[turbofan] Various fixes to allow unboxed doubles as arguments in registers and on the stack.

src/compiler/frame.h

 // Copyright 2014 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_COMPILER_FRAME_H_
 #define V8_COMPILER_FRAME_H_
 
 #include "src/bit-vector.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 // Collects the spill slot requirements and the allocated general and double
 // registers for a compiled function. Frames are usually populated by the
 // register allocator and are used by Linkage to generate code for the prologue
 // and epilogue to compiled code.
 class Frame : public ZoneObject {
  public:
   Frame()
       : register_save_area_size_(0),
         spill_slot_count_(0),
         osr_stack_slot_count_(0),
         allocated_registers_(NULL),
-        allocated_double_registers_(NULL) {}
+        allocated_double_registers_(NULL),
+        pc_on_stack_(true) {}
 
   inline int GetSpillSlotCount() { return spill_slot_count_; }
 
   void SetAllocatedRegisters(BitVector* regs) {
     DCHECK(allocated_registers_ == NULL);
     allocated_registers_ = regs;
   }
 
   void SetAllocatedDoubleRegisters(BitVector* regs) {
     DCHECK(allocated_double_registers_ == NULL);
@@ skipping 28 matching lines @@
       spill_slot_count_ |= 1;
     }
     return spill_slot_count_++;
   }
 
   void ReserveSpillSlots(size_t slot_count) {
     DCHECK_EQ(0, spill_slot_count_);  // can only reserve before allocation.
     spill_slot_count_ = static_cast<int>(slot_count);
   }
 
+  void SetPCOnStack(bool val) { pc_on_stack_ = val; }
+
+  int PCOnStackSize() { return pc_on_stack_ ? kRegisterSize : 0; }
+
  private:
   int register_save_area_size_;
   int spill_slot_count_;
   int osr_stack_slot_count_;
   BitVector* allocated_registers_;
   BitVector* allocated_double_registers_;
+  bool pc_on_stack_;
 
   DISALLOW_COPY_AND_ASSIGN(Frame);
 };
 
 
 // Represents an offset from either the stack pointer or frame pointer.
 class FrameOffset {
  public:
   inline bool from_stack_pointer() { return (offset_ & 1) == kFromSp; }
   inline bool from_frame_pointer() { return (offset_ & 1) == kFromFp; }
@@ skipping 15 matching lines @@
   int offset_;  // Encodes SP or FP in the low order bit.
 
   static const int kFromSp = 1;
   static const int kFromFp = 0;
 };
 }
 }
 }  // namespace v8::internal::compiler
 
 #endif  // V8_COMPILER_FRAME_H_