Improve bool folding

src/IceTargetLoweringX86Base.h

 //===- subzero/src/IceTargetLoweringX86Base.h - x86 lowering ----*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 702 matching lines @@
   }
 
   template <typename... Args>
   void dispatchToConcrete(void (Machine::*Method)(Args...), Args &&... args) {
     (static_cast<Machine *>(this)->*Method)(std::forward<Args>(args)...);
   }
 
   void lowerShift64(InstArithmetic::OpKind Op, Operand *Src0Lo, Operand *Src0Hi,
                     Operand *Src1Lo, Variable *DestLo, Variable *DestHi);
 
   /// Emit the code for a combined compare and branch, or sets the destination

[Jim Stichnoth, 2015/11/11 14:05:20]

Nit 1: "set" instead of "sets".
Nit 2: "if Br == nullptr" (for accuracy, and agreement with setccOrBr).
Nit 3: Document both methods with the same comment.

Suggestion:

  /// Emit the code for a combined icmp/branch or fcmp/branch, or set the
  /// destination variable of the compare if Br == nullptr.
  void lowerIcmpAndBr(const InstIcmp *Icmp, const InstBr *Br);
  void lowerFcmpAndBr(const InstIcmp *Icmp, const InstBr *Br);

Even better if you know how to make this combined comment doxygen-friendly.

[sehr, 2015/11/13 06:00:52]

Doxygen is over my head :-).  Done otherwise.

   /// variable of the compare if branch is nullptr.
+  void lowerFcmpAndBr(const InstFcmp *Fcmp, const InstBr *Br);
+
+  /// Emit the code for a combined compare and branch, or sets the destination
+  /// variable of the compare if branch is nullptr.
   void lowerIcmpAndBr(const InstIcmp *Icmp, const InstBr *Br);
 
   /// Emit a setcc instruction if Br == nullptr; otherwise emit a branch.
   void setccOrBr(typename Traits::Cond::BrCond Condition, Variable *Dest,
                  const InstBr *Br);
 
   /// Emit a mov [1|0] instruction if Br == nullptr; otherwise emit a branch.
   void movOrBr(bool IcmpResult, Variable *Dest, const InstBr *Br);
 
+  /// Emit the code for a combined arithmetic instruction and branch.
+  void lowerArithAndBr(const InstArithmetic *Arith, const InstBr *Br);
+
   /// Complains loudly if invoked because the cpu can handle 64-bit types
   /// natively.
   template <typename T = Traits>
   typename std::enable_if<T::Is64Bit, void>::type lowerIcmp64(const InstIcmp *,
                                                               const InstBr *) {
     llvm::report_fatal_error(
         "Hey, yo! This is x86-64. Watcha doin'? (lowerIcmp64)");
   }
   /// x86lowerIcmp64 handles 64-bit icmp lowering.
   template <typename T = Traits>
   typename std::enable_if<!T::Is64Bit, void>::type
   lowerIcmp64(const InstIcmp *Icmp, const InstBr *Br);
 
   BoolFolding FoldingInfo;
 };
 } // end of namespace X86Internal
 } // end of namespace Ice
 
 #include "IceTargetLoweringX86BaseImpl.h"
 
 #endif // SUBZERO_SRC_ICETARGETLOWERINGX86BASE_H