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[ScopInfo] Do not use ScopStmt in Domain derivation of ScopInfo. NFC
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ScopStmts were being used in the computation of the Domain of the SCoPs
in ScopInfo. Once statements are split, there will not be a 1-to-1
correspondence between Stmts and Basic blocks. Thus this patch avoids
the use of getStmtFor() by creating a map of BB to InvalidDomain and
using it to compute the domain of the statements.

Contributed-by: Nanidini Singhal <cs15mtech01004@iith.ac.in>

Differential Revision: https://reviews.llvm.org/D33942

llvm-svn: 306667
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@Meinersbur
Meinersbur committed Jun 29, 2017
1 parent 8996346 commit 476f855
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Showing 5 changed files with 230 additions and 118 deletions.
88 changes: 53 additions & 35 deletions polly/include/polly/ScopInfo.h
View file
Expand Up @@ -1540,14 +1540,6 @@ class ScopStmt {
/// @param NewDomain The new statement domain.
void restrictDomain(__isl_take isl_set *NewDomain);

/// Compute the isl representation for the SCEV @p E in this stmt.
///
/// @param E The SCEV that should be translated.
/// @param NonNegative Flag to indicate the @p E has to be non-negative.
///
/// Note that this function will also adjust the invalid context accordingly.
__isl_give isl_pw_aff *getPwAff(const SCEV *E, bool NonNegative = false);

/// Get the loop for a dimension.
///
/// @param Dimension The dimension of the induction variable
Expand Down Expand Up @@ -1837,14 +1829,17 @@ class Scop {
/// block in the @p FinishedExitBlocks set so we can later skip edges from
/// within the region to that block.
///
/// @param BB The block for which the domain is currently propagated.
/// @param BBLoop The innermost affine loop surrounding @p BB.
/// @param BB The block for which the domain is currently
/// propagated.
/// @param BBLoop The innermost affine loop surrounding @p BB.
/// @param FinishedExitBlocks Set of region exits the domain was set for.
/// @param LI The LoopInfo for the current function.
///
/// @param LI The LoopInfo for the current function.
/// @param InvalidDomainMap BB to InvalidDomain map for the BB of current
/// region.
void propagateDomainConstraintsToRegionExit(
BasicBlock *BB, Loop *BBLoop,
SmallPtrSetImpl<BasicBlock *> &FinishedExitBlocks, LoopInfo &LI);
SmallPtrSetImpl<BasicBlock *> &FinishedExitBlocks, LoopInfo &LI,
DenseMap<BasicBlock *, __isl_keep isl_set *> &InvalidDomainMap);

/// Compute the union of predecessor domains for @p BB.
///
Expand All @@ -1864,30 +1859,43 @@ class Scop {

/// Add loop carried constraints to the header block of the loop @p L.
///
/// @param L The loop to process.
/// @param LI The LoopInfo for the current function.
/// @param L The loop to process.
/// @param LI The LoopInfo for the current function.
/// @param InvalidDomainMap BB to InvalidDomain map for the BB of current
/// region.
///
/// @returns True if there was no problem and false otherwise.
bool addLoopBoundsToHeaderDomain(Loop *L, LoopInfo &LI);
bool addLoopBoundsToHeaderDomain(
Loop *L, LoopInfo &LI,
DenseMap<BasicBlock *, __isl_keep isl_set *> &InvalidDomainMap);

/// Compute the branching constraints for each basic block in @p R.
///
/// @param R The region we currently build branching conditions for.
/// @param DT The DominatorTree for the current function.
/// @param LI The LoopInfo for the current function.
/// @param R The region we currently build branching conditions
/// for.
/// @param DT The DominatorTree for the current function.
/// @param LI The LoopInfo for the current function.
/// @param InvalidDomainMap BB to InvalidDomain map for the BB of current
/// region.
///
/// @returns True if there was no problem and false otherwise.
bool buildDomainsWithBranchConstraints(Region *R, DominatorTree &DT,
LoopInfo &LI);
bool buildDomainsWithBranchConstraints(
Region *R, DominatorTree &DT, LoopInfo &LI,
DenseMap<BasicBlock *, __isl_keep isl_set *> &InvalidDomainMap);

/// Propagate the domain constraints through the region @p R.
///
/// @param R The region we currently build branching conditions for.
/// @param DT The DominatorTree for the current function.
/// @param LI The LoopInfo for the current function.
/// @param R The region we currently build branching conditions
/// for.
/// @param DT The DominatorTree for the current function.
/// @param LI The LoopInfo for the current function.
/// @param InvalidDomainMap BB to InvalidDomain map for the BB of current
/// region.
///
/// @returns True if there was no problem and false otherwise.
bool propagateDomainConstraints(Region *R, DominatorTree &DT, LoopInfo &LI);
bool propagateDomainConstraints(
Region *R, DominatorTree &DT, LoopInfo &LI,
DenseMap<BasicBlock *, __isl_keep isl_set *> &InvalidDomainMap);

/// Propagate invalid domains of statements through @p R.
///
Expand All @@ -1896,21 +1904,29 @@ class Scop {
/// of error statements and those only reachable via error statements will be
/// replaced by an empty set. Later those will be removed completely.
///
/// @param R The currently traversed region.
/// @param DT The DominatorTree for the current function.
/// @param LI The LoopInfo for the current function.
///
/// @param R The currently traversed region.
/// @param DT The DominatorTree for the current function.
/// @param LI The LoopInfo for the current function.
/// @param InvalidDomainMap BB to InvalidDomain map for the BB of current
/// region.
//
/// @returns True if there was no problem and false otherwise.
bool propagateInvalidStmtDomains(Region *R, DominatorTree &DT, LoopInfo &LI);
bool propagateInvalidStmtDomains(
Region *R, DominatorTree &DT, LoopInfo &LI,
DenseMap<BasicBlock *, __isl_keep isl_set *> &InvalidDomainMap);

/// Compute the domain for each basic block in @p R.
///
/// @param R The region we currently traverse.
/// @param DT The DominatorTree for the current function.
/// @param LI The LoopInfo for the current function.
/// @param R The region we currently traverse.
/// @param DT The DominatorTree for the current function.
/// @param LI The LoopInfo for the current function.
/// @param InvalidDomainMap BB to InvalidDomain map for the BB of current
/// region.
///
/// @returns True if there was no problem and false otherwise.
bool buildDomains(Region *R, DominatorTree &DT, LoopInfo &LI);
bool
buildDomains(Region *R, DominatorTree &DT, LoopInfo &LI,
DenseMap<BasicBlock *, __isl_keep isl_set *> &InvalidDomainMap);

/// Add parameter constraints to @p C that imply a non-empty domain.
__isl_give isl_set *addNonEmptyDomainConstraints(__isl_take isl_set *C) const;
Expand Down Expand Up @@ -2018,7 +2034,9 @@ class Scop {
void buildContext();

/// Add user provided parameter constraints to context (source code).
void addUserAssumptions(AssumptionCache &AC, DominatorTree &DT, LoopInfo &LI);
void addUserAssumptions(
AssumptionCache &AC, DominatorTree &DT, LoopInfo &LI,
DenseMap<BasicBlock *, __isl_keep isl_set *> &InvalidDomainMap);

/// Add user provided parameter constraints to context (command line).
void addUserContext();
Expand Down
21 changes: 20 additions & 1 deletion polly/include/polly/Support/ScopHelper.h
View file
Expand Up @@ -426,5 +426,24 @@ llvm::BasicBlock *getUseBlock(llvm::Use &U);
std::tuple<std::vector<const llvm::SCEV *>, std::vector<int>>
getIndexExpressionsFromGEP(llvm::GetElementPtrInst *GEP,
llvm::ScalarEvolution &SE);

// If the loop is nonaffine/boxed, return the first non-boxed surrounding loop
// for Polly. If the loop is affine, return the loop itself.
//
// @param L Pointer to the Loop object to analyze.
// @param LI Reference to the LoopInfo.
// @param BoxedLoops Set of Boxed Loops we get from the SCoP.
llvm::Loop *getFirstNonBoxedLoopFor(llvm::Loop *L, llvm::LoopInfo &LI,
const BoxedLoopsSetTy &BoxedLoops);

// If the Basic Block belongs to a loop that is nonaffine/boxed, return the
// first non-boxed surrounding loop for Polly. If the loop is affine, return
// the loop itself.
//
// @param BB Pointer to the Basic Block to analyze.
// @param LI Reference to the LoopInfo.
// @param BoxedLoops Set of Boxed Loops we get from the SCoP.
llvm::Loop *getFirstNonBoxedLoopFor(llvm::BasicBlock *BB, llvm::LoopInfo &LI,
const BoxedLoopsSetTy &BoxedLoops);
} // namespace polly
#endif
#endif
35 changes: 29 additions & 6 deletions polly/lib/Analysis/ScopBuilder.cpp
View file
Expand Up @@ -627,10 +627,8 @@ void ScopBuilder::buildAccessFunctions() {

void ScopBuilder::buildStmts(Region &SR) {
if (scop->isNonAffineSubRegion(&SR)) {
Loop *SurroundingLoop = LI.getLoopFor(SR.getEntry());
auto &BoxedLoops = scop->getBoxedLoops();
while (BoxedLoops.count(SurroundingLoop))
SurroundingLoop = SurroundingLoop->getParentLoop();
Loop *SurroundingLoop =
getFirstNonBoxedLoopFor(SR.getEntry(), LI, scop->getBoxedLoops());
scop->addScopStmt(&SR, SurroundingLoop);
return;
}
Expand Down Expand Up @@ -930,6 +928,12 @@ static void verifyUses(Scop *S, LoopInfo &LI, DominatorTree &DT) {
}
#endif

/// Return the block that is the representing block for @p RN.
static inline BasicBlock *getRegionNodeBasicBlock(RegionNode *RN) {
return RN->isSubRegion() ? RN->getNodeAs<Region>()->getEntry()
: RN->getNodeAs<BasicBlock>();
}

void ScopBuilder::buildScop(Region &R, AssumptionCache &AC) {
scop.reset(new Scop(R, SE, LI, *SD.getDetectionContext(&R)));

Expand Down Expand Up @@ -959,10 +963,29 @@ void ScopBuilder::buildScop(Region &R, AssumptionCache &AC) {

scop->buildInvariantEquivalenceClasses();

if (!scop->buildDomains(&R, DT, LI))
/// A map from basic blocks to their invalid domains.
DenseMap<BasicBlock *, isl_set *> InvalidDomainMap;

if (!scop->buildDomains(&R, DT, LI, InvalidDomainMap)) {
for (auto It : InvalidDomainMap)
isl_set_free(It.second);
return;
}

scop->addUserAssumptions(AC, DT, LI, InvalidDomainMap);

// Initialize the invalid domain.
for (ScopStmt &Stmt : scop->Stmts)
if (Stmt.isBlockStmt())
Stmt.setInvalidDomain(
isl_set_copy(InvalidDomainMap[Stmt.getEntryBlock()]));
else
Stmt.setInvalidDomain(
isl_set_copy(InvalidDomainMap[getRegionNodeBasicBlock(
Stmt.getRegion()->getNode())]));

scop->addUserAssumptions(AC, DT, LI);
for (auto It : InvalidDomainMap)
isl_set_free(It.second);

// Remove empty statements.
// Exit early in case there are no executable statements left in this scop.
Expand Down

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