//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/MachineBasicBlock.h"
-#include "llvm/BasicBlock.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/CodeGen/LiveVariables.h"
#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineLoopInfo.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/SlotIndexes.h"
+#include "llvm/IR/BasicBlock.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/ModuleSlotTracker.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
-#include "llvm/Target/TargetRegisterInfo.h"
-#include "llvm/Target/TargetData.h"
-#include "llvm/Target/TargetInstrInfo.h"
-#include "llvm/Target/TargetMachine.h"
-#include "llvm/Assembly/Writer.h"
-#include "llvm/ADT/SmallString.h"
-#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/Support/Debug.h"
-#include "llvm/Support/LeakDetector.h"
#include "llvm/Support/raw_ostream.h"
+#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetRegisterInfo.h"
+#include "llvm/Target/TargetSubtargetInfo.h"
#include <algorithm>
using namespace llvm;
+#define DEBUG_TYPE "codegen"
+
MachineBasicBlock::MachineBasicBlock(MachineFunction &mf, const BasicBlock *bb)
: BB(bb), Number(-1), xParent(&mf), Alignment(0), IsLandingPad(false),
- AddressTaken(false) {
+ AddressTaken(false), CachedMCSymbol(nullptr) {
Insts.Parent = this;
}
MachineBasicBlock::~MachineBasicBlock() {
- LeakDetector::removeGarbageObject(this);
}
-/// getSymbol - Return the MCSymbol for this basic block.
-///
+/// Return the MCSymbol for this basic block.
MCSymbol *MachineBasicBlock::getSymbol() const {
- const MachineFunction *MF = getParent();
- MCContext &Ctx = MF->getContext();
- const char *Prefix = Ctx.getAsmInfo().getPrivateGlobalPrefix();
- return Ctx.GetOrCreateSymbol(Twine(Prefix) + "BB" +
- Twine(MF->getFunctionNumber()) + "_" +
- Twine(getNumber()));
+ if (!CachedMCSymbol) {
+ const MachineFunction *MF = getParent();
+ MCContext &Ctx = MF->getContext();
+ const char *Prefix = Ctx.getAsmInfo()->getPrivateLabelPrefix();
+ CachedMCSymbol = Ctx.getOrCreateSymbol(Twine(Prefix) + "BB" +
+ Twine(MF->getFunctionNumber()) +
+ "_" + Twine(getNumber()));
+ }
+
+ return CachedMCSymbol;
}
return OS;
}
-/// addNodeToList (MBB) - When an MBB is added to an MF, we need to update the
-/// parent pointer of the MBB, the MBB numbering, and any instructions in the
-/// MBB to be on the right operand list for registers.
+/// When an MBB is added to an MF, we need to update the parent pointer of the
+/// MBB, the MBB numbering, and any instructions in the MBB to be on the right
+/// operand list for registers.
///
/// MBBs start out as #-1. When a MBB is added to a MachineFunction, it
/// gets the next available unique MBB number. If it is removed from a
for (MachineBasicBlock::instr_iterator
I = N->instr_begin(), E = N->instr_end(); I != E; ++I)
I->AddRegOperandsToUseLists(RegInfo);
-
- LeakDetector::removeGarbageObject(N);
}
void ilist_traits<MachineBasicBlock>::removeNodeFromList(MachineBasicBlock *N) {
N->getParent()->removeFromMBBNumbering(N->Number);
N->Number = -1;
- LeakDetector::addGarbageObject(N);
}
-
-/// addNodeToList (MI) - When we add an instruction to a basic block
-/// list, we update its parent pointer and add its operands from reg use/def
-/// lists if appropriate.
+/// When we add an instruction to a basic block list, we update its parent
+/// pointer and add its operands from reg use/def lists if appropriate.
void ilist_traits<MachineInstr>::addNodeToList(MachineInstr *N) {
- assert(N->getParent() == 0 && "machine instruction already in a basic block");
+ assert(!N->getParent() && "machine instruction already in a basic block");
N->setParent(Parent);
// Add the instruction's register operands to their corresponding
// use/def lists.
MachineFunction *MF = Parent->getParent();
N->AddRegOperandsToUseLists(MF->getRegInfo());
-
- LeakDetector::removeGarbageObject(N);
}
-/// removeNodeFromList (MI) - When we remove an instruction from a basic block
-/// list, we update its parent pointer and remove its operands from reg use/def
-/// lists if appropriate.
+/// When we remove an instruction from a basic block list, we update its parent
+/// pointer and remove its operands from reg use/def lists if appropriate.
void ilist_traits<MachineInstr>::removeNodeFromList(MachineInstr *N) {
- assert(N->getParent() != 0 && "machine instruction not in a basic block");
+ assert(N->getParent() && "machine instruction not in a basic block");
// Remove from the use/def lists.
- N->RemoveRegOperandsFromUseLists();
-
- N->setParent(0);
+ if (MachineFunction *MF = N->getParent()->getParent())
+ N->RemoveRegOperandsFromUseLists(MF->getRegInfo());
- LeakDetector::addGarbageObject(N);
+ N->setParent(nullptr);
}
-/// transferNodesFromList (MI) - When moving a range of instructions from one
-/// MBB list to another, we need to update the parent pointers and the use/def
-/// lists.
+/// When moving a range of instructions from one MBB list to another, we need to
+/// update the parent pointers and the use/def lists.
void ilist_traits<MachineInstr>::
transferNodesFromList(ilist_traits<MachineInstr> &fromList,
ilist_iterator<MachineInstr> first,
}
MachineBasicBlock::iterator MachineBasicBlock::getFirstNonPHI() {
- instr_iterator I = instr_begin();
- while (I != end() && I->isPHI())
+ instr_iterator I = instr_begin(), E = instr_end();
+ while (I != E && I->isPHI())
++I;
- assert(!I->isInsideBundle() && "First non-phi MI cannot be inside a bundle!");
+ assert((I == E || !I->isInsideBundle()) &&
+ "First non-phi MI cannot be inside a bundle!");
return I;
}
MachineBasicBlock::iterator
MachineBasicBlock::SkipPHIsAndLabels(MachineBasicBlock::iterator I) {
- while (I != end() && (I->isPHI() || I->isLabel() || I->isDebugValue()))
+ iterator E = end();
+ while (I != E && (I->isPHI() || I->isPosition() || I->isDebugValue()))
++I;
// FIXME: This needs to change if we wish to bundle labels / dbg_values
// inside the bundle.
- assert(!I->isInsideBundle() &&
+ assert((I == E || !I->isInsideBundle()) &&
"First non-phi / non-label instruction is inside a bundle!");
return I;
}
MachineBasicBlock::iterator MachineBasicBlock::getFirstTerminator() {
- iterator I = end();
- while (I != begin() && ((--I)->isTerminator() || I->isDebugValue()))
+ iterator B = begin(), E = end(), I = E;
+ while (I != B && ((--I)->isTerminator() || I->isDebugValue()))
; /*noop */
- while (I != end() && !I->isTerminator())
+ while (I != E && !I->isTerminator())
++I;
return I;
}
-MachineBasicBlock::const_iterator
-MachineBasicBlock::getFirstTerminator() const {
- const_iterator I = end();
- while (I != begin() && ((--I)->isTerminator() || I->isDebugValue()))
+MachineBasicBlock::instr_iterator MachineBasicBlock::getFirstInstrTerminator() {
+ instr_iterator B = instr_begin(), E = instr_end(), I = E;
+ while (I != B && ((--I)->isTerminator() || I->isDebugValue()))
; /*noop */
- while (I != end() && !I->isTerminator())
+ while (I != E && !I->isTerminator())
++I;
return I;
}
-MachineBasicBlock::instr_iterator MachineBasicBlock::getFirstInstrTerminator() {
- instr_iterator I = instr_end();
- while (I != instr_begin() && ((--I)->isTerminator() || I->isDebugValue()))
- ; /*noop */
- while (I != instr_end() && !I->isTerminator())
+MachineBasicBlock::iterator MachineBasicBlock::getFirstNonDebugInstr() {
+ // Skip over begin-of-block dbg_value instructions.
+ iterator I = begin(), E = end();
+ while (I != E && I->isDebugValue())
++I;
return I;
}
return end();
}
-MachineBasicBlock::const_iterator
-MachineBasicBlock::getLastNonDebugInstr() const {
- // Skip over end-of-block dbg_value instructions.
- const_instr_iterator B = instr_begin(), I = instr_end();
- while (I != B) {
- --I;
- // Return instruction that starts a bundle.
- if (I->isDebugValue() || I->isInsideBundle())
- continue;
- return I;
- }
- // The block is all debug values.
- return end();
-}
-
const MachineBasicBlock *MachineBasicBlock::getLandingPadSuccessor() const {
// A block with a landing pad successor only has one other successor.
if (succ_size() > 2)
- return 0;
+ return nullptr;
for (const_succ_iterator I = succ_begin(), E = succ_end(); I != E; ++I)
if ((*I)->isLandingPad())
return *I;
- return 0;
+ return nullptr;
}
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
void MachineBasicBlock::dump() const {
print(dbgs());
}
+#endif
StringRef MachineBasicBlock::getName() const {
if (const BasicBlock *LBB = getBasicBlock())
return "(null)";
}
+/// Return a hopefully unique identifier for this block.
+std::string MachineBasicBlock::getFullName() const {
+ std::string Name;
+ if (getParent())
+ Name = (getParent()->getName() + ":").str();
+ if (getBasicBlock())
+ Name += getBasicBlock()->getName();
+ else
+ Name += ("BB" + Twine(getNumber())).str();
+ return Name;
+}
+
void MachineBasicBlock::print(raw_ostream &OS, SlotIndexes *Indexes) const {
const MachineFunction *MF = getParent();
if (!MF) {
<< " is null\n";
return;
}
+ const Function *F = MF->getFunction();
+ const Module *M = F ? F->getParent() : nullptr;
+ ModuleSlotTracker MST(M);
+ print(OS, MST, Indexes);
+}
+
+void MachineBasicBlock::print(raw_ostream &OS, ModuleSlotTracker &MST,
+ SlotIndexes *Indexes) const {
+ const MachineFunction *MF = getParent();
+ if (!MF) {
+ OS << "Can't print out MachineBasicBlock because parent MachineFunction"
+ << " is null\n";
+ return;
+ }
if (Indexes)
OS << Indexes->getMBBStartIdx(this) << '\t';
const char *Comma = "";
if (const BasicBlock *LBB = getBasicBlock()) {
OS << Comma << "derived from LLVM BB ";
- WriteAsOperand(OS, LBB, /*PrintType=*/false);
+ LBB->printAsOperand(OS, /*PrintType=*/false, MST);
Comma = ", ";
}
if (isLandingPad()) { OS << Comma << "EH LANDING PAD"; Comma = ", "; }
if (hasAddressTaken()) { OS << Comma << "ADDRESS TAKEN"; Comma = ", "; }
- if (Alignment) {
+ if (Alignment)
OS << Comma << "Align " << Alignment << " (" << (1u << Alignment)
<< " bytes)";
- Comma = ", ";
- }
OS << '\n';
- const TargetRegisterInfo *TRI = MF->getTarget().getRegisterInfo();
+ const TargetRegisterInfo *TRI = MF->getSubtarget().getRegisterInfo();
if (!livein_empty()) {
if (Indexes) OS << '\t';
OS << " Live Ins:";
- for (livein_iterator I = livein_begin(),E = livein_end(); I != E; ++I)
- OS << ' ' << PrintReg(*I, TRI);
+ for (unsigned LI : make_range(livein_begin(), livein_end())) {
+ OS << ' ' << PrintReg(LI, TRI);
+ }
OS << '\n';
}
// Print the preds of this block according to the CFG.
OS << '\t';
if (I->isInsideBundle())
OS << " * ";
- I->print(OS, &getParent()->getTarget());
+ I->print(OS, MST);
}
// Print the successors of this block according to the CFG.
if (!succ_empty()) {
if (Indexes) OS << '\t';
OS << " Successors according to CFG:";
- for (const_succ_iterator SI = succ_begin(), E = succ_end(); SI != E; ++SI)
+ for (const_succ_iterator SI = succ_begin(), E = succ_end(); SI != E; ++SI) {
OS << " BB#" << (*SI)->getNumber();
+ if (!Weights.empty())
+ OS << '(' << *getWeightIterator(SI) << ')';
+ }
OS << '\n';
}
}
+void MachineBasicBlock::printAsOperand(raw_ostream &OS,
+ bool /*PrintType*/) const {
+ OS << "BB#" << getNumber();
+}
+
void MachineBasicBlock::removeLiveIn(unsigned Reg) {
- std::vector<unsigned>::iterator I =
- std::find(LiveIns.begin(), LiveIns.end(), Reg);
- assert(I != LiveIns.end() && "Not a live in!");
- LiveIns.erase(I);
+ std::vector<unsigned>::iterator I
+ = std::find(LiveIns.begin(), LiveIns.end(), Reg);
+ if (I != LiveIns.end())
+ LiveIns.erase(I);
}
bool MachineBasicBlock::isLiveIn(unsigned Reg) const {
return I != livein_end();
}
+unsigned
+MachineBasicBlock::addLiveIn(unsigned PhysReg, const TargetRegisterClass *RC) {
+ assert(getParent() && "MBB must be inserted in function");
+ assert(TargetRegisterInfo::isPhysicalRegister(PhysReg) && "Expected physreg");
+ assert(RC && "Register class is required");
+ assert((isLandingPad() || this == &getParent()->front()) &&
+ "Only the entry block and landing pads can have physreg live ins");
+
+ bool LiveIn = isLiveIn(PhysReg);
+ iterator I = SkipPHIsAndLabels(begin()), E = end();
+ MachineRegisterInfo &MRI = getParent()->getRegInfo();
+ const TargetInstrInfo &TII = *getParent()->getSubtarget().getInstrInfo();
+
+ // Look for an existing copy.
+ if (LiveIn)
+ for (;I != E && I->isCopy(); ++I)
+ if (I->getOperand(1).getReg() == PhysReg) {
+ unsigned VirtReg = I->getOperand(0).getReg();
+ if (!MRI.constrainRegClass(VirtReg, RC))
+ llvm_unreachable("Incompatible live-in register class.");
+ return VirtReg;
+ }
+
+ // No luck, create a virtual register.
+ unsigned VirtReg = MRI.createVirtualRegister(RC);
+ BuildMI(*this, I, DebugLoc(), TII.get(TargetOpcode::COPY), VirtReg)
+ .addReg(PhysReg, RegState::Kill);
+ if (!LiveIn)
+ addLiveIn(PhysReg);
+ return VirtReg;
+}
+
void MachineBasicBlock::moveBefore(MachineBasicBlock *NewAfter) {
getParent()->splice(NewAfter, this);
}
}
void MachineBasicBlock::updateTerminator() {
- const TargetInstrInfo *TII = getParent()->getTarget().getInstrInfo();
+ const TargetInstrInfo *TII = getParent()->getSubtarget().getInstrInfo();
// A block with no successors has no concerns with fall-through edges.
if (this->succ_empty()) return;
- MachineBasicBlock *TBB = 0, *FBB = 0;
+ MachineBasicBlock *TBB = nullptr, *FBB = nullptr;
SmallVector<MachineOperand, 4> Cond;
DebugLoc dl; // FIXME: this is nowhere
bool B = TII->AnalyzeBranch(*this, TBB, FBB, Cond);
// Finally update the unconditional successor to be reached via a branch
// if it would not be reached by fallthrough.
if (!isLayoutSuccessor(TBB))
- TII->InsertBranch(*this, TBB, 0, Cond, dl);
+ TII->InsertBranch(*this, TBB, nullptr, Cond, dl);
}
} else {
if (FBB) {
if (TII->ReverseBranchCondition(Cond))
return;
TII->RemoveBranch(*this);
- TII->InsertBranch(*this, FBB, 0, Cond, dl);
+ TII->InsertBranch(*this, FBB, nullptr, Cond, dl);
} else if (isLayoutSuccessor(FBB)) {
TII->RemoveBranch(*this);
- TII->InsertBranch(*this, TBB, 0, Cond, dl);
+ TII->InsertBranch(*this, TBB, nullptr, Cond, dl);
}
} else {
+ // Walk through the successors and find the successor which is not
+ // a landing pad and is not the conditional branch destination (in TBB)
+ // as the fallthrough successor.
+ MachineBasicBlock *FallthroughBB = nullptr;
+ for (succ_iterator SI = succ_begin(), SE = succ_end(); SI != SE; ++SI) {
+ if ((*SI)->isLandingPad() || *SI == TBB)
+ continue;
+ assert(!FallthroughBB && "Found more than one fallthrough successor.");
+ FallthroughBB = *SI;
+ }
+ if (!FallthroughBB && canFallThrough()) {
+ // We fallthrough to the same basic block as the conditional jump
+ // targets. Remove the conditional jump, leaving unconditional
+ // fallthrough.
+ // FIXME: This does not seem like a reasonable pattern to support, but
+ // it has been seen in the wild coming out of degenerate ARM test cases.
+ TII->RemoveBranch(*this);
+
+ // Finally update the unconditional successor to be reached via a branch
+ // if it would not be reached by fallthrough.
+ if (!isLayoutSuccessor(TBB))
+ TII->InsertBranch(*this, TBB, nullptr, Cond, dl);
+ return;
+ }
+
// The block has a fallthrough conditional branch.
- MachineBasicBlock *MBBA = *succ_begin();
- MachineBasicBlock *MBBB = *llvm::next(succ_begin());
- if (MBBA == TBB) std::swap(MBBB, MBBA);
if (isLayoutSuccessor(TBB)) {
if (TII->ReverseBranchCondition(Cond)) {
// We can't reverse the condition, add an unconditional branch.
Cond.clear();
- TII->InsertBranch(*this, MBBA, 0, Cond, dl);
+ TII->InsertBranch(*this, FallthroughBB, nullptr, Cond, dl);
return;
}
TII->RemoveBranch(*this);
- TII->InsertBranch(*this, MBBA, 0, Cond, dl);
- } else if (!isLayoutSuccessor(MBBA)) {
+ TII->InsertBranch(*this, FallthroughBB, nullptr, Cond, dl);
+ } else if (!isLayoutSuccessor(FallthroughBB)) {
TII->RemoveBranch(*this);
- TII->InsertBranch(*this, TBB, MBBA, Cond, dl);
+ TII->InsertBranch(*this, TBB, FallthroughBB, Cond, dl);
}
}
}
if (weight != 0 || !Weights.empty())
Weights.push_back(weight);
- Successors.push_back(succ);
- succ->addPredecessor(this);
- }
+ Successors.push_back(succ);
+ succ->addPredecessor(this);
+}
void MachineBasicBlock::removeSuccessor(MachineBasicBlock *succ) {
succ->removePredecessor(this);
void MachineBasicBlock::replaceSuccessor(MachineBasicBlock *Old,
MachineBasicBlock *New) {
- uint32_t weight = 0;
- succ_iterator SI = std::find(Successors.begin(), Successors.end(), Old);
+ if (Old == New)
+ return;
- // If Weight list is empty it means we don't use it (disabled optimization).
- if (!Weights.empty()) {
- weight_iterator WI = getWeightIterator(SI);
- weight = *WI;
+ succ_iterator E = succ_end();
+ succ_iterator NewI = E;
+ succ_iterator OldI = E;
+ for (succ_iterator I = succ_begin(); I != E; ++I) {
+ if (*I == Old) {
+ OldI = I;
+ if (NewI != E)
+ break;
+ }
+ if (*I == New) {
+ NewI = I;
+ if (OldI != E)
+ break;
+ }
}
+ assert(OldI != E && "Old is not a successor of this block");
+ Old->removePredecessor(this);
- // Update the successor information.
- removeSuccessor(SI);
- addSuccessor(New, weight);
+ // If New isn't already a successor, let it take Old's place.
+ if (NewI == E) {
+ New->addPredecessor(this);
+ *OldI = New;
+ return;
+ }
+
+ // New is already a successor.
+ // Update its weight instead of adding a duplicate edge.
+ if (!Weights.empty()) {
+ weight_iterator OldWI = getWeightIterator(OldI);
+ *getWeightIterator(NewI) += *OldWI;
+ Weights.erase(OldWI);
+ }
+ Successors.erase(OldI);
}
void MachineBasicBlock::addPredecessor(MachineBasicBlock *pred) {
while (!fromMBB->succ_empty()) {
MachineBasicBlock *Succ = *fromMBB->succ_begin();
- uint32_t weight = 0;
-
+ uint32_t Weight = 0;
// If Weight list is empty it means we don't use it (disabled optimization).
if (!fromMBB->Weights.empty())
- weight = *fromMBB->Weights.begin();
+ Weight = *fromMBB->Weights.begin();
- addSuccessor(Succ, weight);
+ addSuccessor(Succ, Weight);
fromMBB->removeSuccessor(Succ);
}
}
while (!fromMBB->succ_empty()) {
MachineBasicBlock *Succ = *fromMBB->succ_begin();
- addSuccessor(Succ);
+ uint32_t Weight = 0;
+ if (!fromMBB->Weights.empty())
+ Weight = *fromMBB->Weights.begin();
+ addSuccessor(Succ, Weight);
fromMBB->removeSuccessor(Succ);
// Fix up any PHI nodes in the successor.
}
}
+bool MachineBasicBlock::isPredecessor(const MachineBasicBlock *MBB) const {
+ return std::find(pred_begin(), pred_end(), MBB) != pred_end();
+}
+
bool MachineBasicBlock::isSuccessor(const MachineBasicBlock *MBB) const {
- const_succ_iterator I = std::find(Successors.begin(), Successors.end(), MBB);
- return I != Successors.end();
+ return std::find(succ_begin(), succ_end(), MBB) != succ_end();
}
bool MachineBasicBlock::isLayoutSuccessor(const MachineBasicBlock *MBB) const {
MachineFunction::const_iterator I(this);
- return llvm::next(I) == MachineFunction::const_iterator(MBB);
+ return std::next(I) == MachineFunction::const_iterator(MBB);
}
bool MachineBasicBlock::canFallThrough() {
return false;
// Analyze the branches, if any, at the end of the block.
- MachineBasicBlock *TBB = 0, *FBB = 0;
+ MachineBasicBlock *TBB = nullptr, *FBB = nullptr;
SmallVector<MachineOperand, 4> Cond;
- const TargetInstrInfo *TII = getParent()->getTarget().getInstrInfo();
+ const TargetInstrInfo *TII = getParent()->getSubtarget().getInstrInfo();
if (TII->AnalyzeBranch(*this, TBB, FBB, Cond)) {
// If we couldn't analyze the branch, examine the last instruction.
// If the block doesn't end in a known control barrier, assume fallthrough
- // is possible. The isPredicable check is needed because this code can be
+ // is possible. The isPredicated check is needed because this code can be
// called during IfConversion, where an instruction which is normally a
- // Barrier is predicated and thus no longer an actual control barrier. This
- // is over-conservative though, because if an instruction isn't actually
- // predicated we could still treat it like a barrier.
- return empty() || !back().isBarrier() ||
- back().isPredicable();
+ // Barrier is predicated and thus no longer an actual control barrier.
+ return empty() || !back().isBarrier() || TII->isPredicated(&back());
}
// If there is no branch, control always falls through.
- if (TBB == 0) return true;
+ if (!TBB) return true;
// If there is some explicit branch to the fallthrough block, it can obviously
// reach, even though the branch should get folded to fall through implicitly.
// Otherwise, if it is conditional and has no explicit false block, it falls
// through.
- return FBB == 0;
+ return FBB == nullptr;
}
MachineBasicBlock *
MachineBasicBlock::SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P) {
+ // Splitting the critical edge to a landing pad block is non-trivial. Don't do
+ // it in this generic function.
+ if (Succ->isLandingPad())
+ return nullptr;
+
MachineFunction *MF = getParent();
DebugLoc dl; // FIXME: this is nowhere
+ // Performance might be harmed on HW that implements branching using exec mask
+ // where both sides of the branches are always executed.
+ if (MF->getTarget().requiresStructuredCFG())
+ return nullptr;
+
// We may need to update this's terminator, but we can't do that if
// AnalyzeBranch fails. If this uses a jump table, we won't touch it.
- const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
- MachineBasicBlock *TBB = 0, *FBB = 0;
+ const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
+ MachineBasicBlock *TBB = nullptr, *FBB = nullptr;
SmallVector<MachineOperand, 4> Cond;
if (TII->AnalyzeBranch(*this, TBB, FBB, Cond))
- return NULL;
+ return nullptr;
// Avoid bugpoint weirdness: A block may end with a conditional branch but
// jumps to the same MBB is either case. We have duplicate CFG edges in that
if (TBB && TBB == FBB) {
DEBUG(dbgs() << "Won't split critical edge after degenerate BB#"
<< getNumber() << '\n');
- return NULL;
+ return nullptr;
}
MachineBasicBlock *NMBB = MF->CreateMachineBasicBlock();
- MF->insert(llvm::next(MachineFunction::iterator(this)), NMBB);
+ MF->insert(std::next(MachineFunction::iterator(this)), NMBB);
DEBUG(dbgs() << "Splitting critical edge:"
" BB#" << getNumber()
<< " -- BB#" << NMBB->getNumber()
<< " -- BB#" << Succ->getNumber() << '\n');
+ LiveIntervals *LIS = P->getAnalysisIfAvailable<LiveIntervals>();
+ SlotIndexes *Indexes = P->getAnalysisIfAvailable<SlotIndexes>();
+ if (LIS)
+ LIS->insertMBBInMaps(NMBB);
+ else if (Indexes)
+ Indexes->insertMBBInMaps(NMBB);
+
// On some targets like Mips, branches may kill virtual registers. Make sure
// that LiveVariables is properly updated after updateTerminator replaces the
// terminators.
MachineInstr *MI = I;
for (MachineInstr::mop_iterator OI = MI->operands_begin(),
OE = MI->operands_end(); OI != OE; ++OI) {
- if (!OI->isReg() || !OI->isUse() || !OI->isKill() || OI->isUndef())
+ if (!OI->isReg() || OI->getReg() == 0 ||
+ !OI->isUse() || !OI->isKill() || OI->isUndef())
continue;
unsigned Reg = OI->getReg();
- if (TargetRegisterInfo::isVirtualRegister(Reg) &&
+ if (TargetRegisterInfo::isPhysicalRegister(Reg) ||
LV->getVarInfo(Reg).removeKill(MI)) {
KilledRegs.push_back(Reg);
DEBUG(dbgs() << "Removing terminator kill: " << *MI);
}
}
+ SmallVector<unsigned, 4> UsedRegs;
+ if (LIS) {
+ for (instr_iterator I = getFirstInstrTerminator(), E = instr_end();
+ I != E; ++I) {
+ MachineInstr *MI = I;
+
+ for (MachineInstr::mop_iterator OI = MI->operands_begin(),
+ OE = MI->operands_end(); OI != OE; ++OI) {
+ if (!OI->isReg() || OI->getReg() == 0)
+ continue;
+
+ unsigned Reg = OI->getReg();
+ if (std::find(UsedRegs.begin(), UsedRegs.end(), Reg) == UsedRegs.end())
+ UsedRegs.push_back(Reg);
+ }
+ }
+ }
+
ReplaceUsesOfBlockWith(Succ, NMBB);
+
+ // If updateTerminator() removes instructions, we need to remove them from
+ // SlotIndexes.
+ SmallVector<MachineInstr*, 4> Terminators;
+ if (Indexes) {
+ for (instr_iterator I = getFirstInstrTerminator(), E = instr_end();
+ I != E; ++I)
+ Terminators.push_back(I);
+ }
+
updateTerminator();
+ if (Indexes) {
+ SmallVector<MachineInstr*, 4> NewTerminators;
+ for (instr_iterator I = getFirstInstrTerminator(), E = instr_end();
+ I != E; ++I)
+ NewTerminators.push_back(I);
+
+ for (SmallVectorImpl<MachineInstr*>::iterator I = Terminators.begin(),
+ E = Terminators.end(); I != E; ++I) {
+ if (std::find(NewTerminators.begin(), NewTerminators.end(), *I) ==
+ NewTerminators.end())
+ Indexes->removeMachineInstrFromMaps(*I);
+ }
+ }
+
// Insert unconditional "jump Succ" instruction in NMBB if necessary.
NMBB->addSuccessor(Succ);
if (!NMBB->isLayoutSuccessor(Succ)) {
Cond.clear();
- MF->getTarget().getInstrInfo()->InsertBranch(*NMBB, Succ, NULL, Cond, dl);
+ MF->getSubtarget().getInstrInfo()->InsertBranch(*NMBB, Succ, nullptr, Cond,
+ dl);
+
+ if (Indexes) {
+ for (instr_iterator I = NMBB->instr_begin(), E = NMBB->instr_end();
+ I != E; ++I) {
+ // Some instructions may have been moved to NMBB by updateTerminator(),
+ // so we first remove any instruction that already has an index.
+ if (Indexes->hasIndex(I))
+ Indexes->removeMachineInstrFromMaps(I);
+ Indexes->insertMachineInstrInMaps(I);
+ }
+ }
}
// Fix PHI nodes in Succ so they refer to NMBB instead of this
i->getOperand(ni+1).setMBB(NMBB);
// Inherit live-ins from the successor
- for (MachineBasicBlock::livein_iterator I = Succ->livein_begin(),
- E = Succ->livein_end(); I != E; ++I)
- NMBB->addLiveIn(*I);
+ for (unsigned LI : Succ->liveins())
+ NMBB->addLiveIn(LI);
// Update LiveVariables.
+ const TargetRegisterInfo *TRI = MF->getSubtarget().getRegisterInfo();
if (LV) {
// Restore kills of virtual registers that were killed by the terminators.
while (!KilledRegs.empty()) {
unsigned Reg = KilledRegs.pop_back_val();
for (instr_iterator I = instr_end(), E = instr_begin(); I != E;) {
- if (!(--I)->addRegisterKilled(Reg, NULL, /* addIfNotFound= */ false))
+ if (!(--I)->addRegisterKilled(Reg, TRI, /* addIfNotFound= */ false))
continue;
- LV->getVarInfo(Reg).Kills.push_back(I);
+ if (TargetRegisterInfo::isVirtualRegister(Reg))
+ LV->getVarInfo(Reg).Kills.push_back(I);
DEBUG(dbgs() << "Restored terminator kill: " << *I);
break;
}
LV->addNewBlock(NMBB, this, Succ);
}
- if (MachineDominatorTree *MDT =
- P->getAnalysisIfAvailable<MachineDominatorTree>()) {
- // Update dominator information.
- MachineDomTreeNode *SucccDTNode = MDT->getNode(Succ);
-
- bool IsNewIDom = true;
- for (const_pred_iterator PI = Succ->pred_begin(), E = Succ->pred_end();
- PI != E; ++PI) {
- MachineBasicBlock *PredBB = *PI;
- if (PredBB == NMBB)
- continue;
- if (!MDT->dominates(SucccDTNode, MDT->getNode(PredBB))) {
- IsNewIDom = false;
- break;
+ if (LIS) {
+ // After splitting the edge and updating SlotIndexes, live intervals may be
+ // in one of two situations, depending on whether this block was the last in
+ // the function. If the original block was the last in the function, all
+ // live intervals will end prior to the beginning of the new split block. If
+ // the original block was not at the end of the function, all live intervals
+ // will extend to the end of the new split block.
+
+ bool isLastMBB =
+ std::next(MachineFunction::iterator(NMBB)) == getParent()->end();
+
+ SlotIndex StartIndex = Indexes->getMBBEndIdx(this);
+ SlotIndex PrevIndex = StartIndex.getPrevSlot();
+ SlotIndex EndIndex = Indexes->getMBBEndIdx(NMBB);
+
+ // Find the registers used from NMBB in PHIs in Succ.
+ SmallSet<unsigned, 8> PHISrcRegs;
+ for (MachineBasicBlock::instr_iterator
+ I = Succ->instr_begin(), E = Succ->instr_end();
+ I != E && I->isPHI(); ++I) {
+ for (unsigned ni = 1, ne = I->getNumOperands(); ni != ne; ni += 2) {
+ if (I->getOperand(ni+1).getMBB() == NMBB) {
+ MachineOperand &MO = I->getOperand(ni);
+ unsigned Reg = MO.getReg();
+ PHISrcRegs.insert(Reg);
+ if (MO.isUndef())
+ continue;
+
+ LiveInterval &LI = LIS->getInterval(Reg);
+ VNInfo *VNI = LI.getVNInfoAt(PrevIndex);
+ assert(VNI &&
+ "PHI sources should be live out of their predecessors.");
+ LI.addSegment(LiveInterval::Segment(StartIndex, EndIndex, VNI));
+ }
}
}
- // We know "this" dominates the newly created basic block.
- MachineDomTreeNode *NewDTNode = MDT->addNewBlock(NMBB, this);
+ MachineRegisterInfo *MRI = &getParent()->getRegInfo();
+ for (unsigned i = 0, e = MRI->getNumVirtRegs(); i != e; ++i) {
+ unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
+ if (PHISrcRegs.count(Reg) || !LIS->hasInterval(Reg))
+ continue;
+
+ LiveInterval &LI = LIS->getInterval(Reg);
+ if (!LI.liveAt(PrevIndex))
+ continue;
+
+ bool isLiveOut = LI.liveAt(LIS->getMBBStartIdx(Succ));
+ if (isLiveOut && isLastMBB) {
+ VNInfo *VNI = LI.getVNInfoAt(PrevIndex);
+ assert(VNI && "LiveInterval should have VNInfo where it is live.");
+ LI.addSegment(LiveInterval::Segment(StartIndex, EndIndex, VNI));
+ } else if (!isLiveOut && !isLastMBB) {
+ LI.removeSegment(StartIndex, EndIndex);
+ }
+ }
- // If all the other predecessors of "Succ" are dominated by "Succ" itself
- // then the new block is the new immediate dominator of "Succ". Otherwise,
- // the new block doesn't dominate anything.
- if (IsNewIDom)
- MDT->changeImmediateDominator(SucccDTNode, NewDTNode);
+ // Update all intervals for registers whose uses may have been modified by
+ // updateTerminator().
+ LIS->repairIntervalsInRange(this, getFirstTerminator(), end(), UsedRegs);
}
+ if (MachineDominatorTree *MDT =
+ P->getAnalysisIfAvailable<MachineDominatorTree>())
+ MDT->recordSplitCriticalEdge(this, Succ, NMBB);
+
if (MachineLoopInfo *MLI = P->getAnalysisIfAvailable<MachineLoopInfo>())
if (MachineLoop *TIL = MLI->getLoopFor(this)) {
// If one or the other blocks were not in a loop, the new block is not
return NMBB;
}
-MachineBasicBlock::iterator
-MachineBasicBlock::erase(MachineBasicBlock::iterator I) {
- if (I->isBundle()) {
- MachineBasicBlock::iterator E = llvm::next(I);
- return Insts.erase(I.getInstrIterator(), E.getInstrIterator());
- }
-
- return Insts.erase(I.getInstrIterator());
+/// Prepare MI to be removed from its bundle. This fixes bundle flags on MI's
+/// neighboring instructions so the bundle won't be broken by removing MI.
+static void unbundleSingleMI(MachineInstr *MI) {
+ // Removing the first instruction in a bundle.
+ if (MI->isBundledWithSucc() && !MI->isBundledWithPred())
+ MI->unbundleFromSucc();
+ // Removing the last instruction in a bundle.
+ if (MI->isBundledWithPred() && !MI->isBundledWithSucc())
+ MI->unbundleFromPred();
+ // If MI is not bundled, or if it is internal to a bundle, the neighbor flags
+ // are already fine.
}
-MachineInstr *MachineBasicBlock::remove(MachineInstr *I) {
- if (I->isBundle()) {
- MachineBasicBlock::instr_iterator MII = I; ++MII;
- while (MII != end() && MII->isInsideBundle()) {
- MachineInstr *MI = &*MII++;
- Insts.remove(MI);
- }
- }
+MachineBasicBlock::instr_iterator
+MachineBasicBlock::erase(MachineBasicBlock::instr_iterator I) {
+ unbundleSingleMI(I);
+ return Insts.erase(I);
+}
- return Insts.remove(I);
+MachineInstr *MachineBasicBlock::remove_instr(MachineInstr *MI) {
+ unbundleSingleMI(MI);
+ MI->clearFlag(MachineInstr::BundledPred);
+ MI->clearFlag(MachineInstr::BundledSucc);
+ return Insts.remove(MI);
}
-void MachineBasicBlock::splice(MachineBasicBlock::iterator where,
- MachineBasicBlock *Other,
- MachineBasicBlock::iterator From) {
- if (From->isBundle()) {
- MachineBasicBlock::iterator To = llvm::next(From);
- Insts.splice(where.getInstrIterator(), Other->Insts,
- From.getInstrIterator(), To.getInstrIterator());
- return;
+MachineBasicBlock::instr_iterator
+MachineBasicBlock::insert(instr_iterator I, MachineInstr *MI) {
+ assert(!MI->isBundledWithPred() && !MI->isBundledWithSucc() &&
+ "Cannot insert instruction with bundle flags");
+ // Set the bundle flags when inserting inside a bundle.
+ if (I != instr_end() && I->isBundledWithPred()) {
+ MI->setFlag(MachineInstr::BundledPred);
+ MI->setFlag(MachineInstr::BundledSucc);
}
-
- Insts.splice(where.getInstrIterator(), Other->Insts, From.getInstrIterator());
+ return Insts.insert(I, MI);
}
-/// removeFromParent - This method unlinks 'this' from the containing function,
-/// and returns it, but does not delete it.
+/// This method unlinks 'this' from the containing function, and returns it, but
+/// does not delete it.
MachineBasicBlock *MachineBasicBlock::removeFromParent() {
assert(getParent() && "Not embedded in a function!");
getParent()->remove(this);
return this;
}
-
-/// eraseFromParent - This method unlinks 'this' from the containing function,
-/// and deletes it.
+/// This method unlinks 'this' from the containing function, and deletes it.
void MachineBasicBlock::eraseFromParent() {
assert(getParent() && "Not embedded in a function!");
getParent()->erase(this);
}
-
-/// ReplaceUsesOfBlockWith - Given a machine basic block that branched to
-/// 'Old', change the code and CFG so that it branches to 'New' instead.
+/// Given a machine basic block that branched to 'Old', change the code and CFG
+/// so that it branches to 'New' instead.
void MachineBasicBlock::ReplaceUsesOfBlockWith(MachineBasicBlock *Old,
MachineBasicBlock *New) {
assert(Old != New && "Cannot replace self with self!");
replaceSuccessor(Old, New);
}
-/// CorrectExtraCFGEdges - Various pieces of code can cause excess edges in the
-/// CFG to be inserted. If we have proven that MBB can only branch to DestA and
-/// DestB, remove any other MBB successors from the CFG. DestA and DestB can be
-/// null.
+/// Various pieces of code can cause excess edges in the CFG to be inserted. If
+/// we have proven that MBB can only branch to DestA and DestB, remove any other
+/// MBB successors from the CFG. DestA and DestB can be null.
///
/// Besides DestA and DestB, retain other edges leading to LandingPads
/// (currently there can be only one; we don't check or require that here).
bool Changed = false;
MachineFunction::iterator FallThru =
- llvm::next(MachineFunction::iterator(this));
+ std::next(MachineFunction::iterator(this));
- if (DestA == 0 && DestB == 0) {
+ if (!DestA && !DestB) {
// Block falls through to successor.
DestA = FallThru;
DestB = FallThru;
- } else if (DestA != 0 && DestB == 0) {
+ } else if (DestA && !DestB) {
if (isCond)
// Block ends in conditional jump that falls through to successor.
DestB = FallThru;
MachineBasicBlock::succ_iterator SI = succ_begin();
while (SI != succ_end()) {
const MachineBasicBlock *MBB = *SI;
- if (!SeenMBBs.insert(MBB) ||
+ if (!SeenMBBs.insert(MBB).second ||
(MBB != DestA && MBB != DestB && !MBB->isLandingPad())) {
// This is a superfluous edge, remove it.
SI = removeSuccessor(SI);
return Changed;
}
-/// findDebugLoc - find the next valid DebugLoc starting at MBBI, skipping
-/// any DBG_VALUE instructions. Return UnknownLoc if there is none.
+/// Find the next valid DebugLoc starting at MBBI, skipping any DBG_VALUE
+/// instructions. Return UnknownLoc if there is none.
DebugLoc
MachineBasicBlock::findDebugLoc(instr_iterator MBBI) {
DebugLoc DL;
return DL;
}
-/// getSuccWeight - Return weight of the edge from this block to MBB.
-///
-uint32_t MachineBasicBlock::getSuccWeight(const MachineBasicBlock *succ) const {
+/// Return weight of the edge from this block to MBB.
+uint32_t MachineBasicBlock::getSuccWeight(const_succ_iterator Succ) const {
if (Weights.empty())
return 0;
- const_succ_iterator I = std::find(Successors.begin(), Successors.end(), succ);
- return *getWeightIterator(I);
+ return *getWeightIterator(Succ);
+}
+
+/// Set successor weight of a given iterator.
+void MachineBasicBlock::setSuccWeight(succ_iterator I, uint32_t weight) {
+ if (Weights.empty())
+ return;
+ *getWeightIterator(I) = weight;
}
-/// getWeightIterator - Return wight iterator corresonding to the I successor
-/// iterator
+/// Return wight iterator corresonding to the I successor iterator.
MachineBasicBlock::weight_iterator MachineBasicBlock::
getWeightIterator(MachineBasicBlock::succ_iterator I) {
assert(Weights.size() == Successors.size() && "Async weight list!");
return Weights.begin() + index;
}
-/// getWeightIterator - Return wight iterator corresonding to the I successor
-/// iterator
+/// Return wight iterator corresonding to the I successor iterator.
MachineBasicBlock::const_weight_iterator MachineBasicBlock::
getWeightIterator(MachineBasicBlock::const_succ_iterator I) const {
assert(Weights.size() == Successors.size() && "Async weight list!");
return Weights.begin() + index;
}
-void llvm::WriteAsOperand(raw_ostream &OS, const MachineBasicBlock *MBB,
- bool t) {
- OS << "BB#" << MBB->getNumber();
-}
+/// Return whether (physical) register "Reg" has been <def>ined and not <kill>ed
+/// as of just before "MI".
+///
+/// Search is localised to a neighborhood of
+/// Neighborhood instructions before (searching for defs or kills) and N
+/// instructions after (searching just for defs) MI.
+MachineBasicBlock::LivenessQueryResult
+MachineBasicBlock::computeRegisterLiveness(const TargetRegisterInfo *TRI,
+ unsigned Reg, const_iterator Before,
+ unsigned Neighborhood) const {
+ unsigned N = Neighborhood;
+
+ // Start by searching backwards from Before, looking for kills, reads or defs.
+ const_iterator I(Before);
+ // If this is the first insn in the block, don't search backwards.
+ if (I != begin()) {
+ do {
+ --I;
+
+ MachineOperandIteratorBase::PhysRegInfo Analysis =
+ ConstMIOperands(I).analyzePhysReg(Reg, TRI);
+
+ if (Analysis.Defines)
+ // Outputs happen after inputs so they take precedence if both are
+ // present.
+ return Analysis.DefinesDead ? LQR_Dead : LQR_Live;
+
+ if (Analysis.Kills || Analysis.Clobbers)
+ // Register killed, so isn't live.
+ return LQR_Dead;
+
+ else if (Analysis.ReadsOverlap)
+ // Defined or read without a previous kill - live.
+ return Analysis.Reads ? LQR_Live : LQR_OverlappingLive;
+
+ } while (I != begin() && --N > 0);
+ }
+
+ // Did we get to the start of the block?
+ if (I == begin()) {
+ // If so, the register's state is definitely defined by the live-in state.
+ for (MCRegAliasIterator RAI(Reg, TRI, /*IncludeSelf=*/true);
+ RAI.isValid(); ++RAI) {
+ if (isLiveIn(*RAI))
+ return (*RAI == Reg) ? LQR_Live : LQR_OverlappingLive;
+ }
+ return LQR_Dead;
+ }
+
+ N = Neighborhood;
+
+ // Try searching forwards from Before, looking for reads or defs.
+ I = const_iterator(Before);
+ // If this is the last insn in the block, don't search forwards.
+ if (I != end()) {
+ for (++I; I != end() && N > 0; ++I, --N) {
+ MachineOperandIteratorBase::PhysRegInfo Analysis =
+ ConstMIOperands(I).analyzePhysReg(Reg, TRI);
+
+ if (Analysis.ReadsOverlap)
+ // Used, therefore must have been live.
+ return (Analysis.Reads) ?
+ LQR_Live : LQR_OverlappingLive;
+
+ else if (Analysis.Clobbers || Analysis.Defines)
+ // Defined (but not read) therefore cannot have been live.
+ return LQR_Dead;
+ }
+ }
+
+ // At this point we have no idea of the liveness of the register.
+ return LQR_Unknown;
+}
projects / oota-llvm.git / blobdiff