First step in reducing the size of PC descriptors.

runtime/vm/object.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_OBJECT_H_
 #define VM_OBJECT_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/utils.h"
@@ skipping 2952 matching lines @@
     kTokenPosEntry = 3,     // Token position in source.
     kTryIndexEntry = 4,     // Try block index.
     // We would potentially be adding other objects here like
     // pointer maps for optimized functions, local variables information  etc.
     kNumberOfEntries = 5,
   };
 
  public:
   enum Kind {
     kDeopt,            // Deoptimization continuation point.
-    kEntryPatch,       // Location where to patch entry.
-    kPatchCode,        // Buffer for patching code entry.
-    kLazyDeoptJump,    // Lazy deoptimization trampoline.
     kIcCall,           // IC call.
     kOptStaticCall,    // Call directly to known target, e.g. static call.
     kUnoptStaticCall,  // Call to a known target via a stub.
     kClosureCall,      // Closure call.
     kRuntimeCall,      // Runtime call.
     kReturn,           // Return from function.
     kOsrEntry,         // OSR entry point in unoptimized code.
     kOther
   };
 
@@ skipping 660 matching lines @@
                                bool optimized = false);
   static RawCode* LookupCode(uword pc);
   static RawCode* LookupCodeInVmIsolate(uword pc);
   static RawCode* FindCode(uword pc, int64_t timestamp);
 
   int32_t GetPointerOffsetAt(int index) const {
     return *PointerOffsetAddrAt(index);
   }
   intptr_t GetTokenIndexOfPC(uword pc) const;
 
-  // Find pc, return 0 if not found.
+  enum {
+    kInvalidPc = -1
+  };
+
+  // Returns 0 if code is not patchable
+  uword GetEntryPatchPc() const;
   uword GetPatchCodePc() const;
+
   uword GetLazyDeoptPc() const;
 
+  // Find pc, return 0 if not found.
   uword GetPcForDeoptId(intptr_t deopt_id, PcDescriptors::Kind kind) const;
   intptr_t GetDeoptIdForOsr(uword pc) const;
 
   // Returns true if there is an object in the code between 'start_offset'
   // (inclusive) and 'end_offset' (exclusive).
   bool ObjectExistsInArea(intptr_t start_offest, intptr_t end_offset) const;
 
   // Each (*node_ids)[n] has a an extracted ic data array (*arrays)[n].
   // Returns the maximum id found.
   intptr_t ExtractIcDataArraysAtCalls(
       GrowableArray<intptr_t>* node_ids,
       const GrowableObjectArray& ic_data_objs) const;
 
   // Returns an array indexed by deopt id, containing the extracted ICData.
   RawArray* ExtractTypeFeedbackArray() const;
 
   RawString* Name() const;
   RawString* PrettyName() const;
 
   int64_t compile_timestamp() const {
     return raw_ptr()->compile_timestamp_;
   }
 
+  intptr_t entry_patch_pc_offset() const {
+    return raw_ptr()->entry_patch_pc_offset_;
+  }
+  void set_entry_patch_pc_offset(intptr_t pc) const {
+    raw_ptr()->entry_patch_pc_offset_ = pc;
+  }
+
+
+  intptr_t patch_code_pc_offset() const {
+    return raw_ptr()->patch_code_pc_offset_;
+  }
+  void set_patch_code_pc_offset(intptr_t pc) const {
+    raw_ptr()->patch_code_pc_offset_ = pc;
+  }
+
+
+  intptr_t lazy_deopt_pc_offset() const {
+    return raw_ptr()->lazy_deopt_pc_offset_;
+  }
+  void set_lazy_deopt_pc_offset(intptr_t pc) const {
+    raw_ptr()->lazy_deopt_pc_offset_ = pc;
+  }
+
  private:
   void set_state_bits(intptr_t bits) const;
 
   friend class RawCode;
   enum {
     kOptimizedBit = 0,
     kAliveBit = 1,
   };
 
   class OptimizedBit : public BitField<bool, kOptimizedBit, 1> {};
@@ skipping 3386 matching lines @@
 
 
 RawObject* MegamorphicCache::GetTargetFunction(const Array& array,
                                                intptr_t index) {
   return array.At((index * kEntryLength) + kTargetFunctionIndex);
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_