/// Note that RemoveBranch and InsertBranch must be implemented to support
/// cases where this method returns success.
///
+ /// If AllowModify is true, then this routine is allowed to modify the basic
+ /// block (e.g. delete instructions after the unconditional branch).
+ ///
virtual bool AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
- SmallVectorImpl<MachineOperand> &Cond) const {
+ SmallVectorImpl<MachineOperand> &Cond,
+ bool AllowModify = false) const {
return true;
}
for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; I++) {
MachineBasicBlock *MBB = I, *TBB = 0, *FBB = 0;
SmallVector<MachineOperand, 4> Cond;
- if (!TII->AnalyzeBranch(*MBB, TBB, FBB, Cond))
+ if (!TII->AnalyzeBranch(*MBB, TBB, FBB, Cond, true))
EverMadeChange |= MBB->CorrectExtraCFGEdges(TBB, FBB, !Cond.empty());
EverMadeChange |= OptimizeImpDefsBlock(MBB);
}
MachineBasicBlock *TBB = 0, *FBB = 0;
SmallVector<MachineOperand, 4> Cond;
if (I != MF->end() &&
- !TII->AnalyzeBranch(*CurMBB, TBB, FBB, Cond)) {
+ !TII->AnalyzeBranch(*CurMBB, TBB, FBB, Cond, true)) {
MachineBasicBlock *NextBB = I;
if (TBB == NextBB && !Cond.empty() && !FBB) {
if (!TII->ReverseBranchCondition(Cond)) {
continue;
MachineBasicBlock *TBB = 0, *FBB = 0;
SmallVector<MachineOperand, 4> Cond;
- if (!TII->AnalyzeBranch(*PBB, TBB, FBB, Cond)) {
+ if (!TII->AnalyzeBranch(*PBB, TBB, FBB, Cond, true)) {
// Failing case: IBB is the target of a cbr, and
// we cannot reverse the branch.
SmallVector<MachineOperand, 4> NewCond(Cond);
bool BranchFolder::CanFallThrough(MachineBasicBlock *CurBB) {
MachineBasicBlock *TBB = 0, *FBB = 0;
SmallVector<MachineOperand, 4> Cond;
- bool CurUnAnalyzable = TII->AnalyzeBranch(*CurBB, TBB, FBB, Cond);
+ bool CurUnAnalyzable = TII->AnalyzeBranch(*CurBB, TBB, FBB, Cond, true);
return CanFallThrough(CurBB, CurUnAnalyzable, TBB, FBB, Cond);
}
MachineBasicBlock *PriorTBB = 0, *PriorFBB = 0;
SmallVector<MachineOperand, 4> PriorCond;
bool PriorUnAnalyzable =
- TII->AnalyzeBranch(PrevBB, PriorTBB, PriorFBB, PriorCond);
+ TII->AnalyzeBranch(PrevBB, PriorTBB, PriorFBB, PriorCond, true);
if (!PriorUnAnalyzable) {
// If the CFG for the prior block has extra edges, remove them.
MadeChange |= PrevBB.CorrectExtraCFGEdges(PriorTBB, PriorFBB,
// Analyze the branch in the current block.
MachineBasicBlock *CurTBB = 0, *CurFBB = 0;
SmallVector<MachineOperand, 4> CurCond;
- bool CurUnAnalyzable = TII->AnalyzeBranch(*MBB, CurTBB, CurFBB, CurCond);
+ bool CurUnAnalyzable= TII->AnalyzeBranch(*MBB, CurTBB, CurFBB, CurCond, true);
if (!CurUnAnalyzable) {
// If the CFG for the prior block has extra edges, remove them.
MadeChange |= MBB->CorrectExtraCFGEdges(CurTBB, CurFBB, !CurCond.empty());
// Branch analysis.
bool ARMInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
- SmallVectorImpl<MachineOperand> &Cond) const {
+ SmallVectorImpl<MachineOperand> &Cond,
+ bool AllowModify) const {
// If the block has no terminators, it just falls into the block after it.
MachineBasicBlock::iterator I = MBB.end();
if (I == MBB.begin() || !isUnpredicatedTerminator(--I))
(LastOpc == ARM::B || LastOpc == ARM::tB)) {
TBB = SecondLastInst->getOperand(0).getMBB();
I = LastInst;
- I->eraseFromParent();
+ if (AllowModify)
+ I->eraseFromParent();
return false;
}
SecondLastOpc == ARM::BR_JTadd || SecondLastOpc==ARM::tBR_JTr) &&
(LastOpc == ARM::B || LastOpc == ARM::tB)) {
I = LastInst;
- I->eraseFromParent();
+ if (AllowModify)
+ I->eraseFromParent();
return true;
}
// Branch analysis.
virtual bool AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
- SmallVectorImpl<MachineOperand> &Cond) const;
+ SmallVectorImpl<MachineOperand> &Cond,
+ bool AllowModify) const;
virtual unsigned RemoveBranch(MachineBasicBlock &MBB) const;
virtual unsigned InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
// Branch analysis.
bool AlphaInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,MachineBasicBlock *&TBB,
- MachineBasicBlock *&FBB,
- SmallVectorImpl<MachineOperand> &Cond) const {
+ MachineBasicBlock *&FBB,
+ SmallVectorImpl<MachineOperand> &Cond,
+ bool AllowModify) const {
// If the block has no terminators, it just falls into the block after it.
MachineBasicBlock::iterator I = MBB.end();
if (I == MBB.begin() || !isUnpredicatedTerminator(--I))
LastInst->getOpcode() == Alpha::BR) {
TBB = SecondLastInst->getOperand(0).getMBB();
I = LastInst;
- I->eraseFromParent();
+ if (AllowModify)
+ I->eraseFromParent();
return false;
}
bool AnalyzeBranch(MachineBasicBlock &MBB,MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
- SmallVectorImpl<MachineOperand> &Cond) const;
+ SmallVectorImpl<MachineOperand> &Cond,
+ bool AllowModify) const;
unsigned RemoveBranch(MachineBasicBlock &MBB) const;
void insertNoop(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI) const;
bool
SPUInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
- SmallVectorImpl<MachineOperand> &Cond) const {
+ SmallVectorImpl<MachineOperand> &Cond,
+ bool AllowModify) const {
// If the block has no terminators, it just falls into the block after it.
MachineBasicBlock::iterator I = MBB.end();
if (I == MBB.begin() || !isUnpredicatedTerminator(--I))
if (isUncondBranch(SecondLastInst) && isUncondBranch(LastInst)) {
TBB = SecondLastInst->getOperand(0).getMBB();
I = LastInst;
- I->eraseFromParent();
+ if (AllowModify)
+ I->eraseFromParent();
return false;
}
virtual bool AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
- SmallVectorImpl<MachineOperand> &Cond) const;
+ SmallVectorImpl<MachineOperand> &Cond,
+ bool AllowModify) const;
virtual unsigned RemoveBranch(MachineBasicBlock &MBB) const;
bool MipsInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,
MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
- SmallVectorImpl<MachineOperand> &Cond) const
+ SmallVectorImpl<MachineOperand> &Cond,
+ bool AllowModify) const
{
// If the block has no terminators, it just falls into the block after it.
MachineBasicBlock::iterator I = MBB.end();
if ((SecondLastOpc == Mips::J) && (LastOpc == Mips::J)) {
TBB = SecondLastInst->getOperand(0).getMBB();
I = LastInst;
- I->eraseFromParent();
+ if (AllowModify)
+ I->eraseFromParent();
return false;
}
/// Branch Analysis
virtual bool AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
- SmallVectorImpl<MachineOperand> &Cond) const;
+ SmallVectorImpl<MachineOperand> &Cond,
+ bool AllowModify) const;
virtual unsigned RemoveBranch(MachineBasicBlock &MBB) const;
virtual unsigned InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
// Branch analysis.
bool PPCInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
- SmallVectorImpl<MachineOperand> &Cond) const {
+ SmallVectorImpl<MachineOperand> &Cond,
+ bool AllowModify) const {
// If the block has no terminators, it just falls into the block after it.
MachineBasicBlock::iterator I = MBB.end();
if (I == MBB.begin() || !isUnpredicatedTerminator(--I))
LastInst->getOpcode() == PPC::B) {
TBB = SecondLastInst->getOperand(0).getMBB();
I = LastInst;
- I->eraseFromParent();
+ if (AllowModify)
+ I->eraseFromParent();
return false;
}
// Branch analysis.
virtual bool AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
- SmallVectorImpl<MachineOperand> &Cond) const;
+ SmallVectorImpl<MachineOperand> &Cond,
+ bool AllowModify) const;
virtual unsigned RemoveBranch(MachineBasicBlock &MBB) const;
virtual unsigned InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
bool X86InstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,
MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
- SmallVectorImpl<MachineOperand> &Cond) const {
+ SmallVectorImpl<MachineOperand> &Cond,
+ bool AllowModify) const {
// Start from the bottom of the block and work up, examining the
// terminator instructions.
MachineBasicBlock::iterator I = MBB.end();
return true;
// Handle unconditional branches.
if (I->getOpcode() == X86::JMP) {
+ if (!AllowModify) {
+ TBB = I->getOperand(0).getMBB();
+ return false;
+ }
+
// If the block has any instructions after a JMP, delete them.
while (next(I) != MBB.end())
next(I)->eraseFromParent();
virtual bool isUnpredicatedTerminator(const MachineInstr* MI) const;
virtual bool AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
- SmallVectorImpl<MachineOperand> &Cond) const;
+ SmallVectorImpl<MachineOperand> &Cond,
+ bool AllowModify) const;
virtual unsigned RemoveBranch(MachineBasicBlock &MBB) const;
virtual unsigned InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
///
bool
XCoreInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
- MachineBasicBlock *&FBB,
- SmallVectorImpl<MachineOperand> &Cond) const {
+ MachineBasicBlock *&FBB,
+ SmallVectorImpl<MachineOperand> &Cond,
+ bool AllowModify) const {
// If the block has no terminators, it just falls into the block after it.
MachineBasicBlock::iterator I = MBB.end();
if (I == MBB.begin() || !isUnpredicatedTerminator(--I))
IsBRU(LastInst->getOpcode())) {
TBB = SecondLastInst->getOperand(0).getMBB();
I = LastInst;
- I->eraseFromParent();
+ if (AllowModify)
+ I->eraseFromParent();
return false;
}
virtual bool AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
- SmallVectorImpl<MachineOperand> &Cond) const;
+ SmallVectorImpl<MachineOperand> &Cond,
+ bool AllowModify) const;
virtual unsigned InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
MachineBasicBlock *FBB,