/// counted as part of the following block (i.e., the offset and size for
/// a padded block will both be ==2 mod 4).
std::vector<unsigned> BBSizes;
-
+
/// BBOffsets - the offset of each MBB in bytes, starting from 0.
/// The two-byte pads required for Thumb alignment are counted as part of
/// the following block.
CPUser(MachineInstr *mi, MachineInstr *cpemi, unsigned maxdisp)
: MI(mi), CPEMI(cpemi), MaxDisp(maxdisp) {}
};
-
+
/// CPUsers - Keep track of all of the machine instructions that use various
/// constant pools and their max displacement.
std::vector<CPUser> CPUsers;
-
+
/// CPEntry - One per constant pool entry, keeping the machine instruction
/// pointer, the constpool index, and the number of CPUser's which
/// reference this entry.
/// Original elements are cloned as we go along; the clones are
/// put in the vector of the original element, but have distinct CPIs.
std::vector<std::vector<CPEntry> > CPEntries;
-
+
/// ImmBranch - One per immediate branch, keeping the machine instruction
/// pointer, conditional or unconditional, the max displacement,
/// and (if isCond is true) the corresponding unconditional branch
virtual const char *getPassName() const {
return "ARM constant island placement and branch shortening pass";
}
-
+
private:
void DoInitialPlacement(MachineFunction &Fn,
std::vector<MachineInstr*> &CPEMIs);
void AdjustBBOffsetsAfter(MachineBasicBlock *BB, int delta);
bool DecrementOldEntry(unsigned CPI, MachineInstr* CPEMI);
int LookForExistingCPEntry(CPUser& U, unsigned UserOffset);
- bool LookForWater(CPUser&U, unsigned UserOffset,
+ bool LookForWater(CPUser&U, unsigned UserOffset,
MachineBasicBlock** NewMBB);
- MachineBasicBlock* AcceptWater(MachineBasicBlock *WaterBB,
+ MachineBasicBlock* AcceptWater(MachineBasicBlock *WaterBB,
std::vector<MachineBasicBlock*>::iterator IP);
void CreateNewWater(unsigned CPUserIndex, unsigned UserOffset,
MachineBasicBlock** NewMBB);
bool HandleConstantPoolUser(MachineFunction &Fn, unsigned CPUserIndex);
void RemoveDeadCPEMI(MachineInstr *CPEMI);
bool RemoveUnusedCPEntries();
- bool CPEIsInRange(MachineInstr *MI, unsigned UserOffset,
+ bool CPEIsInRange(MachineInstr *MI, unsigned UserOffset,
MachineInstr *CPEMI, unsigned Disp,
bool DoDump);
bool WaterIsInRange(unsigned UserOffset, MachineBasicBlock *Water,
/// print block size and offset information - debugging
void ARMConstantIslands::dumpBBs() {
for (unsigned J = 0, E = BBOffsets.size(); J !=E; ++J) {
- DOUT << "block " << J << " offset " << BBOffsets[J] <<
+ DOUT << "block " << J << " offset " << BBOffsets[J] <<
" size " << BBSizes[J] << "\n";
}
}
bool ARMConstantIslands::runOnMachineFunction(MachineFunction &Fn) {
MachineConstantPool &MCP = *Fn.getConstantPool();
-
+
TII = Fn.getTarget().getInstrInfo();
AFI = Fn.getInfo<ARMFunctionInfo>();
isThumb = AFI->isThumbFunction();
// the numbers agree with the position of the block in the function.
Fn.RenumberBlocks();
- /// Thumb functions containing constant pools get 2-byte alignment. This is so
- /// we can keep exact track of where the alignment padding goes. Set default.
+ /// Thumb functions containing constant pools get 2-byte alignment.
+ /// This is so we can keep exact track of where the alignment padding goes.
+ /// Set default.
AFI->setAlign(isThumb ? 1U : 2U);
// Perform the initial placement of the constant pool entries. To start with,
if (isThumb)
AFI->setAlign(2U);
}
-
+
/// The next UID to take is the first unused one.
AFI->initConstPoolEntryUId(CPEMIs.size());
-
+
// Do the initial scan of the function, building up information about the
// sizes of each block, the location of all the water, and finding all of the
// constant pool users.
InitialFunctionScan(Fn, CPEMIs);
CPEMIs.clear();
-
+
/// Remove dead constant pool entries.
RemoveUnusedCPEntries();
/// DoInitialPlacement - Perform the initial placement of the constant pool
/// entries. To start with, we put them all at the end of the function.
void ARMConstantIslands::DoInitialPlacement(MachineFunction &Fn,
- std::vector<MachineInstr*> &CPEMIs){
+ std::vector<MachineInstr*> &CPEMIs) {
// Create the basic block to hold the CPE's.
MachineBasicBlock *BB = Fn.CreateMachineBasicBlock();
Fn.push_back(BB);
-
+
// Add all of the constants from the constant pool to the end block, use an
// identity mapping of CPI's to CPE's.
const std::vector<MachineConstantPoolEntry> &CPs =
Fn.getConstantPool()->getConstants();
-
+
const TargetData &TD = *Fn.getTarget().getTargetData();
for (unsigned i = 0, e = CPs.size(); i != e; ++i) {
unsigned Size = TD.getTypeAllocSize(CPs[i].getType());
MachineFunction::iterator MBBI = MBB;
if (next(MBBI) == MBB->getParent()->end()) // Can't fall off end of function.
return false;
-
+
MachineBasicBlock *NextBB = next(MBBI);
for (MachineBasicBlock::succ_iterator I = MBB->succ_begin(),
E = MBB->succ_end(); I != E; ++I)
if (*I == NextBB)
return true;
-
+
return false;
}
for (MachineFunction::iterator MBBI = Fn.begin(), E = Fn.end();
MBBI != E; ++MBBI) {
MachineBasicBlock &MBB = *MBBI;
-
+
// If this block doesn't fall through into the next MBB, then this is
// 'water' that a constant pool island could be placed.
if (!BBHasFallthrough(&MBB))
WaterList.push_back(&MBB);
-
+
unsigned MBBSize = 0;
for (MachineBasicBlock::iterator I = MBB.begin(), E = MBB.end();
I != E; ++I) {
if (I->getOperand(op).isCPI()) {
// We found one. The addressing mode tells us the max displacement
// from the PC that this instruction permits.
-
+
// Basic size info comes from the TSFlags field.
unsigned Bits = 0;
unsigned Scale = 1;
unsigned TSFlags = I->getDesc().TSFlags;
switch (TSFlags & ARMII::AddrModeMask) {
- default:
+ default:
// Constant pool entries can reach anything.
if (I->getOpcode() == ARM::CONSTPOOL_ENTRY)
continue;
// Remember that this is a user of a CP entry.
unsigned CPI = I->getOperand(op).getIndex();
MachineInstr *CPEMI = CPEMIs[CPI];
- unsigned MaxOffs = ((1 << Bits)-1) * Scale;
+ unsigned MaxOffs = ((1 << Bits)-1) * Scale;
CPUsers.push_back(CPUser(I, CPEMI, MaxOffs));
// Increment corresponding CPEntry reference count.
CPEntry *CPE = findConstPoolEntry(CPI, CPEMI);
assert(CPE && "Cannot find a corresponding CPEntry!");
CPE->RefCount++;
-
+
// Instructions can only use one CP entry, don't bother scanning the
// rest of the operands.
break;
/// around inside the function.
unsigned ARMConstantIslands::GetOffsetOf(MachineInstr *MI) const {
MachineBasicBlock *MBB = MI->getParent();
-
+
// The offset is composed of two things: the sum of the sizes of all MBB's
// before this instruction's block, and the offset from the start of the block
// it is in.
// If we're looking for a CONSTPOOL_ENTRY in Thumb, see if this block has
// alignment padding, and compensate if so.
- if (isThumb &&
- MI->getOpcode() == ARM::CONSTPOOL_ENTRY &&
+ if (isThumb &&
+ MI->getOpcode() == ARM::CONSTPOOL_ENTRY &&
Offset%4 != 0)
Offset += 2;
void ARMConstantIslands::UpdateForInsertedWaterBlock(MachineBasicBlock *NewBB) {
// Renumber the MBB's to keep them consequtive.
NewBB->getParent()->RenumberBlocks(NewBB);
-
+
// Insert a size into BBSizes to align it properly with the (newly
// renumbered) block numbers.
BBSizes.insert(BBSizes.begin()+NewBB->getNumber(), 0);
// Likewise for BBOffsets.
BBOffsets.insert(BBOffsets.begin()+NewBB->getNumber(), 0);
-
- // Next, update WaterList. Specifically, we need to add NewMBB as having
+
+ // Next, update WaterList. Specifically, we need to add NewMBB as having
// available water after it.
std::vector<MachineBasicBlock*>::iterator IP =
std::lower_bound(WaterList.begin(), WaterList.end(), NewBB,
MachineFunction &MF = *OrigBB->getParent();
// Create a new MBB for the code after the OrigBB.
- MachineBasicBlock *NewBB = MF.CreateMachineBasicBlock(OrigBB->getBasicBlock());
+ MachineBasicBlock *NewBB =
+ MF.CreateMachineBasicBlock(OrigBB->getBasicBlock());
MachineFunction::iterator MBBI = OrigBB; ++MBBI;
MF.insert(MBBI, NewBB);
-
+
// Splice the instructions starting with MI over to NewBB.
NewBB->splice(NewBB->end(), OrigBB, MI, OrigBB->end());
-
+
// Add an unconditional branch from OrigBB to NewBB.
// Note the new unconditional branch is not being recorded.
// There doesn't seem to be meaningful DebugInfo available; this doesn't
BuildMI(OrigBB, DebugLoc::getUnknownLoc(),
TII->get(isThumb ? ARM::tB : ARM::B)).addMBB(NewBB);
NumSplit++;
-
+
// Update the CFG. All succs of OrigBB are now succs of NewBB.
while (!OrigBB->succ_empty()) {
MachineBasicBlock *Succ = *OrigBB->succ_begin();
OrigBB->removeSuccessor(Succ);
NewBB->addSuccessor(Succ);
-
+
// This pass should be run after register allocation, so there should be no
// PHI nodes to update.
assert((Succ->empty() || Succ->begin()->getOpcode() != TargetInstrInfo::PHI)
&& "PHI nodes should be eliminated by now!");
}
-
+
// OrigBB branches to NewBB.
OrigBB->addSuccessor(NewBB);
-
+
// Update internal data structures to account for the newly inserted MBB.
// This is almost the same as UpdateForInsertedWaterBlock, except that
// the Water goes after OrigBB, not NewBB.
MF.RenumberBlocks(NewBB);
-
+
// Insert a size into BBSizes to align it properly with the (newly
// renumbered) block numbers.
BBSizes.insert(BBSizes.begin()+NewBB->getNumber(), 0);
-
+
// Likewise for BBOffsets.
BBOffsets.insert(BBOffsets.begin()+NewBB->getNumber(), 0);
- // Next, update WaterList. Specifically, we need to add OrigMBB as having
+ // Next, update WaterList. Specifically, we need to add OrigMBB as having
// available water after it (but not if it's already there, which happens
// when splitting before a conditional branch that is followed by an
// unconditional branch - in that case we want to insert NewBB).
for (MachineBasicBlock::iterator I = NewBB->begin(), E = NewBB->end();
I != E; ++I)
NewBBSize += TII->GetInstSizeInBytes(I);
-
+
unsigned OrigBBI = OrigBB->getNumber();
unsigned NewBBI = NewBB->getNumber();
// Set the size of NewBB in BBSizes.
BBSizes[NewBBI] = NewBBSize;
-
+
// We removed instructions from UserMBB, subtract that off from its size.
// Add 2 or 4 to the block to count the unconditional branch we added to it.
unsigned delta = isThumb ? 2 : 4;
}
/// OffsetIsInRange - Checks whether UserOffset (the location of a constant pool
-/// reference) is within MaxDisp of TrialOffset (a proposed location of a
+/// reference) is within MaxDisp of TrialOffset (a proposed location of a
/// constant pool entry).
-bool ARMConstantIslands::OffsetIsInRange(unsigned UserOffset,
+bool ARMConstantIslands::OffsetIsInRange(unsigned UserOffset,
unsigned TrialOffset, unsigned MaxDisp, bool NegativeOK) {
- // On Thumb offsets==2 mod 4 are rounded down by the hardware for
- // purposes of the displacement computation; compensate for that here.
+ // On Thumb offsets==2 mod 4 are rounded down by the hardware for
+ // purposes of the displacement computation; compensate for that here.
// Effectively, the valid range of displacements is 2 bytes smaller for such
// references.
if (isThumb && UserOffset%4 !=0)
{
unsigned MaxDisp = U.MaxDisp;
MachineFunction::iterator I = next(MachineFunction::iterator(Water));
- unsigned CPEOffset = BBOffsets[Water->getNumber()] +
+ unsigned CPEOffset = BBOffsets[Water->getNumber()] +
BBSizes[Water->getNumber()];
// If the CPE is to be inserted before the instruction, that will raise
}
#endif // NDEBUG
-void ARMConstantIslands::AdjustBBOffsetsAfter(MachineBasicBlock *BB,
+void ARMConstantIslands::AdjustBBOffsetsAfter(MachineBasicBlock *BB,
int delta) {
MachineFunction::iterator MBBI = BB; MBBI = next(MBBI);
for(unsigned i=BB->getNumber()+1; i<BB->getParent()->getNumBlockIDs(); i++) {
/// DecrementOldEntry - find the constant pool entry with index CPI
/// and instruction CPEMI, and decrement its refcount. If the refcount
-/// becomes 0 remove the entry and instruction. Returns true if we removed
+/// becomes 0 remove the entry and instruction. Returns true if we removed
/// the entry, false if we didn't.
bool ARMConstantIslands::DecrementOldEntry(unsigned CPI, MachineInstr *CPEMI) {
/// AcceptWater - Small amount of common code factored out of the following.
-MachineBasicBlock* ARMConstantIslands::AcceptWater(MachineBasicBlock *WaterBB,
+MachineBasicBlock* ARMConstantIslands::AcceptWater(MachineBasicBlock *WaterBB,
std::vector<MachineBasicBlock*>::iterator IP) {
DOUT << "found water in range\n";
// Remove the original WaterList entry; we want subsequent
MachineBasicBlock* WaterBB = *IP;
if (WaterIsInRange(UserOffset, WaterBB, U)) {
if (isThumb &&
- (BBOffsets[WaterBB->getNumber()] +
+ (BBOffsets[WaterBB->getNumber()] +
BBSizes[WaterBB->getNumber()])%4 != 0) {
// This is valid Water, but would introduce padding. Remember
// it in case we don't find any Water that doesn't do this.
return false;
}
-/// CreateNewWater - No existing WaterList entry will work for
+/// CreateNewWater - No existing WaterList entry will work for
/// CPUsers[CPUserIndex], so create a place to put the CPE. The end of the
/// block is used if in range, and the conditional branch munged so control
/// flow is correct. Otherwise the block is split to create a hole with an
/// block following which the new island can be inserted (the WaterList
/// is not adjusted).
-void ARMConstantIslands::CreateNewWater(unsigned CPUserIndex,
+void ARMConstantIslands::CreateNewWater(unsigned CPUserIndex,
unsigned UserOffset, MachineBasicBlock** NewMBB) {
CPUser &U = CPUsers[CPUserIndex];
MachineInstr *UserMI = U.MI;
MachineInstr *CPEMI = U.CPEMI;
MachineBasicBlock *UserMBB = UserMI->getParent();
- unsigned OffsetOfNextBlock = BBOffsets[UserMBB->getNumber()] +
+ unsigned OffsetOfNextBlock = BBOffsets[UserMBB->getNumber()] +
BBSizes[UserMBB->getNumber()];
assert(OffsetOfNextBlock== BBOffsets[UserMBB->getNumber()+1]);
// for the unconditional branch we will be adding: 4 bytes on ARM,
// 2 on Thumb. Possible Thumb alignment padding is allowed for
// inside OffsetIsInRange.
- // If the block ends in an unconditional branch already, it is water,
+ // If the block ends in an unconditional branch already, it is water,
// and is known to be out of range, so we'll always be adding a branch.)
if (&UserMBB->back() == UserMI ||
OffsetIsInRange(UserOffset, OffsetOfNextBlock + (isThumb ? 2: 4),
BuildMI(UserMBB, DebugLoc::getUnknownLoc(),
TII->get(UncondBr)).addMBB(*NewMBB);
unsigned MaxDisp = getUnconditionalBrDisp(UncondBr);
- ImmBranches.push_back(ImmBranch(&UserMBB->back(),
+ ImmBranches.push_back(ImmBranch(&UserMBB->back(),
MaxDisp, false, UncondBr));
int delta = isThumb ? 2 : 4;
BBSizes[UserMBB->getNumber()] += delta;
// in the water list. Back past any possible branches (allow for a
// conditional and a maximally long unconditional).
if (BaseInsertOffset >= BBOffsets[UserMBB->getNumber()+1])
- BaseInsertOffset = BBOffsets[UserMBB->getNumber()+1] -
+ BaseInsertOffset = BBOffsets[UserMBB->getNumber()+1] -
(isThumb ? 6 : 8);
unsigned EndInsertOffset = BaseInsertOffset +
CPEMI->getOperand(2).getImm();
Offset += TII->GetInstSizeInBytes(MI),
MI = next(MI)) {
if (CPUIndex < CPUsers.size() && CPUsers[CPUIndex].MI == MI) {
- if (!OffsetIsInRange(Offset, EndInsertOffset,
+ if (!OffsetIsInRange(Offset, EndInsertOffset,
CPUsers[CPUIndex].MaxDisp, !isThumb)) {
BaseInsertOffset -= (isThumb ? 2 : 4);
EndInsertOffset -= (isThumb ? 2 : 4);
/// is out-of-range. If so, pick it up the constant pool value and move it some
/// place in-range. Return true if we changed any addresses (thus must run
/// another pass of branch lengthening), false otherwise.
-bool ARMConstantIslands::HandleConstantPoolUser(MachineFunction &Fn,
- unsigned CPUserIndex){
+bool ARMConstantIslands::HandleConstantPoolUser(MachineFunction &Fn,
+ unsigned CPUserIndex) {
CPUser &U = CPUsers[CPUserIndex];
MachineInstr *UserMI = U.MI;
MachineInstr *CPEMI = U.CPEMI;
// second instruction.
if (UserMI->getOpcode() == ARM::tLEApcrel)
UserOffset += 2;
-
+
// See if the current entry is within range, or there is a clone of it
// in range.
int result = LookForExistingCPEntry(U, UserOffset);
BBOffsets[NewIsland->getNumber()] = BBOffsets[NewMBB->getNumber()];
// Compensate for .align 2 in thumb mode.
- if (isThumb && BBOffsets[NewIsland->getNumber()]%4 != 0)
+ if (isThumb && BBOffsets[NewIsland->getNumber()]%4 != 0)
Size += 2;
// Increase the size of the island block to account for the new entry.
BBSizes[NewIsland->getNumber()] += Size;
AdjustBBOffsetsAfter(NewIsland, Size);
-
+
// Finally, change the CPI in the instruction operand to be ID.
for (unsigned i = 0, e = UserMI->getNumOperands(); i != e; ++i)
if (UserMI->getOperand(i).isCPI()) {
UserMI->getOperand(i).setIndex(ID);
break;
}
-
+
DOUT << " Moved CPE to #" << ID << " CPI=" << CPI << "\t" << *UserMI;
-
+
return true;
}
MadeChange = true;
}
}
- }
+ }
return MadeChange;
}
// BBOffsets[SplitBB] is wrong temporarily, fixed below
}
MachineBasicBlock *NextBB = next(MachineFunction::iterator(MBB));
-
+
DOUT << " Insert B to BB#" << DestBB->getNumber()
<< " also invert condition and change dest. to BB#"
<< NextBB->getNumber() << "\n";
projects / oota-llvm.git / commitdiff