CodeGen: Use mop_iterator instead of MIOperands/ConstMIOperands

MIOperands/ConstMIOperands are classes iterating over the MachineOperand
of a MachineInstr, however MachineInstr::mop_iterator does the same
thing.

I assume these two iterators exist to have a uniform interface to
iterate over the operands of a machine instruction bundle and a single
machine instruction. However in practice I find it more confusing to have 2
different iterator classes, so this patch transforms (nearly all) the
code to use mop_iterators.

The only exception being MIOperands::anlayzePhysReg() and
MIOperands::analyzeVirtReg() still needing an equivalent, I leave that
as an exercise for the next patch.

Differential Revision: http://reviews.llvm.org/D9932

This version is slightly modified from the proposed revision in that it
introduces MachineInstr::getOperandNo to avoid the extra counting
variable in the few loops that previously used MIOperands::getOperandNo.

llvm-svn: 238539

llvm/include/llvm/CodeGen/MachineInstr.h

@@ -331,6 +331,11 @@ class MachineInstr : public ilist_node<MachineInstr> {
         operands_begin() + getDesc().getNumDefs(), operands_end());
   }
 
+  /// Returns the number of the operand iterator \p I points to.
+  unsigned getOperandNo(const_mop_iterator I) const {
+    return I - operands_begin();
+  }
+
   /// Access to memory operands of the instruction
   mmo_iterator memoperands_begin() const { return MemRefs; }
   mmo_iterator memoperands_end() const { return MemRefs + NumMemRefs; }

llvm/lib/CodeGen/EarlyIfConversion.cpp

@@ -226,21 +226,21 @@ bool SSAIfConv::canSpeculateInstrs(MachineBasicBlock *MBB) {
     }
 
     // Check for any dependencies on Head instructions.
-    for (MIOperands MO(I); MO.isValid(); ++MO) {
-      if (MO->isRegMask()) {
+    for (const MachineOperand MO : I->operands()) {
+      if (MO.isRegMask()) {
         DEBUG(dbgs() << "Won't speculate regmask: " << *I);
         return false;
       }
-      if (!MO->isReg())
+      if (!MO.isReg())
         continue;
-      unsigned Reg = MO->getReg();
+      unsigned Reg = MO.getReg();
 
       // Remember clobbered regunits.
-      if (MO->isDef() && TargetRegisterInfo::isPhysicalRegister(Reg))
+      if (MO.isDef() && TargetRegisterInfo::isPhysicalRegister(Reg))
         for (MCRegUnitIterator Units(Reg, TRI); Units.isValid(); ++Units)
           ClobberedRegUnits.set(*Units);
 
-      if (!MO->readsReg() || !TargetRegisterInfo::isVirtualRegister(Reg))
+      if (!MO.readsReg() || !TargetRegisterInfo::isVirtualRegister(Reg))
         continue;
       MachineInstr *DefMI = MRI->getVRegDef(Reg);
       if (!DefMI || DefMI->getParent() != Head)
@@ -284,19 +284,19 @@ bool SSAIfConv::findInsertionPoint() {
     }
 
     // Update live regunits.
-    for (MIOperands MO(I); MO.isValid(); ++MO) {
+    for (const MachineOperand &MO : I->operands()) {
       // We're ignoring regmask operands. That is conservatively correct.
-      if (!MO->isReg())
+      if (!MO.isReg())
         continue;
-      unsigned Reg = MO->getReg();
+      unsigned Reg = MO.getReg();
       if (!TargetRegisterInfo::isPhysicalRegister(Reg))
         continue;
       // I clobbers Reg, so it isn't live before I.
-      if (MO->isDef())
+      if (MO.isDef())
         for (MCRegUnitIterator Units(Reg, TRI); Units.isValid(); ++Units)
           LiveRegUnits.erase(*Units);
       // Unless I reads Reg.
-      if (MO->readsReg())
+      if (MO.readsReg())
         Reads.push_back(Reg);
     }
     // Anything read by I is live before I.

llvm/lib/CodeGen/LiveIntervalAnalysis.cpp

@@ -223,11 +223,11 @@ void LiveIntervals::computeRegMasks() {
     RMB.first = RegMaskSlots.size();
     for (MachineBasicBlock::iterator MI = MBB->begin(), ME = MBB->end();
          MI != ME; ++MI)
-      for (MIOperands MO(MI); MO.isValid(); ++MO) {
-        if (!MO->isRegMask())
+      for (const MachineOperand &MO : MI->operands()) {
+        if (!MO.isRegMask())
           continue;
           RegMaskSlots.push_back(Indexes->getInstructionIndex(MI).getRegSlot());
-          RegMaskBits.push_back(MO->getRegMask());
+          RegMaskBits.push_back(MO.getRegMask());
       }
     // Compute the number of register mask instructions in this block.
     RMB.second = RegMaskSlots.size() - RMB.first;
@@ -927,23 +927,23 @@ class LiveIntervals::HMEditor {
   void updateAllRanges(MachineInstr *MI) {
     DEBUG(dbgs() << "handleMove " << OldIdx << " -> " << NewIdx << ": " << *MI);
     bool hasRegMask = false;
-    for (MIOperands MO(MI); MO.isValid(); ++MO) {
-      if (MO->isRegMask())
+    for (MachineOperand &MO : MI->operands()) {
+      if (MO.isRegMask())
         hasRegMask = true;
-      if (!MO->isReg())
+      if (!MO.isReg())
         continue;
       // Aggressively clear all kill flags.
       // They are reinserted by VirtRegRewriter.
-      if (MO->isUse())
-        MO->setIsKill(false);
+      if (MO.isUse())
+        MO.setIsKill(false);
 
-      unsigned Reg = MO->getReg();
+      unsigned Reg = MO.getReg();
       if (!Reg)
         continue;
       if (TargetRegisterInfo::isVirtualRegister(Reg)) {
         LiveInterval &LI = LIS.getInterval(Reg);
         if (LI.hasSubRanges()) {
-          unsigned SubReg = MO->getSubReg();
+          unsigned SubReg = MO.getSubReg();
           unsigned LaneMask = TRI.getSubRegIndexLaneMask(SubReg);
           for (LiveInterval::SubRange &S : LI.subranges()) {
             if ((S.LaneMask & LaneMask) == 0)

llvm/lib/CodeGen/MachineInstr.cpp

@@ -1092,9 +1092,8 @@ const TargetRegisterClass *MachineInstr::getRegClassConstraintEffectForVReg(
           OpndIt.getOperandNo(), Reg, CurRC, TII, TRI);
   else
     // Otherwise, just check the current operands.
-    for (ConstMIOperands OpndIt(this); OpndIt.isValid() && CurRC; ++OpndIt)
-      CurRC = getRegClassConstraintEffectForVRegImpl(OpndIt.getOperandNo(), Reg,
-                                                     CurRC, TII, TRI);
+    for (unsigned i = 0, e = NumOperands; i < e && CurRC; ++i)
+      CurRC = getRegClassConstraintEffectForVRegImpl(i, Reg, CurRC, TII, TRI);
   return CurRC;
 }
 

llvm/lib/CodeGen/MachineLICM.cpp

@@ -1012,10 +1012,10 @@ bool MachineLICM::HasLoopPHIUse(const MachineInstr *MI) const {
   SmallVector<const MachineInstr*, 8> Work(1, MI);
   do {
     MI = Work.pop_back_val();
-    for (ConstMIOperands MO(MI); MO.isValid(); ++MO) {
-      if (!MO->isReg() || !MO->isDef())
+    for (const MachineOperand &MO : MI->operands()) {
+      if (!MO.isReg() || !MO.isDef())
         continue;
-      unsigned Reg = MO->getReg();
+      unsigned Reg = MO.getReg();
       if (!TargetRegisterInfo::isVirtualRegister(Reg))
         continue;
       for (MachineInstr &UseMI : MRI->use_instructions(Reg)) {

llvm/lib/CodeGen/MachineTraceMetrics.cpp

@@ -627,19 +627,21 @@ static bool getDataDeps(const MachineInstr *UseMI,
                         SmallVectorImpl<DataDep> &Deps,
                         const MachineRegisterInfo *MRI) {
   bool HasPhysRegs = false;
-  for (ConstMIOperands MO(UseMI); MO.isValid(); ++MO) {
-    if (!MO->isReg())
+  for (MachineInstr::const_mop_iterator I = UseMI->operands_begin(),
+       E = UseMI->operands_end(); I != E; ++I) {
+    const MachineOperand &MO = *I;
+    if (!MO.isReg())
       continue;
-    unsigned Reg = MO->getReg();
+    unsigned Reg = MO.getReg();
     if (!Reg)
       continue;
     if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
       HasPhysRegs = true;
       continue;
     }
     // Collect virtual register reads.
-    if (MO->readsReg())
-      Deps.push_back(DataDep(MRI, Reg, MO.getOperandNo()));
+    if (MO.readsReg())
+      Deps.push_back(DataDep(MRI, Reg, UseMI->getOperandNo(I)));
   }
   return HasPhysRegs;
 }
@@ -690,28 +692,30 @@ static void updatePhysDepsDownwards(const MachineInstr *UseMI,
   SmallVector<unsigned, 8> Kills;
   SmallVector<unsigned, 8> LiveDefOps;
 
-  for (ConstMIOperands MO(UseMI); MO.isValid(); ++MO) {
-    if (!MO->isReg())
+  for (MachineInstr::const_mop_iterator MI = UseMI->operands_begin(),
+       ME = UseMI->operands_end(); MI != ME; ++MI) {
+    const MachineOperand &MO = *MI;
+    if (!MO.isReg())
       continue;
-    unsigned Reg = MO->getReg();
+    unsigned Reg = MO.getReg();
     if (!TargetRegisterInfo::isPhysicalRegister(Reg))
       continue;
     // Track live defs and kills for updating RegUnits.
-    if (MO->isDef()) {
-      if (MO->isDead())
+    if (MO.isDef()) {
+      if (MO.isDead())
         Kills.push_back(Reg);
       else
-        LiveDefOps.push_back(MO.getOperandNo());
-    } else if (MO->isKill())
+        LiveDefOps.push_back(UseMI->getOperandNo(MI));
+    } else if (MO.isKill())
       Kills.push_back(Reg);
     // Identify dependencies.
-    if (!MO->readsReg())
+    if (!MO.readsReg())
       continue;
     for (MCRegUnitIterator Units(Reg, TRI); Units.isValid(); ++Units) {
       SparseSet<LiveRegUnit>::iterator I = RegUnits.find(*Units);
       if (I == RegUnits.end())
         continue;
-      Deps.push_back(DataDep(I->MI, I->Op, MO.getOperandNo()));
+      Deps.push_back(DataDep(I->MI, I->Op, UseMI->getOperandNo(MI)));
       break;
     }
   }
@@ -864,15 +868,18 @@ static unsigned updatePhysDepsUpwards(const MachineInstr *MI, unsigned Height,
                                       const TargetInstrInfo *TII,
                                       const TargetRegisterInfo *TRI) {
   SmallVector<unsigned, 8> ReadOps;
-  for (ConstMIOperands MO(MI); MO.isValid(); ++MO) {
-    if (!MO->isReg())
+
+  for (MachineInstr::const_mop_iterator MOI = MI->operands_begin(),
+       MOE = MI->operands_end(); MOI != MOE; ++MOI) {
+    const MachineOperand &MO = *MOI;
+    if (!MO.isReg())
       continue;
-    unsigned Reg = MO->getReg();
+    unsigned Reg = MO.getReg();
     if (!TargetRegisterInfo::isPhysicalRegister(Reg))
       continue;
-    if (MO->readsReg())
-      ReadOps.push_back(MO.getOperandNo());
-    if (!MO->isDef())
+    if (MO.readsReg())
+      ReadOps.push_back(MI->getOperandNo(MOI));
+    if (!MO.isDef())
       continue;
     // This is a def of Reg. Remove corresponding entries from RegUnits, and
     // update MI Height to consider the physreg dependencies.
@@ -885,7 +892,7 @@ static unsigned updatePhysDepsUpwards(const MachineInstr *MI, unsigned Height,
         // We may not know the UseMI of this dependency, if it came from the
         // live-in list. SchedModel can handle a NULL UseMI.
         DepHeight += SchedModel
-          .computeOperandLatency(MI, MO.getOperandNo(), I->MI, I->Op);
+          .computeOperandLatency(MI, MI->getOperandNo(MOI), I->MI, I->Op);
       }
       Height = std::max(Height, DepHeight);
       // This regunit is dead above MI.

llvm/lib/CodeGen/ProcessImplicitDefs.cpp

@@ -68,8 +68,8 @@ bool ProcessImplicitDefs::canTurnIntoImplicitDef(MachineInstr *MI) {
       !MI->isRegSequence() &&
       !MI->isPHI())
     return false;
-  for (MIOperands MO(MI); MO.isValid(); ++MO)
-    if (MO->isReg() && MO->isUse() && MO->readsReg())
+  for (const MachineOperand &MO : MI->operands())
+    if (MO.isReg() && MO.isUse() && MO.readsReg())
       return false;
   return true;
 }
@@ -100,17 +100,17 @@ void ProcessImplicitDefs::processImplicitDef(MachineInstr *MI) {
   MachineBasicBlock::instr_iterator UserE = MI->getParent()->instr_end();
   bool Found = false;
   for (++UserMI; UserMI != UserE; ++UserMI) {
-    for (MIOperands MO(UserMI); MO.isValid(); ++MO) {
-      if (!MO->isReg())
+    for (MachineOperand &MO : UserMI->operands()) {
+      if (!MO.isReg())
         continue;
-      unsigned UserReg = MO->getReg();
+      unsigned UserReg = MO.getReg();
       if (!TargetRegisterInfo::isPhysicalRegister(UserReg) ||
           !TRI->regsOverlap(Reg, UserReg))
         continue;
       // UserMI uses or redefines Reg. Set <undef> flags on all uses.
       Found = true;
-      if (MO->isUse())
-        MO->setIsUndef();
+      if (MO.isUse())
+        MO.setIsUndef();
     }
     if (Found)
       break;

llvm/lib/CodeGen/RegisterCoalescer.cpp

@@ -1834,12 +1834,12 @@ class JoinVals {
 unsigned JoinVals::computeWriteLanes(const MachineInstr *DefMI, bool &Redef)
   const {
   unsigned L = 0;
-  for (ConstMIOperands MO(DefMI); MO.isValid(); ++MO) {
-    if (!MO->isReg() || MO->getReg() != Reg || !MO->isDef())
+  for (const MachineOperand &MO : DefMI->operands()) {
+    if (!MO.isReg() || MO.getReg() != Reg || !MO.isDef())
       continue;
     L |= TRI->getSubRegIndexLaneMask(
-           TRI->composeSubRegIndices(SubIdx, MO->getSubReg()));
-    if (MO->readsReg())
+           TRI->composeSubRegIndices(SubIdx, MO.getSubReg()));
+    if (MO.readsReg())
       Redef = true;
   }
   return L;
@@ -2224,13 +2224,13 @@ bool JoinVals::usesLanes(const MachineInstr *MI, unsigned Reg, unsigned SubIdx,
                          unsigned Lanes) const {
   if (MI->isDebugValue())
     return false;
-  for (ConstMIOperands MO(MI); MO.isValid(); ++MO) {
-    if (!MO->isReg() || MO->isDef() || MO->getReg() != Reg)
+  for (const MachineOperand &MO : MI->operands()) {
+    if (!MO.isReg() || MO.isDef() || MO.getReg() != Reg)
       continue;
-    if (!MO->readsReg())
+    if (!MO.readsReg())
       continue;
     if (Lanes & TRI->getSubRegIndexLaneMask(
-                  TRI->composeSubRegIndices(SubIdx, MO->getSubReg())))
+                  TRI->composeSubRegIndices(SubIdx, MO.getSubReg())))
       return true;
   }
   return false;
@@ -2339,11 +2339,11 @@ void JoinVals::pruneValues(JoinVals &Other,
           // Remove <def,read-undef> flags. This def is now a partial redef.
           // Also remove <def,dead> flags since the joined live range will
           // continue past this instruction.
-          for (MIOperands MO(Indexes->getInstructionFromIndex(Def));
-               MO.isValid(); ++MO) {
-            if (MO->isReg() && MO->isDef() && MO->getReg() == Reg) {
-              MO->setIsUndef(EraseImpDef);
-              MO->setIsDead(false);
+          for (MachineOperand &MO :
+               Indexes->getInstructionFromIndex(Def)->operands()) {
+            if (MO.isReg() && MO.isDef() && MO.getReg() == Reg) {
+              MO.setIsUndef(EraseImpDef);
+              MO.setIsDead(false);
             }
           }
         }

llvm/lib/CodeGen/ScheduleDAGInstrs.cpp

@@ -1106,25 +1106,25 @@ static void toggleBundleKillFlag(MachineInstr *MI, unsigned Reg,
   MachineBasicBlock::instr_iterator Begin = MI;
   MachineBasicBlock::instr_iterator End = getBundleEnd(MI);
   while (Begin != End) {
-    for (MIOperands MO(--End); MO.isValid(); ++MO) {
-      if (!MO->isReg() || MO->isDef() || Reg != MO->getReg())
+    for (MachineOperand &MO : (--End)->operands()) {
+      if (!MO.isReg() || MO.isDef() || Reg != MO.getReg())
         continue;
 
       // DEBUG_VALUE nodes do not contribute to code generation and should
       // always be ignored.  Failure to do so may result in trying to modify
       // KILL flags on DEBUG_VALUE nodes, which is distressing.
-      if (MO->isDebug())
+      if (MO.isDebug())
         continue;
 
       // If the register has the internal flag then it could be killing an
       // internal def of the register.  In this case, just skip.  We only want
       // to toggle the flag on operands visible outside the bundle.
-      if (MO->isInternalRead())
+      if (MO.isInternalRead())
         continue;
 
-      if (MO->isKill() == NewKillState)
+      if (MO.isKill() == NewKillState)
         continue;
-      MO->setIsKill(NewKillState);
+      MO.setIsKill(NewKillState);
       if (NewKillState)
         return;
     }

llvm/lib/Target/ARM/ARMLoadStoreOptimizer.cpp

@@ -762,10 +762,10 @@ void ARMLoadStoreOpt::MergeOpsUpdate(MachineBasicBlock &MBB,
     Regs.push_back(std::make_pair(Reg, isKill));
 
     // Collect any implicit defs of super-registers. They must be preserved.
-    for (MIOperands MO(memOps[i].MBBI); MO.isValid(); ++MO) {
-      if (!MO->isReg() || !MO->isDef() || !MO->isImplicit() || MO->isDead())
+    for (const MachineOperand &MO : memOps[i].MBBI->operands()) {
+      if (!MO.isReg() || !MO.isDef() || !MO.isImplicit() || MO.isDead())
         continue;
-      unsigned DefReg = MO->getReg();
+      unsigned DefReg = MO.getReg();
       if (std::find(ImpDefs.begin(), ImpDefs.end(), DefReg) == ImpDefs.end())
         ImpDefs.push_back(DefReg);
 

llvm/lib/Target/ARM/Thumb2ITBlockPass.cpp

@@ -94,12 +94,12 @@ static void TrackDefUses(MachineInstr *MI,
 /// conservatively remove more kill flags than are necessary, but removing them
 /// is safer than incorrect kill flags remaining on instructions.
 static void ClearKillFlags(MachineInstr *MI, SmallSet<unsigned, 4> &Uses) {
-  for (MIOperands MO(MI); MO.isValid(); ++MO) {
-    if (!MO->isReg() || MO->isDef() || !MO->isKill())
+  for (MachineOperand &MO : MI->operands()) {
+    if (!MO.isReg() || MO.isDef() || !MO.isKill())
       continue;
-    if (!Uses.count(MO->getReg()))
+    if (!Uses.count(MO.getReg()))
       continue;
-    MO->setIsKill(false);
+    MO.setIsKill(false);
   }
 }