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[SCEV] Use LLVM_MARK_AS_BITMASK_ENUM in SCEV. 

Summary:
Obviates the need for mask/clear/setFlags helpers.

There are some expressions here which can be simplified, but to keep
this easy to review, I have not simplified them in this patch.

No functional change.

Reviewers: sanjoy

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D48237

llvm-svn: 334874
This commit is contained in:
Justin Lebar 2018-06-15 23:51:57 +00:00
parent 94405ddb95
commit 6cb702d00d
3 changed files with 40 additions and 84 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

50
llvm/include/llvm/Analysis/ScalarEvolution.h
View File

@ -23,6 +23,7 @@
#include "llvm/ADT/APInt.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/BitmaskEnum.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/DenseMapInfo.h"
#include "llvm/ADT/FoldingSet.h"
@ -113,7 +114,8 @@ public:
FlagNW = (1 << 0), // No self-wrap.
FlagNUW = (1 << 1), // No unsigned wrap.
FlagNSW = (1 << 2), // No signed wrap.
NoWrapMask = (1 << 3) - 1
NoWrapMask = (1 << 3) - 1,
LLVM_MARK_AS_BITMASK_ENUM(/*LargestEnumerator=*/NoWrapMask),
};
explicit SCEV(const FoldingSetNodeIDRef ID, unsigned SCEVTy)
@ -312,37 +314,10 @@ public:
IncrementNUSW = (1 << 0), // No unsigned with signed increment wrap.
IncrementNSSW = (1 << 1), // No signed with signed increment wrap
// (equivalent with SCEV::NSW)
IncrementNoWrapMask = (1 << 2) - 1
IncrementNoWrapMask = IncrementNUSW | IncrementNSSW,
LLVM_MARK_AS_BITMASK_ENUM(/*LargestEnumerator=*/IncrementNoWrapMask),
};
/// Convenient IncrementWrapFlags manipulation methods.
LLVM_NODISCARD static SCEVWrapPredicate::IncrementWrapFlags
clearFlags(SCEVWrapPredicate::IncrementWrapFlags Flags,
SCEVWrapPredicate::IncrementWrapFlags OffFlags) {
assert((Flags & IncrementNoWrapMask) == Flags && "Invalid flags value!");
assert((OffFlags & IncrementNoWrapMask) == OffFlags &&
"Invalid flags value!");
return (SCEVWrapPredicate::IncrementWrapFlags)(Flags & ~OffFlags);
}
LLVM_NODISCARD static SCEVWrapPredicate::IncrementWrapFlags
maskFlags(SCEVWrapPredicate::IncrementWrapFlags Flags, int Mask) {
assert((Flags & IncrementNoWrapMask) == Flags && "Invalid flags value!");
assert((Mask & IncrementNoWrapMask) == Mask && "Invalid mask value!");
return (SCEVWrapPredicate::IncrementWrapFlags)(Flags & Mask);
}
LLVM_NODISCARD static SCEVWrapPredicate::IncrementWrapFlags
setFlags(SCEVWrapPredicate::IncrementWrapFlags Flags,
SCEVWrapPredicate::IncrementWrapFlags OnFlags) {
assert((Flags & IncrementNoWrapMask) == Flags && "Invalid flags value!");
assert((OnFlags & IncrementNoWrapMask) == OnFlags &&
"Invalid flags value!");
return (SCEVWrapPredicate::IncrementWrapFlags)(Flags | OnFlags);
}
/// Returns the set of SCEVWrapPredicate no wrap flags implied by a
/// SCEVAddRecExpr.
LLVM_NODISCARD static SCEVWrapPredicate::IncrementWrapFlags
@ -467,21 +442,6 @@ public:
ProperlyDominatesBlock ///< The SCEV properly dominates the block.
};
/// Convenient NoWrapFlags manipulation that hides enum casts and is
/// visible in the ScalarEvolution name space.
LLVM_NODISCARD static SCEV::NoWrapFlags maskFlags(SCEV::NoWrapFlags Flags,
int Mask) {
return (SCEV::NoWrapFlags)(Flags & Mask);
}
LLVM_NODISCARD static SCEV::NoWrapFlags setFlags(SCEV::NoWrapFlags Flags,
SCEV::NoWrapFlags OnFlags) {
return (SCEV::NoWrapFlags)(Flags | OnFlags);
}
LLVM_NODISCARD static SCEV::NoWrapFlags
clearFlags(SCEV::NoWrapFlags Flags, SCEV::NoWrapFlags OffFlags) {
return (SCEV::NoWrapFlags)(Flags & ~OffFlags);
}
ScalarEvolution(Function &F, TargetLibraryInfo &TLI, AssumptionCache &AC,
DominatorTree &DT, LoopInfo &LI);
ScalarEvolution(ScalarEvolution &&Arg);

2
llvm/include/llvm/Analysis/ScalarEvolutionExpressions.h
View File

@ -331,7 +331,7 @@ class Type;
/// to make it easier to propagate flags.
void setNoWrapFlags(NoWrapFlags Flags) {
if (Flags & (FlagNUW | FlagNSW))
Flags = ScalarEvolution::setFlags(Flags, FlagNW);
Flags |= FlagNW;
SubclassData |= Flags;
}

72
llvm/lib/Analysis/ScalarEvolution.cpp
View File

@ -1428,8 +1428,7 @@ static const SCEV *getPreStartForExtend(const SCEVAddRecExpr *AR, Type *Ty,
// `Step`:
// 1. NSW/NUW flags on the step increment.
auto PreStartFlags =
ScalarEvolution::maskFlags(SA->getNoWrapFlags(), SCEV::FlagNUW);
auto PreStartFlags = SA->getNoWrapFlags() & SCEV::FlagNUW;
const SCEV *PreStart = SE->getAddExpr(DiffOps, PreStartFlags);
const SCEVAddRecExpr *PreAR = dyn_cast<SCEVAddRecExpr>(
SE->getAddRecExpr(PreStart, Step, L, SCEV::FlagAnyWrap));
@ -2218,9 +2217,8 @@ StrengthenNoWrapFlags(ScalarEvolution *SE, SCEVTypes Type,
(void)CanAnalyze;
assert(CanAnalyze && "don't call from other places!");
int SignOrUnsignMask = SCEV::FlagNUW | SCEV::FlagNSW;
SCEV::NoWrapFlags SignOrUnsignWrap =
ScalarEvolution::maskFlags(Flags, SignOrUnsignMask);
SCEV::NoWrapFlags SignOrUnsignMask = SCEV::FlagNUW | SCEV::FlagNSW;
SCEV::NoWrapFlags SignOrUnsignWrap = Flags & SignOrUnsignMask;
// If FlagNSW is true and all the operands are non-negative, infer FlagNUW.
auto IsKnownNonNegative = [&](const SCEV *S) {
@ -2228,10 +2226,9 @@ StrengthenNoWrapFlags(ScalarEvolution *SE, SCEVTypes Type,
};
if (SignOrUnsignWrap == SCEV::FlagNSW && all_of(Ops, IsKnownNonNegative))
Flags =
ScalarEvolution::setFlags(Flags, (SCEV::NoWrapFlags)SignOrUnsignMask);
Flags |= SignOrUnsignMask;
SignOrUnsignWrap = ScalarEvolution::maskFlags(Flags, SignOrUnsignMask);
SignOrUnsignWrap = Flags & SignOrUnsignMask;
if (SignOrUnsignWrap != SignOrUnsignMask &&
(Type == scAddExpr || Type == scMulExpr) && Ops.size() == 2 &&
@ -2255,7 +2252,7 @@ StrengthenNoWrapFlags(ScalarEvolution *SE, SCEVTypes Type,
auto NSWRegion = ConstantRange::makeGuaranteedNoWrapRegion(
Opcode, C, OBO::NoSignedWrap);
if (NSWRegion.contains(SE->getSignedRange(Ops[1])))
Flags = ScalarEvolution::setFlags(Flags, SCEV::FlagNSW);
Flags |= SCEV::FlagNSW;
}
// (A <opcode> C) --> (A <opcode> C)<nuw> if the op doesn't unsign overflow.
@ -2263,7 +2260,7 @@ StrengthenNoWrapFlags(ScalarEvolution *SE, SCEVTypes Type,
auto NUWRegion = ConstantRange::makeGuaranteedNoWrapRegion(
Instruction::Add, C, OBO::NoUnsignedWrap);
if (NUWRegion.contains(SE->getUnsignedRange(Ops[1])))
Flags = ScalarEvolution::setFlags(Flags, SCEV::FlagNUW);
Flags |= SCEV::FlagNUW;
}
}
@ -2590,7 +2587,7 @@ const SCEV *ScalarEvolution::getAddExpr(SmallVectorImpl<const SCEV *> &Ops,
// Build the new addrec. Propagate the NUW and NSW flags if both the
// outer add and the inner addrec are guaranteed to have no overflow.
// Always propagate NW.
Flags = AddRec->getNoWrapFlags(setFlags(Flags, SCEV::FlagNW));
Flags = AddRec->getNoWrapFlags(Flags | SCEV::FlagNW);
const SCEV *NewRec = getAddRecExpr(AddRecOps, AddRecLoop, Flags);
// If all of the other operands were loop invariant, we are done.
@ -2756,7 +2753,7 @@ static bool containsConstantInAddMulChain(const SCEV *StartExpr) {
const SCEV *ScalarEvolution::getMulExpr(SmallVectorImpl<const SCEV *> &Ops,
SCEV::NoWrapFlags Flags,
unsigned Depth) {
assert(Flags == maskFlags(Flags, SCEV::FlagNUW | SCEV::FlagNSW) &&
assert(Flags == (Flags & (SCEV::FlagNUW | SCEV::FlagNSW)) &&
"only nuw or nsw allowed");
assert(!Ops.empty() && "Cannot get empty mul!");
if (Ops.size() == 1) return Ops[0];
@ -2905,7 +2902,7 @@ const SCEV *ScalarEvolution::getMulExpr(SmallVectorImpl<const SCEV *> &Ops,
//
// No self-wrap cannot be guaranteed after changing the step size, but
// will be inferred if either NUW or NSW is true.
Flags = AddRec->getNoWrapFlags(clearFlags(Flags, SCEV::FlagNW));
Flags = AddRec->getNoWrapFlags(Flags & ~SCEV::FlagNW);
const SCEV *NewRec = getAddRecExpr(NewOps, AddRecLoop, Flags);
// If all of the other operands were loop invariant, we are done.
@ -3244,7 +3241,7 @@ const SCEV *ScalarEvolution::getAddRecExpr(const SCEV *Start, const SCEV *Step,
if (const SCEVAddRecExpr *StepChrec = dyn_cast<SCEVAddRecExpr>(Step))
if (StepChrec->getLoop() == L) {
Operands.append(StepChrec->op_begin(), StepChrec->op_end());
return getAddRecExpr(Operands, L, maskFlags(Flags, SCEV::FlagNW));
return getAddRecExpr(Operands, L, Flags & SCEV::FlagNW);
}
Operands.push_back(Step);
@ -3302,7 +3299,7 @@ ScalarEvolution::getAddRecExpr(SmallVectorImpl<const SCEV *> &Operands,
// The outer recurrence keeps its NW flag but only keeps NUW/NSW if the
// inner recurrence has the same property.
SCEV::NoWrapFlags OuterFlags =
maskFlags(Flags, SCEV::FlagNW | NestedAR->getNoWrapFlags());
Flags & (SCEV::FlagNW | NestedAR->getNoWrapFlags());
NestedOperands[0] = getAddRecExpr(Operands, L, OuterFlags);
AllInvariant = all_of(NestedOperands, [&](const SCEV *Op) {
@ -3315,7 +3312,7 @@ ScalarEvolution::getAddRecExpr(SmallVectorImpl<const SCEV *> &Operands,
// The inner recurrence keeps its NW flag but only keeps NUW/NSW if
// the outer recurrence has the same property.
SCEV::NoWrapFlags InnerFlags =
maskFlags(NestedAR->getNoWrapFlags(), SCEV::FlagNW | Flags);
NestedAR->getNoWrapFlags() & (SCEV::FlagNW | Flags);
return getAddRecExpr(NestedOperands, NestedLoop, InnerFlags);
}
}
@ -3900,7 +3897,7 @@ const SCEV *ScalarEvolution::getMinusSCEV(const SCEV *LHS, const SCEV *RHS,
auto AddFlags = SCEV::FlagAnyWrap;
const bool RHSIsNotMinSigned =
!getSignedRangeMin(RHS).isMinSignedValue();
if (maskFlags(Flags, SCEV::FlagNSW) == SCEV::FlagNSW) {
if ((Flags & SCEV::FlagNSW) == SCEV::FlagNSW) {
// Let M be the minimum representable signed value. Then (-1)*RHS
// signed-wraps if and only if RHS is M. That can happen even for
// a NSW subtraction because e.g. (-1)*M signed-wraps even though
@ -4340,7 +4337,7 @@ ScalarEvolution::proveNoWrapViaConstantRanges(const SCEVAddRecExpr *AR) {
auto NSWRegion = ConstantRange::makeGuaranteedNoWrapRegion(
Instruction::Add, IncRange, OBO::NoSignedWrap);
if (NSWRegion.contains(AddRecRange))
Result = ScalarEvolution::setFlags(Result, SCEV::FlagNSW);
Result |= SCEV::FlagNSW;
}
if (!AR->hasNoUnsignedWrap()) {
@ -4350,7 +4347,7 @@ ScalarEvolution::proveNoWrapViaConstantRanges(const SCEVAddRecExpr *AR) {
auto NUWRegion = ConstantRange::makeGuaranteedNoWrapRegion(
Instruction::Add, IncRange, OBO::NoUnsignedWrap);
if (NUWRegion.contains(AddRecRange))
Result = ScalarEvolution::setFlags(Result, SCEV::FlagNUW);
Result |= SCEV::FlagNUW;
}
return Result;
@ -4906,9 +4903,9 @@ const SCEV *ScalarEvolution::createSimpleAffineAddRec(PHINode *PN,
SCEV::NoWrapFlags Flags = SCEV::FlagAnyWrap;
if (BO->IsNUW)
Flags = setFlags(Flags, SCEV::FlagNUW);
Flags |= SCEV::FlagNUW;
if (BO->IsNSW)
Flags = setFlags(Flags, SCEV::FlagNSW);
Flags |= SCEV::FlagNSW;
const SCEV *StartVal = getSCEV(StartValueV);
const SCEV *PHISCEV = getAddRecExpr(StartVal, Accum, L, Flags);
@ -5004,9 +5001,9 @@ const SCEV *ScalarEvolution::createAddRecFromPHI(PHINode *PN) {
if (auto BO = MatchBinaryOp(BEValueV, DT)) {
if (BO->Opcode == Instruction::Add && BO->LHS == PN) {
if (BO->IsNUW)
Flags = setFlags(Flags, SCEV::FlagNUW);
Flags |= SCEV::FlagNUW;
if (BO->IsNSW)
Flags = setFlags(Flags, SCEV::FlagNSW);
Flags |= SCEV::FlagNSW;
}
} else if (GEPOperator *GEP = dyn_cast<GEPOperator>(BEValueV)) {
// If the increment is an inbounds GEP, then we know the address
@ -5016,11 +5013,11 @@ const SCEV *ScalarEvolution::createAddRecFromPHI(PHINode *PN) {
// pointer. We can guarantee that no unsigned wrap occurs if the
// indices form a positive value.
if (GEP->isInBounds() && GEP->getOperand(0) == PN) {
Flags = setFlags(Flags, SCEV::FlagNW);
Flags |= SCEV::FlagNW;
const SCEV *Ptr = getSCEV(GEP->getPointerOperand());
if (isKnownPositive(getMinusSCEV(getSCEV(GEP), Ptr)))
Flags = setFlags(Flags, SCEV::FlagNUW);
Flags |= SCEV::FlagNUW;
}
// We cannot transfer nuw and nsw flags from subtraction
@ -5868,9 +5865,9 @@ SCEV::NoWrapFlags ScalarEvolution::getNoWrapFlagsFromUB(const Value *V) {
// Return early if there are no flags to propagate to the SCEV.
SCEV::NoWrapFlags Flags = SCEV::FlagAnyWrap;
if (BinOp->hasNoUnsignedWrap())
Flags = ScalarEvolution::setFlags(Flags, SCEV::FlagNUW);
Flags |= SCEV::FlagNUW;
if (BinOp->hasNoSignedWrap())
Flags = ScalarEvolution::setFlags(Flags, SCEV::FlagNSW);
Flags |= SCEV::FlagNSW;
if (Flags == SCEV::FlagAnyWrap)
return SCEV::FlagAnyWrap;
@ -11936,15 +11933,15 @@ const SCEV *SCEVWrapPredicate::getExpr() const { return AR; }
bool SCEVWrapPredicate::implies(const SCEVPredicate *N) const {
const auto *Op = dyn_cast<SCEVWrapPredicate>(N);
return Op && Op->AR == AR && setFlags(Flags, Op->Flags) == Flags;
return Op && Op->AR == AR && (Flags | Op->Flags) == Flags;
}
bool SCEVWrapPredicate::isAlwaysTrue() const {
SCEV::NoWrapFlags ScevFlags = AR->getNoWrapFlags();
IncrementWrapFlags IFlags = Flags;
if (ScalarEvolution::setFlags(ScevFlags, SCEV::FlagNSW) == ScevFlags)
IFlags = clearFlags(IFlags, IncrementNSSW);
if ((ScevFlags | SCEV::FlagNSW) == ScevFlags)
IFlags &= ~IncrementNSSW;
return IFlags == IncrementAnyWrap;
}
@ -11965,15 +11962,15 @@ SCEVWrapPredicate::getImpliedFlags(const SCEVAddRecExpr *AR,
SCEV::NoWrapFlags StaticFlags = AR->getNoWrapFlags();
// We can safely transfer the NSW flag as NSSW.
if (ScalarEvolution::setFlags(StaticFlags, SCEV::FlagNSW) == StaticFlags)
if ((StaticFlags | SCEV::FlagNSW) == StaticFlags)
ImpliedFlags = IncrementNSSW;
if (ScalarEvolution::setFlags(StaticFlags, SCEV::FlagNUW) == StaticFlags) {
if ((StaticFlags | SCEV::FlagNUW) == StaticFlags) {
// If the increment is positive, the SCEV NUW flag will also imply the
// WrapPredicate NUSW flag.
if (const auto *Step = dyn_cast<SCEVConstant>(AR->getStepRecurrence(SE)))
if (Step->getValue()->getValue().isNonNegative())
ImpliedFlags = setFlags(ImpliedFlags, IncrementNUSW);
ImpliedFlags |= IncrementNUSW;
}
return ImpliedFlags;
@ -12096,12 +12093,12 @@ void PredicatedScalarEvolution::setNoOverflow(
auto ImpliedFlags = SCEVWrapPredicate::getImpliedFlags(AR, SE);
// Clear the statically implied flags.
Flags = SCEVWrapPredicate::clearFlags(Flags, ImpliedFlags);
Flags &= ~ImpliedFlags;
addPredicate(*SE.getWrapPredicate(AR, Flags));
auto II = FlagsMap.insert({V, Flags});
if (!II.second)
II.first->second = SCEVWrapPredicate::setFlags(Flags, II.first->second);
II.first->second |= Flags;
}
bool PredicatedScalarEvolution::hasNoOverflow(
@ -12109,13 +12106,12 @@ bool PredicatedScalarEvolution::hasNoOverflow(
const SCEV *Expr = getSCEV(V);
const auto *AR = cast<SCEVAddRecExpr>(Expr);
Flags = SCEVWrapPredicate::clearFlags(
Flags, SCEVWrapPredicate::getImpliedFlags(AR, SE));
Flags &= ~SCEVWrapPredicate::getImpliedFlags(AR, SE);
auto II = FlagsMap.find(V);
if (II != FlagsMap.end())
Flags = SCEVWrapPredicate::clearFlags(Flags, II->second);
Flags &= ~II->second;
return Flags == SCEVWrapPredicate::IncrementAnyWrap;
}