Align function starts to target-specific bundle alignment.

src/IceTargetLowering.h

 //===- subzero/src/IceTargetLowering.h - Lowering interface -----*- 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 TargetLowering and LoweringContext
@@ skipping 119 matching lines @@
   // register.  This is generally used to get very direct access to
   // the register such as in the prolog or epilog or for marking
   // scratch registers as killed by a call.
   virtual Variable *getPhysicalRegister(SizeT RegNum) = 0;
   // Returns a printable name for the register.
   virtual IceString getRegName(SizeT RegNum, Type Ty) const = 0;
 
   virtual bool hasFramePointer() const { return false; }
   virtual SizeT getFrameOrStackReg() const = 0;
   virtual size_t typeWidthInBytesOnStack(Type Ty) const = 0;
+  virtual SizeT getBundleAlignLog2Bytes() const = 0;
+  virtual IceString getNonExecBundlePadding() const = 0;

[jvoung (off chromium), 2014/08/28 21:02:22]

IceString, or const char *?

[Jim Stichnoth, 2014/08/28 21:22:22]

I was actually wondering if it should be uint8_t.  That may be more painful to
render in textual assembly, but much easier for an integrated assembler. 
Regardless, the other issue is that we're constraining padding to single-byte
encoded instructions, but that's probably OK.

[jvoung (off chromium), 2014/08/28 22:38:13]

True, we'll need the raw bytes.  I made this an ArrayRef<uint8_t>, and used
raw_ostream's write_hex().

   bool hasComputedFrame() const { return HasComputedFrame; }
   bool shouldDoNopInsertion() const;
   int32_t getStackAdjustment() const { return StackAdjustment; }
   void updateStackAdjustment(int32_t Offset) { StackAdjustment += Offset; }
   void resetStackAdjustment() { StackAdjustment = 0; }
   LoweringContext &getContext() { return Context; }
 
   enum RegSet {
     RegSet_None = 0,
     RegSet_CallerSave = 1 << 0,
@@ skipping 89 matching lines @@
 private:
   TargetGlobalInitLowering(const TargetGlobalInitLowering &)
   LLVM_DELETED_FUNCTION;
   TargetGlobalInitLowering &
   operator=(const TargetGlobalInitLowering &) LLVM_DELETED_FUNCTION;
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICETARGETLOWERING_H