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Merge 64124 frm mainline.
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Turns out AnalyzeBranch can modify the mbb being analyzed. This is a nasty
suprise to some callers, e.g. register coalescer. For now, add an parameter
that tells AnalyzeBranch whether it's safe to modify the mbb. A better
solution is out there, but I don't have time to deal with it right now.


git-svn-id: http://llvm.org/svn/llvm-project/llvm/branches/release_25@64518 91177308-0d34-0410-b5e6-96231b3b80d8
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Tanya Lattner committed Feb 14, 2009
1 parent 7746d36 commit 46d0e98
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Showing 16 changed files with 60 additions and 30 deletions.
6 changes: 5 additions & 1 deletion include/llvm/Target/TargetInstrInfo.h
View file
Expand Up @@ -195,9 +195,13 @@ class TargetInstrInfo {
/// 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;
}

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12 changes: 6 additions & 6 deletions lib/CodeGen/BranchFolding.cpp
View file
Expand Up @@ -191,7 +191,7 @@ bool BranchFolder::runOnMachineFunction(MachineFunction &MF) {
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);
}
Expand Down Expand Up @@ -434,7 +434,7 @@ static void FixTail(MachineBasicBlock* CurMBB, MachineBasicBlock *SuccBB,
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)) {
Expand Down Expand Up @@ -711,7 +711,7 @@ bool BranchFolder::TailMergeBlocks(MachineFunction &MF) {
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);
Expand Down Expand Up @@ -845,7 +845,7 @@ bool BranchFolder::CanFallThrough(MachineBasicBlock *CurBB,
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);
}

Expand Down Expand Up @@ -910,7 +910,7 @@ void BranchFolder::OptimizeBlock(MachineBasicBlock *MBB) {
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,
Expand Down Expand Up @@ -1023,7 +1023,7 @@ void BranchFolder::OptimizeBlock(MachineBasicBlock *MBB) {
// 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());
Expand Down
9 changes: 6 additions & 3 deletions lib/Target/ARM/ARMInstrInfo.cpp
View file
Expand Up @@ -338,7 +338,8 @@ ARMInstrInfo::convertToThreeAddress(MachineFunction::iterator &MFI,
// 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))
Expand Down Expand Up @@ -388,7 +389,8 @@ bool ARMInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,MachineBasicBlock *&TBB,
(LastOpc == ARM::B || LastOpc == ARM::tB)) {
TBB = SecondLastInst->getOperand(0).getMBB();
I = LastInst;
I->eraseFromParent();
if (AllowModify)
I->eraseFromParent();
return false;
}

Expand All @@ -399,7 +401,8 @@ bool ARMInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,MachineBasicBlock *&TBB,
SecondLastOpc == ARM::BR_JTadd || SecondLastOpc==ARM::tBR_JTr) &&
(LastOpc == ARM::B || LastOpc == ARM::tB)) {
I = LastInst;
I->eraseFromParent();
if (AllowModify)
I->eraseFromParent();
return true;
}

Expand Down
3 changes: 2 additions & 1 deletion lib/Target/ARM/ARMInstrInfo.h
View file
Expand Up @@ -176,7 +176,8 @@ class ARMInstrInfo : public TargetInstrInfoImpl {
// 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,
Expand Down
8 changes: 5 additions & 3 deletions lib/Target/Alpha/AlphaInstrInfo.cpp
View file
Expand Up @@ -321,8 +321,9 @@ static unsigned AlphaRevCondCode(unsigned Opcode) {

// 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))
Expand Down Expand Up @@ -373,7 +374,8 @@ bool AlphaInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,MachineBasicBlock *&TB
LastInst->getOpcode() == Alpha::BR) {
TBB = SecondLastInst->getOperand(0).getMBB();
I = LastInst;
I->eraseFromParent();
if (AllowModify)
I->eraseFromParent();
return false;
}

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3 changes: 2 additions & 1 deletion lib/Target/Alpha/AlphaInstrInfo.h
View file
Expand Up @@ -83,7 +83,8 @@ class AlphaInstrInfo : public TargetInstrInfoImpl {

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;
Expand Down
6 changes: 4 additions & 2 deletions lib/Target/CellSPU/SPUInstrInfo.cpp
View file
Expand Up @@ -532,7 +532,8 @@ SPUInstrInfo::foldMemoryOperandImpl(MachineFunction &MF,
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))
Expand Down Expand Up @@ -583,7 +584,8 @@ SPUInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
if (isUncondBranch(SecondLastInst) && isUncondBranch(LastInst)) {
TBB = SecondLastInst->getOperand(0).getMBB();
I = LastInst;
I->eraseFromParent();
if (AllowModify)
I->eraseFromParent();
return false;
}

Expand Down
3 changes: 2 additions & 1 deletion lib/Target/CellSPU/SPUInstrInfo.h
View file
Expand Up @@ -104,7 +104,8 @@ namespace llvm {

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;

Expand Down
6 changes: 4 additions & 2 deletions lib/Target/Mips/MipsInstrInfo.cpp
View file
Expand Up @@ -453,7 +453,8 @@ Mips::CondCode Mips::GetOppositeBranchCondition(Mips::CondCode CC)
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();
Expand Down Expand Up @@ -525,7 +526,8 @@ bool MipsInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,
if ((SecondLastOpc == Mips::J) && (LastOpc == Mips::J)) {
TBB = SecondLastInst->getOperand(0).getMBB();
I = LastInst;
I->eraseFromParent();
if (AllowModify)
I->eraseFromParent();
return false;
}

Expand Down
3 changes: 2 additions & 1 deletion lib/Target/Mips/MipsInstrInfo.h
View file
Expand Up @@ -166,7 +166,8 @@ class MipsInstrInfo : public TargetInstrInfoImpl {
/// 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,
Expand Down
6 changes: 4 additions & 2 deletions lib/Target/PowerPC/PPCInstrInfo.cpp
View file
Expand Up @@ -214,7 +214,8 @@ void PPCInstrInfo::insertNoop(MachineBasicBlock &MBB,
// 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))
Expand Down Expand Up @@ -263,7 +264,8 @@ bool PPCInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,MachineBasicBlock *&TBB,
LastInst->getOpcode() == PPC::B) {
TBB = SecondLastInst->getOperand(0).getMBB();
I = LastInst;
I->eraseFromParent();
if (AllowModify)
I->eraseFromParent();
return false;
}

Expand Down
3 changes: 2 additions & 1 deletion lib/Target/PowerPC/PPCInstrInfo.h
View file
Expand Up @@ -108,7 +108,8 @@ class PPCInstrInfo : public TargetInstrInfoImpl {
// 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,
Expand Down
8 changes: 7 additions & 1 deletion lib/Target/X86/X86InstrInfo.cpp
View file
Expand Up @@ -1488,7 +1488,8 @@ static bool isBrAnalysisUnpredicatedTerminator(const MachineInstr *MI,
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();
Expand All @@ -1504,6 +1505,11 @@ bool X86InstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,
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();
Expand Down
3 changes: 2 additions & 1 deletion lib/Target/X86/X86InstrInfo.h
View file
Expand Up @@ -323,7 +323,8 @@ class X86InstrInfo : public TargetInstrInfoImpl {
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,
Expand Down
8 changes: 5 additions & 3 deletions lib/Target/XCore/XCoreInstrInfo.cpp
View file
Expand Up @@ -228,8 +228,9 @@ static inline XCore::CondCode GetOppositeBranchCondition(XCore::CondCode CC)
///
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))
Expand Down Expand Up @@ -288,7 +289,8 @@ XCoreInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
IsBRU(LastInst->getOpcode())) {
TBB = SecondLastInst->getOperand(0).getMBB();
I = LastInst;
I->eraseFromParent();
if (AllowModify)
I->eraseFromParent();
return false;
}

Expand Down
3 changes: 2 additions & 1 deletion lib/Target/XCore/XCoreInstrInfo.h
View file
Expand Up @@ -56,7 +56,8 @@ class XCoreInstrInfo : public TargetInstrInfoImpl {

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,
Expand Down

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