#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/Statistic.h"
-#include "llvm/Analysis/AssumptionTracker.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/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/raw_ostream.h"
-#include "llvm/Target/TargetLibraryInfo.h"
#include <algorithm>
using namespace llvm;
INITIALIZE_PASS_BEGIN(ScalarEvolution, "scalar-evolution",
"Scalar Evolution Analysis", false, true)
-INITIALIZE_PASS_DEPENDENCY(AssumptionTracker)
+INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
INITIALIZE_PASS_DEPENDENCY(LoopInfo)
INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfo)
+INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
INITIALIZE_PASS_END(ScalarEvolution, "scalar-evolution",
"Scalar Evolution Analysis", false, true)
char ScalarEvolution::ID = 0;
};
}
+// We're trying to construct a SCEV of type `Type' with `Ops' as operands and
+// `OldFlags' as can't-wrap behavior. Infer a more aggressive set of
+// can't-overflow flags for the operation if possible.
+static SCEV::NoWrapFlags
+StrengthenNoWrapFlags(ScalarEvolution *SE, SCEVTypes Type,
+ const SmallVectorImpl<const SCEV *> &Ops,
+ SCEV::NoWrapFlags OldFlags) {
+ using namespace std::placeholders;
+
+ bool CanAnalyze =
+ Type == scAddExpr || Type == scAddRecExpr || Type == scMulExpr;
+ (void)CanAnalyze;
+ assert(CanAnalyze && "don't call from other places!");
+
+ int SignOrUnsignMask = SCEV::FlagNUW | SCEV::FlagNSW;
+ SCEV::NoWrapFlags SignOrUnsignWrap =
+ ScalarEvolution::maskFlags(OldFlags, SignOrUnsignMask);
+
+ // If FlagNSW is true and all the operands are non-negative, infer FlagNUW.
+ auto IsKnownNonNegative =
+ std::bind(std::mem_fn(&ScalarEvolution::isKnownNonNegative), SE, _1);
+
+ if (SignOrUnsignWrap == SCEV::FlagNSW &&
+ std::all_of(Ops.begin(), Ops.end(), IsKnownNonNegative))
+ return ScalarEvolution::setFlags(OldFlags,
+ (SCEV::NoWrapFlags)SignOrUnsignMask);
+
+ return OldFlags;
+}
+
/// getAddExpr - Get a canonical add expression, or something simpler if
/// possible.
const SCEV *ScalarEvolution::getAddExpr(SmallVectorImpl<const SCEV *> &Ops,
"SCEVAddExpr operand types don't match!");
#endif
- // If FlagNSW is true and all the operands are non-negative, infer FlagNUW.
- // And vice-versa.
- int SignOrUnsignMask = SCEV::FlagNUW | SCEV::FlagNSW;
- SCEV::NoWrapFlags SignOrUnsignWrap = maskFlags(Flags, SignOrUnsignMask);
- if (SignOrUnsignWrap && (SignOrUnsignWrap != SignOrUnsignMask)) {
- bool All = true;
- for (SmallVectorImpl<const SCEV *>::const_iterator I = Ops.begin(),
- E = Ops.end(); I != E; ++I)
- if (!isKnownNonNegative(*I)) {
- All = false;
- break;
- }
- if (All) Flags = setFlags(Flags, (SCEV::NoWrapFlags)SignOrUnsignMask);
- }
+ Flags = StrengthenNoWrapFlags(this, scAddExpr, Ops, Flags);
// Sort by complexity, this groups all similar expression types together.
GroupByComplexity(Ops, LI);
"SCEVMulExpr operand types don't match!");
#endif
- // If FlagNSW is true and all the operands are non-negative, infer FlagNUW.
- // And vice-versa.
- int SignOrUnsignMask = SCEV::FlagNUW | SCEV::FlagNSW;
- SCEV::NoWrapFlags SignOrUnsignWrap = maskFlags(Flags, SignOrUnsignMask);
- if (SignOrUnsignWrap && (SignOrUnsignWrap != SignOrUnsignMask)) {
- bool All = true;
- for (SmallVectorImpl<const SCEV *>::const_iterator I = Ops.begin(),
- E = Ops.end(); I != E; ++I)
- if (!isKnownNonNegative(*I)) {
- All = false;
- break;
- }
- if (All) Flags = setFlags(Flags, (SCEV::NoWrapFlags)SignOrUnsignMask);
- }
+ Flags = StrengthenNoWrapFlags(this, scMulExpr, Ops, Flags);
// Sort by complexity, this groups all similar expression types together.
GroupByComplexity(Ops, LI);
// meaningful BE count at this point (and if we don't, we'd be stuck
// with a SCEVCouldNotCompute as the cached BE count).
- // If FlagNSW is true and all the operands are non-negative, infer FlagNUW.
- // And vice-versa.
- int SignOrUnsignMask = SCEV::FlagNUW | SCEV::FlagNSW;
- SCEV::NoWrapFlags SignOrUnsignWrap = maskFlags(Flags, SignOrUnsignMask);
- if (SignOrUnsignWrap && (SignOrUnsignWrap != SignOrUnsignMask)) {
- bool All = true;
- for (SmallVectorImpl<const SCEV *>::const_iterator I = Operands.begin(),
- E = Operands.end(); I != E; ++I)
- if (!isKnownNonNegative(*I)) {
- All = false;
- break;
- }
- if (All) Flags = setFlags(Flags, (SCEV::NoWrapFlags)SignOrUnsignMask);
- }
+ Flags = StrengthenNoWrapFlags(this, scAddRecExpr, Operands, Flags);
// Canonicalize nested AddRecs in by nesting them in order of loop depth.
if (const SCEVAddRecExpr *NestedAR = dyn_cast<SCEVAddRecExpr>(Operands[0])) {
// PHI's incoming blocks are in a different loop, in which case doing so
// risks breaking LCSSA form. Instcombine would normally zap these, but
// it doesn't have DominatorTree information, so it may miss cases.
- if (Value *V = SimplifyInstruction(PN, DL, TLI, DT, AT))
+ if (Value *V = SimplifyInstruction(PN, DL, TLI, DT, AC))
if (LI->replacementPreservesLCSSAForm(PN, V))
return getSCEV(V);
// For a SCEVUnknown, ask ValueTracking.
unsigned BitWidth = getTypeSizeInBits(U->getType());
APInt Zeros(BitWidth, 0), Ones(BitWidth, 0);
- computeKnownBits(U->getValue(), Zeros, Ones, DL, 0, AT, nullptr, DT);
+ computeKnownBits(U->getValue(), Zeros, Ones, DL, 0, AC, nullptr, DT);
return Zeros.countTrailingOnes();
}
// For a SCEVUnknown, ask ValueTracking.
APInt Zeros(BitWidth, 0), Ones(BitWidth, 0);
- computeKnownBits(U->getValue(), Zeros, Ones, DL, 0, AT, nullptr, DT);
+ computeKnownBits(U->getValue(), Zeros, Ones, DL, 0, AC, nullptr, DT);
if (Ones == ~Zeros + 1)
return setUnsignedRange(U, ConservativeResult);
return setUnsignedRange(U,
// For a SCEVUnknown, ask ValueTracking.
if (!U->getValue()->getType()->isIntegerTy() && !DL)
return setSignedRange(U, ConservativeResult);
- unsigned NS = ComputeNumSignBits(U->getValue(), DL, 0, AT, nullptr, DT);
+ unsigned NS = ComputeNumSignBits(U->getValue(), DL, 0, AC, nullptr, DT);
if (NS <= 1)
return setSignedRange(U, ConservativeResult);
return setSignedRange(U, ConservativeResult.intersectWith(
unsigned TZ = A.countTrailingZeros();
unsigned BitWidth = A.getBitWidth();
APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0);
- computeKnownBits(U->getOperand(0), KnownZero, KnownOne, DL,
- 0, AT, nullptr, DT);
+ computeKnownBits(U->getOperand(0), KnownZero, KnownOne, DL, 0, AC,
+ nullptr, DT);
APInt EffectiveMask =
APInt::getLowBitsSet(BitWidth, BitWidth - LZ - TZ).shl(TZ);
return true;
// Check conditions due to any @llvm.assume intrinsics.
- for (auto &CI : AT->assumptions(F)) {
+ for (auto &AssumeVH : AC->assumptions()) {
+ if (!AssumeVH)
+ continue;
+ auto *CI = cast<CallInst>(AssumeVH);
if (!DT->dominates(CI, Latch->getTerminator()))
continue;
}
// Check conditions due to any @llvm.assume intrinsics.
- for (auto &CI : AT->assumptions(F)) {
+ for (auto &AssumeVH : AC->assumptions()) {
+ if (!AssumeVH)
+ continue;
+ auto *CI = cast<CallInst>(AssumeVH);
if (!DT->dominates(CI, L->getHeader()))
continue;
getNotSCEV(FoundLHS));
}
+
+/// If Expr computes ~A, return A else return nullptr
+static const SCEV *MatchNotExpr(const SCEV *Expr) {
+ const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(Expr);
+ if (!Add || Add->getNumOperands() != 2) return nullptr;
+
+ const SCEVConstant *AddLHS = dyn_cast<SCEVConstant>(Add->getOperand(0));
+ if (!(AddLHS && AddLHS->getValue()->getValue().isAllOnesValue()))
+ return nullptr;
+
+ const SCEVMulExpr *AddRHS = dyn_cast<SCEVMulExpr>(Add->getOperand(1));
+ if (!AddRHS || AddRHS->getNumOperands() != 2) return nullptr;
+
+ const SCEVConstant *MulLHS = dyn_cast<SCEVConstant>(AddRHS->getOperand(0));
+ if (!(MulLHS && MulLHS->getValue()->getValue().isAllOnesValue()))
+ return nullptr;
+
+ return AddRHS->getOperand(1);
+}
+
+
+/// Is MaybeMaxExpr an SMax or UMax of Candidate and some other values?
+template<typename MaxExprType>
+static bool IsMaxConsistingOf(const SCEV *MaybeMaxExpr,
+ const SCEV *Candidate) {
+ const MaxExprType *MaxExpr = dyn_cast<MaxExprType>(MaybeMaxExpr);
+ if (!MaxExpr) return false;
+
+ auto It = std::find(MaxExpr->op_begin(), MaxExpr->op_end(), Candidate);
+ return It != MaxExpr->op_end();
+}
+
+
+/// Is MaybeMinExpr an SMin or UMin of Candidate and some other values?
+template<typename MaxExprType>
+static bool IsMinConsistingOf(ScalarEvolution &SE,
+ const SCEV *MaybeMinExpr,
+ const SCEV *Candidate) {
+ const SCEV *MaybeMaxExpr = MatchNotExpr(MaybeMinExpr);
+ if (!MaybeMaxExpr)
+ return false;
+
+ return IsMaxConsistingOf<MaxExprType>(MaybeMaxExpr, SE.getNotSCEV(Candidate));
+}
+
+
+/// Is LHS `Pred` RHS true on the virtue of LHS or RHS being a Min or Max
+/// expression?
+static bool IsKnownPredicateViaMinOrMax(ScalarEvolution &SE,
+ ICmpInst::Predicate Pred,
+ const SCEV *LHS, const SCEV *RHS) {
+ switch (Pred) {
+ default:
+ return false;
+
+ case ICmpInst::ICMP_SGE:
+ std::swap(LHS, RHS);
+ // fall through
+ case ICmpInst::ICMP_SLE:
+ return
+ // min(A, ...) <= A
+ IsMinConsistingOf<SCEVSMaxExpr>(SE, LHS, RHS) ||
+ // A <= max(A, ...)
+ IsMaxConsistingOf<SCEVSMaxExpr>(RHS, LHS);
+
+ case ICmpInst::ICMP_UGE:
+ std::swap(LHS, RHS);
+ // fall through
+ case ICmpInst::ICMP_ULE:
+ return
+ // min(A, ...) <= A
+ IsMinConsistingOf<SCEVUMaxExpr>(SE, LHS, RHS) ||
+ // A <= max(A, ...)
+ IsMaxConsistingOf<SCEVUMaxExpr>(RHS, LHS);
+ }
+
+ llvm_unreachable("covered switch fell through?!");
+}
+
/// isImpliedCondOperandsHelper - Test whether the condition described by
/// Pred, LHS, and RHS is true whenever the condition described by Pred,
/// FoundLHS, and FoundRHS is true.
const SCEV *LHS, const SCEV *RHS,
const SCEV *FoundLHS,
const SCEV *FoundRHS) {
+ auto IsKnownPredicateFull =
+ [this](ICmpInst::Predicate Pred, const SCEV *LHS, const SCEV *RHS) {
+ return isKnownPredicateWithRanges(Pred, LHS, RHS) ||
+ IsKnownPredicateViaMinOrMax(*this, Pred, LHS, RHS);
+ };
+
switch (Pred) {
default: llvm_unreachable("Unexpected ICmpInst::Predicate value!");
case ICmpInst::ICMP_EQ:
break;
case ICmpInst::ICMP_SLT:
case ICmpInst::ICMP_SLE:
- if (isKnownPredicateWithRanges(ICmpInst::ICMP_SLE, LHS, FoundLHS) &&
- isKnownPredicateWithRanges(ICmpInst::ICMP_SGE, RHS, FoundRHS))
+ if (IsKnownPredicateFull(ICmpInst::ICMP_SLE, LHS, FoundLHS) &&
+ IsKnownPredicateFull(ICmpInst::ICMP_SGE, RHS, FoundRHS))
return true;
break;
case ICmpInst::ICMP_SGT:
case ICmpInst::ICMP_SGE:
- if (isKnownPredicateWithRanges(ICmpInst::ICMP_SGE, LHS, FoundLHS) &&
- isKnownPredicateWithRanges(ICmpInst::ICMP_SLE, RHS, FoundRHS))
+ if (IsKnownPredicateFull(ICmpInst::ICMP_SGE, LHS, FoundLHS) &&
+ IsKnownPredicateFull(ICmpInst::ICMP_SLE, RHS, FoundRHS))
return true;
break;
case ICmpInst::ICMP_ULT:
case ICmpInst::ICMP_ULE:
- if (isKnownPredicateWithRanges(ICmpInst::ICMP_ULE, LHS, FoundLHS) &&
- isKnownPredicateWithRanges(ICmpInst::ICMP_UGE, RHS, FoundRHS))
+ if (IsKnownPredicateFull(ICmpInst::ICMP_ULE, LHS, FoundLHS) &&
+ IsKnownPredicateFull(ICmpInst::ICMP_UGE, RHS, FoundRHS))
return true;
break;
case ICmpInst::ICMP_UGT:
case ICmpInst::ICMP_UGE:
- if (isKnownPredicateWithRanges(ICmpInst::ICMP_UGE, LHS, FoundLHS) &&
- isKnownPredicateWithRanges(ICmpInst::ICMP_ULE, RHS, FoundRHS))
+ if (IsKnownPredicateFull(ICmpInst::ICMP_UGE, LHS, FoundLHS) &&
+ IsKnownPredicateFull(ICmpInst::ICMP_ULE, RHS, FoundRHS))
return true;
break;
}
bool ScalarEvolution::runOnFunction(Function &F) {
this->F = &F;
- AT = &getAnalysis<AssumptionTracker>();
+ AC = &getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F);
LI = &getAnalysis<LoopInfo>();
DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>();
DL = DLP ? &DLP->getDataLayout() : nullptr;
- TLI = &getAnalysis<TargetLibraryInfo>();
+ TLI = &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
return false;
}
void ScalarEvolution::getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
- AU.addRequired<AssumptionTracker>();
+ AU.addRequired<AssumptionCacheTracker>();
AU.addRequiredTransitive<LoopInfo>();
AU.addRequiredTransitive<DominatorTreeWrapperPass>();
- AU.addRequired<TargetLibraryInfo>();
+ AU.addRequired<TargetLibraryInfoWrapperPass>();
}
bool ScalarEvolution::hasLoopInvariantBackedgeTakenCount(const Loop *L) {
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