Merge fixed alloca stack adjustments into the prolog

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.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 185 matching lines @@
   /// prolog or epilog or for marking scratch registers as killed by a call. If
   /// a Type is not provided, a target-specific default type is used.
   virtual Variable *getPhysicalRegister(SizeT RegNum,
                                         Type Ty = IceType_void) = 0;
   /// Returns a printable name for the register.
   virtual IceString getRegName(SizeT RegNum, Type Ty) const = 0;
 
   virtual bool hasFramePointer() const { return false; }
   virtual void setHasFramePointer() = 0;
   virtual SizeT getStackReg() const = 0;
+  virtual SizeT getFrameReg() const = 0;
   virtual SizeT getFrameOrStackReg() const = 0;
   virtual size_t typeWidthInBytesOnStack(Type Ty) const = 0;
   virtual uint32_t getStackAlignment() const = 0;
+  virtual void reserveFixedAllocaArea(size_t Size, size_t Align) = 0;
+  virtual int32_t getFrameFixedAllocaOffset() const = 0;
 
   /// Return whether a 64-bit Variable should be split into a Variable64On32.
   virtual bool shouldSplitToVariable64On32(Type Ty) const = 0;
 
   bool hasComputedFrame() const { return HasComputedFrame; }
   /// Returns true if this function calls a function that has the "returns
   /// twice" attribute.
   bool callsReturnsTwice() const { return CallsReturnsTwice; }
   void setCallsReturnsTwice(bool RetTwice) { CallsReturnsTwice = RetTwice; }
   int32_t getStackAdjustment() const { return StackAdjustment; }
@@ skipping 261 matching lines @@
   virtual void lower() {}
 
 protected:
   explicit TargetHeaderLowering(GlobalContext *Ctx) : Ctx(Ctx) {}
   GlobalContext *Ctx;
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICETARGETLOWERING_H