Reduce size of PCDescriptors. Order struct fields so that they do not get padded unnecessarily.

runtime/vm/raw_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_RAW_OBJECT_H_
 #define VM_RAW_OBJECT_H_
 
 #include "platform/assert.h"
 #include "vm/globals.h"
 #include "vm/token.h"
@@ skipping 888 matching lines @@
   friend class MarkingVisitor;
   friend class Function;
 };
 
 
 class RawPcDescriptors : public RawObject {
   RAW_HEAP_OBJECT_IMPLEMENTATION(PcDescriptors);
 
   intptr_t length_;  // Number of descriptors.
 
+  struct PcDescriptorRec {
+    uword pc;
+    int32_t deopt_id;
+    int32_t token_pos;  // Or deopt reason.
+    int16_t try_index;  // Or deopt index.
+    int8_t kind;
+  };
+
   // Variable length data follows here.
-  intptr_t* data() { OPEN_ARRAY_START(intptr_t, intptr_t); }
+  PcDescriptorRec* data() { OPEN_ARRAY_START(PcDescriptorRec, intptr_t); }
 
   friend class Object;
 };
 
 
 // Stackmap is an immutable representation of the layout of the stack at a
 // PC. The stack map representation consists of a bit map which marks each
 // live object index starting from the base of the frame.
 //
 // The Stackmap also consists of a link to the code object corresponding to
@@ skipping 19 matching lines @@
   enum VarInfoKind {
     kStackVar = 1,
     kContextVar,
     kContextLevel,
     kSavedEntryContext,
     kSavedCurrentContext
   };
 
   struct VarInfo {
     intptr_t index;      // Slot index on stack or in context.
-    int8_t   kind;       // Entry kind of type VarInfoKind.
-    int16_t  scope_id;   // Scope to which the variable belongs.
     intptr_t begin_pos;  // Token position of scope start.
     intptr_t end_pos;    // Token position of scope end.
+    int16_t  scope_id;   // Scope to which the variable belongs.
+    int8_t   kind;       // Entry kind of type VarInfoKind.
   };
 
  private:
   RAW_HEAP_OBJECT_IMPLEMENTATION(LocalVarDescriptors);
   intptr_t length_;  // Number of descriptors.
   RawArray* names_;  // Array of [length_] variable names.
 
   // Variable info with [length_] entries.
   VarInfo* data() { OPEN_ARRAY_START(VarInfo, intptr_t); }
 };
@@ skipping 909 matching lines @@
   COMPILE_ASSERT(kTypedDataInt8ArrayViewCid == kTypedDataInt8ArrayCid + 14);
   COMPILE_ASSERT(kExternalTypedDataInt8ArrayCid ==
                  kTypedDataInt8ArrayViewCid + 15);
   COMPILE_ASSERT(kNullCid == kExternalTypedDataInt8ArrayCid + 14);
   return (kNullCid - kTypedDataInt8ArrayCid);
 }
 
 }  // namespace dart
 
 #endif  // VM_RAW_OBJECT_H_