[turbofan] Unify referencing of stack slots

src/frames.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_FRAMES_H_
 #define V8_FRAMES_H_
 
 #include "src/allocation.h"
 #include "src/handles.h"
 #include "src/safepoint-table.h"
@@ skipping 102 matching lines @@
 
 class StandardFrameConstants : public AllStatic {
  public:
   // Fixed part of the frame consists of return address, caller fp,
   // constant pool (if FLAG_enable_embedded_constant_pool), context, and
   // function. StandardFrame::IterateExpressions assumes that kLastObjectOffset
   // is the last object pointer.
   static const int kCPSlotSize =
       FLAG_enable_embedded_constant_pool ? kPointerSize : 0;
   static const int kFixedFrameSizeFromFp =  2 * kPointerSize + kCPSlotSize;
+  static const int kFixedFrameSizeAboveFp = kPCOnStackSize + kFPOnStackSize;
   static const int kFixedFrameSize =
-      kPCOnStackSize + kFPOnStackSize + kFixedFrameSizeFromFp;
+      kFixedFrameSizeAboveFp + kFixedFrameSizeFromFp;
   static const int kExpressionsOffset = -3 * kPointerSize - kCPSlotSize;
   static const int kMarkerOffset = -2 * kPointerSize - kCPSlotSize;
   static const int kContextOffset = -1 * kPointerSize - kCPSlotSize;
   static const int kConstantPoolOffset = kCPSlotSize ? -1 * kPointerSize : 0;
   static const int kCallerFPOffset = 0 * kPointerSize;
   static const int kCallerPCOffset = +1 * kFPOnStackSize;
   static const int kCallerSPOffset = kCallerPCOffset + 1 * kPCOnStackSize;
 
   static const int kLastObjectOffset = kContextOffset;
 };
@@ skipping 536 matching lines @@
 
   virtual void Summarize(List<FrameSummary>* frames);
 
   // Lookup exception handler for current {pc}, returns -1 if none found. Also
   // returns the expected number of stack slots at the handler site.
   virtual int LookupExceptionHandlerInTable(
       int* stack_slots, HandlerTable::CatchPrediction* prediction);
 
   DeoptimizationInputData* GetDeoptimizationData(int* deopt_index);
 
+  static int StackSlotOffsetRelativeToFp(int slot_index);
+
  protected:
   inline explicit OptimizedFrame(StackFrameIteratorBase* iterator);
 
  private:
   friend class StackFrameIteratorBase;
 
   Object* StackSlotAt(int index) const;
 };
 
 
@@ skipping 241 matching lines @@
 };
 
 
 // Reads all frames on the current stack and copies them into the current
 // zone memory.
 Vector<StackFrame*> CreateStackMap(Isolate* isolate, Zone* zone);
 
 } }  // namespace v8::internal
 
 #endif  // V8_FRAMES_H_