[CodeGen] Use range-based for loops (NFC) (#97467)

Author: kazutakahirata

llvm/lib/CodeGen/AggressiveAntiDepBreaker.cpp

@@ -124,13 +124,13 @@ AggressiveAntiDepBreaker::AggressiveAntiDepBreaker(
       TRI(MF.getSubtarget().getRegisterInfo()), RegClassInfo(RCI) {
   /* Collect a bitset of all registers that are only broken if they
      are on the critical path. */
-  for (unsigned i = 0, e = CriticalPathRCs.size(); i < e; ++i) {
-    BitVector CPSet = TRI->getAllocatableSet(MF, CriticalPathRCs[i]);
+  for (const TargetRegisterClass *RC : CriticalPathRCs) {
+    BitVector CPSet = TRI->getAllocatableSet(MF, RC);
     if (CriticalPathSet.none())
       CriticalPathSet = CPSet;
     else
       CriticalPathSet |= CPSet;
-   }
+  }
 
    LLVM_DEBUG(dbgs() << "AntiDep Critical-Path Registers:");
    LLVM_DEBUG(for (unsigned r

llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp

@@ -438,11 +438,11 @@ void CombinerHelper::applyCombineShuffleConcat(MachineInstr &MI,
   LLT SrcTy = MRI.getType(Ops[0]);
   Register UndefReg = 0;
 
-  for (unsigned i = 0; i < Ops.size(); i++) {
-    if (Ops[i] == 0) {
+  for (Register &Reg : Ops) {
+    if (Reg == 0) {
       if (UndefReg == 0)
         UndefReg = Builder.buildUndef(SrcTy).getReg(0);
-      Ops[i] = UndefReg;
+      Reg = UndefReg;
     }
   }
 

llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

@@ -10238,8 +10238,8 @@ void SelectionDAGBuilder::emitInlineAsmError(const CallBase &Call,
     return;
 
   SmallVector<SDValue, 1> Ops;
-  for (unsigned i = 0, e = ValueVTs.size(); i != e; ++i)
-    Ops.push_back(DAG.getUNDEF(ValueVTs[i]));
+  for (const EVT &VT : ValueVTs)
+    Ops.push_back(DAG.getUNDEF(VT));
 
   setValue(&Call, DAG.getMergeValues(Ops, getCurSDLoc()));
 }
@@ -12516,12 +12516,12 @@ void SelectionDAGBuilder::visitCallBrLandingPad(const CallInst &I) {
 
       // getRegistersForValue may produce 1 to many registers based on whether
       // the OpInfo.ConstraintVT is legal on the target or not.
-      for (size_t i = 0, e = OpInfo.AssignedRegs.Regs.size(); i != e; ++i) {
+      for (unsigned &Reg : OpInfo.AssignedRegs.Regs) {
         Register OriginalDef = FollowCopyChain(MRI, InitialDef++);
         if (Register::isPhysicalRegister(OriginalDef))
           FuncInfo.MBB->addLiveIn(OriginalDef);
         // Update the assigned registers to use the original defs.
-        OpInfo.AssignedRegs.Regs[i] = OriginalDef;
+        Reg = OriginalDef;
       }
 
       SDValue V = OpInfo.AssignedRegs.getCopyFromRegs(