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Revert 85799 for now. It might be breaking llvm-gcc driver.

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85827 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng
2009-11-02 21:49:14 +00:00
parent 907eebd5a6
commit 454ac8961b
3 changed files with 21 additions and 52 deletions
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63
lib/CodeGen/MachineLICM.cpp
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@@ -56,12 +56,12 @@ namespace {
// State that is updated as we process loops
bool Changed; // True if a loop is changed.
bool FirstInLoop; // True if it's the first LICM in the loop.
MachineLoop *CurLoop; // The current loop we are working on.
MachineBasicBlock *CurPreheader; // The preheader for CurLoop.
// For each opcode, keep a list of potentail CSE instructions.
DenseMap<unsigned, std::vector<const MachineInstr*> > CSEMap;
// For each BB and opcode pair, keep a list of hoisted instructions.
DenseMap<std::pair<unsigned, unsigned>,
std::vector<const MachineInstr*> > CSEMap;
public:
static char ID; // Pass identification, replacement for typeid
MachineLICM() : MachineFunctionPass(&ID) {}
@@ -115,11 +115,6 @@ namespace {
/// that is safe to hoist, this instruction is called to do the dirty work.
///
void Hoist(MachineInstr *MI);
/// InitCSEMap - Initialize the CSE map with instructions that are in the
/// current loop preheader that may become duplicates of instructions that
/// are hoisted out of the loop.
void InitCSEMap(MachineBasicBlock *BB);
};
} // end anonymous namespace
@@ -145,7 +140,7 @@ static bool LoopIsOuterMostWithPreheader(MachineLoop *CurLoop) {
bool MachineLICM::runOnMachineFunction(MachineFunction &MF) {
DEBUG(errs() << "******** Machine LICM ********\n");
Changed = FirstInLoop = false;
Changed = false;
TM = &MF.getTarget();
TII = TM->getInstrInfo();
TRI = TM->getRegisterInfo();
@@ -157,7 +152,8 @@ bool MachineLICM::runOnMachineFunction(MachineFunction &MF) {
DT = &getAnalysis<MachineDominatorTree>();
AA = &getAnalysis<AliasAnalysis>();
for (MachineLoopInfo::iterator I = LI->begin(), E = LI->end(); I != E; ++I) {
for (MachineLoopInfo::iterator
I = LI->begin(), E = LI->end(); I != E; ++I) {
CurLoop = *I;
// Only visit outer-most preheader-sporting loops.
@@ -174,11 +170,7 @@ bool MachineLICM::runOnMachineFunction(MachineFunction &MF) {
if (!CurPreheader)
continue;
// CSEMap is initialized for loop header when the first instruction is
// being hoisted.
FirstInLoop = true;
HoistRegion(DT->getNode(CurLoop->getHeader()));
CSEMap.clear();
}
return Changed;
@@ -199,7 +191,10 @@ void MachineLICM::HoistRegion(MachineDomTreeNode *N) {
for (MachineBasicBlock::iterator
MII = BB->begin(), E = BB->end(); MII != E; ) {
MachineBasicBlock::iterator NextMII = MII; ++NextMII;
Hoist(&*MII);
MachineInstr &MI = *MII;
Hoist(&MI);
MII = NextMII;
}
@@ -435,27 +430,6 @@ MachineInstr *MachineLICM::ExtractHoistableLoad(MachineInstr *MI) {
return NewMIs[0];
}
void MachineLICM::InitCSEMap(MachineBasicBlock *BB) {
for (MachineBasicBlock::iterator I = BB->begin(),E = BB->end(); I != E; ++I) {
const MachineInstr *MI = &*I;
// FIXME: For now, only hoist re-materilizable instructions. LICM will
// increase register pressure. We want to make sure it doesn't increase
// spilling.
if (TII->isTriviallyReMaterializable(MI, AA)) {
unsigned Opcode = MI->getOpcode();
DenseMap<unsigned, std::vector<const MachineInstr*> >::iterator
CI = CSEMap.find(Opcode);
if (CI != CSEMap.end())
CI->second.push_back(MI);
else {
std::vector<const MachineInstr*> CSEMIs;
CSEMIs.push_back(MI);
CSEMap.insert(std::make_pair(Opcode, CSEMIs));
}
}
}
}
/// Hoist - When an instruction is found to use only loop invariant operands
/// that are safe to hoist, this instruction is called to do the dirty work.
///
@@ -480,14 +454,11 @@ void MachineLICM::Hoist(MachineInstr *MI) {
errs() << "\n";
});
// If this is the first instruction being hoisted to the preheader,
// initialize the CSE map with potential common expressions.
InitCSEMap(CurPreheader);
// Look for opportunity to CSE the hoisted instruction.
unsigned Opcode = MI->getOpcode();
DenseMap<unsigned, std::vector<const MachineInstr*> >::iterator
CI = CSEMap.find(Opcode);
std::pair<unsigned, unsigned> BBOpcPair =
std::make_pair(CurPreheader->getNumber(), MI->getOpcode());
DenseMap<std::pair<unsigned, unsigned>,
std::vector<const MachineInstr*> >::iterator CI = CSEMap.find(BBOpcPair);
bool DoneCSE = false;
if (CI != CSEMap.end()) {
const MachineInstr *Dup = LookForDuplicate(MI, CI->second, RegInfo);
@@ -506,15 +477,15 @@ void MachineLICM::Hoist(MachineInstr *MI) {
// Otherwise, splice the instruction to the preheader.
if (!DoneCSE) {
CurPreheader->splice(CurPreheader->getFirstTerminator(),MI->getParent(),MI);
CurPreheader->splice(CurPreheader->getFirstTerminator(),
MI->getParent(), MI);
// Add to the CSE map.
if (CI != CSEMap.end())
CI->second.push_back(MI);
else {
std::vector<const MachineInstr*> CSEMIs;
CSEMIs.push_back(MI);
CSEMap.insert(std::make_pair(Opcode, CSEMIs));
CSEMap.insert(std::make_pair(BBOpcPair, CSEMIs));
}
}