[CodeGen, Target] Use MachineBasicBlock::terminators (NFC)

Author: kazutakahirata

llvm/lib/CodeGen/ModuloSchedule.cpp

@@ -141,13 +141,11 @@ void ModuloScheduleExpander::generatePipelinedLoop() {
 
   // Copy any terminator instructions to the new kernel, and update
   // names as needed.
-  for (MachineBasicBlock::iterator I = BB->getFirstTerminator(),
-                                   E = BB->instr_end();
-       I != E; ++I) {
-    MachineInstr *NewMI = MF.CloneMachineInstr(&*I);
+  for (MachineInstr &MI : BB->terminators()) {
+    MachineInstr *NewMI = MF.CloneMachineInstr(&MI);
     updateInstruction(NewMI, false, MaxStageCount, 0, VRMap);
     KernelBB->push_back(NewMI);
-    InstrMap[NewMI] = &*I;
+    InstrMap[NewMI] = &MI;
   }
 
   NewKernel = KernelBB;

llvm/lib/Target/AArch64/AArch64CondBrTuning.cpp

@@ -295,10 +295,7 @@ bool AArch64CondBrTuning::runOnMachineFunction(MachineFunction &MF) {
   bool Changed = false;
   for (MachineBasicBlock &MBB : MF) {
     bool LocalChange = false;
-    for (MachineBasicBlock::iterator I = MBB.getFirstTerminator(),
-                                     E = MBB.end();
-         I != E; ++I) {
-      MachineInstr &MI = *I;
+    for (MachineInstr &MI : MBB.terminators()) {
       switch (MI.getOpcode()) {
       default:
         break;

llvm/lib/Target/AMDGPU/SIInstrInfo.cpp

@@ -2464,19 +2464,15 @@ bool SIInstrInfo::analyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
 
 unsigned SIInstrInfo::removeBranch(MachineBasicBlock &MBB,
                                    int *BytesRemoved) const {
-  MachineBasicBlock::iterator I = MBB.getFirstTerminator();
-
   unsigned Count = 0;
   unsigned RemovedSize = 0;
-  while (I != MBB.end()) {
-    MachineBasicBlock::iterator Next = std::next(I);
+  for (MachineInstr &MI : llvm::make_early_inc_range(MBB.terminators())) {
     // Skip over artificial terminators when removing instructions.
-    if (I->isBranch() || I->isReturn()) {
-      RemovedSize += getInstSizeInBytes(*I);
-      I->eraseFromParent();
+    if (MI.isBranch() || MI.isReturn()) {
+      RemovedSize += getInstSizeInBytes(MI);
+      MI.eraseFromParent();
       ++Count;
     }
-    I = Next;
   }
 
   if (BytesRemoved)

llvm/lib/Target/Hexagon/HexagonFrameLowering.cpp

@@ -343,8 +343,8 @@ static bool hasTailCall(const MachineBasicBlock &MBB) {
 
 /// Returns true if MBB contains an instruction that returns.
 static bool hasReturn(const MachineBasicBlock &MBB) {
-    for (auto I = MBB.getFirstTerminator(), E = MBB.end(); I != E; ++I)
-      if (I->isReturn())
+    for (const MachineInstr &MI : MBB.terminators())
+      if (MI.isReturn())
         return true;
     return false;
 }

llvm/lib/Target/SystemZ/SystemZMachineScheduler.cpp

@@ -106,13 +106,12 @@ void SystemZPostRASchedStrategy::enterMBB(MachineBasicBlock *NextMBB) {
 
   // Emit incoming terminator(s). Be optimistic and assume that branch
   // prediction will generally do "the right thing".
-  for (MachineBasicBlock::iterator I = SinglePredMBB->getFirstTerminator();
-       I != SinglePredMBB->end(); I++) {
-    LLVM_DEBUG(dbgs() << "** Emitting incoming branch: "; I->dump(););
-    bool TakenBranch = (I->isBranch() &&
-                        (TII->getBranchInfo(*I).isIndirect() ||
-                         TII->getBranchInfo(*I).getMBBTarget() == MBB));
-    HazardRec->emitInstruction(&*I, TakenBranch);
+  for (MachineInstr &MI : SinglePredMBB->terminators()) {
+    LLVM_DEBUG(dbgs() << "** Emitting incoming branch: "; MI.dump(););
+    bool TakenBranch = (MI.isBranch() &&
+                        (TII->getBranchInfo(MI).isIndirect() ||
+                         TII->getBranchInfo(MI).getMBBTarget() == MBB));
+    HazardRec->emitInstruction(&MI, TakenBranch);
     if (TakenBranch)
       break;
   }