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llvm-project/polly/lib/Analysis/ScopDetection.cpp

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//===----- ScopDetection.cpp - Detect Scops --------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Detect the maximal Scops of a function.
//
// A static control part (Scop) is a subgraph of the control flow graph (CFG)
// that only has statically known control flow and can therefore be described
// within the polyhedral model.
//
// Every Scop fullfills these restrictions:
//
// * It is a single entry single exit region
//
// * Only affine linear bounds in the loops
//
// Every natural loop in a Scop must have a number of loop iterations that can
// be described as an affine linear function in surrounding loop iterators or
// parameters. (A parameter is a scalar that does not change its value during
// execution of the Scop).
//
// * Only comparisons of affine linear expressions in conditions
//
// * All loops and conditions perfectly nested
//
// The control flow needs to be structured such that it could be written using
// just 'for' and 'if' statements, without the need for any 'goto', 'break' or
// 'continue'.
//
// * Side effect free functions call
//
// Only function calls and intrinsics that do not have side effects are allowed
// (readnone).
//
// The Scop detection finds the largest Scops by checking if the largest
// region is a Scop. If this is not the case, its canonical subregions are
// checked until a region is a Scop. It is now tried to extend this Scop by
// creating a larger non canonical region.
//
//===----------------------------------------------------------------------===//
#include "polly/CodeGen/BlockGenerators.h"
#include "polly/LinkAllPasses.h"
#include "polly/Options.h"
#include "polly/ScopDetection.h"
#include "polly/Support/SCEVValidator.h"
#include "polly/Support/ScopHelper.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/RegionIterator.h"
#include "llvm/Analysis/ScalarEvolution.h"
#include "llvm/Analysis/ScalarEvolutionExpressions.h"
#include "llvm/DebugInfo.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/DiagnosticInfo.h"
#include "llvm/IR/DiagnosticPrinter.h"
#define DEBUG_TYPE "polly-detect"
#include "llvm/Support/Debug.h"
#include <set>
using namespace llvm;
using namespace polly;
static cl::opt<bool>
DetectScopsWithoutLoops("polly-detect-scops-in-functions-without-loops",
cl::desc("Detect scops in functions without loops"),
cl::Hidden, cl::init(false), cl::cat(PollyCategory));
static cl::opt<bool>
DetectRegionsWithoutLoops("polly-detect-scops-in-regions-without-loops",
cl::desc("Detect scops in regions without loops"),
cl::Hidden, cl::init(false), cl::cat(PollyCategory));
static cl::opt<std::string>
OnlyFunction("polly-only-func", cl::desc("Only run on a single function"),
cl::value_desc("function-name"), cl::ValueRequired, cl::init(""),
cl::cat(PollyCategory));
static cl::opt<std::string>
OnlyRegion("polly-only-region",
cl::desc("Only run on certain regions (The provided identifier must "
"appear in the name of the region's entry block"),
cl::value_desc("identifier"), cl::ValueRequired, cl::init(""),
cl::cat(PollyCategory));
static cl::opt<bool>
IgnoreAliasing("polly-ignore-aliasing",
cl::desc("Ignore possible aliasing of the array bases"),
cl::Hidden, cl::init(false), cl::cat(PollyCategory));
static cl::opt<bool>
ReportLevel("polly-report",
cl::desc("Print information about the activities of Polly"),
cl::init(false), cl::cat(PollyCategory));
static cl::opt<bool>
AllowNonAffine("polly-allow-nonaffine",
cl::desc("Allow non affine access functions in arrays"),
cl::Hidden, cl::init(false), cl::cat(PollyCategory));
static cl::opt<bool, true>
TrackFailures("polly-detect-track-failures",
cl::desc("Track failure strings in detecting scop regions"),
cl::location(PollyTrackFailures), cl::Hidden, cl::init(false),
cl::cat(PollyCategory));
bool polly::PollyTrackFailures = false;
//===----------------------------------------------------------------------===//
// Statistics.
STATISTIC(ValidRegion, "Number of regions that a valid part of Scop");
#define BADSCOP_STAT(NAME, DESC) \
STATISTIC(Bad##NAME##ForScop, "Number of bad regions for Scop: " DESC)
#define INVALID(NAME, MESSAGE) \
do { \
if (PollyTrackFailures) { \
std::string Buf; \
raw_string_ostream fmt(Buf); \
fmt << MESSAGE; \
fmt.flush(); \
LastFailure = Buf; \
} \
DEBUG(dbgs() << MESSAGE); \
DEBUG(dbgs() << "\n"); \
assert(!Context.Verifying && #NAME); \
if (!Context.Verifying) \
++Bad##NAME##ForScop; \
} while (0)
#define INVALID_NOVERIFY(NAME, MESSAGE) \
do { \
if (PollyTrackFailures) { \
std::string Buf; \
raw_string_ostream fmt(Buf); \
fmt << MESSAGE; \
fmt.flush(); \
LastFailure = Buf; \
} \
DEBUG(dbgs() << MESSAGE); \
DEBUG(dbgs() << "\n"); \
/* DISABLED: assert(!Context.Verifying && #NAME); */ \
if (!Context.Verifying) \
++Bad##NAME##ForScop; \
} while (0)
BADSCOP_STAT(CFG, "CFG too complex");
BADSCOP_STAT(IndVar, "Non canonical induction variable in loop");
BADSCOP_STAT(IndEdge, "Found invalid region entering edges");
BADSCOP_STAT(LoopBound, "Loop bounds can not be computed");
BADSCOP_STAT(FuncCall, "Function call with side effects appeared");
BADSCOP_STAT(AffFunc, "Expression not affine");
BADSCOP_STAT(Alias, "Found base address alias");
BADSCOP_STAT(SimpleLoop, "Loop not in -loop-simplify form");
BADSCOP_STAT(Other, "Others");
class DiagnosticScopFound : public DiagnosticInfo {
private:
static int PluginDiagnosticKind;
Function &F;
std::string FileName;
unsigned EntryLine, ExitLine;
public:
DiagnosticScopFound(Function &F, std::string FileName, unsigned EntryLine,
unsigned ExitLine)
: DiagnosticInfo(PluginDiagnosticKind, DS_Note), F(F), FileName(FileName),
EntryLine(EntryLine), ExitLine(ExitLine) {}
virtual void print(DiagnosticPrinter &DP) const;
static bool classof(const DiagnosticInfo *DI) {
return DI->getKind() == PluginDiagnosticKind;
}
};
int DiagnosticScopFound::PluginDiagnosticKind = 10;
void DiagnosticScopFound::print(DiagnosticPrinter &DP) const {
DP << "Polly detected an optimizable loop region (scop) in function '" << F
<< "'\n";
if (FileName.empty()) {
DP << "Scop location is unknown. Compile with debug info "
"(-g) to get more precise information. ";
return;
}
DP << FileName << ":" << EntryLine << ": Start of scop\n";
DP << FileName << ":" << ExitLine << ": End of scop";
}
//===----------------------------------------------------------------------===//
// ScopDetection.
bool ScopDetection::isMaxRegionInScop(const Region &R) const {
// The Region is valid only if it could be found in the set.
return ValidRegions.count(&R);
}
std::string ScopDetection::regionIsInvalidBecause(const Region *R) const {
if (!InvalidRegions.count(R))
return "";
return InvalidRegions.find(R)->second;
}
bool ScopDetection::isValidCFG(BasicBlock &BB,
DetectionContext &Context) const {
Region &RefRegion = Context.CurRegion;
TerminatorInst *TI = BB.getTerminator();
// Return instructions are only valid if the region is the top level region.
if (isa<ReturnInst>(TI) && !RefRegion.getExit() && TI->getNumOperands() == 0)
return true;
BranchInst *Br = dyn_cast<BranchInst>(TI);
if (!Br) {
INVALID(CFG, "Non branch instruction terminates BB: " + BB.getName());
return false;
}
if (Br->isUnconditional())
return true;
Value *Condition = Br->getCondition();
// UndefValue is not allowed as condition.
if (isa<UndefValue>(Condition)) {
INVALID(AffFunc, "Condition based on 'undef' value in BB: " + BB.getName());
return false;
}
// Only Constant and ICmpInst are allowed as condition.
if (!(isa<Constant>(Condition) || isa<ICmpInst>(Condition))) {
INVALID(AffFunc, "Condition in BB '" + BB.getName() +
"' neither constant nor an icmp instruction");
return false;
}
// Allow perfectly nested conditions.
assert(Br->getNumSuccessors() == 2 && "Unexpected number of successors");
if (ICmpInst *ICmp = dyn_cast<ICmpInst>(Condition)) {
// Unsigned comparisons are not allowed. They trigger overflow problems
// in the code generation.
//
// TODO: This is not sufficient and just hides bugs. However it does pretty
// well.
if (ICmp->isUnsigned())
return false;
// Are both operands of the ICmp affine?
if (isa<UndefValue>(ICmp->getOperand(0)) ||
isa<UndefValue>(ICmp->getOperand(1))) {
INVALID(AffFunc, "undef operand in branch at BB: " + BB.getName());
return false;
}
Loop *L = LI->getLoopFor(ICmp->getParent());
const SCEV *LHS = SE->getSCEVAtScope(ICmp->getOperand(0), L);
const SCEV *RHS = SE->getSCEVAtScope(ICmp->getOperand(1), L);
if (!isAffineExpr(&Context.CurRegion, LHS, *SE) ||
!isAffineExpr(&Context.CurRegion, RHS, *SE)) {
INVALID(AffFunc, "Non affine branch in BB '" << BB.getName()
<< "' with LHS: " << *LHS
<< " and RHS: " << *RHS);
return false;
}
}
// Allow loop exit conditions.
Loop *L = LI->getLoopFor(&BB);
if (L && L->getExitingBlock() == &BB)
return true;
// Allow perfectly nested conditions.
Region *R = RI->getRegionFor(&BB);
if (R->getEntry() != &BB) {
INVALID(CFG, "Not well structured condition at BB: " + BB.getName());
return false;
}
return true;
}
bool ScopDetection::isValidCallInst(CallInst &CI) {
if (CI.mayHaveSideEffects() || CI.doesNotReturn())
return false;
if (CI.doesNotAccessMemory())
return true;
Function *CalledFunction = CI.getCalledFunction();
// Indirect calls are not supported.
if (CalledFunction == 0)
return false;
// TODO: Intrinsics.
return false;
}
std::string ScopDetection::formatInvalidAlias(AliasSet &AS) const {
std::string Message;
raw_string_ostream OS(Message);
OS << "Possible aliasing: ";
std::vector<Value *> Pointers;
for (AliasSet::iterator AI = AS.begin(), AE = AS.end(); AI != AE; ++AI)
Pointers.push_back(AI.getPointer());
std::sort(Pointers.begin(), Pointers.end());
for (std::vector<Value *>::iterator PI = Pointers.begin(),
PE = Pointers.end();
;) {
Value *V = *PI;
if (V->getName().size() == 0)
OS << "\"" << *V << "\"";
else
OS << "\"" << V->getName() << "\"";
++PI;
if (PI != PE)
OS << ", ";
else
break;
}
return OS.str();
}
bool ScopDetection::isInvariant(const Value &Val, const Region &Reg) const {
// A reference to function argument or constant value is invariant.
if (isa<Argument>(Val) || isa<Constant>(Val))
return true;
const Instruction *I = dyn_cast<Instruction>(&Val);
if (!I)
return false;
if (!Reg.contains(I))
return true;
if (I->mayHaveSideEffects())
return false;
// When Val is a Phi node, it is likely not invariant. We do not check whether
// Phi nodes are actually invariant, we assume that Phi nodes are usually not
// invariant. Recursively checking the operators of Phi nodes would lead to
// infinite recursion.
if (isa<PHINode>(*I))
return false;
// Check that all operands of the instruction are
// themselves invariant.
const Instruction::const_op_iterator OE = I->op_end();
for (Instruction::const_op_iterator OI = I->op_begin(); OI != OE; ++OI) {
if (!isInvariant(**OI, Reg))
return false;
}
// When the instruction is a load instruction, check that no write to memory
// in the region aliases with the load.
if (const LoadInst *LI = dyn_cast<LoadInst>(I)) {
AliasAnalysis::Location Loc = AA->getLocation(LI);
const Region::const_block_iterator BE = Reg.block_end();
// Check if any basic block in the region can modify the location pointed to
// by 'Loc'. If so, 'Val' is (likely) not invariant in the region.
for (Region::const_block_iterator BI = Reg.block_begin(); BI != BE; ++BI) {
const BasicBlock &BB = **BI;
if (AA->canBasicBlockModify(BB, Loc))
return false;
}
}
return true;
}
bool ScopDetection::isValidMemoryAccess(Instruction &Inst,
DetectionContext &Context) const {
Value *Ptr = getPointerOperand(Inst);
Loop *L = LI->getLoopFor(Inst.getParent());
const SCEV *AccessFunction = SE->getSCEVAtScope(Ptr, L);
const SCEVUnknown *BasePointer;
Value *BaseValue;
BasePointer = dyn_cast<SCEVUnknown>(SE->getPointerBase(AccessFunction));
if (!BasePointer) {
INVALID(AffFunc, "No base pointer");
return false;
}
BaseValue = BasePointer->getValue();
if (isa<UndefValue>(BaseValue)) {
INVALID(AffFunc, "Undefined base pointer");
return false;
}
// Check that the base address of the access is invariant in the current
// region.
if (!isInvariant(*BaseValue, Context.CurRegion)) {
// Verification of this property is difficult as the independent blocks
// pass may introduce aliasing that we did not have when running the
// scop detection.
INVALID_NOVERIFY(
AffFunc, "Base address not invariant in current region:" << *BaseValue);
return false;
}
AccessFunction = SE->getMinusSCEV(AccessFunction, BasePointer);
if (!AllowNonAffine &&
!isAffineExpr(&Context.CurRegion, AccessFunction, *SE, BaseValue)) {
INVALID(AffFunc, "Non affine access function: " << *AccessFunction);
return false;
}
// FIXME: Alias Analysis thinks IntToPtrInst aliases with alloca instructions
// created by IndependentBlocks Pass.
if (isa<IntToPtrInst>(BaseValue)) {
INVALID(Other, "Find bad intToptr prt: " << *BaseValue);
return false;
}
if (IgnoreAliasing)
return true;
// Check if the base pointer of the memory access does alias with
// any other pointer. This cannot be handled at the moment.
AliasSet &AS =
Context.AST.getAliasSetForPointer(BaseValue, AliasAnalysis::UnknownSize,
Inst.getMetadata(LLVMContext::MD_tbaa));
// INVALID triggers an assertion in verifying mode, if it detects that a
// SCoP was detected by SCoP detection and that this SCoP was invalidated by
// a pass that stated it would preserve the SCoPs. We disable this check as
// the independent blocks pass may create memory references which seem to
// alias, if -basicaa is not available. They actually do not, but as we can
// not proof this without -basicaa we would fail. We disable this check to
// not cause irrelevant verification failures.
if (!AS.isMustAlias()) {
INVALID_NOVERIFY(Alias, formatInvalidAlias(AS));
return false;
}
return true;
}
bool ScopDetection::isValidInstruction(Instruction &Inst,
DetectionContext &Context) const {
if (PHINode *PN = dyn_cast<PHINode>(&Inst))
if (!canSynthesize(PN, LI, SE, &Context.CurRegion)) {
if (SCEVCodegen) {
INVALID(IndVar,
"SCEV of PHI node refers to SSA names in region: " << Inst);
return false;
} else {
INVALID(IndVar, "Non canonical PHI node: " << Inst);
return false;
}
}
// We only check the call instruction but not invoke instruction.
if (CallInst *CI = dyn_cast<CallInst>(&Inst)) {
if (isValidCallInst(*CI))
return true;
INVALID(FuncCall, "Call instruction: " << Inst);
return false;
}
if (!Inst.mayWriteToMemory() && !Inst.mayReadFromMemory()) {
if (!isa<AllocaInst>(Inst))
return true;
INVALID(Other, "Alloca instruction: " << Inst);
return false;
}
// Check the access function.
if (isa<LoadInst>(Inst) || isa<StoreInst>(Inst))
return isValidMemoryAccess(Inst, Context);
// We do not know this instruction, therefore we assume it is invalid.
INVALID(Other, "Unknown instruction: " << Inst);
return false;
}
bool ScopDetection::isValidLoop(Loop *L, DetectionContext &Context) const {
if (!SCEVCodegen) {
// If code generation is not in scev based mode, we need to ensure that
// each loop has a canonical induction variable.
PHINode *IndVar = L->getCanonicalInductionVariable();
if (!IndVar) {
INVALID(IndVar,
"No canonical IV at loop header: " << L->getHeader()->getName());
return false;
}
}
// Is the loop count affine?
const SCEV *LoopCount = SE->getBackedgeTakenCount(L);
if (!isAffineExpr(&Context.CurRegion, LoopCount, *SE)) {
INVALID(LoopBound, "Non affine loop bound '" << *LoopCount << "' in loop: "
<< L->getHeader()->getName());
return false;
}
return true;
}
Region *ScopDetection::expandRegion(Region &R) {
// Initial no valid region was found (greater than R)
Region *LastValidRegion = NULL;
Region *ExpandedRegion = R.getExpandedRegion();
DEBUG(dbgs() << "\tExpanding " << R.getNameStr() << "\n");
while (ExpandedRegion) {
DetectionContext Context(*ExpandedRegion, *AA, false /* verifying */);
DEBUG(dbgs() << "\t\tTrying " << ExpandedRegion->getNameStr() << "\n");
// Check the exit first (cheap)
if (isValidExit(Context)) {
// If the exit is valid check all blocks
// - if true, a valid region was found => store it + keep expanding
// - if false, .tbd. => stop (should this really end the loop?)
if (!allBlocksValid(Context))
break;
// Delete unnecessary regions (allocated by getExpandedRegion)
if (LastValidRegion)
delete LastValidRegion;
// Store this region, because it is the greatest valid (encountered so
// far).
LastValidRegion = ExpandedRegion;
// Create and test the next greater region (if any)
ExpandedRegion = ExpandedRegion->getExpandedRegion();
} else {
// Create and test the next greater region (if any)
Region *TmpRegion = ExpandedRegion->getExpandedRegion();
// Delete unnecessary regions (allocated by getExpandedRegion)
delete ExpandedRegion;
ExpandedRegion = TmpRegion;
}
}
DEBUG({
if (LastValidRegion)
dbgs() << "\tto " << LastValidRegion->getNameStr() << "\n";
else
dbgs() << "\tExpanding " << R.getNameStr() << " failed\n";
});
return LastValidRegion;
}
static bool regionWithoutLoops(Region &R, LoopInfo *LI) {
for (Region::block_iterator I = R.block_begin(), E = R.block_end(); I != E;
++I)
if (R.contains(LI->getLoopFor(*I)))
return false;
return true;
}
// Remove all direct and indirect children of region R from the region set Regs,
// but do not recurse further if the first child has been found.
//
// Return the number of regions erased from Regs.
static unsigned eraseAllChildren(std::set<const Region *> &Regs,
const Region *R) {
unsigned Count = 0;
for (Region::const_iterator I = R->begin(), E = R->end(); I != E; ++I) {
if (Regs.find(*I) != Regs.end()) {
++Count;
Regs.erase(*I);
} else {
Count += eraseAllChildren(Regs, *I);
}
}
return Count;
}
void ScopDetection::findScops(Region &R) {
if (!DetectRegionsWithoutLoops && regionWithoutLoops(R, LI))
return;
DetectionContext Context(R, *AA, false /*verifying*/);
LastFailure = "";
if (isValidRegion(Context)) {
++ValidRegion;
ValidRegions.insert(&R);
return;
}
InvalidRegions[&R] = LastFailure;
for (Region::iterator I = R.begin(), E = R.end(); I != E; ++I)
findScops(**I);
// Try to expand regions.
//
// As the region tree normally only contains canonical regions, non canonical
// regions that form a Scop are not found. Therefore, those non canonical
// regions are checked by expanding the canonical ones.
std::vector<Region *> ToExpand;
for (Region::iterator I = R.begin(), E = R.end(); I != E; ++I)
ToExpand.push_back(*I);
for (std::vector<Region *>::iterator RI = ToExpand.begin(),
RE = ToExpand.end();
RI != RE; ++RI) {
Region *CurrentRegion = *RI;
// Skip invalid regions. Regions may become invalid, if they are element of
// an already expanded region.
if (ValidRegions.find(CurrentRegion) == ValidRegions.end())
continue;
Region *ExpandedR = expandRegion(*CurrentRegion);
if (!ExpandedR)
continue;
R.addSubRegion(ExpandedR, true);
ValidRegions.insert(ExpandedR);
ValidRegions.erase(CurrentRegion);
// Erase all (direct and indirect) children of ExpandedR from the valid
// regions and update the number of valid regions.
ValidRegion -= eraseAllChildren(ValidRegions, ExpandedR);
}
}
bool ScopDetection::allBlocksValid(DetectionContext &Context) const {
Region &R = Context.CurRegion;
for (Region::block_iterator I = R.block_begin(), E = R.block_end(); I != E;
++I) {
Loop *L = LI->getLoopFor(*I);
if (L && L->getHeader() == *I && !isValidLoop(L, Context))
return false;
}
for (Region::block_iterator I = R.block_begin(), E = R.block_end(); I != E;
++I)
if (!isValidCFG(**I, Context))
return false;
for (Region::block_iterator BI = R.block_begin(), E = R.block_end(); BI != E;
++BI)
for (BasicBlock::iterator I = (*BI)->begin(), E = --(*BI)->end(); I != E;
++I)
if (!isValidInstruction(*I, Context))
return false;
return true;
}
bool ScopDetection::isValidExit(DetectionContext &Context) const {
Region &R = Context.CurRegion;
// PHI nodes are not allowed in the exit basic block.
if (BasicBlock *Exit = R.getExit()) {
BasicBlock::iterator I = Exit->begin();
if (I != Exit->end() && isa<PHINode>(*I)) {
INVALID(Other, "PHI node in exit BB");
return false;
}
}
return true;
}
bool ScopDetection::isValidRegion(DetectionContext &Context) const {
Region &R = Context.CurRegion;
DEBUG(dbgs() << "Checking region: " << R.getNameStr() << "\n\t");
if (R.isTopLevelRegion()) {
DEBUG(dbgs() << "Top level region is invalid"; dbgs() << "\n");
return false;
}
if (!R.getEntry()->getName().count(OnlyRegion)) {
DEBUG({
dbgs() << "Region entry does not match -polly-region-only";
dbgs() << "\n";
});
return false;
}
if (!R.getEnteringBlock()) {
BasicBlock *entry = R.getEntry();
Loop *L = LI->getLoopFor(entry);
if (L) {
if (!L->isLoopSimplifyForm()) {
INVALID(SimpleLoop, "Loop not in simplify form is invalid!");
return false;
}
for (pred_iterator PI = pred_begin(entry), PE = pred_end(entry); PI != PE;
++PI) {
// Region entering edges come from the same loop but outside the region
// are not allowed.
if (L->contains(*PI) && !R.contains(*PI)) {
INVALID(IndEdge, "Region has invalid entering edges!");
return false;
}
}
}
}
// SCoP cannot contain the entry block of the function, because we need
// to insert alloca instruction there when translate scalar to array.
if (R.getEntry() == &(R.getEntry()->getParent()->getEntryBlock())) {
INVALID(Other, "Region containing entry block of function is invalid!");
return false;
}
if (!isValidExit(Context))
return false;
if (!allBlocksValid(Context))
return false;
DEBUG(dbgs() << "OK\n");
return true;
}
bool ScopDetection::isValidFunction(llvm::Function &F) {
return !InvalidFunctions.count(&F);
}
void ScopDetection::getDebugLocation(const Region *R, unsigned &LineBegin,
unsigned &LineEnd, std::string &FileName) {
LineBegin = -1;
LineEnd = 0;
for (Region::const_block_iterator RI = R->block_begin(), RE = R->block_end();
RI != RE; ++RI)
for (BasicBlock::iterator BI = (*RI)->begin(), BE = (*RI)->end(); BI != BE;
++BI) {
DebugLoc DL = BI->getDebugLoc();
if (DL.isUnknown())
continue;
DIScope Scope(DL.getScope(BI->getContext()));
if (FileName.empty())
FileName = Scope.getFilename();
unsigned NewLine = DL.getLine();
LineBegin = std::min(LineBegin, NewLine);
LineEnd = std::max(LineEnd, NewLine);
}
}
void ScopDetection::printLocations(llvm::Function &F) {
for (iterator RI = begin(), RE = end(); RI != RE; ++RI) {
unsigned LineEntry, LineExit;
std::string FileName;
getDebugLocation(*RI, LineEntry, LineExit, FileName);
DiagnosticScopFound Diagnostic(F, FileName, LineEntry, LineExit);
F.getContext().diagnose(Diagnostic);
}
}
bool ScopDetection::runOnFunction(llvm::Function &F) {
LI = &getAnalysis<LoopInfo>();
RI = &getAnalysis<RegionInfo>();
if (!DetectScopsWithoutLoops && LI->empty())
return false;
AA = &getAnalysis<AliasAnalysis>();
SE = &getAnalysis<ScalarEvolution>();
Region *TopRegion = RI->getTopLevelRegion();
releaseMemory();
if (OnlyFunction != "" && F.getName() != OnlyFunction)
return false;
if (!isValidFunction(F))
return false;
findScops(*TopRegion);
if (ReportLevel >= 1)
printLocations(F);
return false;
}
void polly::ScopDetection::verifyRegion(const Region &R) const {
assert(isMaxRegionInScop(R) && "Expect R is a valid region.");
DetectionContext Context(const_cast<Region &>(R), *AA, true /*verifying*/);
isValidRegion(Context);
}
void polly::ScopDetection::verifyAnalysis() const {
for (RegionSet::const_iterator I = ValidRegions.begin(),
E = ValidRegions.end();
I != E; ++I)
verifyRegion(**I);
}
void ScopDetection::getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired<DominatorTreeWrapperPass>();
AU.addRequired<PostDominatorTree>();
AU.addRequired<LoopInfo>();
AU.addRequired<ScalarEvolution>();
// We also need AA and RegionInfo when we are verifying analysis.
AU.addRequiredTransitive<AliasAnalysis>();
AU.addRequiredTransitive<RegionInfo>();
AU.setPreservesAll();
}
void ScopDetection::print(raw_ostream &OS, const Module *) const {
for (RegionSet::const_iterator I = ValidRegions.begin(),
E = ValidRegions.end();
I != E; ++I)
OS << "Valid Region for Scop: " << (*I)->getNameStr() << '\n';
OS << "\n";
}
void ScopDetection::releaseMemory() {
ValidRegions.clear();
InvalidRegions.clear();
// Do not clear the invalid function set.
}
char ScopDetection::ID = 0;
Pass *polly::createScopDetectionPass() { return new ScopDetection(); }
INITIALIZE_PASS_BEGIN(ScopDetection, "polly-detect",
"Polly - Detect static control parts (SCoPs)", false,
false);
INITIALIZE_AG_DEPENDENCY(AliasAnalysis);
INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass);
INITIALIZE_PASS_DEPENDENCY(LoopInfo);
INITIALIZE_PASS_DEPENDENCY(PostDominatorTree);
INITIALIZE_PASS_DEPENDENCY(RegionInfo);
INITIALIZE_PASS_DEPENDENCY(ScalarEvolution);
INITIALIZE_PASS_END(ScopDetection, "polly-detect",
"Polly - Detect static control parts (SCoPs)", false, false)
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