LLVM: lib/Transforms/Utils/LoopPeel.cpp File Reference (original) (raw)
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| Namespaces | |
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| namespace | llvm |
| This is an optimization pass for GlobalISel generic memory operations. |
| Macros | |
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| #define | DEBUG_TYPE "loop-peel" |
| Functions | |
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| STATISTIC (NumPeeled, "Number of loops peeled") | |
| STATISTIC (NumPeeledEnd, "Number of loops peeled from end") | |
| static unsigned | peelToTurnInvariantLoadsDereferenceable (Loop &L, DominatorTree &DT, AssumptionCache *AC) |
| static bool | shouldPeelLastIteration (Loop &L, CmpPredicate Pred, const SCEVAddRecExpr *LeftAR, const SCEV *RightSCEV, ScalarEvolution &SE, const TargetTransformInfo &TTI) |
| Returns true if the last iteration can be peeled off and the condition (Pred LeftAR, RightSCEV) is known at the last iteration and the inverse condition is known at the second-to-last. | |
| static std::pair< unsigned, unsigned > | countToEliminateCompares (Loop &L, unsigned MaxPeelCount, ScalarEvolution &SE, const TargetTransformInfo &TTI) |
| static bool | violatesLegacyMultiExitLoopCheck (Loop *L) |
| This "heuristic" exactly matches implicit behavior which used to exist inside getLoopEstimatedTripCount. | |
| static void | cloneLoopBlocks (Loop *L, unsigned IterNumber, bool PeelLast, BasicBlock *InsertTop, BasicBlock *InsertBot, BasicBlock *OrigPreHeader, SmallVectorImpl< std::pair< BasicBlock *, BasicBlock * > > &ExitEdges, SmallVectorImpl< BasicBlock * > &NewBlocks, LoopBlocksDFS &LoopBlocks, ValueToValueMapTy &VMap, ValueToValueMapTy &LVMap, DominatorTree *DT, LoopInfo *LI, ArrayRef< MDNode * > LoopLocalNoAliasDeclScopes, ScalarEvolution &SE) |
| Clones the body of the loop L, putting it between InsertTop and InsertBot. |
| Variables | |
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| static cl::opt< unsigned > | llvm::UnrollPeelCount ("unroll-peel-count", cl::Hidden, cl::desc("Set the unroll peeling count, for testing purposes")) |
| static cl::opt< bool > | llvm::UnrollAllowPeeling ("unroll-allow-peeling", cl::init(true), cl::Hidden, cl::desc("Allows loops to be peeled when the dynamic " "trip count is known to be low.")) |
| static cl::opt< bool > | llvm::UnrollAllowLoopNestsPeeling ("unroll-allow-loop-nests-peeling", cl::init(false), cl::Hidden, cl::desc("Allows loop nests to be peeled.")) |
| static cl::opt< unsigned > | llvm::UnrollPeelMaxCount ("unroll-peel-max-count", cl::init(7), cl::Hidden, cl::desc("Max average trip count which will cause loop peeling.")) |
| static cl::opt< unsigned > | llvm::UnrollForcePeelCount ("unroll-force-peel-count", cl::init(0), cl::Hidden, cl::desc("Force a peel count regardless of profiling information.")) |
| static cl::opt< bool > | llvm::DisableAdvancedPeeling ("disable-advanced-peeling", cl::init(false), cl::Hidden, cl::desc("Disable advance peeling. Issues for convergent targets (D134803).")) |
| static cl::opt< bool > | llvm::EnablePeelingForIV ("enable-peeling-for-iv", cl::init(false), cl::Hidden, cl::desc("Enable peeling to convert Phi nodes into IVs")) |
| static const char * | llvm::PeeledCountMetaData = "llvm.loop.peeled.count" |
◆ DEBUG_TYPE
#define DEBUG_TYPE "loop-peel"
◆ cloneLoopBlocks()
| void cloneLoopBlocks ( Loop * L, unsigned IterNumber, bool PeelLast, BasicBlock * InsertTop, BasicBlock * InsertBot, BasicBlock * OrigPreHeader, SmallVectorImpl< std::pair< BasicBlock *, BasicBlock * > > & ExitEdges, SmallVectorImpl< BasicBlock * > & NewBlocks, LoopBlocksDFS & LoopBlocks, ValueToValueMapTy & VMap, ValueToValueMapTy & LVMap, DominatorTree * DT, LoopInfo * LI, ArrayRef< MDNode * > LoopLocalNoAliasDeclScopes, ScalarEvolution & SE ) | static |
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Clones the body of the loop L, putting it between InsertTop and InsertBot.
Parameters
| IterNumber | The serial number of the iteration currently being peeled off. | |
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| PeelLast | Peel off the last iterations from L. | |
| ExitEdges | The exit edges of the original loop. | |
| [out] | NewBlocks | A list of the blocks in the newly created clone |
| [out] | VMap | The value map between the loop and the new clone. |
| LoopBlocks | A helper for DFS-traversal of the loop. | |
| LVMap | A value-map that maps instructions from the original loop to instructions in the last peeled-off iteration. |
Definition at line 901 of file LoopPeel.cpp.
References llvm::LoopBase< BlockT, LoopT >::addBasicBlockToLoop(), llvm::PHINode::addIncoming(), llvm::DominatorTreeBase< NodeT, IsPostDom >::addNewBlock(), assert(), B(), llvm::cast(), llvm::DominatorTreeBase< NodeT, IsPostDom >::changeImmediateDominator(), llvm::cloneAndAdaptNoAliasScopes(), llvm::CloneBasicBlock(), llvm::cloneLoop(), llvm::dyn_cast(), llvm::Instruction::eraseFromParent(), F, llvm::ScalarEvolution::forgetLcssaPhiWithNewPredecessor(), llvm::DomTreeNodeBase< NodeT >::getBlock(), llvm::BasicBlock::getFirstNonPHIIt(), llvm::DomTreeNodeBase< NodeT >::getIDom(), llvm::PHINode::getIncomingValueForBlock(), llvm::LoopInfoBase< BlockT, LoopT >::getLoopFor(), llvm::DominatorTreeBase< NodeT, IsPostDom >::getNode(), llvm::BasicBlock::getTerminator(), llvm::Value::getType(), I, llvm::isa(), PHI, llvm::SmallVectorTemplateBase< T, bool >::push_back(), and llvm::Instruction::setSuccessor().
Referenced by llvm::peelLoop().
◆ countToEliminateCompares()
Definition at line 545 of file LoopPeel.cpp.
References assert(), llvm::cast(), llvm::Depth, llvm::dyn_cast(), llvm::SCEVAddRecExpr::evaluateAtIteration(), llvm::ScalarEvolution::evaluatePredicate(), llvm::ScalarEvolution::getAddExpr(), llvm::ScalarEvolution::getConstant(), llvm::ScalarEvolution::getConstantMaxBackedgeTakenCount(), llvm::CmpInst::getInversePredicate(), llvm::SCEVAddRecExpr::getLoop(), llvm::ScalarEvolution::getMonotonicPredicateType(), llvm::ScalarEvolution::getSCEV(), llvm::SCEVAddRecExpr::getStepRecurrence(), llvm::CmpInst::getSwappedPredicate(), llvm::SCEV::getType(), llvm::Value::getType(), llvm::SCEVNAryExpr::hasNoSelfWrap(), I, llvm::CmpInst::ICMP_SGT, llvm::CmpInst::ICMP_SLT, llvm::CmpInst::ICMP_UGT, llvm::CmpInst::ICMP_ULT, llvm::isa(), llvm::SCEVAddRecExpr::isAffine(), llvm::ICmpInst::isEquality(), llvm::Type::isIntegerTy(), llvm::ScalarEvolution::isKnownNegative(), llvm::ScalarEvolution::isKnownPositive(), llvm::ScalarEvolution::isKnownPredicate(), LHS, llvm::PatternMatch::m_And(), llvm::PatternMatch::m_ICmp(), llvm::PatternMatch::m_Or(), llvm::PatternMatch::m_Value(), llvm::SCEVPatternMatch::match(), RHS, shouldPeelLastIteration(), and std::swap().
Referenced by llvm::computePeelCount().
◆ peelToTurnInvariantLoadsDereferenceable()
Definition at line 422 of file LoopPeel.cpp.
References llvm::any_of(), llvm::SmallPtrSetImpl< PtrType >::contains(), DL, llvm::DominatorTree::dominates(), llvm::dyn_cast(), llvm::BasicBlock::getTerminator(), llvm::Value::getType(), I, llvm::SmallPtrSetImpl< PtrType >::insert_range(), llvm::isa(), and llvm::isDereferenceablePointer().
Referenced by llvm::computePeelCount().
◆ shouldPeelLastIteration()
Returns true if the last iteration can be peeled off and the condition (Pred LeftAR, RightSCEV) is known at the last iteration and the inverse condition is known at the second-to-last.
Definition at line 507 of file LoopPeel.cpp.
References llvm::ScalarEvolution::applyLoopGuards(), llvm::canPeelLastIteration(), llvm::ScalarEvolution::LoopGuards::collect(), llvm::SCEVAddRecExpr::evaluateAtIteration(), llvm::ScalarEvolution::getBackedgeTakenCount(), llvm::CmpInst::getInversePredicate(), llvm::ScalarEvolution::getMinusSCEV(), llvm::ScalarEvolution::getOne(), llvm::SCEV::getType(), llvm::SCEVExpander::isHighCostExpansion(), llvm::ScalarEvolution::isKnownNonZero(), llvm::ScalarEvolution::isKnownPredicate(), and llvm::SCEVCheapExpansionBudget.
Referenced by countToEliminateCompares().
◆ STATISTIC() [1/2]
| STATISTIC | ( | NumPeeled | , |
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| "Number of loops peeled" | ) |
◆ STATISTIC() [2/2]
| STATISTIC | ( | NumPeeledEnd | , |
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| "Number of loops peeled from end" | ) |
◆ violatesLegacyMultiExitLoopCheck()
| bool violatesLegacyMultiExitLoopCheck ( Loop * L) | static |
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