
+CodeExtractor::LifetimeMarkerInfo
+CodeExtractor::getLifetimeMarkers(Instruction *Addr,
+ BasicBlock *ExitBlock) const {
+ LifetimeMarkerInfo Info;
+
+ for (User *U : Addr->users()) {
+ IntrinsicInst *IntrInst = dyn_cast<IntrinsicInst>(U);
+ if (IntrInst) {
+ if (IntrInst->getIntrinsicID() == Intrinsic::lifetime_start) {
+ // Do not handle the case where Addr has multiple start markers.
+ if (Info.LifeStart)
+ return {};
+ Info.LifeStart = IntrInst;
+ }
+ if (IntrInst->getIntrinsicID() == Intrinsic::lifetime_end) {
+ if (Info.LifeEnd)
+ return {};
+ Info.LifeEnd = IntrInst;
+ }
+ continue;
+ }
+ // Find untracked uses of the address, bail.
+ if (!definedInRegion(Blocks, U))
+ return {};
+ }
+
+ if (!Info.LifeStart || !Info.LifeEnd)
+ return {};
+
+ Info.SinkLifeStart = !definedInRegion(Blocks, Info.LifeStart);
+ Info.HoistLifeEnd = !definedInRegion(Blocks, Info.LifeEnd);
+ // Do legality check.
+ if ((Info.SinkLifeStart || Info.HoistLifeEnd) &&
+ !isLegalToShrinkwrapLifetimeMarkers(Addr))
+ return {};
+
+ // Check to see if we have a place to do hoisting, if not, bail.
+ if (Info.HoistLifeEnd && !ExitBlock)
+ return {};
+
+ return Info;
+}
+
void CodeExtractor::findAllocas(ValueSet &SinkCands, ValueSet &HoistCands,
BasicBlock *&ExitBlock) const {
Function *Func = (*Blocks.begin())->getParent();
ExitBlock = getCommonExitBlock(Blocks);
+ auto moveOrIgnoreLifetimeMarkers =
+ [&](const LifetimeMarkerInfo &LMI) -> bool {
+ if (!LMI.LifeStart)
+ return false;
+ if (LMI.SinkLifeStart) {
+ LLVM_DEBUG(dbgs() << "Sinking lifetime.start: " << *LMI.LifeStart
+ << "\n");
+ SinkCands.insert(LMI.LifeStart);
+ }
+ if (LMI.HoistLifeEnd) {
+ LLVM_DEBUG(dbgs() << "Hoisting lifetime.end: " << *LMI.LifeEnd << "\n");
+ HoistCands.insert(LMI.LifeEnd);
+ }
+ return true;
+ };
+
for (BasicBlock &BB : *Func) {
if (Blocks.count(&BB))
continue;
@@ -423,96 +486,51 @@ void CodeExtractor::findAllocas(ValueSet
if (!AI)
continue;
- // Find the pair of life time markers for address 'Addr' that are either
- // defined inside the outline region or can legally be shrinkwrapped into
- // the outline region. If there are not other untracked uses of the
- // address, return the pair of markers if found; otherwise return a pair
- // of nullptr.
- auto GetLifeTimeMarkers =
- [&](Instruction *Addr, bool &SinkLifeStart,
- bool &HoistLifeEnd) -> std::pair<Instruction *, Instruction *> {
- Instruction *LifeStart = nullptr, *LifeEnd = nullptr;
-
- for (User *U : Addr->users()) {
- IntrinsicInst *IntrInst = dyn_cast<IntrinsicInst>(U);
- if (IntrInst) {
- if (IntrInst->getIntrinsicID() == Intrinsic::lifetime_start) {
- // Do not handle the case where AI has multiple start markers.
- if (LifeStart)
- return std::make_pair<Instruction *>(nullptr, nullptr);
- LifeStart = IntrInst;
- }
- if (IntrInst->getIntrinsicID() == Intrinsic::lifetime_end) {
- if (LifeEnd)
- return std::make_pair<Instruction *>(nullptr, nullptr);
- LifeEnd = IntrInst;
- }
- continue;
- }
- // Find untracked uses of the address, bail.
- if (!definedInRegion(Blocks, U))
- return std::make_pair<Instruction *>(nullptr, nullptr);
- }
-
- if (!LifeStart || !LifeEnd)
- return std::make_pair<Instruction *>(nullptr, nullptr);
-
- SinkLifeStart = !definedInRegion(Blocks, LifeStart);
- HoistLifeEnd = !definedInRegion(Blocks, LifeEnd);
- // Do legality Check.
- if ((SinkLifeStart || HoistLifeEnd) &&
- !isLegalToShrinkwrapLifetimeMarkers(Addr))
- return std::make_pair<Instruction *>(nullptr, nullptr);
-
- // Check to see if we have a place to do hoisting, if not, bail.
- if (HoistLifeEnd && !ExitBlock)
- return std::make_pair<Instruction *>(nullptr, nullptr);
-
- return std::make_pair(LifeStart, LifeEnd);
- };
-
- bool SinkLifeStart = false, HoistLifeEnd = false;
- auto Markers = GetLifeTimeMarkers(AI, SinkLifeStart, HoistLifeEnd);
-
- if (Markers.first) {
- if (SinkLifeStart)
- SinkCands.insert(Markers.first);
+ LifetimeMarkerInfo MarkerInfo = getLifetimeMarkers(AI, ExitBlock);
+ bool Moved = moveOrIgnoreLifetimeMarkers(MarkerInfo);
+ if (Moved) {
+ LLVM_DEBUG(dbgs() << "Sinking alloca: " << *AI << "\n");
SinkCands.insert(AI);
- if (HoistLifeEnd)
- HoistCands.insert(Markers.second);
continue;
}
- // Follow the bitcast.
- Instruction *MarkerAddr = nullptr;
+ // Follow any bitcasts.
+ SmallVector<Instruction *, 2> Bitcasts;
+ SmallVector<LifetimeMarkerInfo, 2> BitcastLifetimeInfo;
for (User *U : AI->users()) {
if (U->stripInBoundsConstantOffsets() == AI) {
- SinkLifeStart = false;
- HoistLifeEnd = false;
Instruction *Bitcast = cast<Instruction>(U);
- Markers = GetLifeTimeMarkers(Bitcast, SinkLifeStart, HoistLifeEnd);
- if (Markers.first) {
- MarkerAddr = Bitcast;
+ LifetimeMarkerInfo LMI = getLifetimeMarkers(Bitcast, ExitBlock);
+ if (LMI.LifeStart) {
+ Bitcasts.push_back(Bitcast);
+ BitcastLifetimeInfo.push_back(LMI);
continue;
}
}
// Found unknown use of AI.
if (!definedInRegion(Blocks, U)) {
- MarkerAddr = nullptr;
+ Bitcasts.clear();
break;
}
}
- if (MarkerAddr) {
- if (SinkLifeStart)
- SinkCands.insert(Markers.first);
- if (!definedInRegion(Blocks, MarkerAddr))
- SinkCands.insert(MarkerAddr);
- SinkCands.insert(AI);
- if (HoistLifeEnd)
- HoistCands.insert(Markers.second);
+ // Either no bitcasts reference the alloca or there are unknown uses.
+ if (Bitcasts.empty())
+ continue;
+
+ Instruction *BitcastAddr = Bitcasts.back();
+ const LifetimeMarkerInfo &LMI = BitcastLifetimeInfo.back();
+ assert(LMI.LifeStart &&
+ "Unsafe to sink bitcast without lifetime markers");
+ moveOrIgnoreLifetimeMarkers(LMI);
+ if (!definedInRegion(Blocks, BitcastAddr)) {
+ LLVM_DEBUG(dbgs() << "Sinking bitcast-of-alloca: " << *BitcastAddr
+ << "\n");
+ SinkCands.insert(BitcastAddr);
}
+ LLVM_DEBUG(dbgs() << "Sinking alloca (via bitcast): " << *AI << "\n");
+ SinkCands.insert(AI);
}
}
}
@@ -1412,7 +1430,7 @@ Function *CodeExtractor::extractCodeRegi
// Find inputs to, outputs from the code region.
findInputsOutputs(inputs, outputs, SinkingCands);
- // Now sink all instructions which only have non-phi uses inside the region
+ // Now sink all instructions which only have non-phi uses inside the region.
for (auto *II : SinkingCands)
cast<Instruction>(II)->moveBefore(*newFuncRoot,
newFuncRoot->getFirstInsertionPt());
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