}
virtual bool runOnMachineFunction(MachineFunction &MF);
-
+
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesCFG();
MachineFunctionPass::getAnalysisUsage(AU);
virtual void releaseMemory() {
ScopeMap.clear();
Exps.clear();
+ AllocatableRegs.clear();
+ ReservedRegs.clear();
}
private:
ScopedHTType VNT;
SmallVector<MachineInstr*, 64> Exps;
unsigned CurrVN;
+ BitVector AllocatableRegs;
+ BitVector ReservedRegs;
bool PerformTrivialCoalescing(MachineInstr *MI, MachineBasicBlock *MBB);
bool isPhysDefTriviallyDead(unsigned Reg,
} // end anonymous namespace
char MachineCSE::ID = 0;
+char &llvm::MachineCSEID = MachineCSE::ID;
INITIALIZE_PASS_BEGIN(MachineCSE, "machine-cse",
"Machine Common Subexpression Elimination", false, false)
INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree)
INITIALIZE_PASS_END(MachineCSE, "machine-cse",
"Machine Common Subexpression Elimination", false, false)
-FunctionPass *llvm::createMachineCSEPass() { return new MachineCSE(); }
-
bool MachineCSE::PerformTrivialCoalescing(MachineInstr *MI,
MachineBasicBlock *MBB) {
bool Changed = false;
bool SeenDef = false;
for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {
const MachineOperand &MO = I->getOperand(i);
+ if (MO.isRegMask() && MO.clobbersPhysReg(Reg))
+ SeenDef = true;
if (!MO.isReg() || !MO.getReg())
continue;
if (!TRI->regsOverlap(MO.getReg(), Reg))
SeenDef = true;
}
if (SeenDef)
- // See a def of Reg (or an alias) before encountering any use, it's
+ // See a def of Reg (or an alias) before encountering any use, it's
// trivially dead.
return true;
if (MO.isDef() &&
(MO.isDead() || isPhysDefTriviallyDead(Reg, I, MBB->end())))
continue;
- PhysRefs.insert(Reg);
+ for (MCRegAliasIterator AI(Reg, TRI, true); AI.isValid(); ++AI)
+ PhysRefs.insert(*AI);
if (MO.isDef())
PhysDefs.push_back(Reg);
- for (const unsigned *Alias = TRI->getAliasSet(Reg); *Alias; ++Alias)
- PhysRefs.insert(*Alias);
}
return !PhysRefs.empty();
return false;
for (unsigned i = 0, e = PhysDefs.size(); i != e; ++i) {
- if (TRI->isInAllocatableClass(PhysDefs[i]))
- // Avoid extending live range of physical registers unless
- // they are unallocatable.
+ if (AllocatableRegs.test(PhysDefs[i]) || ReservedRegs.test(PhysDefs[i]))
+ // Avoid extending live range of physical registers if they are
+ //allocatable or reserved.
return false;
}
CrossMBB = true;
if (I == EE) {
assert(CrossMBB && "Reaching end-of-MBB without finding MI?");
+ (void)CrossMBB;
CrossMBB = false;
NonLocal = true;
I = MBB->begin();
for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {
const MachineOperand &MO = I->getOperand(i);
+ // RegMasks go on instructions like calls that clobber lots of physregs.
+ // Don't attempt to CSE across such an instruction.
+ if (MO.isRegMask())
+ return false;
if (!MO.isReg() || !MO.isDef())
continue;
unsigned MOReg = MO.getReg();
MRI = &MF.getRegInfo();
AA = &getAnalysis<AliasAnalysis>();
DT = &getAnalysis<MachineDominatorTree>();
+ AllocatableRegs = TRI->getAllocatableSet(MF);
+ ReservedRegs = TRI->getReservedRegs(MF);
return PerformCSE(DT->getRootNode());
}