Doxygenize the documentation comments

src/IceTargetLoweringARM32.h

 //===- subzero/src/IceTargetLoweringARM32.h - ARM32 lowering ----*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
-//
-// This file declares the TargetLoweringARM32 class, which implements the
-// TargetLowering interface for the ARM 32-bit architecture.
-//
+///
+/// \file
+/// This file declares the TargetLoweringARM32 class, which implements the
+/// TargetLowering interface for the ARM 32-bit architecture.
+///
 //===----------------------------------------------------------------------===//
 
 #ifndef SUBZERO_SRC_ICETARGETLOWERINGARM32_H
 #define SUBZERO_SRC_ICETARGETLOWERINGARM32_H
 
 #include "IceDefs.h"
 #include "IceInstARM32.h"
 #include "IceRegistersARM32.h"
 #include "IceTargetLowering.h"
 
@@ skipping 36 matching lines @@
   void emit(const ConstantUndef *C) const final;
   void emit(const ConstantInteger32 *C) const final;
   void emit(const ConstantInteger64 *C) const final;
   void emit(const ConstantFloat *C) const final;
   void emit(const ConstantDouble *C) const final;
 
   void lowerArguments() override;
   void addProlog(CfgNode *Node) override;
   void addEpilog(CfgNode *Node) override;
 
-  // Ensure that a 64-bit Variable has been split into 2 32-bit
-  // Variables, creating them if necessary.  This is needed for all
-  // I64 operations.
+  /// Ensure that a 64-bit Variable has been split into 2 32-bit
+  /// Variables, creating them if necessary.  This is needed for all
+  /// I64 operations.
   void split64(Variable *Var);
   Operand *loOperand(Operand *Operand);
   Operand *hiOperand(Operand *Operand);
   void finishArgumentLowering(Variable *Arg, Variable *FramePtr,
                               size_t BasicFrameOffset, size_t &InArgsSizeBytes);
 
   enum ARM32InstructionSet {
     Begin,
     // Neon is the PNaCl baseline instruction set.
     Neon = Begin,
@@ skipping 28 matching lines @@
   void lowerUnreachable(const InstUnreachable *Inst) override;
   void prelowerPhis() override;
   void lowerPhiAssignments(CfgNode *Node,
                            const AssignList &Assignments) override;
   void doAddressOptLoad() override;
   void doAddressOptStore() override;
   void randomlyInsertNop(float Probability) override;
 
   enum OperandLegalization {
     Legal_None = 0,
-    Legal_Reg = 1 << 0,  // physical register, not stack location
-    Legal_Flex = 1 << 1, // A flexible operand2, which can hold rotated
-                         // small immediates, or shifted registers.
-    Legal_Mem = 1 << 2,  // includes [r0, r1 lsl #2] as well as [sp, #12]
+    Legal_Reg = 1 << 0,  /// physical register, not stack location
+    Legal_Flex = 1 << 1, /// A flexible operand2, which can hold rotated
+                         /// small immediates, or shifted registers.
+    Legal_Mem = 1 << 2,  /// includes [r0, r1 lsl #2] as well as [sp, #12]
     Legal_All = ~Legal_None
   };
   typedef uint32_t LegalMask;
   Operand *legalize(Operand *From, LegalMask Allowed = Legal_All,
                     int32_t RegNum = Variable::NoRegister);
   Variable *legalizeToVar(Operand *From, int32_t RegNum = Variable::NoRegister);
   OperandARM32Mem *formMemoryOperand(Operand *Ptr, Type Ty);
 
   Variable *makeReg(Type Ty, int32_t RegNum = Variable::NoRegister);
   static Type stackSlotType();
   Variable *copyToReg(Operand *Src, int32_t RegNum = Variable::NoRegister);
   void alignRegisterPow2(Variable *Reg, uint32_t Align);
 
-  // Returns a vector in a register with the given constant entries.
+  /// Returns a vector in a register with the given constant entries.
   Variable *makeVectorOfZeros(Type Ty, int32_t RegNum = Variable::NoRegister);
 
   void makeRandomRegisterPermutation(
       llvm::SmallVectorImpl<int32_t> &Permutation,
       const llvm::SmallBitVector &ExcludeRegisters) const override;
 
   // The following are helpers that insert lowered ARM32 instructions
   // with minimal syntactic overhead, so that the lowering code can
   // look as close to assembly as practical.
 
@@ skipping 52 matching lines @@
     Context.insert(InstARM32Lsl::create(Func, Dest, Src0, Src1, Pred));
   }
   void _lsr(Variable *Dest, Variable *Src0, Operand *Src1,
             CondARM32::Cond Pred = CondARM32::AL) {
     Context.insert(InstARM32Lsr::create(Func, Dest, Src0, Src1, Pred));
   }
   void _mla(Variable *Dest, Variable *Src0, Variable *Src1, Variable *Acc,
             CondARM32::Cond Pred = CondARM32::AL) {
     Context.insert(InstARM32Mla::create(Func, Dest, Src0, Src1, Acc, Pred));
   }
-  // If Dest=nullptr is passed in, then a new variable is created,
-  // marked as infinite register allocation weight, and returned
-  // through the in/out Dest argument.
+  /// If Dest=nullptr is passed in, then a new variable is created,
+  /// marked as infinite register allocation weight, and returned
+  /// through the in/out Dest argument.
   void _mov(Variable *&Dest, Operand *Src0,
             CondARM32::Cond Pred = CondARM32::AL,
             int32_t RegNum = Variable::NoRegister) {
     if (Dest == nullptr)
       Dest = makeReg(Src0->getType(), RegNum);
     Context.insert(InstARM32Mov::create(Func, Dest, Src0, Pred));
   }
   void _mov_nonkillable(Variable *Dest, Operand *Src0,
                         CondARM32::Cond Pred = CondARM32::AL) {
     Inst *NewInst = InstARM32Mov::create(Func, Dest, Src0, Pred);
     NewInst->setDestNonKillable();
     Context.insert(NewInst);
   }
-  // The Operand can only be a 16-bit immediate or a ConstantRelocatable
-  // (with an upper16 relocation).
+  /// The Operand can only be a 16-bit immediate or a ConstantRelocatable
+  /// (with an upper16 relocation).
   void _movt(Variable *Dest, Operand *Src0,
              CondARM32::Cond Pred = CondARM32::AL) {
     Context.insert(InstARM32Movt::create(Func, Dest, Src0, Pred));
   }
   void _movw(Variable *Dest, Operand *Src0,
              CondARM32::Cond Pred = CondARM32::AL) {
     Context.insert(InstARM32Movw::create(Func, Dest, Src0, Pred));
   }
   void _mul(Variable *Dest, Variable *Src0, Variable *Src1,
             CondARM32::Cond Pred = CondARM32::AL) {
@@ skipping 68 matching lines @@
   bool UsesFramePointer = false;
   bool NeedsStackAlignment = false;
   bool MaybeLeafFunc = true;
   size_t SpillAreaSizeBytes = 0;
   llvm::SmallBitVector TypeToRegisterSet[IceType_NUM];
   llvm::SmallBitVector ScratchRegs;
   llvm::SmallBitVector RegsUsed;
   VarList PhysicalRegisters[IceType_NUM];
   static IceString RegNames[];
 
-  // Helper class that understands the Calling Convention and register
-  // assignments. The first few integer type parameters can use r0-r3,
-  // regardless of their position relative to the floating-point/vector
-  // arguments in the argument list. Floating-point and vector arguments
-  // can use q0-q3 (aka d0-d7, s0-s15). Technically, arguments that can
-  // start with registers but extend beyond the available registers can be
-  // split between the registers and the stack. However, this is typically
-  // for passing GPR structs by value, and PNaCl transforms expand this out.
-  //
-  // Also, at the point before the call, the stack must be aligned.
+  /// Helper class that understands the Calling Convention and register
+  /// assignments. The first few integer type parameters can use r0-r3,
+  /// regardless of their position relative to the floating-point/vector
+  /// arguments in the argument list. Floating-point and vector arguments
+  /// can use q0-q3 (aka d0-d7, s0-s15). Technically, arguments that can
+  /// start with registers but extend beyond the available registers can be
+  /// split between the registers and the stack. However, this is typically
+  /// for passing GPR structs by value, and PNaCl transforms expand this out.
+  ///
+  /// Also, at the point before the call, the stack must be aligned.
   class CallingConv {
     CallingConv(const CallingConv &) = delete;
     CallingConv &operator=(const CallingConv &) = delete;
 
   public:
     CallingConv() : NumGPRRegsUsed(0) {}
     ~CallingConv() = default;
 
     bool I64InRegs(std::pair<int32_t, int32_t> *Regs);
     bool I32InReg(int32_t *Reg);
@@ skipping 45 matching lines @@
 protected:
   explicit TargetHeaderARM32(GlobalContext *Ctx);
 
 private:
   ~TargetHeaderARM32() = default;
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICETARGETLOWERINGARM32_H