[MIBundles] Move analyzeVirtReg out of MIBundleOperands iterator (NFC).

[fhahn]

Summary

analyzeVirtReg does not really fit into the iterator and moving it
makes it easier to change the base iterator.

[qcolombet]

LGTM

llvm/include/llvm/CodeGen/MachineInstrBundle.h

public:
 
   /// getOperandNo - Returns the number of the current operand relative to its
   /// instruction.
   ///
   unsigned getOperandNo() const {
     return OpI - InstrI->operands_begin();
   }
 
-  /// VirtRegInfo - Information about a virtual register used by a set of operands.
-  ///
-  struct VirtRegInfo {
-    /// Reads - One of the operands read the virtual register.  This does not
-    /// include undef or internal use operands, see MO::readsReg().
-    bool Reads;
-
-    /// Writes - One of the operands writes the virtual register.
-    bool Writes;
-
-    /// Tied - Uses and defs must use the same register. This can be because of
-    /// a two-address constraint, or there may be a partial redefinition of a
-    /// sub-register.
-    bool Tied;
-  };
-
   /// Information about how a physical register Reg is used by a set of
   /// operands.
   struct PhysRegInfo {
     /// There is a regmask operand indicating Reg is clobbered.
     /// \see MachineOperand::CreateRegMask().
     bool Clobbered;
 
     /// Reg or one of its aliases is defined. The definition may only cover
struct PhysRegInfo {
     /// Reg is Defined and all defs of reg or an overlapping register are
     /// dead.
     bool PartialDeadDef;
 
     /// There is a use operand of reg or a super-register with kill flag set.
     bool Killed;
   };
 
-  /// analyzeVirtReg - Analyze how the current instruction or bundle uses a
-  /// virtual register.  This function should not be called after operator++(),
-  /// it expects a fresh iterator.
-  ///
-  /// @param Reg The virtual register to analyze.
-  /// @param Ops When set, this vector will receive an (MI, OpNum) entry for
-  ///            each operand referring to Reg.
-  /// @returns A filled-in RegInfo struct.
-  VirtRegInfo analyzeVirtReg(unsigned Reg,
-           SmallVectorImpl<std::pair<MachineInstr*, unsigned> > *Ops = nullptr);
-
   /// analyzePhysReg - Analyze how the current instruction or bundle uses a
   /// physical register.  This function should not be called after operator++(),
   /// it expects a fresh iterator.
   ///
   /// @param Reg The physical register to analyze.
   /// @returns A filled-in PhysRegInfo struct.
   PhysRegInfo analyzePhysReg(unsigned Reg, const TargetRegisterInfo *TRI);
 };

 class ConstMIBundleOperands : public MachineOperandIteratorBase {
 public:
   ConstMIBundleOperands(const MachineInstr &MI)
       : MachineOperandIteratorBase(const_cast<MachineInstr &>(MI), true) {}
   const MachineOperand &operator* () const { return deref(); }
   const MachineOperand *operator->() const { return &deref(); }
 };
 
+/// VirtRegInfo - Information about a virtual register used by a set of
+/// operands.
+///
+struct VirtRegInfo {
+  /// Reads - One of the operands read the virtual register.  This does not
+  /// include undef or internal use operands, see MO::readsReg().
+  bool Reads;
+
+  /// Writes - One of the operands writes the virtual register.
+  bool Writes;
+
+  /// Tied - Uses and defs must use the same register. This can be because of
+  /// a two-address constraint, or there may be a partial redefinition of a
+  /// sub-register.
+  bool Tied;
+};
+
+/// AnalyzeVirtRegInBundle - Analyze how the current instruction or bundle uses
+/// a virtual register.  This function should not be called after operator++(),
+/// it expects a fresh iterator.
+///
+/// @param Reg The virtual register to analyze.
+/// @param Ops When set, this vector will receive an (MI, OpNum) entry for
+///            each operand referring to Reg.
+/// @returns A filled-in RegInfo struct.
+VirtRegInfo AnalyzeVirtRegInBundle(
+    MachineInstr &MI, unsigned Reg,
+    SmallVectorImpl<std::pair<MachineInstr *, unsigned>> *Ops = nullptr);
+
 } // End llvm namespace
 
 #endif

llvm/lib/CodeGen/InlineSpiller.cpp

bool InlineSpiller::canGuaranteeAssignmentAfterRemat(unsigned VReg,
   // with the same problem, we need to revisit this.
   return (MI.getOpcode() != TargetOpcode::STATEPOINT);
 }
 
 /// reMaterializeFor - Attempt to rematerialize before MI instead of reloading.
 bool InlineSpiller::reMaterializeFor(LiveInterval &VirtReg, MachineInstr &MI) {
   // Analyze instruction
   SmallVector<std::pair<MachineInstr *, unsigned>, 8> Ops;
-  MIBundleOperands::VirtRegInfo RI =
-      MIBundleOperands(MI).analyzeVirtReg(VirtReg.reg, &Ops);
+  VirtRegInfo RI = AnalyzeVirtRegInBundle(MI, VirtReg.reg, &Ops);
 
   if (!RI.Reads)
     return false;
 
   SlotIndex UseIdx = LIS.getInstructionIndex(MI).getRegSlot(true);
   VNInfo *ParentVNI = VirtReg.getVNInfoAt(UseIdx.getBaseIndex());
 
   if (!ParentVNI) {
for (MachineBasicBlock::iterator I = B; I != E; ++I) {
     dbgs() << SlotIndent << Idx << '\t' << *I;
   }
 }
 #endif
 
 /// foldMemoryOperand - Try folding stack slot references in Ops into their
 /// instructions.
 ///
-/// @param Ops    Operand indices from analyzeVirtReg().
+/// @param Ops    Operand indices from AnalyzeVirtRegInBundle().
 /// @param LoadMI Load instruction to use instead of stack slot when non-null.
 /// @return       True on success.
 bool InlineSpiller::
 foldMemoryOperand(ArrayRef<std::pair<MachineInstr *, unsigned>> Ops,
                   MachineInstr *LoadMI) {
   if (Ops.empty())
     return false;
   // Don't attempt folding in bundles.
if (SnippetCopies.count(MI))
       continue;
 
     // Stack slot accesses may coalesce away.
     if (coalesceStackAccess(MI, Reg))
       continue;
 
     // Analyze instruction.
     SmallVector<std::pair<MachineInstr*, unsigned>, 8> Ops;
-    MIBundleOperands::VirtRegInfo RI =
-        MIBundleOperands(*MI).analyzeVirtReg(Reg, &Ops);
+    VirtRegInfo RI = AnalyzeVirtRegInBundle(*MI, Reg, &Ops);
 
     // Find the slot index where this instruction reads and writes OldLI.
     // This is usually the def slot, except for tied early clobbers.
     SlotIndex Idx = LIS.getInstructionIndex(*MI).getRegSlot();
     if (VNInfo *VNI = OldLI.getVNInfoAt(Idx.getRegSlot(true)))
       if (SlotIndex::isSameInstr(Idx, VNI->def))
         Idx = VNI->def;
 

llvm/lib/CodeGen/MachineInstrBundle.cpp

for (++MII; MII != MIE; ) {
         Changed = true;
       }
     }
   }
 
   return Changed;
 }
 
-//===----------------------------------------------------------------------===//
-// MachineOperand iterator
-//===----------------------------------------------------------------------===//
-
-MachineOperandIteratorBase::VirtRegInfo
-MachineOperandIteratorBase::analyzeVirtReg(unsigned Reg,
-                    SmallVectorImpl<std::pair<MachineInstr*, unsigned> > *Ops) {
-  VirtRegInfo RI = { false, false, false };
-  for(; isValid(); ++*this) {
-    MachineOperand &MO = deref();
+VirtRegInfo llvm::AnalyzeVirtRegInBundle(
+    MachineInstr &MI, unsigned Reg,
+    SmallVectorImpl<std::pair<MachineInstr *, unsigned>> *Ops) {
+  VirtRegInfo RI = {false, false, false};
+  for (MIBundleOperands O(MI); O.isValid(); ++O) {
+    MachineOperand &MO = *O;
     if (!MO.isReg() || MO.getReg() != Reg)
       continue;
 
     // Remember each (MI, OpNo) that refers to Reg.
     if (Ops)
-      Ops->push_back(std::make_pair(MO.getParent(), getOperandNo()));
+      Ops->push_back(std::make_pair(MO.getParent(), O.getOperandNo()));
 
     // Both defs and uses can read virtual registers.
     if (MO.readsReg()) {
       RI.Reads = true;
       if (MO.isDef())
         RI.Tied = true;
     }
 
     // Only defs can write.
     if (MO.isDef())
       RI.Writes = true;
-    else if (!RI.Tied && MO.getParent()->isRegTiedToDefOperand(getOperandNo()))
+    else if (!RI.Tied &&
+             MO.getParent()->isRegTiedToDefOperand(O.getOperandNo()))
       RI.Tied = true;
   }
   return RI;
 }
 
+//===----------------------------------------------------------------------===//
+// MachineOperand iterator
+//===----------------------------------------------------------------------===//
+
 MachineOperandIteratorBase::PhysRegInfo
 MachineOperandIteratorBase::analyzePhysReg(unsigned Reg,
                                            const TargetRegisterInfo *TRI) {
   bool AllDefsDead = true;
   PhysRegInfo PRI = {false, false, false, false, false, false, false, false};
 
   assert(Register::isPhysicalRegister(Reg) &&
          "analyzePhysReg not given a physical register!");