WIP: CodeGen: Use MachineInstr& in MachineInstrBundle.h, NFC

Update APIs in MachineInstrBundle.h to take and return MachineInstr&
instead of MachineInstr* when the instruction cannot be null.  Besides
being a nice cleanup, this is tacking toward a fix for PR26753.

llvm-svn: 262141

4 files changed, 25 insertions, 29 deletions

diff --git a/llvm/include/llvm/CodeGen/MachineInstrBuilder.h b/llvm/include/llvm/CodeGen/MachineInstrBuilder.h
index 641791a7bbb..f19d426a310 100644
--- a/llvm/include/llvm/CodeGen/MachineInstrBuilder.h
+++ b/llvm/include/llvm/CodeGen/MachineInstrBuilder.h
@@ -447,7 +447,7 @@ public:
   /// Create an MIBundleBuilder representing an existing instruction or bundle
   /// that has MI as its head.
   explicit MIBundleBuilder(MachineInstr *MI)
-    : MBB(*MI->getParent()), Begin(MI), End(getBundleEnd(MI)) {}
+      : MBB(*MI->getParent()), Begin(MI), End(getBundleEnd(*MI)) {}
 
   /// Return a reference to the basic block containing this bundle.
   MachineBasicBlock &getMBB() const { return MBB; }
diff --git a/llvm/include/llvm/CodeGen/MachineInstrBundle.h b/llvm/include/llvm/CodeGen/MachineInstrBundle.h
index 4e88606c05a..9b374cf7991 100644
--- a/llvm/include/llvm/CodeGen/MachineInstrBundle.h
+++ b/llvm/include/llvm/CodeGen/MachineInstrBundle.h
@@ -43,23 +43,22 @@ bool finalizeBundles(MachineFunction &MF);
 
 /// getBundleStart - Returns the first instruction in the bundle containing MI.
 ///
-inline MachineInstr *getBundleStart(MachineInstr *MI) {
+inline MachineInstr &getBundleStart(MachineInstr &MI) {
   MachineBasicBlock::instr_iterator I(MI);
   while (I->isBundledWithPred())
     --I;
-  return &*I;
+  return *I;
 }
 
-inline const MachineInstr *getBundleStart(const MachineInstr *MI) {
+inline const MachineInstr &getBundleStart(const MachineInstr &MI) {
   MachineBasicBlock::const_instr_iterator I(MI);
   while (I->isBundledWithPred())
     --I;
-  return &*I;
+  return *I;
 }
 
 /// Return an iterator pointing beyond the bundle containing MI.
-inline MachineBasicBlock::instr_iterator
-getBundleEnd(MachineInstr *MI) {
+inline MachineBasicBlock::instr_iterator getBundleEnd(MachineInstr &MI) {
   MachineBasicBlock::instr_iterator I(MI);
   while (I->isBundledWithSucc())
     ++I;
@@ -68,7 +67,7 @@ getBundleEnd(MachineInstr *MI) {
 
 /// Return an iterator pointing beyond the bundle containing MI.
 inline MachineBasicBlock::const_instr_iterator
-getBundleEnd(const MachineInstr *MI) {
+getBundleEnd(const MachineInstr &MI) {
   MachineBasicBlock::const_instr_iterator I(MI);
   while (I->isBundledWithSucc())
     ++I;
@@ -114,12 +113,12 @@ protected:
   /// @param MI The instruction to examine.
   /// @param WholeBundle When true, visit all operands on the entire bundle.
   ///
-  explicit MachineOperandIteratorBase(MachineInstr *MI, bool WholeBundle) {
+  explicit MachineOperandIteratorBase(MachineInstr &MI, bool WholeBundle) {
     if (WholeBundle) {
-      InstrI = getBundleStart(MI)->getIterator();
-      InstrE = MI->getParent()->instr_end();
+      InstrI = getBundleStart(MI).getIterator();
+      InstrE = MI.getParent()->instr_end();
     } else {
-      InstrI = InstrE = MI->getIterator();
+      InstrI = InstrE = MI.getIterator();
       ++InstrE;
     }
     OpI = InstrI->operands_begin();
@@ -216,7 +215,7 @@ public:
 ///
 class MIOperands : public MachineOperandIteratorBase {
 public:
-  MIOperands(MachineInstr *MI) : MachineOperandIteratorBase(MI, false) {}
+  MIOperands(MachineInstr &MI) : MachineOperandIteratorBase(MI, false) {}
   MachineOperand &operator* () const { return deref(); }
   MachineOperand *operator->() const { return &deref(); }
 };
@@ -225,8 +224,8 @@ public:
 ///
 class ConstMIOperands : public MachineOperandIteratorBase {
 public:
-  ConstMIOperands(const MachineInstr *MI)
-    : MachineOperandIteratorBase(const_cast<MachineInstr*>(MI), false) {}
+  ConstMIOperands(const MachineInstr &MI)
+      : MachineOperandIteratorBase(const_cast<MachineInstr &>(MI), false) {}
   const MachineOperand &operator* () const { return deref(); }
   const MachineOperand *operator->() const { return &deref(); }
 };
@@ -236,7 +235,7 @@ public:
 ///
 class MIBundleOperands : public MachineOperandIteratorBase {
 public:
-  MIBundleOperands(MachineInstr *MI) : MachineOperandIteratorBase(MI, true) {}
+  MIBundleOperands(MachineInstr &MI) : MachineOperandIteratorBase(MI, true) {}
   MachineOperand &operator* () const { return deref(); }
   MachineOperand *operator->() const { return &deref(); }
 };
@@ -246,8 +245,8 @@ public:
 ///
 class ConstMIBundleOperands : public MachineOperandIteratorBase {
 public:
-  ConstMIBundleOperands(const MachineInstr *MI)
-    : MachineOperandIteratorBase(const_cast<MachineInstr*>(MI), true) {}
+  ConstMIBundleOperands(const MachineInstr &MI)
+      : MachineOperandIteratorBase(const_cast<MachineInstr &>(MI), true) {}
   const MachineOperand &operator* () const { return deref(); }
   const MachineOperand *operator->() const { return &deref(); }
 };
diff --git a/llvm/include/llvm/CodeGen/MachineRegisterInfo.h b/llvm/include/llvm/CodeGen/MachineRegisterInfo.h
index af948324789..65fb1be8c83 100644
--- a/llvm/include/llvm/CodeGen/MachineRegisterInfo.h
+++ b/llvm/include/llvm/CodeGen/MachineRegisterInfo.h
@@ -835,10 +835,10 @@ public:
           advance();
         } while (Op && Op->getParent() == P);
       } else if (ByBundle) {
-        MachineInstr *P = getBundleStart(Op->getParent());
+        MachineInstr &P = getBundleStart(*Op->getParent());
         do {
           advance();
-        } while (Op && getBundleStart(Op->getParent()) == P);
+        } while (Op && &getBundleStart(*Op->getParent()) == &P);
       }
 
       return *this;
@@ -937,10 +937,10 @@ public:
           advance();
         } while (Op && Op->getParent() == P);
       } else if (ByBundle) {
-        MachineInstr *P = getBundleStart(Op->getParent());
+        MachineInstr &P = getBundleStart(*Op->getParent());
         do {
           advance();
-        } while (Op && getBundleStart(Op->getParent()) == P);
+        } while (Op && &getBundleStart(*Op->getParent()) == &P);
       }
 
       return *this;
@@ -952,15 +952,12 @@ public:
     // Retrieve a reference to the current operand.
     MachineInstr &operator*() const {
       assert(Op && "Cannot dereference end iterator!");
-      if (ByBundle) return *(getBundleStart(Op->getParent()));
+      if (ByBundle)
+        return getBundleStart(*Op->getParent());
       return *Op->getParent();
     }
 
-    MachineInstr *operator->() const {
-      assert(Op && "Cannot dereference end iterator!");
-      if (ByBundle) return getBundleStart(Op->getParent());
-      return Op->getParent();
-    }
+    MachineInstr *operator->() const { return &operator*(); }
   };
 };
 
diff --git a/llvm/include/llvm/CodeGen/SlotIndexes.h b/llvm/include/llvm/CodeGen/SlotIndexes.h
index 907e43b92e9..71af879e142 100644
--- a/llvm/include/llvm/CodeGen/SlotIndexes.h
+++ b/llvm/include/llvm/CodeGen/SlotIndexes.h
@@ -421,7 +421,7 @@ namespace llvm {
     /// Returns the base index for the given instruction.
     SlotIndex getInstructionIndex(const MachineInstr &MI) const {
       // Instructions inside a bundle have the same number as the bundle itself.
-      Mi2IndexMap::const_iterator itr = mi2iMap.find(getBundleStart(&MI));
+      Mi2IndexMap::const_iterator itr = mi2iMap.find(&getBundleStart(MI));
       assert(itr != mi2iMap.end() && "Instruction not found in maps.");
       return itr->second;
     }