llvm/lib/VMCore/Pass.cpp
2008-06-21 19:47:03 +00:00

323 lines
10 KiB
C++

//===- Pass.cpp - LLVM Pass Infrastructure Implementation -----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the LLVM Pass infrastructure. It is primarily
// responsible with ensuring that passes are executed and batched together
// optimally.
//
//===----------------------------------------------------------------------===//
#include "llvm/Pass.h"
#include "llvm/PassManager.h"
#include "llvm/Module.h"
#include "llvm/ModuleProvider.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/ManagedStatic.h"
#include <algorithm>
#include <map>
#include <set>
using namespace llvm;
//===----------------------------------------------------------------------===//
// Pass Implementation
//
// Force out-of-line virtual method.
Pass::~Pass() {
delete Resolver;
}
// Force out-of-line virtual method.
ModulePass::~ModulePass() { }
bool Pass::mustPreserveAnalysisID(const PassInfo *AnalysisID) const {
return Resolver->getAnalysisToUpdate(AnalysisID, true) != 0;
}
// dumpPassStructure - Implement the -debug-passes=Structure option
void Pass::dumpPassStructure(unsigned Offset) {
cerr << std::string(Offset*2, ' ') << getPassName() << "\n";
}
/// getPassName - Return a nice clean name for a pass. This usually
/// implemented in terms of the name that is registered by one of the
/// Registration templates, but can be overloaded directly.
///
const char *Pass::getPassName() const {
if (const PassInfo *PI = getPassInfo())
return PI->getPassName();
return "Unnamed pass: implement Pass::getPassName()";
}
// print - Print out the internal state of the pass. This is called by Analyze
// to print out the contents of an analysis. Otherwise it is not necessary to
// implement this method.
//
void Pass::print(std::ostream &O,const Module*) const {
O << "Pass::print not implemented for pass: '" << getPassName() << "'!\n";
}
// dump - call print(cerr);
void Pass::dump() const {
print(*cerr.stream(), 0);
}
//===----------------------------------------------------------------------===//
// ImmutablePass Implementation
//
// Force out-of-line virtual method.
ImmutablePass::~ImmutablePass() { }
//===----------------------------------------------------------------------===//
// FunctionPass Implementation
//
// run - On a module, we run this pass by initializing, runOnFunction'ing once
// for every function in the module, then by finalizing.
//
bool FunctionPass::runOnModule(Module &M) {
bool Changed = doInitialization(M);
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
if (!I->isDeclaration()) // Passes are not run on external functions!
Changed |= runOnFunction(*I);
return Changed | doFinalization(M);
}
// run - On a function, we simply initialize, run the function, then finalize.
//
bool FunctionPass::run(Function &F) {
// Passes are not run on external functions!
if (F.isDeclaration()) return false;
bool Changed = doInitialization(*F.getParent());
Changed |= runOnFunction(F);
return Changed | doFinalization(*F.getParent());
}
//===----------------------------------------------------------------------===//
// BasicBlockPass Implementation
//
// To run this pass on a function, we simply call runOnBasicBlock once for each
// function.
//
bool BasicBlockPass::runOnFunction(Function &F) {
bool Changed = doInitialization(F);
for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I)
Changed |= runOnBasicBlock(*I);
return Changed | doFinalization(F);
}
//===----------------------------------------------------------------------===//
// Pass Registration mechanism
//
namespace {
class PassRegistrar {
/// PassInfoMap - Keep track of the passinfo object for each registered llvm
/// pass.
typedef std::map<intptr_t, const PassInfo*> MapType;
MapType PassInfoMap;
/// AnalysisGroupInfo - Keep track of information for each analysis group.
struct AnalysisGroupInfo {
const PassInfo *DefaultImpl;
std::set<const PassInfo *> Implementations;
AnalysisGroupInfo() : DefaultImpl(0) {}
};
/// AnalysisGroupInfoMap - Information for each analysis group.
std::map<const PassInfo *, AnalysisGroupInfo> AnalysisGroupInfoMap;
public:
const PassInfo *GetPassInfo(intptr_t TI) const {
MapType::const_iterator I = PassInfoMap.find(TI);
return I != PassInfoMap.end() ? I->second : 0;
}
void RegisterPass(const PassInfo &PI) {
bool Inserted =
PassInfoMap.insert(std::make_pair(PI.getTypeInfo(),&PI)).second;
assert(Inserted && "Pass registered multiple times!"); Inserted=Inserted;
}
void UnregisterPass(const PassInfo &PI) {
MapType::iterator I = PassInfoMap.find(PI.getTypeInfo());
assert(I != PassInfoMap.end() && "Pass registered but not in map!");
// Remove pass from the map.
PassInfoMap.erase(I);
}
void EnumerateWith(PassRegistrationListener *L) {
for (MapType::const_iterator I = PassInfoMap.begin(),
E = PassInfoMap.end(); I != E; ++I)
L->passEnumerate(I->second);
}
/// Analysis Group Mechanisms.
void RegisterAnalysisGroup(PassInfo *InterfaceInfo,
const PassInfo *ImplementationInfo,
bool isDefault) {
AnalysisGroupInfo &AGI = AnalysisGroupInfoMap[InterfaceInfo];
assert(AGI.Implementations.count(ImplementationInfo) == 0 &&
"Cannot add a pass to the same analysis group more than once!");
AGI.Implementations.insert(ImplementationInfo);
if (isDefault) {
assert(AGI.DefaultImpl == 0 && InterfaceInfo->getNormalCtor() == 0 &&
"Default implementation for analysis group already specified!");
assert(ImplementationInfo->getNormalCtor() &&
"Cannot specify pass as default if it does not have a default ctor");
AGI.DefaultImpl = ImplementationInfo;
InterfaceInfo->setNormalCtor(ImplementationInfo->getNormalCtor());
}
}
};
}
static std::vector<PassRegistrationListener*> *Listeners = 0;
// FIXME: This should use ManagedStatic to manage the pass registrar.
// Unfortunately, we can't do this, because passes are registered with static
// ctors, and having llvm_shutdown clear this map prevents successful
// ressurection after llvm_shutdown is run.
static PassRegistrar *getPassRegistrar() {
static PassRegistrar *PassRegistrarObj = 0;
if (!PassRegistrarObj)
PassRegistrarObj = new PassRegistrar();
return PassRegistrarObj;
}
// getPassInfo - Return the PassInfo data structure that corresponds to this
// pass...
const PassInfo *Pass::getPassInfo() const {
return lookupPassInfo(PassID);
}
const PassInfo *Pass::lookupPassInfo(intptr_t TI) {
return getPassRegistrar()->GetPassInfo(TI);
}
void PassInfo::registerPass() {
getPassRegistrar()->RegisterPass(*this);
// Notify any listeners.
if (Listeners)
for (std::vector<PassRegistrationListener*>::iterator
I = Listeners->begin(), E = Listeners->end(); I != E; ++I)
(*I)->passRegistered(this);
}
void PassInfo::unregisterPass() {
getPassRegistrar()->UnregisterPass(*this);
}
//===----------------------------------------------------------------------===//
// Analysis Group Implementation Code
//===----------------------------------------------------------------------===//
// RegisterAGBase implementation
//
RegisterAGBase::RegisterAGBase(const char *Name, intptr_t InterfaceID,
intptr_t PassID, bool isDefault)
: PassInfo(Name, InterfaceID),
ImplementationInfo(0), isDefaultImplementation(isDefault) {
InterfaceInfo = const_cast<PassInfo*>(Pass::lookupPassInfo(InterfaceID));
if (InterfaceInfo == 0) {
// First reference to Interface, register it now.
registerPass();
InterfaceInfo = this;
}
assert(isAnalysisGroup() &&
"Trying to join an analysis group that is a normal pass!");
if (PassID) {
ImplementationInfo = Pass::lookupPassInfo(PassID);
assert(ImplementationInfo &&
"Must register pass before adding to AnalysisGroup!");
// Make sure we keep track of the fact that the implementation implements
// the interface.
PassInfo *IIPI = const_cast<PassInfo*>(ImplementationInfo);
IIPI->addInterfaceImplemented(InterfaceInfo);
getPassRegistrar()->RegisterAnalysisGroup(InterfaceInfo, IIPI, isDefault);
}
}
//===----------------------------------------------------------------------===//
// PassRegistrationListener implementation
//
// PassRegistrationListener ctor - Add the current object to the list of
// PassRegistrationListeners...
PassRegistrationListener::PassRegistrationListener() {
if (!Listeners) Listeners = new std::vector<PassRegistrationListener*>();
Listeners->push_back(this);
}
// dtor - Remove object from list of listeners...
PassRegistrationListener::~PassRegistrationListener() {
std::vector<PassRegistrationListener*>::iterator I =
std::find(Listeners->begin(), Listeners->end(), this);
assert(Listeners && I != Listeners->end() &&
"PassRegistrationListener not registered!");
Listeners->erase(I);
if (Listeners->empty()) {
delete Listeners;
Listeners = 0;
}
}
// enumeratePasses - Iterate over the registered passes, calling the
// passEnumerate callback on each PassInfo object.
//
void PassRegistrationListener::enumeratePasses() {
getPassRegistrar()->EnumerateWith(this);
}
//===----------------------------------------------------------------------===//
// AnalysisUsage Class Implementation
//
namespace {
struct GetCFGOnlyPasses : public PassRegistrationListener {
std::vector<AnalysisID> &CFGOnlyList;
GetCFGOnlyPasses(std::vector<AnalysisID> &L) : CFGOnlyList(L) {}
void passEnumerate(const PassInfo *P) {
if (P->isCFGOnlyPass())
CFGOnlyList.push_back(P);
}
};
}
// setPreservesCFG - This function should be called to by the pass, iff they do
// not:
//
// 1. Add or remove basic blocks from the function
// 2. Modify terminator instructions in any way.
//
// This function annotates the AnalysisUsage info object to say that analyses
// that only depend on the CFG are preserved by this pass.
//
void AnalysisUsage::setPreservesCFG() {
// Since this transformation doesn't modify the CFG, it preserves all analyses
// that only depend on the CFG (like dominators, loop info, etc...)
GetCFGOnlyPasses(Preserved).enumeratePasses();
}