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llvm-project/polly/lib/Support/ScopHelper.cpp
Christian Clauss 5aafc6d58f
[Polly] Fix typos discovered by codespell (#124545) 
Patch created using the following command line:
```bash
codespell polly --skip="*.pdf,polly/lib/External/*" --write-changes \
  --ignore-words-list=couter,createor,distribues,doble,identty,indention,indx,olt,ore,padd,sais,te,theses
```
2025-01-27 16:18:47 +01:00

878 lines
29 KiB
C++
Raw Blame History

//===- ScopHelper.cpp - Some Helper Functions for Scop. ------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// Small functions that help with Scop and LLVM-IR.
//
//===----------------------------------------------------------------------===//
#include "polly/Support/ScopHelper.h"
#include "polly/Options.h"
#include "polly/ScopInfo.h"
#include "polly/Support/SCEVValidator.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/RegionInfo.h"
#include "llvm/Analysis/ScalarEvolution.h"
#include "llvm/Analysis/ScalarEvolutionExpressions.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/LoopUtils.h"
#include "llvm/Transforms/Utils/ScalarEvolutionExpander.h"
#include <optional>
using namespace llvm;
using namespace polly;
#define DEBUG_TYPE "polly-scop-helper"
static cl::list<std::string> DebugFunctions(
"polly-debug-func",
cl::desc("Allow calls to the specified functions in SCoPs even if their "
"side-effects are unknown. This can be used to do debug output in "
"Polly-transformed code."),
cl::Hidden, cl::CommaSeparated, cl::cat(PollyCategory));
// Ensures that there is just one predecessor to the entry node from outside the
// region.
// The identity of the region entry node is preserved.
static void simplifyRegionEntry(Region *R, DominatorTree *DT, LoopInfo *LI,
RegionInfo *RI) {
BasicBlock *EnteringBB = R->getEnteringBlock();
BasicBlock *Entry = R->getEntry();
// Before (one of):
//
// \ / //
// EnteringBB //
// | \------> //
// \ / | //
// Entry <--\ Entry <--\ //
// / \ / / \ / //
// .... .... //
// Create single entry edge if the region has multiple entry edges.
if (!EnteringBB) {
SmallVector<BasicBlock *, 4> Preds;
for (BasicBlock *P : predecessors(Entry))
if (!R->contains(P))
Preds.push_back(P);
BasicBlock *NewEntering =
SplitBlockPredecessors(Entry, Preds, ".region_entering", DT, LI);
if (RI) {
// The exit block of predecessing regions must be changed to NewEntering
for (BasicBlock *ExitPred : predecessors(NewEntering)) {
Region *RegionOfPred = RI->getRegionFor(ExitPred);
if (RegionOfPred->getExit() != Entry)
continue;
while (!RegionOfPred->isTopLevelRegion() &&
RegionOfPred->getExit() == Entry) {
RegionOfPred->replaceExit(NewEntering);
RegionOfPred = RegionOfPred->getParent();
}
}
// Make all ancestors use EnteringBB as entry; there might be edges to it
Region *AncestorR = R->getParent();
RI->setRegionFor(NewEntering, AncestorR);
while (!AncestorR->isTopLevelRegion() && AncestorR->getEntry() == Entry) {
AncestorR->replaceEntry(NewEntering);
AncestorR = AncestorR->getParent();
}
}
EnteringBB = NewEntering;
}
assert(R->getEnteringBlock() == EnteringBB);
// After:
//
// \ / //
// EnteringBB //
// | //
// | //
// Entry <--\ //
// / \ / //
// .... //
}
// Ensure that the region has a single block that branches to the exit node.
static void simplifyRegionExit(Region *R, DominatorTree *DT, LoopInfo *LI,
RegionInfo *RI) {
BasicBlock *ExitBB = R->getExit();
BasicBlock *ExitingBB = R->getExitingBlock();
// Before:
//
// (Region) ______/ //
// \ | / //
// ExitBB //
// / \ //
if (!ExitingBB) {
SmallVector<BasicBlock *, 4> Preds;
for (BasicBlock *P : predecessors(ExitBB))
if (R->contains(P))
Preds.push_back(P);
// Preds[0] Preds[1] otherBB //
// \ | ________/ //
// \ | / //
// BB //
ExitingBB =
SplitBlockPredecessors(ExitBB, Preds, ".region_exiting", DT, LI);
// Preds[0] Preds[1] otherBB //
// \ / / //
// BB.region_exiting / //
// \ / //
// BB //
if (RI)
RI->setRegionFor(ExitingBB, R);
// Change the exit of nested regions, but not the region itself,
R->replaceExitRecursive(ExitingBB);
R->replaceExit(ExitBB);
}
assert(ExitingBB == R->getExitingBlock());
// After:
//
// \ / //
// ExitingBB _____/ //
// \ / //
// ExitBB //
// / \ //
}
void polly::simplifyRegion(Region *R, DominatorTree *DT, LoopInfo *LI,
RegionInfo *RI) {
assert(R && !R->isTopLevelRegion());
assert(!RI || RI == R->getRegionInfo());
assert((!RI || DT) &&
"RegionInfo requires DominatorTree to be updated as well");
simplifyRegionEntry(R, DT, LI, RI);
simplifyRegionExit(R, DT, LI, RI);
assert(R->isSimple());
}
// Split the block into two successive blocks.
//
// Like llvm::SplitBlock, but also preserves RegionInfo
static BasicBlock *splitBlock(BasicBlock *Old, Instruction *SplitPt,
DominatorTree *DT, llvm::LoopInfo *LI,
RegionInfo *RI) {
assert(Old && SplitPt);
// Before:
//
// \ / //
// Old //
// / \ //
BasicBlock *NewBlock = llvm::SplitBlock(Old, SplitPt, DT, LI);
if (RI) {
Region *R = RI->getRegionFor(Old);
RI->setRegionFor(NewBlock, R);
}
// After:
//
// \ / //
// Old //
// | //
// NewBlock //
// / \ //
return NewBlock;
}
void polly::splitEntryBlockForAlloca(BasicBlock *EntryBlock, DominatorTree *DT,
LoopInfo *LI, RegionInfo *RI) {
// Find first non-alloca instruction. Every basic block has a non-alloca
// instruction, as every well formed basic block has a terminator.
BasicBlock::iterator I = EntryBlock->begin();
while (isa<AllocaInst>(I))
++I;
// splitBlock updates DT, LI and RI.
splitBlock(EntryBlock, &*I, DT, LI, RI);
}
void polly::splitEntryBlockForAlloca(BasicBlock *EntryBlock, Pass *P) {
auto *DTWP = P->getAnalysisIfAvailable<DominatorTreeWrapperPass>();
auto *DT = DTWP ? &DTWP->getDomTree() : nullptr;
auto *LIWP = P->getAnalysisIfAvailable<LoopInfoWrapperPass>();
auto *LI = LIWP ? &LIWP->getLoopInfo() : nullptr;
RegionInfoPass *RIP = P->getAnalysisIfAvailable<RegionInfoPass>();
RegionInfo *RI = RIP ? &RIP->getRegionInfo() : nullptr;
// splitBlock updates DT, LI and RI.
polly::splitEntryBlockForAlloca(EntryBlock, DT, LI, RI);
}
void polly::recordAssumption(polly::RecordedAssumptionsTy *RecordedAssumptions,
polly::AssumptionKind Kind, isl::set Set,
DebugLoc Loc, polly::AssumptionSign Sign,
BasicBlock *BB, bool RTC) {
assert((Set.is_params() || BB) &&
"Assumptions without a basic block must be parameter sets");
if (RecordedAssumptions)
RecordedAssumptions->push_back({Kind, Sign, Set, Loc, BB, RTC});
}
/// ScopExpander generates IR the the value of a SCEV that represents a value
/// from a SCoP.
///
/// IMPORTANT: There are two ScalarEvolutions at play here. First, the SE that
/// was used to analyze the original SCoP (not actually referenced anywhere
/// here, but passed as argument to make the distinction clear). Second, GenSE
/// which is the SE for the function that the code is emitted into. SE and GenSE
/// may be different when the generated code is to be emitted into an outlined
/// function, e.g. for a parallel loop. That is, each SCEV is to be used only by
/// the SE that "owns" it and ScopExpander handles the translation between them.
/// The SCEVVisitor methods are only to be called on SCEVs of the original SE.
/// Their job is to create a new SCEV for GenSE. The nested SCEVExpander is to
/// be used only with SCEVs belonging to GenSE. Currently SCEVs do not store a
/// reference to the ScalarEvolution they belong to, so a mixup does not
/// immediately cause a crash but certainly is a violation of its interface.
///
/// The SCEVExpander will __not__ generate any code for an existing SDiv/SRem
/// instruction but just use it, if it is referenced as a SCEVUnknown. We want
/// however to generate new code if the instruction is in the analyzed region
/// and we generate code outside/in front of that region. Hence, we generate the
/// code for the SDiv/SRem operands in front of the analyzed region and then
/// create a new SDiv/SRem operation there too.
struct ScopExpander final : SCEVVisitor<ScopExpander, const SCEV *> {
friend struct SCEVVisitor<ScopExpander, const SCEV *>;
explicit ScopExpander(const Region &R, ScalarEvolution &SE, Function *GenFn,
ScalarEvolution &GenSE, const DataLayout &DL,
const char *Name, ValueMapT *VMap,
LoopToScevMapT *LoopMap, BasicBlock *RTCBB)
: Expander(GenSE, DL, Name, /*PreserveLCSSA=*/false), Name(Name), R(R),
VMap(VMap), LoopMap(LoopMap), RTCBB(RTCBB), GenSE(GenSE), GenFn(GenFn) {
}
Value *expandCodeFor(const SCEV *E, Type *Ty, Instruction *IP) {
assert(isInGenRegion(IP) &&
"ScopExpander assumes to be applied to generated code region");
const SCEV *GenE = visit(E);
return Expander.expandCodeFor(GenE, Ty, IP);
}
const SCEV *visit(const SCEV *E) {
// Cache the expansion results for intermediate SCEV expressions. A SCEV
// expression can refer to an operand multiple times (e.g. "x*x), so
// a naive visitor takes exponential time.
if (SCEVCache.count(E))
return SCEVCache[E];
const SCEV *Result = SCEVVisitor::visit(E);
SCEVCache[E] = Result;
return Result;
}
private:
SCEVExpander Expander;
const char *Name;
const Region &R;
ValueMapT *VMap;
LoopToScevMapT *LoopMap;
BasicBlock *RTCBB;
DenseMap<const SCEV *, const SCEV *> SCEVCache;
ScalarEvolution &GenSE;
Function *GenFn;
/// Is the instruction part of the original SCoP (in contrast to be located in
/// the code-generated region)?
bool isInOrigRegion(Instruction *Inst) {
Function *Fn = R.getEntry()->getParent();
bool isInOrigRegion = Inst->getFunction() == Fn && R.contains(Inst);
assert((isInOrigRegion || GenFn == Inst->getFunction()) &&
"Instruction expected to be either in the SCoP or the translated "
"region");
return isInOrigRegion;
}
bool isInGenRegion(Instruction *Inst) { return !isInOrigRegion(Inst); }
const SCEV *visitGenericInst(const SCEVUnknown *E, Instruction *Inst,
Instruction *IP) {
if (!Inst || isInGenRegion(Inst))
return E;
assert(!Inst->mayThrow() && !Inst->mayReadOrWriteMemory() &&
!isa<PHINode>(Inst));
auto *InstClone = Inst->clone();
for (auto &Op : Inst->operands()) {
assert(GenSE.isSCEVable(Op->getType()));
const SCEV *OpSCEV = GenSE.getSCEV(Op);
auto *OpClone = expandCodeFor(OpSCEV, Op->getType(), IP);
InstClone->replaceUsesOfWith(Op, OpClone);
}
InstClone->setName(Name + Inst->getName());
InstClone->insertBefore(IP->getIterator());
return GenSE.getSCEV(InstClone);
}
const SCEV *visitUnknown(const SCEVUnknown *E) {
// If a value mapping was given try if the underlying value is remapped.
Value *NewVal = VMap ? VMap->lookup(E->getValue()) : nullptr;
if (NewVal) {
const SCEV *NewE = GenSE.getSCEV(NewVal);
// While the mapped value might be different the SCEV representation might
// not be. To this end we will check before we go into recursion here.
// FIXME: SCEVVisitor must only visit SCEVs that belong to the original
// SE. This calls it on SCEVs that belong GenSE.
if (E != NewE)
return visit(NewE);
}
Instruction *Inst = dyn_cast<Instruction>(E->getValue());
Instruction *IP;
if (Inst && isInGenRegion(Inst))
IP = Inst;
else if (R.getEntry()->getParent() != GenFn) {
// RTCBB is in the original function, but we are generating for a
// subfunction so we cannot emit to RTCBB. Usually, we land here only
// because E->getValue() is not an instruction but a global or constant
// which do not need to emit anything.
IP = GenFn->getEntryBlock().getTerminator();
} else if (Inst && RTCBB->getParent() == Inst->getFunction())
IP = RTCBB->getTerminator();
else
IP = RTCBB->getParent()->getEntryBlock().getTerminator();
if (!Inst || (Inst->getOpcode() != Instruction::SRem &&
Inst->getOpcode() != Instruction::SDiv))
return visitGenericInst(E, Inst, IP);
const SCEV *LHSScev = GenSE.getSCEV(Inst->getOperand(0));
const SCEV *RHSScev = GenSE.getSCEV(Inst->getOperand(1));
if (!GenSE.isKnownNonZero(RHSScev))
RHSScev = GenSE.getUMaxExpr(RHSScev, GenSE.getConstant(E->getType(), 1));
Value *LHS = expandCodeFor(LHSScev, E->getType(), IP);
Value *RHS = expandCodeFor(RHSScev, E->getType(), IP);
Inst =
BinaryOperator::Create((Instruction::BinaryOps)Inst->getOpcode(), LHS,
RHS, Inst->getName() + Name, IP->getIterator());
return GenSE.getSCEV(Inst);
}
/// The following functions will just traverse the SCEV and rebuild it using
/// GenSE and the new operands returned by the traversal.
///
///{
const SCEV *visitConstant(const SCEVConstant *E) { return E; }
const SCEV *visitVScale(const SCEVVScale *E) { return E; }
const SCEV *visitPtrToIntExpr(const SCEVPtrToIntExpr *E) {
return GenSE.getPtrToIntExpr(visit(E->getOperand()), E->getType());
}
const SCEV *visitTruncateExpr(const SCEVTruncateExpr *E) {
return GenSE.getTruncateExpr(visit(E->getOperand()), E->getType());
}
const SCEV *visitZeroExtendExpr(const SCEVZeroExtendExpr *E) {
return GenSE.getZeroExtendExpr(visit(E->getOperand()), E->getType());
}
const SCEV *visitSignExtendExpr(const SCEVSignExtendExpr *E) {
return GenSE.getSignExtendExpr(visit(E->getOperand()), E->getType());
}
const SCEV *visitUDivExpr(const SCEVUDivExpr *E) {
auto *RHSScev = visit(E->getRHS());
if (!GenSE.isKnownNonZero(RHSScev))
RHSScev = GenSE.getUMaxExpr(RHSScev, GenSE.getConstant(E->getType(), 1));
return GenSE.getUDivExpr(visit(E->getLHS()), RHSScev);
}
const SCEV *visitAddExpr(const SCEVAddExpr *E) {
SmallVector<const SCEV *, 4> NewOps;
for (const SCEV *Op : E->operands())
NewOps.push_back(visit(Op));
return GenSE.getAddExpr(NewOps);
}
const SCEV *visitMulExpr(const SCEVMulExpr *E) {
SmallVector<const SCEV *, 4> NewOps;
for (const SCEV *Op : E->operands())
NewOps.push_back(visit(Op));
return GenSE.getMulExpr(NewOps);
}
const SCEV *visitUMaxExpr(const SCEVUMaxExpr *E) {
SmallVector<const SCEV *, 4> NewOps;
for (const SCEV *Op : E->operands())
NewOps.push_back(visit(Op));
return GenSE.getUMaxExpr(NewOps);
}
const SCEV *visitSMaxExpr(const SCEVSMaxExpr *E) {
SmallVector<const SCEV *, 4> NewOps;
for (const SCEV *Op : E->operands())
NewOps.push_back(visit(Op));
return GenSE.getSMaxExpr(NewOps);
}
const SCEV *visitUMinExpr(const SCEVUMinExpr *E) {
SmallVector<const SCEV *, 4> NewOps;
for (const SCEV *Op : E->operands())
NewOps.push_back(visit(Op));
return GenSE.getUMinExpr(NewOps);
}
const SCEV *visitSMinExpr(const SCEVSMinExpr *E) {
SmallVector<const SCEV *, 4> NewOps;
for (const SCEV *Op : E->operands())
NewOps.push_back(visit(Op));
return GenSE.getSMinExpr(NewOps);
}
const SCEV *visitSequentialUMinExpr(const SCEVSequentialUMinExpr *E) {
SmallVector<const SCEV *, 4> NewOps;
for (const SCEV *Op : E->operands())
NewOps.push_back(visit(Op));
return GenSE.getUMinExpr(NewOps, /*Sequential=*/true);
}
const SCEV *visitAddRecExpr(const SCEVAddRecExpr *E) {
SmallVector<const SCEV *, 4> NewOps;
for (const SCEV *Op : E->operands())
NewOps.push_back(visit(Op));
const Loop *L = E->getLoop();
const SCEV *GenLRepl = LoopMap ? LoopMap->lookup(L) : nullptr;
if (!GenLRepl)
return GenSE.getAddRecExpr(NewOps, L, E->getNoWrapFlags());
// evaluateAtIteration replaces the SCEVAddrExpr with a direct calculation.
const SCEV *Evaluated =
SCEVAddRecExpr::evaluateAtIteration(NewOps, GenLRepl, GenSE);
// FIXME: This emits a SCEV for GenSE (since GenLRepl will refer to the
// induction variable of a generated loop), so we should not use SCEVVisitor
// with it. However, it still contains references to the SCoP region.
return visit(Evaluated);
}
///}
};
Value *polly::expandCodeFor(Scop &S, llvm::ScalarEvolution &SE,
llvm::Function *GenFn, ScalarEvolution &GenSE,
const DataLayout &DL, const char *Name,
const SCEV *E, Type *Ty, Instruction *IP,
ValueMapT *VMap, LoopToScevMapT *LoopMap,
BasicBlock *RTCBB) {
ScopExpander Expander(S.getRegion(), SE, GenFn, GenSE, DL, Name, VMap,
LoopMap, RTCBB);
return Expander.expandCodeFor(E, Ty, IP);
}
Value *polly::getConditionFromTerminator(Instruction *TI) {
if (BranchInst *BR = dyn_cast<BranchInst>(TI)) {
if (BR->isUnconditional())
return ConstantInt::getTrue(Type::getInt1Ty(TI->getContext()));
return BR->getCondition();
}
if (SwitchInst *SI = dyn_cast<SwitchInst>(TI))
return SI->getCondition();
return nullptr;
}
Loop *polly::getLoopSurroundingScop(Scop &S, LoopInfo &LI) {
// Start with the smallest loop containing the entry and expand that
// loop until it contains all blocks in the region. If there is a loop
// containing all blocks in the region check if it is itself contained
// and if so take the parent loop as it will be the smallest containing
// the region but not contained by it.
Loop *L = LI.getLoopFor(S.getEntry());
while (L) {
bool AllContained = true;
for (auto *BB : S.blocks())
AllContained &= L->contains(BB);
if (AllContained)
break;
L = L->getParentLoop();
}
return L ? (S.contains(L) ? L->getParentLoop() : L) : nullptr;
}
unsigned polly::getNumBlocksInLoop(Loop *L) {
unsigned NumBlocks = L->getNumBlocks();
SmallVector<BasicBlock *, 4> ExitBlocks;
L->getExitBlocks(ExitBlocks);
for (auto ExitBlock : ExitBlocks) {
if (isa<UnreachableInst>(ExitBlock->getTerminator()))
NumBlocks++;
}
return NumBlocks;
}
unsigned polly::getNumBlocksInRegionNode(RegionNode *RN) {
if (!RN->isSubRegion())
return 1;
Region *R = RN->getNodeAs<Region>();
return std::distance(R->block_begin(), R->block_end());
}
Loop *polly::getRegionNodeLoop(RegionNode *RN, LoopInfo &LI) {
if (!RN->isSubRegion()) {
BasicBlock *BB = RN->getNodeAs<BasicBlock>();
Loop *L = LI.getLoopFor(BB);
// Unreachable statements are not considered to belong to a LLVM loop, as
// they are not part of an actual loop in the control flow graph.
// Nevertheless, we handle certain unreachable statements that are common
// when modeling run-time bounds checks as being part of the loop to be
// able to model them and to later eliminate the run-time bounds checks.
//
// Specifically, for basic blocks that terminate in an unreachable and
// where the immediate predecessor is part of a loop, we assume these
// basic blocks belong to the loop the predecessor belongs to. This
// allows us to model the following code.
//
// for (i = 0; i < N; i++) {
// if (i > 1024)
// abort(); <- this abort might be translated to an
// unreachable
//
// A[i] = ...
// }
if (!L && isa<UnreachableInst>(BB->getTerminator()) && BB->getPrevNode())
L = LI.getLoopFor(BB->getPrevNode());
return L;
}
Region *NonAffineSubRegion = RN->getNodeAs<Region>();
Loop *L = LI.getLoopFor(NonAffineSubRegion->getEntry());
while (L && NonAffineSubRegion->contains(L))
L = L->getParentLoop();
return L;
}
static bool hasVariantIndex(GetElementPtrInst *Gep, Loop *L, Region &R,
ScalarEvolution &SE) {
for (const Use &Val : llvm::drop_begin(Gep->operands(), 1)) {
const SCEV *PtrSCEV = SE.getSCEVAtScope(Val, L);
Loop *OuterLoop = R.outermostLoopInRegion(L);
if (!SE.isLoopInvariant(PtrSCEV, OuterLoop))
return true;
}
return false;
}
bool polly::isHoistableLoad(LoadInst *LInst, Region &R, LoopInfo &LI,
ScalarEvolution &SE, const DominatorTree &DT,
const InvariantLoadsSetTy &KnownInvariantLoads) {
Loop *L = LI.getLoopFor(LInst->getParent());
auto *Ptr = LInst->getPointerOperand();
// A LoadInst is hoistable if the address it is loading from is also
// invariant; in this case: another invariant load (whether that address
// is also not written to has to be checked separately)
// TODO: This only checks for a LoadInst->GetElementPtrInst->LoadInst
// pattern generated by the Chapel frontend, but generally this applies
// for any chain of instruction that does not also depend on any
// induction variable
if (auto *GepInst = dyn_cast<GetElementPtrInst>(Ptr)) {
if (!hasVariantIndex(GepInst, L, R, SE)) {
if (auto *DecidingLoad =
dyn_cast<LoadInst>(GepInst->getPointerOperand())) {
if (KnownInvariantLoads.count(DecidingLoad))
return true;
}
}
}
const SCEV *PtrSCEV = SE.getSCEVAtScope(Ptr, L);
while (L && R.contains(L)) {
if (!SE.isLoopInvariant(PtrSCEV, L))
return false;
L = L->getParentLoop();
}
for (auto *User : Ptr->users()) {
auto *UserI = dyn_cast<Instruction>(User);
if (!UserI || UserI->getFunction() != LInst->getFunction() ||
!R.contains(UserI))
continue;
if (!UserI->mayWriteToMemory())
continue;
auto &BB = *UserI->getParent();
if (DT.dominates(&BB, LInst->getParent()))
return false;
bool DominatesAllPredecessors = true;
if (R.isTopLevelRegion()) {
for (BasicBlock &I : *R.getEntry()->getParent())
if (isa<ReturnInst>(I.getTerminator()) && !DT.dominates(&BB, &I))
DominatesAllPredecessors = false;
} else {
for (auto Pred : predecessors(R.getExit()))
if (R.contains(Pred) && !DT.dominates(&BB, Pred))
DominatesAllPredecessors = false;
}
if (!DominatesAllPredecessors)
continue;
return false;
}
return true;
}
bool polly::isIgnoredIntrinsic(const Value *V) {
if (auto *IT = dyn_cast<IntrinsicInst>(V)) {
switch (IT->getIntrinsicID()) {
// Lifetime markers are supported/ignored.
case llvm::Intrinsic::lifetime_start:
case llvm::Intrinsic::lifetime_end:
// Invariant markers are supported/ignored.
case llvm::Intrinsic::invariant_start:
case llvm::Intrinsic::invariant_end:
// Some misc annotations are supported/ignored.
case llvm::Intrinsic::var_annotation:
case llvm::Intrinsic::ptr_annotation:
case llvm::Intrinsic::annotation:
case llvm::Intrinsic::donothing:
case llvm::Intrinsic::assume:
// Some debug info intrinsics are supported/ignored.
case llvm::Intrinsic::dbg_value:
case llvm::Intrinsic::dbg_declare:
return true;
default:
break;
}
}
return false;
}
bool polly::canSynthesize(const Value *V, const Scop &S, ScalarEvolution *SE,
Loop *Scope) {
if (!V || !SE->isSCEVable(V->getType()))
return false;
const InvariantLoadsSetTy &ILS = S.getRequiredInvariantLoads();
if (const SCEV *Scev = SE->getSCEVAtScope(const_cast<Value *>(V), Scope))
if (!isa<SCEVCouldNotCompute>(Scev))
if (!hasScalarDepsInsideRegion(Scev, &S.getRegion(), Scope, false, ILS))
return true;
return false;
}
llvm::BasicBlock *polly::getUseBlock(const llvm::Use &U) {
Instruction *UI = dyn_cast<Instruction>(U.getUser());
if (!UI)
return nullptr;
if (PHINode *PHI = dyn_cast<PHINode>(UI))
return PHI->getIncomingBlock(U);
return UI->getParent();
}
llvm::Loop *polly::getFirstNonBoxedLoopFor(llvm::Loop *L, llvm::LoopInfo &LI,
const BoxedLoopsSetTy &BoxedLoops) {
while (BoxedLoops.count(L))
L = L->getParentLoop();
return L;
}
llvm::Loop *polly::getFirstNonBoxedLoopFor(llvm::BasicBlock *BB,
llvm::LoopInfo &LI,
const BoxedLoopsSetTy &BoxedLoops) {
Loop *L = LI.getLoopFor(BB);
return getFirstNonBoxedLoopFor(L, LI, BoxedLoops);
}
bool polly::isDebugCall(Instruction *Inst) {
auto *CI = dyn_cast<CallInst>(Inst);
if (!CI)
return false;
Function *CF = CI->getCalledFunction();
if (!CF)
return false;
return std::find(DebugFunctions.begin(), DebugFunctions.end(),
CF->getName()) != DebugFunctions.end();
}
static bool hasDebugCall(BasicBlock *BB) {
for (Instruction &Inst : *BB) {
if (isDebugCall(&Inst))
return true;
}
return false;
}
bool polly::hasDebugCall(ScopStmt *Stmt) {
// Quick skip if no debug functions have been defined.
if (DebugFunctions.empty())
return false;
if (!Stmt)
return false;
for (Instruction *Inst : Stmt->getInstructions())
if (isDebugCall(Inst))
return true;
if (Stmt->isRegionStmt()) {
for (BasicBlock *RBB : Stmt->getRegion()->blocks())
if (RBB != Stmt->getEntryBlock() && ::hasDebugCall(RBB))
return true;
}
return false;
}
/// Find a property in a LoopID.
static MDNode *findNamedMetadataNode(MDNode *LoopMD, StringRef Name) {
if (!LoopMD)
return nullptr;
for (const MDOperand &X : drop_begin(LoopMD->operands(), 1)) {
auto *OpNode = dyn_cast<MDNode>(X.get());
if (!OpNode)
continue;
auto *OpName = dyn_cast<MDString>(OpNode->getOperand(0));
if (!OpName)
continue;
if (OpName->getString() == Name)
return OpNode;
}
return nullptr;
}
static std::optional<const MDOperand *> findNamedMetadataArg(MDNode *LoopID,
StringRef Name) {
MDNode *MD = findNamedMetadataNode(LoopID, Name);
if (!MD)
return std::nullopt;
switch (MD->getNumOperands()) {
case 1:
return nullptr;
case 2:
return &MD->getOperand(1);
default:
llvm_unreachable("loop metadata has 0 or 1 operand");
}
}
std::optional<Metadata *> polly::findMetadataOperand(MDNode *LoopMD,
StringRef Name) {
MDNode *MD = findNamedMetadataNode(LoopMD, Name);
if (!MD)
return std::nullopt;
switch (MD->getNumOperands()) {
case 1:
return nullptr;
case 2:
return MD->getOperand(1).get();
default:
llvm_unreachable("loop metadata must have 0 or 1 operands");
}
}
static std::optional<bool> getOptionalBoolLoopAttribute(MDNode *LoopID,
StringRef Name) {
MDNode *MD = findNamedMetadataNode(LoopID, Name);
if (!MD)
return std::nullopt;
switch (MD->getNumOperands()) {
case 1:
return true;
case 2:
if (ConstantInt *IntMD =
mdconst::extract_or_null<ConstantInt>(MD->getOperand(1).get()))
return IntMD->getZExtValue();
return true;
}
llvm_unreachable("unexpected number of options");
}
bool polly::getBooleanLoopAttribute(MDNode *LoopID, StringRef Name) {
return getOptionalBoolLoopAttribute(LoopID, Name).value_or(false);
}
std::optional<int> polly::getOptionalIntLoopAttribute(MDNode *LoopID,
StringRef Name) {
const MDOperand *AttrMD =
findNamedMetadataArg(LoopID, Name).value_or(nullptr);
if (!AttrMD)
return std::nullopt;
ConstantInt *IntMD = mdconst::extract_or_null<ConstantInt>(AttrMD->get());
if (!IntMD)
return std::nullopt;
return IntMD->getSExtValue();
}
bool polly::hasDisableAllTransformsHint(Loop *L) {
return llvm::hasDisableAllTransformsHint(L);
}
bool polly::hasDisableAllTransformsHint(llvm::MDNode *LoopID) {
return getBooleanLoopAttribute(LoopID, "llvm.loop.disable_nonforced");
}
isl::id polly::getIslLoopAttr(isl::ctx Ctx, BandAttr *Attr) {
assert(Attr && "Must be a valid BandAttr");
// The name "Loop" signals that this id contains a pointer to a BandAttr.
// The ScheduleOptimizer also uses the string "Inter iteration alias-free" in
// markers, but it's user pointer is an llvm::Value.
isl::id Result = isl::id::alloc(Ctx, "Loop with Metadata", Attr);
Result = isl::manage(isl_id_set_free_user(Result.release(), [](void *Ptr) {
BandAttr *Attr = reinterpret_cast<BandAttr *>(Ptr);
delete Attr;
}));
return Result;
}
isl::id polly::createIslLoopAttr(isl::ctx Ctx, Loop *L) {
if (!L)
return {};
// A loop without metadata does not need to be annotated.
MDNode *LoopID = L->getLoopID();
if (!LoopID)
return {};
BandAttr *Attr = new BandAttr();
Attr->OriginalLoop = L;
Attr->Metadata = L->getLoopID();
return getIslLoopAttr(Ctx, Attr);
}
bool polly::isLoopAttr(const isl::id &Id) {
if (Id.is_null())
return false;
return Id.get_name() == "Loop with Metadata";
}
BandAttr *polly::getLoopAttr(const isl::id &Id) {
if (!isLoopAttr(Id))
return nullptr;
return reinterpret_cast<BandAttr *>(Id.get_user());
}
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