Move deopt reason into PcDescriptor so the EAX/RAX register is not destroyed. Some cleanups in PC d…

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 2150 matching lines @@
   HEAP_OBJECT_IMPLEMENTATION(LocalVarDescriptors, Object);
   friend class Class;
 };
 
 
 class PcDescriptors : public Object {
  private:
   // Describes the layout of PC descriptor data.
   enum {
     kPcEntry = 0,      // PC value of the descriptor, unique.
-    kKindEntry,
-    kDeoptIdEntry,     // Deopt id.
-    kTokenPosEntry,    // Token position in source of PC.
-    kTryIndexEntry,    // Try block index of PC.
+    kKindEntry = 1,
+    kDeoptIdEntry = 2,      // Deopt id.
+    kTokenPosEntry = 3,     // Token position in source.
+    kDeoptReasonEntry = 3,  // DeoptReasonId.
+    kTryIndexEntry = 4,     // Try block index.
+    kDeoptIndexEntry = 4,   // Deoptimization array index.
     // We would potentially be adding other objects here like
     // pointer maps for optimized functions, local variables information  etc.
-    kNumberOfEntries
+    kNumberOfEntries = 5,
   };
 
  public:
   enum Kind {
     kDeopt = 0,   // Deoptimization continuation point.
     kDeoptIndex,  // Index into deopt info array.
     kPatchCode,   // Buffer for patching code entry.
     kIcCall,      // IC call.
     kFuncCall,    // Call to known target, e.g. static call, closure call.
     kReturn,      // Return from function.
     kOther
   };
 
   intptr_t Length() const;
 
   uword PC(intptr_t index) const;
   PcDescriptors::Kind DescriptorKind(intptr_t index) const;
   const char* KindAsStr(intptr_t index) const;
   intptr_t DeoptId(intptr_t index) const;
   intptr_t TokenPos(intptr_t index) const;
   intptr_t TryIndex(intptr_t index) const;
+  // Different encoding for kDeoptIndex.
   // Index into the deopt-info array of Code object.
   intptr_t DeoptIndex(intptr_t index) const;
+  intptr_t DeoptReason(intptr_t index) const;
 
   void AddDescriptor(intptr_t index,
                      uword pc,
                      PcDescriptors::Kind kind,
                      intptr_t deopt_id,
-                     intptr_t token_pos,
-                     intptr_t try_index) const {
+                     intptr_t token_pos,  // Or deopt reason.
+                     intptr_t try_index) const {  // Or deopt index.
     SetPC(index, pc);
     SetKind(index, kind);
     SetDeoptId(index, deopt_id);
     SetTokenPos(index, token_pos);
     SetTryIndex(index, try_index);
   }
 
   static const intptr_t kBytesPerElement = (kNumberOfEntries * kWordSize);
   static const intptr_t kMaxElements = kSmiMax / kBytesPerElement;
 
@@ skipping 3197 matching lines @@
     if (this->CharAt(i) != str.CharAt(begin_index + i)) {
       return false;
     }
   }
   return true;
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_