llvm-6502/lib/CodeGen/MachineModuleInfo.cpp
Chris Lattner 401e10c4fb implement a new magic global "llvm.compiler.used" which is like llvm.used, but
doesn't cause ".no_dead_strip" to be emitted on darwin.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76399 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-20 06:14:25 +00:00

369 lines
12 KiB
C++

//===-- llvm/CodeGen/MachineModuleInfo.cpp ----------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/Constants.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/DerivedTypes.h"
#include "llvm/GlobalVariable.h"
#include "llvm/Intrinsics.h"
#include "llvm/Instructions.h"
#include "llvm/Module.h"
#include "llvm/Support/Dwarf.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/Streams.h"
using namespace llvm;
using namespace llvm::dwarf;
// Handle the Pass registration stuff necessary to use TargetData's.
static RegisterPass<MachineModuleInfo>
X("machinemoduleinfo", "Module Information");
char MachineModuleInfo::ID = 0;
//===----------------------------------------------------------------------===//
MachineModuleInfo::MachineModuleInfo()
: ImmutablePass(&ID)
, LabelIDList()
, FrameMoves()
, LandingPads()
, Personalities()
, CallsEHReturn(0)
, CallsUnwindInit(0)
, DbgInfoAvailable(false)
{
// Always emit "no personality" info
Personalities.push_back(NULL);
}
MachineModuleInfo::~MachineModuleInfo() {
}
/// doInitialization - Initialize the state for a new module.
///
bool MachineModuleInfo::doInitialization() {
return false;
}
/// doFinalization - Tear down the state after completion of a module.
///
bool MachineModuleInfo::doFinalization() {
return false;
}
/// BeginFunction - Begin gathering function meta information.
///
void MachineModuleInfo::BeginFunction(MachineFunction *MF) {
// Coming soon.
}
/// EndFunction - Discard function meta information.
///
void MachineModuleInfo::EndFunction() {
// Clean up frame info.
FrameMoves.clear();
// Clean up exception info.
LandingPads.clear();
TypeInfos.clear();
FilterIds.clear();
FilterEnds.clear();
CallsEHReturn = 0;
CallsUnwindInit = 0;
}
/// AnalyzeModule - Scan the module for global debug information.
///
void MachineModuleInfo::AnalyzeModule(Module &M) {
// Insert functions in the llvm.used array (but not llvm.compiler.used) into
// UsedFunctions.
GlobalVariable *GV = M.getGlobalVariable("llvm.used");
if (!GV || !GV->hasInitializer()) return;
// Should be an array of 'i8*'.
ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer());
if (InitList == 0) return;
for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
if (Function *F =
dyn_cast<Function>(InitList->getOperand(i)->stripPointerCasts()))
UsedFunctions.insert(F);
}
//===-EH-------------------------------------------------------------------===//
/// getOrCreateLandingPadInfo - Find or create an LandingPadInfo for the
/// specified MachineBasicBlock.
LandingPadInfo &MachineModuleInfo::getOrCreateLandingPadInfo
(MachineBasicBlock *LandingPad) {
unsigned N = LandingPads.size();
for (unsigned i = 0; i < N; ++i) {
LandingPadInfo &LP = LandingPads[i];
if (LP.LandingPadBlock == LandingPad)
return LP;
}
LandingPads.push_back(LandingPadInfo(LandingPad));
return LandingPads[N];
}
/// addInvoke - Provide the begin and end labels of an invoke style call and
/// associate it with a try landing pad block.
void MachineModuleInfo::addInvoke(MachineBasicBlock *LandingPad,
unsigned BeginLabel, unsigned EndLabel) {
LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
LP.BeginLabels.push_back(BeginLabel);
LP.EndLabels.push_back(EndLabel);
}
/// addLandingPad - Provide the label of a try LandingPad block.
///
unsigned MachineModuleInfo::addLandingPad(MachineBasicBlock *LandingPad) {
unsigned LandingPadLabel = NextLabelID();
LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
LP.LandingPadLabel = LandingPadLabel;
return LandingPadLabel;
}
/// addPersonality - Provide the personality function for the exception
/// information.
void MachineModuleInfo::addPersonality(MachineBasicBlock *LandingPad,
Function *Personality) {
LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
LP.Personality = Personality;
for (unsigned i = 0; i < Personalities.size(); ++i)
if (Personalities[i] == Personality)
return;
Personalities.push_back(Personality);
}
/// addCatchTypeInfo - Provide the catch typeinfo for a landing pad.
///
void MachineModuleInfo::addCatchTypeInfo(MachineBasicBlock *LandingPad,
std::vector<GlobalVariable *> &TyInfo) {
LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
for (unsigned N = TyInfo.size(); N; --N)
LP.TypeIds.push_back(getTypeIDFor(TyInfo[N - 1]));
}
/// addFilterTypeInfo - Provide the filter typeinfo for a landing pad.
///
void MachineModuleInfo::addFilterTypeInfo(MachineBasicBlock *LandingPad,
std::vector<GlobalVariable *> &TyInfo) {
LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
std::vector<unsigned> IdsInFilter(TyInfo.size());
for (unsigned I = 0, E = TyInfo.size(); I != E; ++I)
IdsInFilter[I] = getTypeIDFor(TyInfo[I]);
LP.TypeIds.push_back(getFilterIDFor(IdsInFilter));
}
/// addCleanup - Add a cleanup action for a landing pad.
///
void MachineModuleInfo::addCleanup(MachineBasicBlock *LandingPad) {
LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
LP.TypeIds.push_back(0);
}
/// TidyLandingPads - Remap landing pad labels and remove any deleted landing
/// pads.
void MachineModuleInfo::TidyLandingPads() {
for (unsigned i = 0; i != LandingPads.size(); ) {
LandingPadInfo &LandingPad = LandingPads[i];
LandingPad.LandingPadLabel = MappedLabel(LandingPad.LandingPadLabel);
// Special case: we *should* emit LPs with null LP MBB. This indicates
// "nounwind" case.
if (!LandingPad.LandingPadLabel && LandingPad.LandingPadBlock) {
LandingPads.erase(LandingPads.begin() + i);
continue;
}
for (unsigned j=0; j != LandingPads[i].BeginLabels.size(); ) {
unsigned BeginLabel = MappedLabel(LandingPad.BeginLabels[j]);
unsigned EndLabel = MappedLabel(LandingPad.EndLabels[j]);
if (!BeginLabel || !EndLabel) {
LandingPad.BeginLabels.erase(LandingPad.BeginLabels.begin() + j);
LandingPad.EndLabels.erase(LandingPad.EndLabels.begin() + j);
continue;
}
LandingPad.BeginLabels[j] = BeginLabel;
LandingPad.EndLabels[j] = EndLabel;
++j;
}
// Remove landing pads with no try-ranges.
if (LandingPads[i].BeginLabels.empty()) {
LandingPads.erase(LandingPads.begin() + i);
continue;
}
// If there is no landing pad, ensure that the list of typeids is empty.
// If the only typeid is a cleanup, this is the same as having no typeids.
if (!LandingPad.LandingPadBlock ||
(LandingPad.TypeIds.size() == 1 && !LandingPad.TypeIds[0]))
LandingPad.TypeIds.clear();
++i;
}
}
/// getTypeIDFor - Return the type id for the specified typeinfo. This is
/// function wide.
unsigned MachineModuleInfo::getTypeIDFor(GlobalVariable *TI) {
for (unsigned i = 0, N = TypeInfos.size(); i != N; ++i)
if (TypeInfos[i] == TI) return i + 1;
TypeInfos.push_back(TI);
return TypeInfos.size();
}
/// getFilterIDFor - Return the filter id for the specified typeinfos. This is
/// function wide.
int MachineModuleInfo::getFilterIDFor(std::vector<unsigned> &TyIds) {
// If the new filter coincides with the tail of an existing filter, then
// re-use the existing filter. Folding filters more than this requires
// re-ordering filters and/or their elements - probably not worth it.
for (std::vector<unsigned>::iterator I = FilterEnds.begin(),
E = FilterEnds.end(); I != E; ++I) {
unsigned i = *I, j = TyIds.size();
while (i && j)
if (FilterIds[--i] != TyIds[--j])
goto try_next;
if (!j)
// The new filter coincides with range [i, end) of the existing filter.
return -(1 + i);
try_next:;
}
// Add the new filter.
int FilterID = -(1 + FilterIds.size());
FilterIds.reserve(FilterIds.size() + TyIds.size() + 1);
for (unsigned I = 0, N = TyIds.size(); I != N; ++I)
FilterIds.push_back(TyIds[I]);
FilterEnds.push_back(FilterIds.size());
FilterIds.push_back(0); // terminator
return FilterID;
}
/// getPersonality - Return the personality function for the current function.
Function *MachineModuleInfo::getPersonality() const {
// FIXME: Until PR1414 will be fixed, we're using 1 personality function per
// function
return !LandingPads.empty() ? LandingPads[0].Personality : NULL;
}
/// getPersonalityIndex - Return unique index for current personality
/// function. NULL personality function should always get zero index.
unsigned MachineModuleInfo::getPersonalityIndex() const {
const Function* Personality = NULL;
// Scan landing pads. If there is at least one non-NULL personality - use it.
for (unsigned i = 0; i != LandingPads.size(); ++i)
if (LandingPads[i].Personality) {
Personality = LandingPads[i].Personality;
break;
}
for (unsigned i = 0; i < Personalities.size(); ++i) {
if (Personalities[i] == Personality)
return i;
}
// This should never happen
llvm_unreachable("Personality function should be set!");
return 0;
}
//===----------------------------------------------------------------------===//
/// DebugLabelFolding pass - This pass prunes out redundant labels. This allows
/// a info consumer to determine if the range of two labels is empty, by seeing
/// if the labels map to the same reduced label.
namespace llvm {
struct DebugLabelFolder : public MachineFunctionPass {
static char ID;
DebugLabelFolder() : MachineFunctionPass(&ID) {}
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.addPreservedID(MachineLoopInfoID);
AU.addPreservedID(MachineDominatorsID);
MachineFunctionPass::getAnalysisUsage(AU);
}
virtual bool runOnMachineFunction(MachineFunction &MF);
virtual const char *getPassName() const { return "Label Folder"; }
};
char DebugLabelFolder::ID = 0;
bool DebugLabelFolder::runOnMachineFunction(MachineFunction &MF) {
// Get machine module info.
MachineModuleInfo *MMI = getAnalysisIfAvailable<MachineModuleInfo>();
if (!MMI) return false;
// Track if change is made.
bool MadeChange = false;
// No prior label to begin.
unsigned PriorLabel = 0;
// Iterate through basic blocks.
for (MachineFunction::iterator BB = MF.begin(), E = MF.end();
BB != E; ++BB) {
// Iterate through instructions.
for (MachineBasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ) {
// Is it a label.
if (I->isDebugLabel() && !MMI->isDbgLabelUsed(I->getOperand(0).getImm())){
// The label ID # is always operand #0, an immediate.
unsigned NextLabel = I->getOperand(0).getImm();
// If there was an immediate prior label.
if (PriorLabel) {
// Remap the current label to prior label.
MMI->RemapLabel(NextLabel, PriorLabel);
// Delete the current label.
I = BB->erase(I);
// Indicate a change has been made.
MadeChange = true;
continue;
} else {
// Start a new round.
PriorLabel = NextLabel;
}
} else {
// No consecutive labels.
PriorLabel = 0;
}
++I;
}
}
return MadeChange;
}
FunctionPass *createDebugLabelFoldingPass() { return new DebugLabelFolder(); }
}