#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/RegisterScavenging.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetMachine.h"
break;
unsigned Reg = I->getOperand(0).getReg();
ImpDefRegs.insert(Reg);
- for (const uint16_t *SubRegs = TRI->getSubRegisters(Reg);
- unsigned SubReg = *SubRegs; ++SubRegs)
- ImpDefRegs.insert(SubReg);
+ for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs)
+ ImpDefRegs.insert(*SubRegs);
++I;
}
if (ImpDefRegs.empty())
TII = tii;
TRI = tri;
MMI = mmi;
+ RS = NULL;
- RS = TRI->requiresRegisterScavenging(MF) ? new RegScavenger() : NULL;
+ // Use a RegScavenger to help update liveness when required.
+ MachineRegisterInfo &MRI = MF.getRegInfo();
+ if (MRI.tracksLiveness() && TRI->trackLivenessAfterRegAlloc(MF))
+ RS = new RegScavenger();
+ else
+ MRI.invalidateLiveness();
// Fix CFG. The later algorithms expect it to be right.
bool MadeChange = false;
// instructions that would be deleted in the merge.
MachineFunction *MF = MBB1->getParent();
if (EffectiveTailLen >= 2 &&
- MF->getFunction()->hasFnAttr(Attribute::OptimizeForSize) &&
+ MF->getFunction()->getFnAttributes().hasOptimizeForSizeAttr() &&
(I1 == MBB1->begin() || I2 == MBB2->begin()))
return true;
}
bool BranchFolder::TailMergeBlocks(MachineFunction &MF) {
-
- if (!EnableTailMerge) return false;
-
bool MadeChange = false;
+ if (!EnableTailMerge) return MadeChange;
// First find blocks with no successors.
MergePotentials.clear();
if (MergePotentials.size() == TailMergeThreshold)
for (unsigned i = 0, e = MergePotentials.size(); i != e; ++i)
TriedMerging.insert(MergePotentials[i].getBlock());
+
// See if we can do any tail merging on those.
if (MergePotentials.size() >= 2)
MadeChange |= TryTailMergeBlocks(NULL, NULL);
for (MachineFunction::iterator I = llvm::next(MF.begin()), E = MF.end();
I != E; ++I) {
- if (I->pred_size() >= 2) {
- SmallPtrSet<MachineBasicBlock *, 8> UniquePreds;
- MachineBasicBlock *IBB = I;
- MachineBasicBlock *PredBB = prior(I);
- MergePotentials.clear();
- for (MachineBasicBlock::pred_iterator P = I->pred_begin(),
- E2 = I->pred_end();
- P != E2 && MergePotentials.size() < TailMergeThreshold; ++P) {
- MachineBasicBlock *PBB = *P;
- if (TriedMerging.count(PBB))
- continue;
- // Skip blocks that loop to themselves, can't tail merge these.
- if (PBB == IBB)
- continue;
- // Visit each predecessor only once.
- if (!UniquePreds.insert(PBB))
- continue;
- // Skip blocks which may jump to a landing pad. Can't tail merge these.
- if (PBB->getLandingPadSuccessor())
- continue;
- MachineBasicBlock *TBB = 0, *FBB = 0;
- SmallVector<MachineOperand, 4> 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);
- if (!Cond.empty() && TBB == IBB) {
- if (TII->ReverseBranchCondition(NewCond))
+ if (I->pred_size() < 2) continue;
+ SmallPtrSet<MachineBasicBlock *, 8> UniquePreds;
+ MachineBasicBlock *IBB = I;
+ MachineBasicBlock *PredBB = prior(I);
+ MergePotentials.clear();
+ for (MachineBasicBlock::pred_iterator P = I->pred_begin(),
+ E2 = I->pred_end();
+ P != E2 && MergePotentials.size() < TailMergeThreshold; ++P) {
+ MachineBasicBlock *PBB = *P;
+ if (TriedMerging.count(PBB))
+ continue;
+
+ // Skip blocks that loop to themselves, can't tail merge these.
+ if (PBB == IBB)
+ continue;
+
+ // Visit each predecessor only once.
+ if (!UniquePreds.insert(PBB))
+ continue;
+
+ // Skip blocks which may jump to a landing pad. Can't tail merge these.
+ if (PBB->getLandingPadSuccessor())
+ continue;
+
+ MachineBasicBlock *TBB = 0, *FBB = 0;
+ SmallVector<MachineOperand, 4> 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);
+ if (!Cond.empty() && TBB == IBB) {
+ if (TII->ReverseBranchCondition(NewCond))
+ continue;
+ // This is the QBB case described above
+ if (!FBB)
+ FBB = llvm::next(MachineFunction::iterator(PBB));
+ }
+
+ // Failing case: the only way IBB can be reached from PBB is via
+ // exception handling. Happens for landing pads. Would be nice to have
+ // a bit in the edge so we didn't have to do all this.
+ if (IBB->isLandingPad()) {
+ MachineFunction::iterator IP = PBB; IP++;
+ MachineBasicBlock *PredNextBB = NULL;
+ if (IP != MF.end())
+ PredNextBB = IP;
+ if (TBB == NULL) {
+ if (IBB != PredNextBB) // fallthrough
+ continue;
+ } else if (FBB) {
+ if (TBB != IBB && FBB != IBB) // cbr then ubr
+ continue;
+ } else if (Cond.empty()) {
+ if (TBB != IBB) // ubr
+ continue;
+ } else {
+ if (TBB != IBB && IBB != PredNextBB) // cbr
continue;
- // This is the QBB case described above
- if (!FBB)
- FBB = llvm::next(MachineFunction::iterator(PBB));
- }
- // Failing case: the only way IBB can be reached from PBB is via
- // exception handling. Happens for landing pads. Would be nice
- // to have a bit in the edge so we didn't have to do all this.
- if (IBB->isLandingPad()) {
- MachineFunction::iterator IP = PBB; IP++;
- MachineBasicBlock *PredNextBB = NULL;
- if (IP != MF.end())
- PredNextBB = IP;
- if (TBB == NULL) {
- if (IBB != PredNextBB) // fallthrough
- continue;
- } else if (FBB) {
- if (TBB != IBB && FBB != IBB) // cbr then ubr
- continue;
- } else if (Cond.empty()) {
- if (TBB != IBB) // ubr
- continue;
- } else {
- if (TBB != IBB && IBB != PredNextBB) // cbr
- continue;
- }
- }
- // Remove the unconditional branch at the end, if any.
- if (TBB && (Cond.empty() || FBB)) {
- DebugLoc dl; // FIXME: this is nowhere
- TII->RemoveBranch(*PBB);
- if (!Cond.empty())
- // reinsert conditional branch only, for now
- TII->InsertBranch(*PBB, (TBB == IBB) ? FBB : TBB, 0, NewCond, dl);
}
- MergePotentials.push_back(MergePotentialsElt(HashEndOfMBB(PBB), *P));
}
+
+ // Remove the unconditional branch at the end, if any.
+ if (TBB && (Cond.empty() || FBB)) {
+ DebugLoc dl; // FIXME: this is nowhere
+ TII->RemoveBranch(*PBB);
+ if (!Cond.empty())
+ // reinsert conditional branch only, for now
+ TII->InsertBranch(*PBB, (TBB == IBB) ? FBB : TBB, 0, NewCond, dl);
+ }
+
+ MergePotentials.push_back(MergePotentialsElt(HashEndOfMBB(PBB), *P));
}
- // If this is a large problem, avoid visiting the same basic blocks
- // multiple times.
- if (MergePotentials.size() == TailMergeThreshold)
- for (unsigned i = 0, e = MergePotentials.size(); i != e; ++i)
- TriedMerging.insert(MergePotentials[i].getBlock());
- if (MergePotentials.size() >= 2)
- MadeChange |= TryTailMergeBlocks(IBB, PredBB);
- // Reinsert an unconditional branch if needed.
- // The 1 below can occur as a result of removing blocks in
- // TryTailMergeBlocks.
- PredBB = prior(I); // this may have been changed in TryTailMergeBlocks
- if (MergePotentials.size() == 1 &&
- MergePotentials.begin()->getBlock() != PredBB)
- FixTail(MergePotentials.begin()->getBlock(), IBB, TII);
}
+
+ // If this is a large problem, avoid visiting the same basic blocks multiple
+ // times.
+ if (MergePotentials.size() == TailMergeThreshold)
+ for (unsigned i = 0, e = MergePotentials.size(); i != e; ++i)
+ TriedMerging.insert(MergePotentials[i].getBlock());
+
+ if (MergePotentials.size() >= 2)
+ MadeChange |= TryTailMergeBlocks(IBB, PredBB);
+
+ // Reinsert an unconditional branch if needed. The 1 below can occur as a
+ // result of removing blocks in TryTailMergeBlocks.
+ PredBB = prior(I); // this may have been changed in TryTailMergeBlocks
+ if (MergePotentials.size() == 1 &&
+ MergePotentials.begin()->getBlock() != PredBB)
+ FixTail(MergePotentials.begin()->getBlock(), IBB, TII);
}
+
return MadeChange;
}
}
/// findHoistingInsertPosAndDeps - Find the location to move common instructions
-/// in successors to. The location is ususally just before the terminator,
+/// in successors to. The location is usually just before the terminator,
/// however if the terminator is a conditional branch and its previous
/// instruction is the flag setting instruction, the previous instruction is
/// the preferred location. This function also gathers uses and defs of the
if (!Reg)
continue;
if (MO.isUse()) {
- Uses.insert(Reg);
- for (const uint16_t *AS = TRI->getAliasSet(Reg); *AS; ++AS)
- Uses.insert(*AS);
+ for (MCRegAliasIterator AI(Reg, TRI, true); AI.isValid(); ++AI)
+ Uses.insert(*AI);
} else if (!MO.isDead())
// Don't try to hoist code in the rare case the terminator defines a
// register that is later used.
if (!Reg)
continue;
if (MO.isUse()) {
- Uses.insert(Reg);
- for (const uint16_t *AS = TRI->getAliasSet(Reg); *AS; ++AS)
- Uses.insert(*AS);
+ for (MCRegAliasIterator AI(Reg, TRI, true); AI.isValid(); ++AI)
+ Uses.insert(*AI);
} else {
- if (Uses.count(Reg)) {
- Uses.erase(Reg);
- for (const uint16_t *SR = TRI->getSubRegisters(Reg); *SR; ++SR)
- Uses.erase(*SR); // Use getSubRegisters to be conservative
+ if (Uses.erase(Reg)) {
+ for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs)
+ Uses.erase(*SubRegs); // Use sub-registers to be conservative
}
- Defs.insert(Reg);
- for (const uint16_t *AS = TRI->getAliasSet(Reg); *AS; ++AS)
- Defs.insert(*AS);
+ for (MCRegAliasIterator AI(Reg, TRI, true); AI.isValid(); ++AI)
+ Defs.insert(*AI);
}
}
unsigned Reg = MO.getReg();
if (!Reg || !LocalDefsSet.count(Reg))
continue;
- for (const uint16_t *OR = TRI->getOverlaps(Reg); *OR; ++OR)
- LocalDefsSet.erase(*OR);
+ for (MCRegAliasIterator AI(Reg, TRI, true); AI.isValid(); ++AI)
+ LocalDefsSet.erase(*AI);
}
// Track local defs so we can update liveins.
if (!Reg)
continue;
LocalDefs.push_back(Reg);
- for (const uint16_t *OR = TRI->getOverlaps(Reg); *OR; ++OR)
- LocalDefsSet.insert(*OR);
+ for (MCRegAliasIterator AI(Reg, TRI, true); AI.isValid(); ++AI)
+ LocalDefsSet.insert(*AI);
}
HasDups = true;
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