Add Om1 lowering with no optimizations

src/IceGlobalContext.h

 //===- subzero/src/IceGlobalContext.h - Global context defs -----*- 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 aspects of the compilation that persist across
@@ skipping 12 matching lines @@
 #include "IceTypes.h"
 
 namespace Ice {
 
 // TODO: Accesses to all non-const fields of GlobalContext need to
 // be synchronized, especially the constant pool, the allocator, and
 // the output streams.
 class GlobalContext {
 public:
   GlobalContext(llvm::raw_ostream *OsDump, llvm::raw_ostream *OsEmit,
-                VerboseMask Mask, IceString TestPrefix);
+                VerboseMask Mask, TargetArch Arch, OptLevel Opt,
+                IceString TestPrefix);
   ~GlobalContext();
 
   // Returns true if any of the specified options in the verbose mask
   // are set.  If the argument is omitted, it checks if any verbose
   // options at all are set.  IceV_Timing is treated specially, so
   // that running with just IceV_Timing verbosity doesn't trigger an
   // avalanche of extra output.
   bool isVerbose(VerboseMask Mask = (IceV_All & ~IceV_Timing)) const {
     return VMask & Mask;
   }
   void setVerbose(VerboseMask Mask) { VMask = Mask; }
   void addVerbose(VerboseMask Mask) { VMask |= Mask; }
   void subVerbose(VerboseMask Mask) { VMask &= ~Mask; }
 
   Ostream &getStrDump() { return StrDump; }
   Ostream &getStrEmit() { return StrEmit; }
 
+  TargetArch getTargetArch() const { return Arch; }
+  OptLevel getOptLevel() const { return Opt; }
+
   // When emitting assembly, we allow a string to be prepended to
   // names of translated functions.  This makes it easier to create an
   // execution test against a reference translator like llc, with both
   // translators using the same bitcode as input.
   IceString getTestPrefix() const { return TestPrefix; }
   IceString mangleName(const IceString &Name) const;
 
+  // The purpose of HasEmitted is to add a header comment at the
+  // beginning of assembly code emission, doing it once per file
+  // rather than once per function.
+  bool testAndSetHasEmittedFirstMethod() {
+    bool HasEmitted = HasEmittedFirstMethod;
+    HasEmittedFirstMethod = true;
+    return HasEmitted;
+  }
+
   // Manage Constants.
   // getConstant*() functions are not const because they might add
   // something to the constant pool.
   Constant *getConstantInt(Type Ty, uint64_t ConstantInt64);
   Constant *getConstantFloat(float Value);
   Constant *getConstantDouble(double Value);
   // Returns a symbolic constant.
   Constant *getConstantSym(Type Ty, int64_t Offset, const IceString &Name = "",
                            bool SuppressMangling = false);
 
   // Allocate data of type T using the global allocator.
   template <typename T> T *allocate() { return Allocator.Allocate<T>(); }
 
 private:
   Ostream StrDump; // Stream for dumping / diagnostics
   Ostream StrEmit; // Stream for code emission
 
   llvm::BumpPtrAllocator Allocator;
   VerboseMask VMask;
   llvm::OwningPtr<class ConstantPool> ConstPool;
+  const TargetArch Arch;
+  const OptLevel Opt;
   const IceString TestPrefix;
+  bool HasEmittedFirstMethod;
   GlobalContext(const GlobalContext &) LLVM_DELETED_FUNCTION;
   GlobalContext &operator=(const GlobalContext &) LLVM_DELETED_FUNCTION;
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICEGLOBALCONTEXT_H