#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Support/Debug.h"
+#include "llvm/Support/RecyclingAllocator.h"
using namespace llvm;
private:
const unsigned LookAheadLimit;
- typedef ScopedHashTableScope<MachineInstr*, unsigned,
- MachineInstrExpressionTrait> ScopeType;
+ typedef RecyclingAllocator<BumpPtrAllocator,
+ ScopedHashTableVal<MachineInstr*, unsigned> > AllocatorTy;
+ typedef ScopedHashTable<MachineInstr*, unsigned,
+ MachineInstrExpressionTrait, AllocatorTy> ScopedHTType;
+ typedef ScopedHTType::ScopeTy ScopeType;
DenseMap<MachineBasicBlock*, ScopeType*> ScopeMap;
- ScopedHashTable<MachineInstr*, unsigned, MachineInstrExpressionTrait> VNT;
+ ScopedHTType VNT;
SmallVector<MachineInstr*, 64> Exps;
unsigned CurrVN;
if (!MO.isReg() || !MO.isUse())
continue;
unsigned Reg = MO.getReg();
- if (!Reg || TargetRegisterInfo::isPhysicalRegister(Reg))
+ if (!TargetRegisterInfo::isVirtualRegister(Reg))
continue;
if (!MRI->hasOneNonDBGUse(Reg))
// Only coalesce single use copies. This ensure the copy will be
return false;
// Ignore stuff that we obviously can't move.
- const TargetInstrDesc &TID = MI->getDesc();
- if (TID.mayStore() || TID.isCall() || TID.isTerminator() ||
- TID.hasUnmodeledSideEffects())
+ if (MI->mayStore() || MI->isCall() || MI->isTerminator() ||
+ MI->hasUnmodeledSideEffects())
return false;
- if (TID.mayLoad()) {
+ if (MI->mayLoad()) {
// Okay, this instruction does a load. As a refinement, we allow the target
// to decide whether the loaded value is actually a constant. If so, we can
// actually use it as a load.
MachineInstr *CSMI, MachineInstr *MI) {
// FIXME: Heuristics that works around the lack the live range splitting.
- // Heuristics #1: Don't cse "cheap" computating if the def is not local or in an
- // immediate predecessor. We don't want to increase register pressure and end up
- // causing other computation to be spilled.
- if (MI->getDesc().isAsCheapAsAMove()) {
+ // Heuristics #1: Don't CSE "cheap" computation if the def is not local or in
+ // an immediate predecessor. We don't want to increase register pressure and
+ // end up causing other computation to be spilled.
+ if (MI->isAsCheapAsAMove()) {
MachineBasicBlock *CSBB = CSMI->getParent();
MachineBasicBlock *BB = MI->getParent();
- if (CSBB != BB &&
- find(CSBB->succ_begin(), CSBB->succ_end(), BB) == CSBB->succ_end())
+ if (CSBB != BB && !CSBB->isSuccessor(BB))
return false;
}
bool HasVRegUse = false;
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
const MachineOperand &MO = MI->getOperand(i);
- if (MO.isReg() && MO.isUse() && MO.getReg() &&
+ if (MO.isReg() && MO.isUse() &&
TargetRegisterInfo::isVirtualRegister(MO.getReg())) {
HasVRegUse = true;
break;
if (!FoundCSE) {
// Look for trivial copy coalescing opportunities.
if (PerformTrivialCoalescing(MI, MBB)) {
+ Changed = true;
+
// After coalescing MI itself may become a copy.
if (MI->isCopyLike())
continue;
// Commute commutable instructions.
bool Commuted = false;
- if (!FoundCSE && MI->getDesc().isCommutable()) {
+ if (!FoundCSE && MI->isCommutable()) {
MachineInstr *NewMI = TII->commuteInstruction(MI);
if (NewMI) {
Commuted = true;
FoundCSE = VNT.count(NewMI);
- if (NewMI != MI)
+ if (NewMI != MI) {
// New instruction. It doesn't need to be kept.
NewMI->eraseFromParent();
- else if (!FoundCSE)
+ Changed = true;
+ } else if (!FoundCSE)
// MI was changed but it didn't help, commute it back!
(void)TII->commuteInstruction(MI);
}
unsigned NewReg = CSMI->getOperand(i).getReg();
if (OldReg == NewReg)
continue;
+
assert(TargetRegisterInfo::isVirtualRegister(OldReg) &&
TargetRegisterInfo::isVirtualRegister(NewReg) &&
"Do not CSE physical register defs!");
+
if (!isProfitableToCSE(NewReg, OldReg, CSMI, MI)) {
DoCSE = false;
break;
}
+
+ // Don't perform CSE if the result of the old instruction cannot exist
+ // within the register class of the new instruction.
+ const TargetRegisterClass *OldRC = MRI->getRegClass(OldReg);
+ if (!MRI->constrainRegClass(NewReg, OldRC)) {
+ DoCSE = false;
+ break;
+ }
+
CSEPairs.push_back(std::make_pair(OldReg, NewReg));
--NumDefs;
}
++NumPhysCSEs;
if (Commuted)
++NumCommutes;
+ Changed = true;
} else {
DEBUG(dbgs() << "*** Not profitable, avoid CSE!\n");
VNT.insert(MI, CurrVN++);