llvm-project/llvm/lib/Analysis/LoopPass.cpp

170 lines
5.1 KiB
C++
Raw Normal View History

2007-02-22 16:56:17 +08:00
//===- LoopPass.cpp - Loop Pass and Loop Pass Manager ---------------------===//
//
// 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 implements LoopPass and LPPassManager. All loop optimization
// and transformation passes are derived from LoopPass. LPPassManager is
// responsible for managing LoopPasses.
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/LoopPass.h"
using namespace llvm;
//===----------------------------------------------------------------------===//
// LPPassManager
//
/// LPPassManager manages FPPassManagers and CalLGraphSCCPasses.
LPPassManager::LPPassManager(int Depth) : PMDataManager(Depth) {
skipThisLoop = false;
redoThisLoop = false;
}
/// Delete loop from the loop queue. This is used by Loop pass to inform
/// Loop Pass Manager that it should skip rest of the passes for this loop.
void LPPassManager::deleteLoopFromQueue(Loop *L) {
// Do not pop loop from LQ here. It will be done by runOnFunction while loop.
skipThisLoop = true;
}
// 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) {
redoThisLoop = true;
}
// Recurse through all subloops and all loops into LQ.
static void addLoopIntoQueue(Loop *L, std::deque<Loop *> &LQ) {
for (Loop::iterator I = L->begin(), E = L->end(); I != E; ++I)
addLoopIntoQueue(*I, LQ);
LQ.push_back(L);
}
2007-02-22 16:56:17 +08:00
/// 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) {
LoopInfo &LI = getAnalysis<LoopInfo>();
bool Changed = false;
// Populate Loop Queue
for (LoopInfo::iterator I = LI.begin(), E = LI.end(); I != E; ++I)
addLoopIntoQueue(*I, LQ);
// 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);
}
}
2007-02-22 16:56:17 +08:00
// Walk Loops
while (!LQ.empty()) {
Loop *L = LQ.back();
skipThisLoop = false;
redoThisLoop = false;
2007-02-22 16:56:17 +08:00
// Run all passes on current SCC
for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
2007-02-22 16:56:17 +08:00
Pass *P = getContainedPass(Index);
AnalysisUsage AnUsage;
P->getAnalysisUsage(AnUsage);
dumpPassInfo(P, EXECUTION_MSG, ON_LOOP_MSG, "");
2007-02-22 16:56:17 +08:00
dumpAnalysisSetInfo("Required", P, AnUsage.getRequiredSet());
initializeAnalysisImpl(P);
StartPassTimer(P);
LoopPass *LP = dynamic_cast<LoopPass *>(P);
assert (LP && "Invalid LPPassManager member");
LP->runOnLoop(L, *this);
2007-02-22 16:56:17 +08:00
StopPassTimer(P);
if (Changed)
dumpPassInfo(P, MODIFICATION_MSG, ON_LOOP_MSG, "");
2007-02-22 16:56:17 +08:00
dumpAnalysisSetInfo("Preserved", P, AnUsage.getPreservedSet());
removeNotPreservedAnalysis(P);
recordAvailableAnalysis(P);
removeDeadPasses(P, "", ON_LOOP_MSG);
if (skipThisLoop)
// Do not run other passes on this loop.
break;
2007-02-22 16:56:17 +08:00
}
// Pop the loop from queue after running all passes.
LQ.pop_back();
if (redoThisLoop)
LQ.push_back(L);
2007-02-22 16:56:17 +08:00
}
// Finalization
for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
Pass *P = getContainedPass(Index);
LoopPass *LP = dynamic_cast <LoopPass *>(P);
if (LP)
Changed |= LP->doFinalization();
}
2007-02-22 16:56:17 +08:00
return Changed;
}
//===----------------------------------------------------------------------===//
// LoopPass
/// 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) {
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);
// [2] Set up new manager's top level manager
PMTopLevelManager *TPM = PMD->getTopLevelManager();
TPM->addIndirectPassManager(LPPM);
// [3] Assign manager to manage this new manager. This may create
// and push new managers into PMS
Pass *P = dynamic_cast<Pass *>(LPPM);
P->assignPassManager(PMS);
// [4] Push new manager into PMS
PMS.push(LPPM);
}
LPPM->add(this);
}