//
// The LLVM Compiler Infrastructure
//
-// This file was developed by Devang Patel and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/LoopPass.h"
-#include "llvm/Analysis/ScalarEvolutionExpander.h"
+#include "llvm/IR/IRPrintingPasses.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/PassManager.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/Timer.h"
+#include "llvm/Support/raw_ostream.h"
using namespace llvm;
+#define DEBUG_TYPE "loop-pass-manager"
+
+namespace {
+
+/// PrintLoopPass - Print a Function corresponding to a Loop.
+///
+class PrintLoopPassWrapper : public LoopPass {
+ PrintLoopPass P;
+
+public:
+ static char ID;
+ PrintLoopPassWrapper() : LoopPass(ID) {}
+ PrintLoopPassWrapper(raw_ostream &OS, const std::string &Banner)
+ : LoopPass(ID), P(OS, Banner) {}
+
+ void getAnalysisUsage(AnalysisUsage &AU) const override {
+ AU.setPreservesAll();
+ }
+
+ bool runOnLoop(Loop *L, LPPassManager &) override {
+ auto BBI = find_if(L->blocks().begin(), L->blocks().end(),
+ [](BasicBlock *BB) { return BB; });
+ if (BBI != L->blocks().end() &&
+ isFunctionInPrintList((*BBI)->getParent()->getName()))
+ P.run(*L);
+ return false;
+ }
+};
+
+char PrintLoopPassWrapper::ID = 0;
+}
+
//===----------------------------------------------------------------------===//
// LPPassManager
//
char LPPassManager::ID = 0;
-/// LPPassManager manages FPPassManagers and CalLGraphSCCPasses.
-
-LPPassManager::LPPassManager(int Depth)
- : FunctionPass((intptr_t)&ID), PMDataManager(Depth) {
- skipThisLoop = false;
- redoThisLoop = false;
- LI = NULL;
- CurrentLoop = NULL;
-}
-/// Delete loop from the loop queue and loop hierarcy (LoopInfo).
-void LPPassManager::deleteLoopFromQueue(Loop *L) {
-
- if (Loop *ParentLoop = L->getParentLoop()) { // Not a top-level loop.
- // Reparent all of the blocks in this loop. Since BBLoop had a parent,
- // they are now all in it.
- for (Loop::block_iterator I = L->block_begin(), E = L->block_end();
- I != E; ++I)
- if (LI->getLoopFor(*I) == L) // Don't change blocks in subloops.
- LI->changeLoopFor(*I, ParentLoop);
-
- // Remove the loop from its parent loop.
- for (Loop::iterator I = ParentLoop->begin(), E = ParentLoop->end();;
- ++I) {
- assert(I != E && "Couldn't find loop");
- if (*I == L) {
- ParentLoop->removeChildLoop(I);
- break;
- }
- }
-
- // Move all subloops into the parent loop.
- while (L->begin() != L->end())
- ParentLoop->addChildLoop(L->removeChildLoop(L->end()-1));
- } else {
- // Reparent all of the blocks in this loop. Since BBLoop had no parent,
- // they no longer in a loop at all.
-
- for (unsigned i = 0; i != L->getBlocks().size(); ++i) {
- // Don't change blocks in subloops.
- if (LI->getLoopFor(L->getBlocks()[i]) == L) {
- LI->removeBlock(L->getBlocks()[i]);
- --i;
- }
- }
-
- // Remove the loop from the top-level LoopInfo object.
- for (LoopInfo::iterator I = LI->begin(), E = LI->end();; ++I) {
- assert(I != E && "Couldn't find loop");
- if (*I == L) {
- LI->removeLoop(I);
- break;
- }
- }
-
- // Move all of the subloops to the top-level.
- while (L->begin() != L->end())
- LI->addTopLevelLoop(L->removeChildLoop(L->end()-1));
- }
+LPPassManager::LPPassManager()
+ : FunctionPass(ID), PMDataManager() {
+ LI = nullptr;
+ CurrentLoop = nullptr;
+}
- delete L;
+// Inset loop into loop nest (LoopInfo) and loop queue (LQ).
+Loop &LPPassManager::addLoop(Loop *ParentLoop) {
+ // Create a new loop. LI will take ownership.
+ Loop *L = new Loop();
- // If L is current loop then skip rest of the passes and let
- // runOnFunction remove L from LQ. Otherwise, remove L from LQ now
- // and continue applying other passes on CurrentLoop.
- if (CurrentLoop == L) {
- skipThisLoop = true;
- return;
+ // Insert into the loop nest and the loop queue.
+ if (!ParentLoop) {
+ // This is the top level loop.
+ LI->addTopLevelLoop(L);
+ LQ.push_front(L);
+ return *L;
}
- for (std::deque<Loop *>::iterator I = LQ.begin(),
- E = LQ.end(); I != E; ++I) {
- if (*I == L) {
- LQ.erase(I);
+ ParentLoop->addChildLoop(L);
+ // Insert L into the loop queue after the parent loop.
+ for (auto I = LQ.begin(), E = LQ.end(); I != E; ++I) {
+ if (*I == L->getParentLoop()) {
+ // deque does not support insert after.
+ ++I;
+ LQ.insert(I, 1, L);
break;
}
}
+ return *L;
}
-// Inset loop into loop nest (LoopInfo) and loop queue (LQ).
-void LPPassManager::insertLoop(Loop *L, Loop *ParentLoop) {
-
- assert (CurrentLoop != L && "Cannot insert CurrentLoop");
-
- // Insert into loop nest
- if (ParentLoop)
- ParentLoop->addChildLoop(L);
- else
- LI->addTopLevelLoop(L);
+/// cloneBasicBlockSimpleAnalysis - Invoke cloneBasicBlockAnalysis hook for
+/// all loop passes.
+void LPPassManager::cloneBasicBlockSimpleAnalysis(BasicBlock *From,
+ BasicBlock *To, Loop *L) {
+ for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
+ LoopPass *LP = getContainedPass(Index);
+ LP->cloneBasicBlockAnalysis(From, To, L);
+ }
+}
- // Insert L into loop queue
- if (L == CurrentLoop)
- redoLoop(L);
- else if (!ParentLoop)
- // This is top level loop.
- LQ.push_front(L);
- else {
- // Insert L after ParentLoop
- for (std::deque<Loop *>::iterator I = LQ.begin(),
- E = LQ.end(); I != E; ++I) {
- if (*I == ParentLoop) {
- // deque does not support insert after.
- ++I;
- LQ.insert(I, 1, L);
- break;
- }
+/// deleteSimpleAnalysisValue - Invoke deleteAnalysisValue hook for all passes.
+void LPPassManager::deleteSimpleAnalysisValue(Value *V, Loop *L) {
+ if (BasicBlock *BB = dyn_cast<BasicBlock>(V)) {
+ for (BasicBlock::iterator BI = BB->begin(), BE = BB->end(); BI != BE;
+ ++BI) {
+ Instruction &I = *BI;
+ deleteSimpleAnalysisValue(&I, L);
}
}
+ for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
+ LoopPass *LP = getContainedPass(Index);
+ LP->deleteAnalysisValue(V, L);
+ }
}
-// Reoptimize this loop. LPPassManager will re-insert this loop into the
-// queue. This allows LoopPass to change loop nest for the loop. This
-// utility may send LPPassManager into infinite loops so use caution.
-void LPPassManager::redoLoop(Loop *L) {
- assert (CurrentLoop == L && "Can redo only CurrentLoop");
- redoThisLoop = true;
+/// Invoke deleteAnalysisLoop hook for all passes.
+void LPPassManager::deleteSimpleAnalysisLoop(Loop *L) {
+ for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
+ LoopPass *LP = getContainedPass(Index);
+ LP->deleteAnalysisLoop(L);
+ }
}
+
// Recurse through all subloops and all loops into LQ.
static void addLoopIntoQueue(Loop *L, std::deque<Loop *> &LQ) {
LQ.push_back(L);
- for (Loop::iterator I = L->begin(), E = L->end(); I != E; ++I)
+ for (Loop::reverse_iterator I = L->rbegin(), E = L->rend(); I != E; ++I)
addLoopIntoQueue(*I, LQ);
}
/// Pass Manager itself does not invalidate any analysis info.
void LPPassManager::getAnalysisUsage(AnalysisUsage &Info) const {
- // LPPassManager needs LoopInfo. In the long term LoopInfo class will
+ // LPPassManager needs LoopInfo. In the long term LoopInfo class will
// become part of LPPassManager.
- Info.addRequired<LoopInfo>();
- // Used by IndVar doInitialization.
- Info.addRequired<ScalarEvolution>();
+ Info.addRequired<LoopInfoWrapperPass>();
Info.setPreservesAll();
}
/// run - Execute all of the passes scheduled for execution. Keep track of
/// whether any of the passes modifies the function, and if so, return true.
bool LPPassManager::runOnFunction(Function &F) {
- LI = &getAnalysis<LoopInfo>();
+ auto &LIWP = getAnalysis<LoopInfoWrapperPass>();
+ LI = &LIWP.getLoopInfo();
bool Changed = false;
- // Populate Loop Queue
- for (LoopInfo::iterator I = LI->begin(), E = LI->end(); I != E; ++I)
+ // Collect inherited analysis from Module level pass manager.
+ populateInheritedAnalysis(TPM->activeStack);
+
+ // Populate the loop queue in reverse program order. There is no clear need to
+ // process sibling loops in either forward or reverse order. There may be some
+ // advantage in deleting uses in a later loop before optimizing the
+ // definitions in an earlier loop. If we find a clear reason to process in
+ // forward order, then a forward variant of LoopPassManager should be created.
+ //
+ // Note that LoopInfo::iterator visits loops in reverse program
+ // order. Here, reverse_iterator gives us a forward order, and the LoopQueue
+ // reverses the order a third time by popping from the back.
+ for (LoopInfo::reverse_iterator I = LI->rbegin(), E = LI->rend(); I != E; ++I)
addLoopIntoQueue(*I, LQ);
+ if (LQ.empty()) // No loops, skip calling finalizers
+ return false;
+
// Initialization
for (std::deque<Loop *>::const_iterator I = LQ.begin(), E = LQ.end();
I != E; ++I) {
Loop *L = *I;
- for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
- Pass *P = getContainedPass(Index);
- LoopPass *LP = dynamic_cast<LoopPass *>(P);
- if (LP)
- Changed |= LP->doInitialization(L, *this);
+ for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
+ LoopPass *P = getContainedPass(Index);
+ Changed |= P->doInitialization(L, *this);
}
}
// Walk Loops
while (!LQ.empty()) {
-
- CurrentLoop = LQ.back();
- skipThisLoop = false;
- redoThisLoop = false;
+ bool LoopWasDeleted = false;
+ CurrentLoop = LQ.back();
- // Run all passes on current SCC
- for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
-
- Pass *P = getContainedPass(Index);
- AnalysisUsage AnUsage;
- P->getAnalysisUsage(AnUsage);
+ // Run all passes on the current Loop.
+ for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
+ LoopPass *P = getContainedPass(Index);
- dumpPassInfo(P, EXECUTION_MSG, ON_LOOP_MSG, "");
- dumpAnalysisSetInfo("Required", P, AnUsage.getRequiredSet());
+ dumpPassInfo(P, EXECUTION_MSG, ON_LOOP_MSG,
+ CurrentLoop->getHeader()->getName());
+ dumpRequiredSet(P);
initializeAnalysisImpl(P);
- StartPassTimer(P);
- LoopPass *LP = dynamic_cast<LoopPass *>(P);
- assert (LP && "Invalid LPPassManager member");
- LP->runOnLoop(CurrentLoop, *this);
- StopPassTimer(P);
+ {
+ PassManagerPrettyStackEntry X(P, *CurrentLoop->getHeader());
+ TimeRegion PassTimer(getPassTimer(P));
+
+ Changed |= P->runOnLoop(CurrentLoop, *this);
+ }
+ LoopWasDeleted = CurrentLoop->isInvalid();
if (Changed)
- dumpPassInfo(P, MODIFICATION_MSG, ON_LOOP_MSG, "");
- dumpAnalysisSetInfo("Preserved", P, AnUsage.getPreservedSet());
-
+ dumpPassInfo(P, MODIFICATION_MSG, ON_LOOP_MSG,
+ LoopWasDeleted ? "<deleted>"
+ : CurrentLoop->getHeader()->getName());
+ dumpPreservedSet(P);
+
+ if (LoopWasDeleted) {
+ // Notify passes that the loop is being deleted.
+ deleteSimpleAnalysisLoop(CurrentLoop);
+ } else {
+ // Manually check that this loop is still healthy. This is done
+ // instead of relying on LoopInfo::verifyLoop since LoopInfo
+ // is a function pass and it's really expensive to verify every
+ // loop in the function every time. That level of checking can be
+ // enabled with the -verify-loop-info option.
+ {
+ TimeRegion PassTimer(getPassTimer(&LIWP));
+ CurrentLoop->verifyLoop();
+ }
+
+ // Then call the regular verifyAnalysis functions.
+ verifyPreservedAnalysis(P);
+
+ F.getContext().yield();
+ }
+
removeNotPreservedAnalysis(P);
recordAvailableAnalysis(P);
- removeDeadPasses(P, "", ON_LOOP_MSG);
+ removeDeadPasses(P, LoopWasDeleted ? "<deleted>"
+ : CurrentLoop->getHeader()->getName(),
+ ON_LOOP_MSG);
- if (skipThisLoop)
+ if (LoopWasDeleted)
// Do not run other passes on this loop.
break;
}
-
+
+ // If the loop was deleted, release all the loop passes. This frees up
+ // some memory, and avoids trouble with the pass manager trying to call
+ // verifyAnalysis on them.
+ if (LoopWasDeleted) {
+ for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
+ Pass *P = getContainedPass(Index);
+ freePass(P, "<deleted>", ON_LOOP_MSG);
+ }
+ }
+
// Pop the loop from queue after running all passes.
LQ.pop_back();
-
- if (redoThisLoop)
- LQ.push_back(CurrentLoop);
}
-
+
// Finalization
for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
- Pass *P = getContainedPass(Index);
- LoopPass *LP = dynamic_cast <LoopPass *>(P);
- if (LP)
- Changed |= LP->doFinalization();
+ LoopPass *P = getContainedPass(Index);
+ Changed |= P->doFinalization();
}
return Changed;
}
+/// Print passes managed by this manager
+void LPPassManager::dumpPassStructure(unsigned Offset) {
+ errs().indent(Offset*2) << "Loop Pass Manager\n";
+ for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
+ Pass *P = getContainedPass(Index);
+ P->dumpPassStructure(Offset + 1);
+ dumpLastUses(P, Offset+1);
+ }
+}
+
//===----------------------------------------------------------------------===//
// LoopPass
+Pass *LoopPass::createPrinterPass(raw_ostream &O,
+ const std::string &Banner) const {
+ return new PrintLoopPassWrapper(O, Banner);
+}
+
// Check if this pass is suitable for the current LPPassManager, if
// available. This pass P is not suitable for a LPPassManager if P
// is not preserving higher level analysis info used by other
// LPPassManger as expected.
void LoopPass::preparePassManager(PMStack &PMS) {
- // Find LPPassManager
- while (!PMS.empty()) {
- if (PMS.top()->getPassManagerType() > PMT_LoopPassManager)
- PMS.pop();
- else;
- break;
- }
-
- LPPassManager *LPPM = dynamic_cast<LPPassManager *>(PMS.top());
+ // Find LPPassManager
+ while (!PMS.empty() &&
+ PMS.top()->getPassManagerType() > PMT_LoopPassManager)
+ PMS.pop();
// If this pass is destroying high level information that is used
// by other passes that are managed by LPM then do not insert
// this pass in current LPM. Use new LPPassManager.
- if (LPPM && !LPPM->preserveHigherLevelAnalysis(this))
+ if (PMS.top()->getPassManagerType() == PMT_LoopPassManager &&
+ !PMS.top()->preserveHigherLevelAnalysis(this))
PMS.pop();
}
/// Assign pass manager to manage this pass.
void LoopPass::assignPassManager(PMStack &PMS,
PassManagerType PreferredType) {
- // Find LPPassManager
- while (!PMS.empty()) {
- if (PMS.top()->getPassManagerType() > PMT_LoopPassManager)
- PMS.pop();
- else;
- break;
- }
-
- LPPassManager *LPPM = dynamic_cast<LPPassManager *>(PMS.top());
-
- // Create new Loop Pass Manager if it does not exist.
- if (!LPPM) {
+ // Find LPPassManager
+ while (!PMS.empty() &&
+ PMS.top()->getPassManagerType() > PMT_LoopPassManager)
+ PMS.pop();
+ LPPassManager *LPPM;
+ if (PMS.top()->getPassManagerType() == PMT_LoopPassManager)
+ LPPM = (LPPassManager*)PMS.top();
+ else {
+ // Create new Loop Pass Manager if it does not exist.
assert (!PMS.empty() && "Unable to create Loop Pass Manager");
PMDataManager *PMD = PMS.top();
- // [1] Create new Call Graph Pass Manager
- LPPM = new LPPassManager(PMD->getDepth() + 1);
+ // [1] Create new Loop Pass Manager
+ LPPM = new LPPassManager();
LPPM->populateInheritedAnalysis(PMS);
// [2] Set up new manager's top level manager
// [3] Assign manager to manage this new manager. This may create
// and push new managers into PMS
- Pass *P = dynamic_cast<Pass *>(LPPM);
+ Pass *P = LPPM->getAsPass();
TPM->schedulePass(P);
// [4] Push new manager into PMS
LPPM->add(this);
}
+// Containing function has Attribute::OptimizeNone and transformation
+// passes should skip it.
+bool LoopPass::skipOptnoneFunction(const Loop *L) const {
+ const Function *F = L->getHeader()->getParent();
+ if (F && F->hasFnAttribute(Attribute::OptimizeNone)) {
+ // FIXME: Report this to dbgs() only once per function.
+ DEBUG(dbgs() << "Skipping pass '" << getPassName()
+ << "' in function " << F->getName() << "\n");
+ // FIXME: Delete loop from pass manager's queue?
+ return true;
+ }
+ return false;
+}