LLVM  4.0.0
Macros | Typedefs | Functions | Variables
ScalarEvolution.cpp File Reference
#include "llvm/Analysis/ScalarEvolution.h"
#include "llvm/ADT/Optional.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/ScopeExit.h"
#include "llvm/ADT/Sequence.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/AssumptionCache.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/ScalarEvolutionExpressions.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/IR/ConstantRange.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/GetElementPtrTypeIterator.h"
#include "llvm/IR/GlobalAlias.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/InstIterator.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Metadata.h"
#include "llvm/IR/Operator.h"
#include "llvm/IR/PatternMatch.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Support/SaveAndRestore.h"
#include <algorithm>
Include dependency graph for ScalarEvolution.cpp:

Go to the source code of this file.

Macros

#define DEBUG_TYPE   "scalar-evolution"
 

Typedefs

typedef DenseMap< const Loop
*, std::string > 
VerifyMap
 

Functions

 STATISTIC (NumArrayLenItCounts,"Number of trip counts computed with array length")
 
 STATISTIC (NumTripCountsComputed,"Number of loops with predictable loop counts")
 
 STATISTIC (NumTripCountsNotComputed,"Number of loops without predictable loop counts")
 
 STATISTIC (NumBruteForceTripCountsComputed,"Number of loops with trip counts computed by force")
 
static int CompareValueComplexity (SmallSet< std::pair< Value *, Value * >, 8 > &EqCache, const LoopInfo *const LI, Value *LV, Value *RV, unsigned Depth)
 Compare the two values LV and RV in terms of their "complexity" where "complexity" is a partial (and somewhat ad-hoc) relation used to order operands in SCEV expressions. More...
 
static int CompareSCEVComplexity (SmallSet< std::pair< const SCEV *, const SCEV * >, 8 > &EqCacheSCEV, const LoopInfo *const LI, const SCEV *LHS, const SCEV *RHS, unsigned Depth=0)
 
static void GroupByComplexity (SmallVectorImpl< const SCEV * > &Ops, LoopInfo *LI)
 Given a list of SCEV objects, order them by their complexity, and group objects of the same complexity together by value. More...
 
static int sizeOfSCEV (const SCEV *S)
 
static const SCEVBinomialCoefficient (const SCEV *It, unsigned K, ScalarEvolution &SE, Type *ResultTy)
 Compute BC(It, K). The result has width W. Assume, K > 0. More...
 
static const SCEVgetSignedOverflowLimitForStep (const SCEV *Step, ICmpInst::Predicate *Pred, ScalarEvolution *SE)
 
static const SCEVgetUnsignedOverflowLimitForStep (const SCEV *Step, ICmpInst::Predicate *Pred, ScalarEvolution *SE)
 
template<typename ExtendOpTy >
static const SCEVgetPreStartForExtend (const SCEVAddRecExpr *AR, Type *Ty, ScalarEvolution *SE)
 
template<typename ExtendOpTy >
static const SCEVgetExtendAddRecStart (const SCEVAddRecExpr *AR, Type *Ty, ScalarEvolution *SE)
 
static bool CollectAddOperandsWithScales (DenseMap< const SCEV *, APInt > &M, SmallVectorImpl< const SCEV * > &NewOps, APInt &AccumulatedConstant, const SCEV *const *Ops, size_t NumOperands, const APInt &Scale, ScalarEvolution &SE)
 Process the given Ops list, which is a list of operands to be added under the given scale, update the given map. More...
 
static SCEV::NoWrapFlags StrengthenNoWrapFlags (ScalarEvolution *SE, SCEVTypes Type, const SmallVectorImpl< const SCEV * > &Ops, SCEV::NoWrapFlags Flags)
 
static uint64_t umul_ov (uint64_t i, uint64_t j, bool &Overflow)
 
static uint64_t Choose (uint64_t n, uint64_t k, bool &Overflow)
 Compute the result of "n choose k", the binomial coefficient. More...
 
static bool containsConstantSomewhere (const SCEV *StartExpr)
 Determine if any of the operands in this SCEV are a constant or if any of the add or multiply expressions in this SCEV contain a constant. More...
 
static const APInt gcd (const SCEVConstant *C1, const SCEVConstant *C2)
 
static std::pair< const SCEV
*, ConstantInt * > 
splitAddExpr (const SCEV *S)
 Try to split a SCEVAddExpr into a pair of {SCEV, ConstantInt}. More...
 
static void PushDefUseChildren (Instruction *I, SmallVectorImpl< Instruction * > &Worklist)
 Push users of the given Instruction onto the given Worklist. More...
 
static Optional< BinaryOp > MatchBinaryOp (Value *V, DominatorTree &DT)
 Try to map V into a BinaryOp, and return None on failure. More...
 
static bool IsAvailableOnEntry (const Loop *L, DominatorTree &DT, const SCEV *S, BasicBlock *BB)
 
static bool BrPHIToSelect (DominatorTree &DT, BranchInst *BI, PHINode *Merge, Value *&C, Value *&LHS, Value *&RHS)
 
static Optional< ConstantRangeGetRangeFromMetadata (Value *V)
 Helper method to assign a range to V from metadata present in the IR. More...
 
static unsigned getConstantTripCount (const SCEVConstant *ExitCount)
 
static void PushLoopPHIs (const Loop *L, SmallVectorImpl< Instruction * > &Worklist)
 Push PHI nodes in the header of the given loop onto the given Worklist. More...
 
static ConstantIntEvaluateConstantChrecAtConstant (const SCEVAddRecExpr *AddRec, ConstantInt *C, ScalarEvolution &SE)
 
static bool CanConstantFold (const Instruction *I)
 Return true if we can constant fold an instruction of the specified type, assuming that all operands were constants. More...
 
static bool canConstantEvolve (Instruction *I, const Loop *L)
 Determine whether this instruction can constant evolve within this loop assuming its operands can all constant evolve. More...
 
static PHINodegetConstantEvolvingPHIOperands (Instruction *UseInst, const Loop *L, DenseMap< Instruction *, PHINode * > &PHIMap)
 getConstantEvolvingPHIOperands - Implement getConstantEvolvingPHI by recursing through each instruction operand until reaching a loop header phi. More...
 
static PHINodegetConstantEvolvingPHI (Value *V, const Loop *L)
 getConstantEvolvingPHI - Given an LLVM value and a loop, return a PHI node in the loop that V is derived from. More...
 
static ConstantEvaluateExpression (Value *V, const Loop *L, DenseMap< Instruction *, Constant * > &Vals, const DataLayout &DL, const TargetLibraryInfo *TLI)
 EvaluateExpression - Given an expression that passes the getConstantEvolvingPHI predicate, evaluate its value assuming the PHI node in the loop has the value PHIVal. More...
 
static ConstantgetOtherIncomingValue (PHINode *PN, BasicBlock *BB)
 
static ConstantBuildConstantFromSCEV (const SCEV *V)
 This builds up a Constant using the ConstantExpr interface. More...
 
static const SCEVSolveLinEquationWithOverflow (const APInt &A, const APInt &B, ScalarEvolution &SE)
 Finds the minimum unsigned root of the following equation: More...
 
static Optional< std::pair
< const SCEVConstant *, const
SCEVConstant * > > 
SolveQuadraticEquation (const SCEVAddRecExpr *AddRec, ScalarEvolution &SE)
 Find the roots of the quadratic equation for the given quadratic chrec {L,+,M,+,N}. More...
 
static bool HasSameValue (const SCEV *A, const SCEV *B)
 SCEV structural equivalence is usually sufficient for testing whether two expressions are equal, however for the purposes of looking for a condition guarding a loop, it can be useful to be a little more general, since a front-end may have replicated the controlling expression. More...
 
static const SCEVMatchNotExpr (const SCEV *Expr)
 If Expr computes ~A, return A else return nullptr. More...
 
template<typename MaxExprType >
static bool IsMaxConsistingOf (const SCEV *MaybeMaxExpr, const SCEV *Candidate)
 Is MaybeMaxExpr an SMax or UMax of Candidate and some other values? More...
 
template<typename MaxExprType >
static bool IsMinConsistingOf (ScalarEvolution &SE, const SCEV *MaybeMinExpr, const SCEV *Candidate)
 Is MaybeMinExpr an SMin or UMin of Candidate and some other values? More...
 
static bool IsKnownPredicateViaAddRecStart (ScalarEvolution &SE, ICmpInst::Predicate Pred, const SCEV *LHS, const SCEV *RHS)
 
static bool IsKnownPredicateViaMinOrMax (ScalarEvolution &SE, ICmpInst::Predicate Pred, const SCEV *LHS, const SCEV *RHS)
 Is LHS Pred RHS true on the virtue of LHS or RHS being a Min or Max expression? More...
 
static bool containsUndefs (const SCEV *S)
 
static bool findArrayDimensionsRec (ScalarEvolution &SE, SmallVectorImpl< const SCEV * > &Terms, SmallVectorImpl< const SCEV * > &Sizes)
 
static bool containsParameters (SmallVectorImpl< const SCEV * > &Terms)
 
static int numberOfTerms (const SCEV *S)
 
static const SCEVremoveConstantFactors (ScalarEvolution &SE, const SCEV *T)
 
static void PrintLoopInfo (raw_ostream &OS, ScalarEvolution *SE, const Loop *L)
 
static StringRef loopDispositionToStr (ScalarEvolution::LoopDisposition LD)
 
static void replaceSubString (std::string &Str, StringRef From, StringRef To)
 replaceSubString - Replaces all occurrences of From in Str with To. More...
 
static void getLoopBackedgeTakenCounts (Loop *L, VerifyMap &Map, ScalarEvolution &SE)
 getLoopBackedgeTakenCounts - Helper method for verifyAnalysis. More...
 
 INITIALIZE_PASS_BEGIN (ScalarEvolutionWrapperPass,"scalar-evolution","Scalar Evolution Analysis", false, true) INITIALIZE_PASS_END(ScalarEvolutionWrapperPass
 

Variables

static cl::opt< unsignedMaxBruteForceIterations ("scalar-evolution-max-iterations", cl::ReallyHidden, cl::desc("Maximum number of iterations SCEV will ""symbolically execute a constant ""derived loop"), cl::init(100))
 
static cl::opt< boolVerifySCEV ("verify-scev", cl::desc("Verify ScalarEvolution's backedge taken counts (slow)"))
 
static cl::opt< boolVerifySCEVMap ("verify-scev-maps", cl::desc("Verify no dangling value in ScalarEvolution's ""ExprValueMap (slow)"))
 
static cl::opt< unsignedMulOpsInlineThreshold ("scev-mulops-inline-threshold", cl::Hidden, cl::desc("Threshold for inlining multiplication operands into a SCEV"), cl::init(1000))
 
static cl::opt< unsignedMaxSCEVCompareDepth ("scalar-evolution-max-scev-compare-depth", cl::Hidden, cl::desc("Maximum depth of recursive SCEV complexity comparisons"), cl::init(32))
 
static cl::opt< unsignedMaxValueCompareDepth ("scalar-evolution-max-value-compare-depth", cl::Hidden, cl::desc("Maximum depth of recursive value complexity comparisons"), cl::init(2))
 
scalar evolution
 
scalar Scalar Evolution Analysis
 
scalar Scalar Evolution false
 

Macro Definition Documentation

#define DEBUG_TYPE   "scalar-evolution"

Definition at line 98 of file ScalarEvolution.cpp.

Typedef Documentation

typedef DenseMap<const Loop *, std::string> VerifyMap

Definition at line 9949 of file ScalarEvolution.cpp.

Function Documentation

static const SCEV* BinomialCoefficient ( const SCEV It,
unsigned  K,
ScalarEvolution SE,
Type ResultTy 
)
static
static bool BrPHIToSelect ( DominatorTree DT,
BranchInst BI,
PHINode Merge,
Value *&  C,
Value *&  LHS,
Value *&  RHS 
)
static
static Constant* BuildConstantFromSCEV ( const SCEV V)
static
static bool canConstantEvolve ( Instruction I,
const Loop L 
)
static

Determine whether this instruction can constant evolve within this loop assuming its operands can all constant evolve.

Definition at line 6392 of file ScalarEvolution.cpp.

References CanConstantFold(), llvm::LoopBase< N, M >::contains(), llvm::LoopBase< N, M >::getHeader(), and llvm::Instruction::getParent().

Referenced by EvaluateExpression(), getConstantEvolvingPHI(), and getConstantEvolvingPHIOperands().

static bool CanConstantFold ( const Instruction I)
static

Return true if we can constant fold an instruction of the specified type, assuming that all operands were constants.

Definition at line 6378 of file ScalarEvolution.cpp.

References llvm::canConstantFoldCallTo().

Referenced by canConstantEvolve().

static uint64_t Choose ( uint64_t  n,
uint64_t  k,
bool Overflow 
)
static

Compute the result of "n choose k", the binomial coefficient.

If an intermediate computation overflows, Overflow will be set and the return will be garbage. Overflow is not cleared on absence of overflow.

Definition at line 2466 of file ScalarEvolution.cpp.

References i, and umul_ov().

Referenced by llvm::ScalarEvolution::getMulExpr().

static bool CollectAddOperandsWithScales ( DenseMap< const SCEV *, APInt > &  M,
SmallVectorImpl< const SCEV * > &  NewOps,
APInt AccumulatedConstant,
const SCEV *const Ops,
size_t  NumOperands,
const APInt Scale,
ScalarEvolution SE 
)
static

Process the given Ops list, which is a list of operands to be added under the given scale, update the given map.

This is a helper function for getAddRecExpr. As an example of what it does, given a sequence of operands that would form an add expression like this:

m + n + 13 + (A * (o + p + (B * (q + m + 29)))) + r + (-1 * r)

where A and B are constants, update the map with these values:

(m, 1+A*B), (n, 1), (o, A), (p, A), (q, A*B), (r, 0)

and add 13 + A*B*29 to AccumulatedConstant. This will allow getAddRecExpr to produce this:

13+A*B*29 + n + (m * (1+A*B)) + ((o + p) * A) + (q * A*B)

This form often exposes folding opportunities that are hidden in the original operand list.

Return true iff it appears that any interesting folding opportunities may be exposed. This helps getAddRecExpr short-circuit extra work in the common case where no interesting opportunities are present, and is also used as a check to avoid infinite recursion.

Definition at line 1977 of file ScalarEvolution.cpp.

References llvm::MCID::Add, C, llvm::dyn_cast(), llvm::ScalarEvolution::getMulExpr(), llvm::SCEVNAryExpr::getNumOperands(), llvm::SCEVNAryExpr::getOperand(), i, llvm::DenseMapBase< DenseMap< KeyT, ValueT, KeyInfoT, BucketT >, KeyT, ValueT, KeyInfoT, BucketT >::insert(), llvm::SCEVNAryExpr::op_begin(), llvm::SCEVNAryExpr::op_end(), and llvm::SmallVectorTemplateBase< T, isPodLike< T >::value >::push_back().

Referenced by llvm::ScalarEvolution::getAddExpr().

static int CompareSCEVComplexity ( SmallSet< std::pair< const SCEV *, const SCEV * >, 8 > &  EqCacheSCEV,
const LoopInfo *const  LI,
const SCEV LHS,
const SCEV RHS,
unsigned  Depth = 0 
)
static

Definition at line 563 of file ScalarEvolution.cpp.

References llvm::Depth, llvm::SCEV::getSCEVType(), and MaxSCEVCompareDepth.

Referenced by GroupByComplexity().

static int CompareValueComplexity ( SmallSet< std::pair< Value *, Value * >, 8 > &  EqCache,
const LoopInfo *const  LI,
Value LV,
Value RV,
unsigned  Depth 
)
static

Compare the two values LV and RV in terms of their "complexity" where "complexity" is a partial (and somewhat ad-hoc) relation used to order operands in SCEV expressions.

EqCache is a set of pairs of values that have been previously deemed to be "equally complex" by this routine. It is intended to avoid exponential time complexity in cases like:

a = f(x, y) b = f(a, a) c = f(b, b)

d = f(x, y) e = f(d, d) f = f(e, e)

CompareValueComplexity(f, c)

Since we do not continue running this routine on expression trees once we have seen unequal values, there is no need to track them in the cache.

Definition at line 486 of file ScalarEvolution.cpp.

References MaxValueCompareDepth.

static bool containsConstantSomewhere ( const SCEV StartExpr)
static

Determine if any of the operands in this SCEV are a constant or if any of the add or multiply expressions in this SCEV contain a constant.

Definition at line 2491 of file ScalarEvolution.cpp.

References llvm::SmallVectorImpl< T >::append(), llvm::SmallVectorBase::empty(), llvm::SmallVectorImpl< T >::pop_back_val(), and llvm::SmallVectorTemplateBase< T, isPodLike< T >::value >::push_back().

Referenced by llvm::ScalarEvolution::getMulExpr().

static bool containsParameters ( SmallVectorImpl< const SCEV * > &  Terms)
inlinestatic
static bool containsUndefs ( const SCEV S)
inlinestatic

Definition at line 8990 of file ScalarEvolution.cpp.

References llvm::PPCISD::SC, and llvm::SCEVExprContains().

static ConstantInt* EvaluateConstantChrecAtConstant ( const SCEVAddRecExpr AddRec,
ConstantInt C,
ScalarEvolution SE 
)
static
static Constant* EvaluateExpression ( Value V,
const Loop L,
DenseMap< Instruction *, Constant * > &  Vals,
const DataLayout DL,
const TargetLibraryInfo TLI 
)
static

EvaluateExpression - Given an expression that passes the getConstantEvolvingPHI predicate, evaluate its value assuming the PHI node in the loop has the value PHIVal.

If we can't fold this expression for some reason, return null.

Definition at line 6465 of file ScalarEvolution.cpp.

References C, canConstantEvolve(), llvm::ConstantFoldCompareInstOperands(), llvm::ConstantFoldInstOperands(), llvm::ConstantFoldLoadFromConstPtr(), llvm::dyn_cast(), llvm::User::getNumOperands(), llvm::User::getOperand(), llvm::Value::getType(), i, llvm::LoadInst::isVolatile(), and llvm::DenseMapBase< DenseMap< KeyT, ValueT, KeyInfoT, BucketT >, KeyT, ValueT, KeyInfoT, BucketT >::lookup().

static bool findArrayDimensionsRec ( ScalarEvolution SE,
SmallVectorImpl< const SCEV * > &  Terms,
SmallVectorImpl< const SCEV * > &  Sizes 
)
static
static const APInt gcd ( const SCEVConstant C1,
const SCEVConstant C2 
)
static
static PHINode* getConstantEvolvingPHI ( Value V,
const Loop L 
)
static

getConstantEvolvingPHI - Given an LLVM value and a loop, return a PHI node in the loop that V is derived from.

We allow arbitrary operations along the way, but the operands of an operation must either be constants or a value derived from a constant PHI. If this expression does not fit with these constraints, return null.

Definition at line 6449 of file ScalarEvolution.cpp.

References canConstantEvolve(), llvm::dyn_cast(), and getConstantEvolvingPHIOperands().

static PHINode* getConstantEvolvingPHIOperands ( Instruction UseInst,
const Loop L,
DenseMap< Instruction *, PHINode * > &  PHIMap 
)
static

getConstantEvolvingPHIOperands - Implement getConstantEvolvingPHI by recursing through each instruction operand until reaching a loop header phi.

Definition at line 6410 of file ScalarEvolution.cpp.

References canConstantEvolve(), llvm::dyn_cast(), llvm::DenseMapBase< DenseMap< KeyT, ValueT, KeyInfoT, BucketT >, KeyT, ValueT, KeyInfoT, BucketT >::lookup(), llvm::User::operands(), and P.

Referenced by getConstantEvolvingPHI().

static unsigned getConstantTripCount ( const SCEVConstant ExitCount)
static
template<typename ExtendOpTy >
static const SCEV* getExtendAddRecStart ( const SCEVAddRecExpr AR,
Type Ty,
ScalarEvolution SE 
)
static

Definition at line 1390 of file ScalarEvolution.cpp.

References llvm::ScalarEvolution::getAddExpr().

static void getLoopBackedgeTakenCounts ( Loop L,
VerifyMap Map,
ScalarEvolution SE 
)
static

getLoopBackedgeTakenCounts - Helper method for verifyAnalysis.

Definition at line 9962 of file ScalarEvolution.cpp.

References llvm::ScalarEvolution::getBackedgeTakenCount(), L, llvm::SCEV::print(), replaceSubString(), llvm::reverse(), and llvm::raw_string_ostream::str().

Referenced by llvm::ScalarEvolution::verify().

static Constant* getOtherIncomingValue ( PHINode PN,
BasicBlock BB 
)
static
template<typename ExtendOpTy >
static const SCEV* getPreStartForExtend ( const SCEVAddRecExpr AR,
Type Ty,
ScalarEvolution SE 
)
static
static Optional<ConstantRange> GetRangeFromMetadata ( Value V)
static

Helper method to assign a range to V from metadata present in the IR.

Definition at line 4490 of file ScalarEvolution.cpp.

References llvm::getConstantRangeFromMetadata(), llvm::Instruction::getMetadata(), llvm::LLVMContext::MD_range, and llvm::None.

static const SCEV* getSignedOverflowLimitForStep ( const SCEV Step,
ICmpInst::Predicate *  Pred,
ScalarEvolution SE 
)
static
static const SCEV* getUnsignedOverflowLimitForStep ( const SCEV Step,
ICmpInst::Predicate *  Pred,
ScalarEvolution SE 
)
static
static void GroupByComplexity ( SmallVectorImpl< const SCEV * > &  Ops,
LoopInfo LI 
)
static

Given a list of SCEV objects, order them by their complexity, and group objects of the same complexity together by value.

When this routine is finished, we know that any duplicates in the vector are consecutive and that complexity is monotonically increasing.

Note that we go take special precautions to ensure that we get deterministic results from this routine. In other words, we don't want the results of this to depend on where the addresses of various SCEV objects happened to land in memory.

Definition at line 705 of file ScalarEvolution.cpp.

References llvm::SmallVectorTemplateCommon< T >::begin(), CompareSCEVComplexity(), llvm::SmallVectorTemplateCommon< T >::end(), llvm::SCEV::getSCEVType(), i, llvm::SmallVectorTemplateCommon< T >::size(), and std::swap().

Referenced by llvm::ScalarEvolution::getAddExpr(), llvm::ScalarEvolution::getMulExpr(), llvm::ScalarEvolution::getSMaxExpr(), and llvm::ScalarEvolution::getUMaxExpr().

static bool HasSameValue ( const SCEV A,
const SCEV B 
)
static

SCEV structural equivalence is usually sufficient for testing whether two expressions are equal, however for the purposes of looking for a condition guarding a loop, it can be useful to be a little more general, since a front-end may have replicated the controlling expression.

Definition at line 7354 of file ScalarEvolution.cpp.

References A, B, and llvm::Instruction::isIdenticalTo().

Referenced by llvm::ScalarEvolution::SimplifyICmpOperands().

INITIALIZE_PASS_BEGIN ( ScalarEvolutionWrapperPass  ,
"scalar-evolution ,
"Scalar Evolution Analysis ,
false  ,
true   
)
static bool IsAvailableOnEntry ( const Loop L,
DominatorTree DT,
const SCEV S,
BasicBlock BB 
)
static
static bool IsKnownPredicateViaAddRecStart ( ScalarEvolution SE,
ICmpInst::Predicate  Pred,
const SCEV LHS,
const SCEV RHS 
)
static
static bool IsKnownPredicateViaMinOrMax ( ScalarEvolution SE,
ICmpInst::Predicate  Pred,
const SCEV LHS,
const SCEV RHS 
)
static

Is LHS Pred RHS true on the virtue of LHS or RHS being a Min or Max expression?

Definition at line 8460 of file ScalarEvolution.cpp.

References llvm::CmpInst::ICMP_SGE, llvm::CmpInst::ICMP_SLE, llvm::CmpInst::ICMP_UGE, llvm::CmpInst::ICMP_ULE, LLVM_FALLTHROUGH, llvm_unreachable, and std::swap().

template<typename MaxExprType >
static bool IsMaxConsistingOf ( const SCEV MaybeMaxExpr,
const SCEV Candidate 
)
static

Is MaybeMaxExpr an SMax or UMax of Candidate and some other values?

Definition at line 8404 of file ScalarEvolution.cpp.

References llvm::dyn_cast(), and llvm::find().

template<typename MaxExprType >
static bool IsMinConsistingOf ( ScalarEvolution SE,
const SCEV MaybeMinExpr,
const SCEV Candidate 
)
static

Is MaybeMinExpr an SMin or UMin of Candidate and some other values?

Definition at line 8415 of file ScalarEvolution.cpp.

References llvm::ScalarEvolution::getNotSCEV(), and MatchNotExpr().

static StringRef loopDispositionToStr ( ScalarEvolution::LoopDisposition  LD)
static
static Optional<BinaryOp> MatchBinaryOp ( Value V,
DominatorTree DT 
)
static
static const SCEV* MatchNotExpr ( const SCEV Expr)
static

If Expr computes ~A, return A else return nullptr.

Definition at line 8387 of file ScalarEvolution.cpp.

References llvm::MCID::Add, llvm::dyn_cast(), llvm::SCEVNAryExpr::getNumOperands(), llvm::SCEVNAryExpr::getOperand(), and llvm::SCEV::isAllOnesValue().

Referenced by IsMinConsistingOf().

static int numberOfTerms ( const SCEV S)
inlinestatic

Definition at line 9200 of file ScalarEvolution.cpp.

Referenced by llvm::ScalarEvolution::findArrayDimensions().

static void PrintLoopInfo ( raw_ostream OS,
ScalarEvolution SE,
const Loop L 
)
static
static void PushDefUseChildren ( Instruction I,
SmallVectorImpl< Instruction * > &  Worklist 
)
static

Push users of the given Instruction onto the given Worklist.

Definition at line 3713 of file ScalarEvolution.cpp.

References llvm::SmallVectorTemplateBase< T, isPodLike< T >::value >::push_back(), and llvm::Value::users().

Referenced by llvm::ScalarEvolution::forgetLoop(), and llvm::ScalarEvolution::forgetValue().

static void PushLoopPHIs ( const Loop L,
SmallVectorImpl< Instruction * > &  Worklist 
)
static

Push PHI nodes in the header of the given loop onto the given Worklist.

Definition at line 5457 of file ScalarEvolution.cpp.

References llvm::BasicBlock::begin(), llvm::dyn_cast(), llvm::LoopBase< N, M >::getHeader(), I, and llvm::SmallVectorTemplateBase< T, isPodLike< T >::value >::push_back().

Referenced by llvm::ScalarEvolution::forgetLoop().

static const SCEV* removeConstantFactors ( ScalarEvolution SE,
const SCEV T 
)
static
static void replaceSubString ( std::string &  Str,
StringRef  From,
StringRef  To 
)
static

replaceSubString - Replaces all occurrences of From in Str with To.

Definition at line 9952 of file ScalarEvolution.cpp.

References llvm::StringRef::data(), and llvm::StringRef::size().

Referenced by getLoopBackedgeTakenCounts().

static int sizeOfSCEV ( const SCEV S)
inlinestatic

Definition at line 747 of file ScalarEvolution.cpp.

References F, llvm::ARM_MB::ST, and llvm::SCEVTraversal< SV >::visitAll().

static const SCEV* SolveLinEquationWithOverflow ( const APInt A,
const APInt B,
ScalarEvolution SE 
)
static

Finds the minimum unsigned root of the following equation:

A * X = B (mod N)

where N = 2^BW and BW is the common bit width of A and B. The signedness of A and B isn't important.

If the equation does not have a solution, SCEVCouldNotCompute is returned.

Definition at line 7017 of file ScalarEvolution.cpp.

References assert(), B, llvm::APInt::countTrailingZeros(), llvm::APInt::getBitWidth(), llvm::ScalarEvolution::getConstant(), llvm::ScalarEvolution::getCouldNotCompute(), llvm::APInt::lshr(), llvm::APIntOps::lshr(), llvm::APInt::multiplicativeInverse(), llvm::APInt::setBit(), llvm::APInt::trunc(), and llvm::APInt::zext().

static Optional<std::pair<const SCEVConstant *,const SCEVConstant *> > SolveQuadraticEquation ( const SCEVAddRecExpr AddRec,
ScalarEvolution SE 
)
static

Find the roots of the quadratic equation for the given quadratic chrec {L,+,M,+,N}.

This returns either the two roots (which might be the same) or two SCEVCouldNotCompute objects.

Definition at line 7062 of file ScalarEvolution.cpp.

References A, assert(), B, C, Context, llvm::dyn_cast(), llvm::ConstantInt::get(), llvm::ScalarEvolution::getConstant(), llvm::ScalarEvolution::getContext(), llvm::SCEVNAryExpr::getNumOperands(), llvm::SCEVNAryExpr::getOperand(), llvm::APInt::isMinValue(), L, N, NC, llvm::None, llvm::APInt::sdiv(), and llvm::APIntOps::sdiv().

Referenced by llvm::SCEVAddRecExpr::getNumIterationsInRange().

static std::pair<const SCEV *, ConstantInt *> splitAddExpr ( const SCEV S)
static

Try to split a SCEVAddExpr into a pair of {SCEV, ConstantInt}.

If S is a SCEVAddExpr and is composed of a sub SCEV S' and an offset I, then return {S', I}, else return {S, nullptr}.

Definition at line 3414 of file ScalarEvolution.cpp.

References llvm::MCID::Add, and llvm::dyn_cast().

Referenced by llvm::ScalarEvolution::eraseValueFromMap(), and llvm::ScalarEvolution::getSCEV().

STATISTIC ( NumArrayLenItCounts  ,
"Number of trip counts computed with array length"   
)
STATISTIC ( NumTripCountsComputed  ,
"Number of loops with predictable loop counts"   
)
STATISTIC ( NumTripCountsNotComputed  ,
"Number of loops without predictable loop counts"   
)
STATISTIC ( NumBruteForceTripCountsComputed  ,
"Number of loops with trip counts computed by force"   
)
static SCEV::NoWrapFlags StrengthenNoWrapFlags ( ScalarEvolution SE,
SCEVTypes  Type,
const SmallVectorImpl< const SCEV * > &  Ops,
SCEV::NoWrapFlags  Flags 
)
static
static uint64_t umul_ov ( uint64_t  i,
uint64_t  j,
bool Overflow 
)
static

Definition at line 2457 of file ScalarEvolution.cpp.

Referenced by Choose(), and llvm::ScalarEvolution::getMulExpr().

Variable Documentation

scalar Scalar Evolution Analysis

Definition at line 10063 of file ScalarEvolution.cpp.

scalar evolution

Definition at line 10063 of file ScalarEvolution.cpp.

scalar Scalar Evolution false

Definition at line 10063 of file ScalarEvolution.cpp.

cl::opt<unsigned> MaxBruteForceIterations("scalar-evolution-max-iterations", cl::ReallyHidden, cl::desc("Maximum number of iterations SCEV will ""symbolically execute a constant ""derived loop"), cl::init(100))
static
cl::opt<unsigned> MaxSCEVCompareDepth("scalar-evolution-max-scev-compare-depth", cl::Hidden, cl::desc("Maximum depth of recursive SCEV complexity comparisons"), cl::init(32))
static

Referenced by CompareSCEVComplexity().

cl::opt<unsigned> MaxValueCompareDepth("scalar-evolution-max-value-compare-depth", cl::Hidden, cl::desc("Maximum depth of recursive value complexity comparisons"), cl::init(2))
static

Referenced by CompareValueComplexity().

cl::opt<unsigned> MulOpsInlineThreshold("scev-mulops-inline-threshold", cl::Hidden, cl::desc("Threshold for inlining multiplication operands into a SCEV"), cl::init(1000))
static
cl::opt<bool> VerifySCEV("verify-scev", cl::desc("Verify ScalarEvolution's backedge taken counts (slow)"))
static
cl::opt<bool> VerifySCEVMap("verify-scev-maps", cl::desc("Verify no dangling value in ScalarEvolution's ""ExprValueMap (slow)"))
static