More PcDescriptor cleanups.

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 898 matching lines @@
     kIcCall          = kDeopt << 1,  // IC call.
     kOptStaticCall   = kIcCall << 1,  // Call directly to known target.
     kUnoptStaticCall = kOptStaticCall << 1,  // Call to a known target via stub.
     kClosureCall     = kUnoptStaticCall << 1,  // Closure call.
     kRuntimeCall     = kClosureCall << 1,  // Runtime call.
     kOsrEntry        = kRuntimeCall << 1,  // OSR entry point in unopt. code.
     kOther           = kOsrEntry << 1,
     kAnyKind         = 0xFF
   };
 
+  // Compressed version assumes try_index is always -1 and does not store it.
   struct PcDescriptorRec {
     uword pc;
-    int32_t deopt_id;
-    int32_t token_pos;  // Or deopt reason.
-    int16_t try_index;  // Or deopt index.
-    uint8_t kind_;
 
-    Kind kind() const { return static_cast<Kind>(kind_); }
+    Kind kind() const {
+      return static_cast<Kind>(deopt_id_and_kind_ & kAnyKind);
+    }
+    void set_kind(Kind kind) {
+      deopt_id_and_kind_ = (deopt_id_and_kind_ & 0xFFFFFF00) | kind;
+    }
+
+    int16_t try_index() const {
+      if (is_compressed()) {
+        return -1;
+      }
+      return try_index_;
+    }
+    void set_try_index(int16_t value) {
+      if (is_compressed()) {
+        ASSERT(value == -1);
+        return;
+      }
+      try_index_ = value;
+    }
+
+    intptr_t token_pos() const { return token_pos_ >> 1; }
+    void set_token_pos(int32_t value, bool compressed) {
+      int32_t bit = compressed ? 0x1 : 0x0;
+      token_pos_ = (value << 1) | bit;
+    }
+
+    intptr_t deopt_id() const { return deopt_id_and_kind_ >> 8; }
+    void set_deopt_id(int32_t value) {
+      ASSERT(Utils::IsInt(24, value));
+      deopt_id_and_kind_ = (deopt_id_and_kind_ & 0xFF) | (value << 8);
+    }
+
+   private:
+    bool is_compressed() const {
+      return (token_pos_ & 0x1) == 1;
+    }
+
+    int32_t deopt_id_and_kind_;  // Bits 31..8 -> deopt_id, bits 7..0 kind.
+    int32_t token_pos_;  // Bits 31..1 -> token_pos, bit 1 -> compressed flag;
+    int16_t try_index_;

[siva, 2014/07/14 19:42:01]

Might make sense to make 'pc' also private and provide accessor
methods pc() and set_pc()

[srdjan, 2014/07/14 23:55:25]

Done.

   };
 
+  static const intptr_t kFullRecSize = sizeof(PcDescriptorRec);
+  static const intptr_t kCompressedRecSize = kFullRecSize - sizeof(int16_t);
+
  private:
   RAW_HEAP_OBJECT_IMPLEMENTATION(PcDescriptors);
 
+  intptr_t record_size_in_bytes_;
   intptr_t length_;  // Number of descriptors.
 
   // Variable length data follows here.
-  PcDescriptorRec* data() { OPEN_ARRAY_START(PcDescriptorRec, intptr_t); }
+  uint8_t* data() { OPEN_ARRAY_START(uint8_t, 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 952 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_