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

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//===---------- TempScopInfo.cpp - Extract TempScops ---------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Collect information about the control flow regions detected by the Scop
// detection, such that this information can be translated info its polyhedral
// representation.
//
//===----------------------------------------------------------------------===//
#include "polly/TempScopInfo.h"
#include "polly/LinkAllPasses.h"
#include "polly/Support/GICHelper.h"
#include "polly/Support/ScopHelper.h"
#include "polly/Support/SCEVValidator.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/RegionIterator.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Assembly/Writer.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/ScalarEvolution.h"
#include "llvm/ADT/STLExtras.h"
#define DEBUG_TYPE "polly-analyze-ir"
#include "llvm/Support/Debug.h"
using namespace llvm;
using namespace polly;
//===----------------------------------------------------------------------===//
/// Helper Class
void Comparison::print(raw_ostream &OS) const {
// Not yet implemented.
}
/// Helper function to print the condition
static void printBBCond(raw_ostream &OS, const BBCond &Cond) {
assert(!Cond.empty() && "Unexpected empty condition!");
Cond[0].print(OS);
for (unsigned i = 1, e = Cond.size(); i != e; ++i) {
OS << " && ";
Cond[i].print(OS);
}
}
inline raw_ostream &operator<<(raw_ostream &OS, const BBCond &Cond) {
printBBCond(OS, Cond);
return OS;
}
//===----------------------------------------------------------------------===//
// TempScop implementation
TempScop::~TempScop() {
if (MayASInfo) delete MayASInfo;
}
void TempScop::print(raw_ostream &OS, ScalarEvolution *SE, LoopInfo *LI) const {
OS << "Scop: " << R.getNameStr() << "\tParameters: (";
// Print Parameters.
for (ParamSetType::const_iterator PI = Params.begin(), PE = Params.end();
PI != PE; ++PI)
OS << **PI << ", ";
OS << "), Max Loop Depth: "<< MaxLoopDepth <<"\n";
printDetail(OS, SE, LI, &R, 0);
}
void TempScop::printDetail(llvm::raw_ostream &OS, ScalarEvolution *SE,
LoopInfo *LI, const Region *CurR,
unsigned ind) const {
}
void TempScopInfo::buildAccessFunctions(Region &R, ParamSetType &Parameter,
BasicBlock &BB) {
AccFuncSetType Functions;
for (BasicBlock::iterator I = BB.begin(), E = --BB.end(); I != E; ++I) {
Instruction &Inst = *I;
if (isa<LoadInst>(&Inst) || isa<StoreInst>(&Inst)) {
unsigned Size;
enum IRAccess::TypeKind Type;
if (LoadInst *Load = dyn_cast<LoadInst>(&Inst)) {
Size = TD->getTypeStoreSize(Load->getType());
Type = IRAccess::READ;
} else {
StoreInst *Store = cast<StoreInst>(&Inst);
Size = TD->getTypeStoreSize(Store->getValueOperand()->getType());
Type = IRAccess::WRITE;
}
const SCEV *AccessFunction = SE->getSCEV(getPointerOperand(Inst));
Functions.push_back(std::make_pair(IRAccess(Type, AccessFunction, Size),
&Inst));
}
}
if (Functions.empty())
return;
AccFuncSetType &Accs = AccFuncMap[&BB];
Accs.insert(Accs.end(), Functions.begin(), Functions.end());
}
void TempScopInfo::buildLoopBounds(TempScop &Scop) {
Region &R = Scop.getMaxRegion();
unsigned MaxLoopDepth = 0;
for (Region::block_iterator I = R.block_begin(), E = R.block_end();
I != E; ++I) {
Loop *L = LI->getLoopFor(I->getNodeAs<BasicBlock>());
if (!L || !R.contains(L))
continue;
if (LoopBounds.find(L) != LoopBounds.end())
continue;
const SCEV *BackedgeTakenCount = SE->getBackedgeTakenCount(L);
LoopBounds[L] = BackedgeTakenCount;
Loop *OL = R.outermostLoopInRegion(L);
unsigned LoopDepth = L->getLoopDepth() - OL->getLoopDepth() + 1;
if (LoopDepth > MaxLoopDepth)
MaxLoopDepth = LoopDepth;
}
Scop.MaxLoopDepth = MaxLoopDepth;
}
void TempScopInfo::buildAffineCondition(Value &V, bool inverted,
Comparison **Comp,
TempScop &Scop) const {
if (ConstantInt *C = dyn_cast<ConstantInt>(&V)) {
// If this is always true condition, we will create 1 >= 0,
// otherwise we will create 1 == 0.
const SCEV *LHS = SE->getConstant(C->getType(), 0);
const SCEV *RHS = SE->getConstant(C->getType(), 1);
if (C->isOne() == inverted)
*Comp = new Comparison(RHS, LHS, ICmpInst::ICMP_NE);
else
*Comp = new Comparison(LHS, LHS, ICmpInst::ICMP_EQ);
return;
}
ICmpInst *ICmp = dyn_cast<ICmpInst>(&V);
assert(ICmp && "Only ICmpInst of constant as condition supported!");
const SCEV *LHS = SE->getSCEV(ICmp->getOperand(0)),
*RHS = SE->getSCEV(ICmp->getOperand(1));
ICmpInst::Predicate Pred = ICmp->getPredicate();
// Invert the predicate if needed.
if (inverted)
Pred = ICmpInst::getInversePredicate(Pred);
switch (Pred) {
case ICmpInst::ICMP_UGT:
case ICmpInst::ICMP_UGE:
case ICmpInst::ICMP_ULT:
case ICmpInst::ICMP_ULE:
// TODO: At the moment we need to see everything as signed. This is an
// correctness issue that needs to be solved.
//AffLHS->setUnsigned();
//AffRHS->setUnsigned();
break;
default:
break;
}
*Comp = new Comparison(LHS, RHS, Pred);
}
void TempScopInfo::buildCondition(BasicBlock *BB, BasicBlock *RegionEntry,
TempScop &Scop) {
BBCond Cond;
DomTreeNode *BBNode = DT->getNode(BB), *EntryNode = DT->getNode(RegionEntry);
assert(BBNode && EntryNode && "Get null node while building condition!");
// Walk up the dominance tree until reaching the entry node. Add all
// conditions on the path to BB except if BB postdominates the block
// containing the condition.
while (BBNode != EntryNode) {
BasicBlock *CurBB = BBNode->getBlock();
BBNode = BBNode->getIDom();
assert(BBNode && "BBNode should not reach the root node!");
if (PDT->dominates(CurBB, BBNode->getBlock()))
continue;
BranchInst *Br = dyn_cast<BranchInst>(BBNode->getBlock()->getTerminator());
assert(Br && "A Valid Scop should only contain branch instruction");
if (Br->isUnconditional())
continue;
// Is BB on the ELSE side of the branch?
bool inverted = DT->dominates(Br->getSuccessor(1), BB);
Comparison *Cmp;
buildAffineCondition(*(Br->getCondition()), inverted, &Cmp, Scop);
Cond.push_back(*Cmp);
}
if (!Cond.empty())
BBConds[BB] = Cond;
}
TempScop *TempScopInfo::buildTempScop(Region &R) {
TempScop *TScop = new TempScop(R, LoopBounds, BBConds, AccFuncMap);
for (Region::block_iterator I = R.block_begin(), E = R.block_end();
I != E; ++I) {
BasicBlock *BB = I->getNodeAs<BasicBlock>();
buildAccessFunctions(R, TScop->getParamSet(), *BB);
buildCondition(BB, R.getEntry(), *TScop);
}
buildLoopBounds(*TScop);
// Build the MayAliasSets.
TScop->MayASInfo->buildMayAliasSets(*TScop, *AA);
return TScop;
}
TempScop *TempScopInfo::getTempScop(const Region *R) const {
TempScopMapType::const_iterator at = TempScops.find(R);
return at == TempScops.end() ? 0 : at->second;
}
void TempScopInfo::print(raw_ostream &OS, const Module *) const {
for (TempScopMapType::const_iterator I = TempScops.begin(),
E = TempScops.end(); I != E; ++I)
I->second->print(OS, SE, LI);
}
bool TempScopInfo::runOnFunction(Function &F) {
DT = &getAnalysis<DominatorTree>();
PDT = &getAnalysis<PostDominatorTree>();
SE = &getAnalysis<ScalarEvolution>();
LI = &getAnalysis<LoopInfo>();
SD = &getAnalysis<ScopDetection>();
AA = &getAnalysis<AliasAnalysis>();
TD = &getAnalysis<TargetData>();
for (ScopDetection::iterator I = SD->begin(), E = SD->end(); I != E; ++I) {
Region *R = const_cast<Region*>(*I);
TempScops.insert(std::make_pair(R, buildTempScop(*R)));
}
return false;
}
void TempScopInfo::getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired<TargetData>();
AU.addRequiredTransitive<DominatorTree>();
AU.addRequiredTransitive<PostDominatorTree>();
AU.addRequiredTransitive<LoopInfo>();
AU.addRequiredTransitive<ScalarEvolution>();
AU.addRequiredTransitive<ScopDetection>();
AU.addRequiredID(IndependentBlocksID);
AU.addRequired<AliasAnalysis>();
AU.setPreservesAll();
}
TempScopInfo::~TempScopInfo() {
clear();
}
void TempScopInfo::clear() {
BBConds.clear();
LoopBounds.clear();
AccFuncMap.clear();
DeleteContainerSeconds(TempScops);
TempScops.clear();
}
//===----------------------------------------------------------------------===//
// TempScop information extraction pass implement
char TempScopInfo::ID = 0;
INITIALIZE_PASS_BEGIN(TempScopInfo, "polly-analyze-ir",
"Polly - Analyse the LLVM-IR in the detected regions",
false, false)
INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
INITIALIZE_PASS_DEPENDENCY(DominatorTree)
INITIALIZE_PASS_DEPENDENCY(LoopInfo)
INITIALIZE_PASS_DEPENDENCY(PostDominatorTree)
INITIALIZE_PASS_DEPENDENCY(RegionInfo)
INITIALIZE_PASS_DEPENDENCY(ScalarEvolution)
INITIALIZE_PASS_DEPENDENCY(TargetData)
INITIALIZE_PASS_END(TempScopInfo, "polly-analyze-ir",
"Polly - Analyse the LLVM-IR in the detected regions",
false, false)
Pass *polly::createTempScopInfoPass() {
return new TempScopInfo();
}