[llvm] 62d11b2 - Revert "Revert "[SCEV] Add SCEVType to represent `vscale`.""
Paul Walker via llvm-commits
llvm-commits at lists.llvm.org
Thu Mar 2 05:15:36 PST 2023
Author: Paul Walker
Date: 2023-03-02T13:14:07Z
New Revision: 62d11b2ccaeec8abc12e07aa009c922d72fd6377
URL: https://github.com/llvm/llvm-project/commit/62d11b2ccaeec8abc12e07aa009c922d72fd6377
DIFF: https://github.com/llvm/llvm-project/commit/62d11b2ccaeec8abc12e07aa009c922d72fd6377.diff
LOG: Revert "Revert "[SCEV] Add SCEVType to represent `vscale`.""
Relanding after fixing Polly related build error.
This reverts commit 7b26dcae9eaf8cdcba7fef032fd83d060dffd4b4.
Added:
Modified:
llvm/include/llvm/Analysis/ScalarEvolution.h
llvm/include/llvm/Analysis/ScalarEvolutionDivision.h
llvm/include/llvm/Analysis/ScalarEvolutionExpressions.h
llvm/include/llvm/Transforms/Utils/ScalarEvolutionExpander.h
llvm/lib/Analysis/ScalarEvolution.cpp
llvm/lib/Analysis/ScalarEvolutionDivision.cpp
llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
polly/include/polly/Support/SCEVAffinator.h
polly/lib/Support/SCEVAffinator.cpp
polly/lib/Support/SCEVValidator.cpp
polly/lib/Support/ScopHelper.cpp
Removed:
################################################################################
diff --git a/llvm/include/llvm/Analysis/ScalarEvolution.h b/llvm/include/llvm/Analysis/ScalarEvolution.h
index 0201942183e68..6cb8fec4737fa 100644
--- a/llvm/include/llvm/Analysis/ScalarEvolution.h
+++ b/llvm/include/llvm/Analysis/ScalarEvolution.h
@@ -566,6 +566,7 @@ class ScalarEvolution {
const SCEV *getLosslessPtrToIntExpr(const SCEV *Op, unsigned Depth = 0);
const SCEV *getPtrToIntExpr(const SCEV *Op, Type *Ty);
const SCEV *getTruncateExpr(const SCEV *Op, Type *Ty, unsigned Depth = 0);
+ const SCEV *getVScale(Type *Ty);
const SCEV *getZeroExtendExpr(const SCEV *Op, Type *Ty, unsigned Depth = 0);
const SCEV *getZeroExtendExprImpl(const SCEV *Op, Type *Ty,
unsigned Depth = 0);
diff --git a/llvm/include/llvm/Analysis/ScalarEvolutionDivision.h b/llvm/include/llvm/Analysis/ScalarEvolutionDivision.h
index 7d5902d317952..3283d438ccb51 100644
--- a/llvm/include/llvm/Analysis/ScalarEvolutionDivision.h
+++ b/llvm/include/llvm/Analysis/ScalarEvolutionDivision.h
@@ -48,6 +48,8 @@ struct SCEVDivision : public SCEVVisitor<SCEVDivision, void> {
void visitConstant(const SCEVConstant *Numerator);
+ void visitVScale(const SCEVVScale *Numerator);
+
void visitAddRecExpr(const SCEVAddRecExpr *Numerator);
void visitAddExpr(const SCEVAddExpr *Numerator);
diff --git a/llvm/include/llvm/Analysis/ScalarEvolutionExpressions.h b/llvm/include/llvm/Analysis/ScalarEvolutionExpressions.h
index 1b14d74e015ec..0a1c900c3954b 100644
--- a/llvm/include/llvm/Analysis/ScalarEvolutionExpressions.h
+++ b/llvm/include/llvm/Analysis/ScalarEvolutionExpressions.h
@@ -39,6 +39,7 @@ enum SCEVTypes : unsigned short {
// These should be ordered in terms of increasing complexity to make the
// folders simpler.
scConstant,
+ scVScale,
scTruncate,
scZeroExtend,
scSignExtend,
@@ -75,6 +76,23 @@ class SCEVConstant : public SCEV {
static bool classof(const SCEV *S) { return S->getSCEVType() == scConstant; }
};
+/// This class represents the value of vscale, as used when defining the length
+/// of a scalable vector or returned by the llvm.vscale() intrinsic.
+class SCEVVScale : public SCEV {
+ friend class ScalarEvolution;
+
+ SCEVVScale(const FoldingSetNodeIDRef ID, Type *ty)
+ : SCEV(ID, scVScale, 0), Ty(ty) {}
+
+ Type *Ty;
+
+public:
+ Type *getType() const { return Ty; }
+
+ /// Methods for support type inquiry through isa, cast, and dyn_cast:
+ static bool classof(const SCEV *S) { return S->getSCEVType() == scVScale; }
+};
+
inline unsigned short computeExpressionSize(ArrayRef<const SCEV *> Args) {
APInt Size(16, 1);
for (const auto *Arg : Args)
@@ -579,9 +597,6 @@ class SCEVUnknown final : public SCEV, private CallbackVH {
public:
Value *getValue() const { return getValPtr(); }
- /// Check whether this represents vscale.
- bool isVScale() const;
-
Type *getType() const { return getValPtr()->getType(); }
/// Methods for support type inquiry through isa, cast, and dyn_cast:
@@ -595,6 +610,8 @@ template <typename SC, typename RetVal = void> struct SCEVVisitor {
switch (S->getSCEVType()) {
case scConstant:
return ((SC *)this)->visitConstant((const SCEVConstant *)S);
+ case scVScale:
+ return ((SC *)this)->visitVScale((const SCEVVScale *)S);
case scPtrToInt:
return ((SC *)this)->visitPtrToIntExpr((const SCEVPtrToIntExpr *)S);
case scTruncate:
@@ -662,6 +679,7 @@ template <typename SV> class SCEVTraversal {
switch (S->getSCEVType()) {
case scConstant:
+ case scVScale:
case scUnknown:
continue;
case scPtrToInt:
@@ -751,6 +769,8 @@ class SCEVRewriteVisitor : public SCEVVisitor<SC, const SCEV *> {
const SCEV *visitConstant(const SCEVConstant *Constant) { return Constant; }
+ const SCEV *visitVScale(const SCEVVScale *VScale) { return VScale; }
+
const SCEV *visitPtrToIntExpr(const SCEVPtrToIntExpr *Expr) {
const SCEV *Operand = ((SC *)this)->visit(Expr->getOperand());
return Operand == Expr->getOperand()
diff --git a/llvm/include/llvm/Transforms/Utils/ScalarEvolutionExpander.h b/llvm/include/llvm/Transforms/Utils/ScalarEvolutionExpander.h
index 131e24f685e89..555897083469a 100644
--- a/llvm/include/llvm/Transforms/Utils/ScalarEvolutionExpander.h
+++ b/llvm/include/llvm/Transforms/Utils/ScalarEvolutionExpander.h
@@ -457,6 +457,8 @@ class SCEVExpander : public SCEVVisitor<SCEVExpander, Value *> {
Value *visitConstant(const SCEVConstant *S) { return S->getValue(); }
+ Value *visitVScale(const SCEVVScale *S);
+
Value *visitPtrToIntExpr(const SCEVPtrToIntExpr *S);
Value *visitTruncateExpr(const SCEVTruncateExpr *S);
diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index f997b1950a4d4..b07429492d814 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -271,6 +271,9 @@ void SCEV::print(raw_ostream &OS) const {
case scConstant:
cast<SCEVConstant>(this)->getValue()->printAsOperand(OS, false);
return;
+ case scVScale:
+ OS << "vscale";
+ return;
case scPtrToInt: {
const SCEVPtrToIntExpr *PtrToInt = cast<SCEVPtrToIntExpr>(this);
const SCEV *Op = PtrToInt->getOperand();
@@ -366,17 +369,9 @@ void SCEV::print(raw_ostream &OS) const {
OS << "(" << *UDiv->getLHS() << " /u " << *UDiv->getRHS() << ")";
return;
}
- case scUnknown: {
- const SCEVUnknown *U = cast<SCEVUnknown>(this);
- if (U->isVScale()) {
- OS << "vscale";
- return;
- }
-
- // Otherwise just print it normally.
- U->getValue()->printAsOperand(OS, false);
+ case scUnknown:
+ cast<SCEVUnknown>(this)->getValue()->printAsOperand(OS, false);
return;
- }
case scCouldNotCompute:
OS << "***COULDNOTCOMPUTE***";
return;
@@ -388,6 +383,8 @@ Type *SCEV::getType() const {
switch (getSCEVType()) {
case scConstant:
return cast<SCEVConstant>(this)->getType();
+ case scVScale:
+ return cast<SCEVVScale>(this)->getType();
case scPtrToInt:
case scTruncate:
case scZeroExtend:
@@ -419,6 +416,7 @@ Type *SCEV::getType() const {
ArrayRef<const SCEV *> SCEV::operands() const {
switch (getSCEVType()) {
case scConstant:
+ case scVScale:
case scUnknown:
return {};
case scPtrToInt:
@@ -501,6 +499,18 @@ ScalarEvolution::getConstant(Type *Ty, uint64_t V, bool isSigned) {
return getConstant(ConstantInt::get(ITy, V, isSigned));
}
+const SCEV *ScalarEvolution::getVScale(Type *Ty) {
+ FoldingSetNodeID ID;
+ ID.AddInteger(scVScale);
+ ID.AddPointer(Ty);
+ void *IP = nullptr;
+ if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP))
+ return S;
+ SCEV *S = new (SCEVAllocator) SCEVVScale(ID.Intern(SCEVAllocator), Ty);
+ UniqueSCEVs.InsertNode(S, IP);
+ return S;
+}
+
SCEVCastExpr::SCEVCastExpr(const FoldingSetNodeIDRef ID, SCEVTypes SCEVTy,
const SCEV *op, Type *ty)
: SCEV(ID, SCEVTy, computeExpressionSize(op)), Op(op), Ty(ty) {}
@@ -560,10 +570,6 @@ void SCEVUnknown::allUsesReplacedWith(Value *New) {
setValPtr(New);
}
-bool SCEVUnknown::isVScale() const {
- return match(getValue(), m_VScale());
-}
-
//===----------------------------------------------------------------------===//
// SCEV Utilities
//===----------------------------------------------------------------------===//
@@ -714,6 +720,12 @@ CompareSCEVComplexity(EquivalenceClasses<const SCEV *> &EqCacheSCEV,
return LA.ult(RA) ? -1 : 1;
}
+ case scVScale: {
+ const auto *LTy = cast<IntegerType>(cast<SCEVVScale>(LHS)->getType());
+ const auto *RTy = cast<IntegerType>(cast<SCEVVScale>(RHS)->getType());
+ return LTy->getBitWidth() - RTy->getBitWidth();
+ }
+
case scAddRecExpr: {
const SCEVAddRecExpr *LA = cast<SCEVAddRecExpr>(LHS);
const SCEVAddRecExpr *RA = cast<SCEVAddRecExpr>(RHS);
@@ -4015,6 +4027,8 @@ class SCEVSequentialMinMaxDeduplicatingVisitor final
RetVal visitConstant(const SCEVConstant *Constant) { return Constant; }
+ RetVal visitVScale(const SCEVVScale *VScale) { return VScale; }
+
RetVal visitPtrToIntExpr(const SCEVPtrToIntExpr *Expr) { return Expr; }
RetVal visitTruncateExpr(const SCEVTruncateExpr *Expr) { return Expr; }
@@ -4061,6 +4075,7 @@ class SCEVSequentialMinMaxDeduplicatingVisitor final
static bool scevUnconditionallyPropagatesPoisonFromOperands(SCEVTypes Kind) {
switch (Kind) {
case scConstant:
+ case scVScale:
case scTruncate:
case scZeroExtend:
case scSignExtend:
@@ -4104,6 +4119,7 @@ static bool impliesPoison(const SCEV *AssumedPoison, const SCEV *S) {
if (!scevUnconditionallyPropagatesPoisonFromOperands(S->getSCEVType())) {
switch (S->getSCEVType()) {
case scConstant:
+ case scVScale:
case scTruncate:
case scZeroExtend:
case scSignExtend:
@@ -4315,15 +4331,8 @@ const SCEV *ScalarEvolution::getUMinExpr(SmallVectorImpl<const SCEV *> &Ops,
const SCEV *
ScalarEvolution::getSizeOfExpr(Type *IntTy, TypeSize Size) {
const SCEV *Res = getConstant(IntTy, Size.getKnownMinValue());
- if (Size.isScalable()) {
- // TODO: Why is there no ConstantExpr::getVScale()?
- Type *SrcElemTy = ScalableVectorType::get(Type::getInt8Ty(getContext()), 1);
- Constant *NullPtr = Constant::getNullValue(SrcElemTy->getPointerTo());
- Constant *One = ConstantInt::get(IntTy, 1);
- Constant *GEP = ConstantExpr::getGetElementPtr(SrcElemTy, NullPtr, One);
- Constant *VScale = ConstantExpr::getPtrToInt(GEP, IntTy);
- Res = getMulExpr(Res, getUnknown(VScale));
- }
+ if (Size.isScalable())
+ Res = getMulExpr(Res, getVScale(IntTy));
return Res;
}
@@ -5887,6 +5896,7 @@ static bool IsAvailableOnEntry(const Loop *L, DominatorTree &DT, const SCEV *S,
bool follow(const SCEV *S) {
switch (S->getSCEVType()) {
case scConstant:
+ case scVScale:
case scPtrToInt:
case scTruncate:
case scZeroExtend:
@@ -6274,6 +6284,8 @@ uint32_t ScalarEvolution::GetMinTrailingZerosImpl(const SCEV *S) {
switch (S->getSCEVType()) {
case scConstant:
return cast<SCEVConstant>(S)->getAPInt().countr_zero();
+ case scVScale:
+ return 0;
case scTruncate: {
const SCEVTruncateExpr *T = cast<SCEVTruncateExpr>(S);
return std::min(GetMinTrailingZeros(T->getOperand()),
@@ -6504,6 +6516,7 @@ ScalarEvolution::getRangeRefIter(const SCEV *S,
break;
[[fallthrough]];
case scConstant:
+ case scVScale:
case scTruncate:
case scZeroExtend:
case scSignExtend:
@@ -6607,6 +6620,8 @@ const ConstantRange &ScalarEvolution::getRangeRef(
switch (S->getSCEVType()) {
case scConstant:
llvm_unreachable("Already handled above.");
+ case scVScale:
+ return setRange(S, SignHint, std::move(ConservativeResult));
case scTruncate: {
const SCEVTruncateExpr *Trunc = cast<SCEVTruncateExpr>(S);
ConstantRange X = getRangeRef(Trunc->getOperand(), SignHint, Depth + 1);
@@ -9711,6 +9726,7 @@ static Constant *BuildConstantFromSCEV(const SCEV *V) {
switch (V->getSCEVType()) {
case scCouldNotCompute:
case scAddRecExpr:
+ case scVScale:
return nullptr;
case scConstant:
return cast<SCEVConstant>(V)->getValue();
@@ -9794,6 +9810,7 @@ static Constant *BuildConstantFromSCEV(const SCEV *V) {
const SCEV *ScalarEvolution::computeSCEVAtScope(const SCEV *V, const Loop *L) {
switch (V->getSCEVType()) {
case scConstant:
+ case scVScale:
return V;
case scAddRecExpr: {
// If this is a loop recurrence for a loop that does not contain L, then we
@@ -9892,6 +9909,7 @@ const SCEV *ScalarEvolution::computeSCEVAtScope(const SCEV *V, const Loop *L) {
case scSequentialUMinExpr:
return getSequentialMinMaxExpr(V->getSCEVType(), NewOps);
case scConstant:
+ case scVScale:
case scAddRecExpr:
case scUnknown:
case scCouldNotCompute:
@@ -13677,6 +13695,7 @@ ScalarEvolution::LoopDisposition
ScalarEvolution::computeLoopDisposition(const SCEV *S, const Loop *L) {
switch (S->getSCEVType()) {
case scConstant:
+ case scVScale:
return LoopInvariant;
case scAddRecExpr: {
const SCEVAddRecExpr *AR = cast<SCEVAddRecExpr>(S);
@@ -13775,6 +13794,7 @@ ScalarEvolution::BlockDisposition
ScalarEvolution::computeBlockDisposition(const SCEV *S, const BasicBlock *BB) {
switch (S->getSCEVType()) {
case scConstant:
+ case scVScale:
return ProperlyDominatesBlock;
case scAddRecExpr: {
// This uses a "dominates" query instead of "properly dominates" query
diff --git a/llvm/lib/Analysis/ScalarEvolutionDivision.cpp b/llvm/lib/Analysis/ScalarEvolutionDivision.cpp
index 0619569bf8168..e1dd834cfb100 100644
--- a/llvm/lib/Analysis/ScalarEvolutionDivision.cpp
+++ b/llvm/lib/Analysis/ScalarEvolutionDivision.cpp
@@ -126,6 +126,10 @@ void SCEVDivision::visitConstant(const SCEVConstant *Numerator) {
}
}
+void SCEVDivision::visitVScale(const SCEVVScale *Numerator) {
+ return cannotDivide(Numerator);
+}
+
void SCEVDivision::visitAddRecExpr(const SCEVAddRecExpr *Numerator) {
const SCEV *StartQ, *StartR, *StepQ, *StepR;
if (!Numerator->isAffine())
diff --git a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index 67c404a085df7..e5da0652a4ab7 100644
--- a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -976,6 +976,7 @@ static bool isHighCostExpansion(const SCEV *S,
switch (S->getSCEVType()) {
case scUnknown:
case scConstant:
+ case scVScale:
return false;
case scTruncate:
return isHighCostExpansion(cast<SCEVTruncateExpr>(S)->getOperand(),
@@ -2812,9 +2813,10 @@ static bool isCompatibleIVType(Value *LVal, Value *RVal) {
/// SCEVUnknown, we simply return the rightmost SCEV operand.
static const SCEV *getExprBase(const SCEV *S) {
switch (S->getSCEVType()) {
- default: // uncluding scUnknown.
+ default: // including scUnknown.
return S;
case scConstant:
+ case scVScale:
return nullptr;
case scTruncate:
return getExprBase(cast<SCEVTruncateExpr>(S)->getOperand());
diff --git a/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp b/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
index 24f1966edd37a..902eee26a4567 100644
--- a/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
+++ b/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
@@ -680,6 +680,7 @@ const Loop *SCEVExpander::getRelevantLoop(const SCEV *S) {
switch (S->getSCEVType()) {
case scConstant:
+ case scVScale:
return nullptr; // A constant has no relevant loops.
case scTruncate:
case scZeroExtend:
@@ -1744,6 +1745,10 @@ Value *SCEVExpander::visitSequentialUMinExpr(const SCEVSequentialUMinExpr *S) {
return expandMinMaxExpr(S, Intrinsic::umin, "umin", /*IsSequential*/true);
}
+Value *SCEVExpander::visitVScale(const SCEVVScale *S) {
+ return Builder.CreateVScale(ConstantInt::get(S->getType(), 1));
+}
+
Value *SCEVExpander::expandCodeForImpl(const SCEV *SH, Type *Ty,
Instruction *IP) {
setInsertPoint(IP);
@@ -2124,6 +2129,7 @@ template<typename T> static InstructionCost costAndCollectOperands(
llvm_unreachable("Attempt to use a SCEVCouldNotCompute object!");
case scUnknown:
case scConstant:
+ case scVScale:
return 0;
case scPtrToInt:
Cost = CastCost(Instruction::PtrToInt);
@@ -2260,6 +2266,7 @@ bool SCEVExpander::isHighCostExpansionHelper(
case scCouldNotCompute:
llvm_unreachable("Attempt to use a SCEVCouldNotCompute object!");
case scUnknown:
+ case scVScale:
// Assume to be zero-cost.
return false;
case scConstant: {
diff --git a/polly/include/polly/Support/SCEVAffinator.h b/polly/include/polly/Support/SCEVAffinator.h
index 35e87dfd9cd8a..63a341a01309b 100644
--- a/polly/include/polly/Support/SCEVAffinator.h
+++ b/polly/include/polly/Support/SCEVAffinator.h
@@ -99,6 +99,7 @@ class SCEVAffinator final : public llvm::SCEVVisitor<SCEVAffinator, PWACtx> {
PWACtx visit(const llvm::SCEV *E);
PWACtx visitConstant(const llvm::SCEVConstant *E);
+ PWACtx visitVScale(const llvm::SCEVVScale *E);
PWACtx visitPtrToIntExpr(const llvm::SCEVPtrToIntExpr *E);
PWACtx visitTruncateExpr(const llvm::SCEVTruncateExpr *E);
PWACtx visitZeroExtendExpr(const llvm::SCEVZeroExtendExpr *E);
diff --git a/polly/lib/Support/SCEVAffinator.cpp b/polly/lib/Support/SCEVAffinator.cpp
index d1998d190ea1c..c579dc18a6f52 100644
--- a/polly/lib/Support/SCEVAffinator.cpp
+++ b/polly/lib/Support/SCEVAffinator.cpp
@@ -266,6 +266,10 @@ PWACtx SCEVAffinator::visitConstant(const SCEVConstant *Expr) {
isl::manage(isl_pw_aff_from_aff(isl_aff_val_on_domain(ls, v))));
}
+PWACtx SCEVAffinator::visitVScale(const SCEVVScale *VScale) {
+ llvm_unreachable("SCEVVScale not yet supported");
+}
+
PWACtx SCEVAffinator::visitPtrToIntExpr(const SCEVPtrToIntExpr *Expr) {
return visit(Expr->getOperand(0));
}
diff --git a/polly/lib/Support/SCEVValidator.cpp b/polly/lib/Support/SCEVValidator.cpp
index 7f2a4910c6f27..e3d9818597ea6 100644
--- a/polly/lib/Support/SCEVValidator.cpp
+++ b/polly/lib/Support/SCEVValidator.cpp
@@ -134,6 +134,12 @@ class SCEVValidator : public SCEVVisitor<SCEVValidator, ValidatorResult> {
return ValidatorResult(SCEVType::INT);
}
+ ValidatorResult visitVScale(const SCEVVScale *VScale) {
+ // We do not support VScale constants.
+ LLVM_DEBUG(dbgs() << "INVALID: VScale is not supported");
+ return ValidatorResult(SCEVType::INVALID);
+ }
+
ValidatorResult visitZeroExtendOrTruncateExpr(const SCEV *Expr,
const SCEV *Operand) {
ValidatorResult Op = visit(Operand);
diff --git a/polly/lib/Support/ScopHelper.cpp b/polly/lib/Support/ScopHelper.cpp
index 90786756730e1..afdb61f25b6c1 100644
--- a/polly/lib/Support/ScopHelper.cpp
+++ b/polly/lib/Support/ScopHelper.cpp
@@ -338,6 +338,7 @@ struct ScopExpander final : SCEVVisitor<ScopExpander, const SCEV *> {
///
///{
const SCEV *visitConstant(const SCEVConstant *E) { return E; }
+ const SCEV *visitVScale(const SCEVVScale *E) { return E; }
const SCEV *visitPtrToIntExpr(const SCEVPtrToIntExpr *E) {
return SE.getPtrToIntExpr(visit(E->getOperand()), E->getType());
}
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