Finishes removing intptr_t from raw object fields.

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 847 matching lines @@
   RawArray* static_calls_target_table_;  // (code-offset, function, code).
   RawArray* stackmaps_;
   RawLocalVarDescriptors* var_descriptors_;
   RawArray* comments_;
   RawObject** to() {
     return reinterpret_cast<RawObject**>(&ptr()->comments_);
   }
 
   // Compilation timestamp.
   int64_t compile_timestamp_;
-  intptr_t pointer_offsets_length_;
+
+  // state_bits_ is a bitfield with three fields:
+  // The optimized bit, the alive bit, and a count of the number of pointer
+  // offsets.
   // Alive: If true, the embedded object pointers will be visited during GC.
-  // This field cannot be shorter because of alignment issues on x64
-  // architectures.
-  intptr_t state_bits_;  // state, is_optimized, is_alive.
+  int32_t state_bits_;
 
   // PC offsets for code patching.
-  intptr_t entry_patch_pc_offset_;
-  intptr_t patch_code_pc_offset_;
-  intptr_t lazy_deopt_pc_offset_;
+  int32_t entry_patch_pc_offset_;
+  int32_t patch_code_pc_offset_;
+  int32_t lazy_deopt_pc_offset_;
 
   // Variable length data follows here.
   int32_t* data() { OPEN_ARRAY_START(int32_t, int32_t); }
 
   friend class StackFrame;
   friend class MarkingVisitor;
   friend class Function;
 };
 
 
 class RawInstructions : public RawObject {
   RAW_HEAP_OBJECT_IMPLEMENTATION(Instructions);
 
   RawObject** from() {
     return reinterpret_cast<RawObject**>(&ptr()->code_);
   }
   RawCode* code_;
   RawArray* object_pool_;
   RawObject** to() {
     return reinterpret_cast<RawObject**>(&ptr()->object_pool_);
   }
-  intptr_t size_;
+  int32_t size_;
 
   // Variable length data follows here.
   uint8_t* data() { OPEN_ARRAY_START(uint8_t, uint8_t); }
 
   // Private helper function used while visiting stack frames. The
   // code which iterates over dart frames is also called during GC and
   // is not allowed to create handles.
   static bool ContainsPC(RawObject* raw_obj, uword pc);
 
   friend class RawCode;
@@ skipping 71 matching lines @@
   };
 
   static intptr_t RecordSize(bool has_try_index);
 
  private:
   RAW_HEAP_OBJECT_IMPLEMENTATION(PcDescriptors);
 
   static const intptr_t kFullRecSize;
   static const intptr_t kCompressedRecSize;
 
-  intptr_t record_size_in_bytes_;
-  intptr_t length_;  // Number of descriptors.
+  int32_t record_size_in_bytes_;
+  int32_t length_;  // Number of descriptors.
 
   // Variable length data follows here.
   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
 // the frame which the stack map is describing.  The bit map representation
 // is optimized for dense and small bit maps, without any upper bound.
 class RawStackmap : public RawObject {
   RAW_HEAP_OBJECT_IMPLEMENTATION(Stackmap);
 
-  // TODO(kmillikin): We need a small number of bits to encode the register
-  // count.  Consider packing them in with the length.
-  intptr_t length_;  // Length of payload, in bits.
-  intptr_t register_bit_count_;  // Live register bits, included in length_.
+  // Regarding changing this to a bitfield: ARM64 requires register_bit_count_
+  // to be as large as 96, meaning 7 bits, leaving 25 bits for the length, or
+  // as large as ~33 million entries. If that is sufficient, then these two
+  // fields can be merged into a BitField.
+  int32_t length_;  // Length of payload, in bits.
+  int32_t register_bit_count_;  // Live register bits, included in length_.
 
-  uword pc_;  // PC corresponding to this stack map representation.
+  // Offset from code entry point corresponding to this stack map
+  // representation.
+  uint32_t pc_offset_;
 
   // Variable length data follows here (bitmap of the stack layout).
   uint8_t* data() { OPEN_ARRAY_START(uint8_t, uint8_t); }
 };
 
 
 class RawLocalVarDescriptors : public RawObject {
  public:
   enum VarInfoKind {
     kStackVar = 1,
     kContextVar,
     kContextLevel,
     kSavedEntryContext,
     kSavedCurrentContext
   };
 
+  enum {
+    kKindPos = 0,
+    kKindSize = 8,
+    kIndexPos = 9,

[Florian Schneider, 2014/09/03 09:29:53]

This is off by one since 9+24=33.


kIndexPos = kKindPos + kkindSize,
kIndexSize = kPayloadSize - kIndexPos


where kPayloadSize = sizeof(int32_t) * kBitsPerByte

[zra, 2014/09/03 19:26:45]

Thanks for catching this!

+    // Since there are 24 bits for the stack slot index, Functions can have
+    // only ~16.7 million stack slots.
+    kIndexSize = 24,
+    kMaxIndex = (1 << (kIndexSize - 1)) - 1,
+  };
+
+  // The index can be < 0.

[Florian Schneider, 2014/09/03 09:29:53]

Ideally, BitField would take the signedness of the first template parameter into
account by itself.

Alternatively, take a look at locations.h and how stack index is implemented
there. Just store the index with a bias-value added to that it is always
positive.

[zra, 2014/09/03 19:26:45]

The first template parameter of BitField is frequently non-numeric, so detecting
signedness here for template specialization seems like it might be tricky. Going
with bias suggestion.

+  class IndexBits {
+   public:
+    static bool is_valid(int32_t val) {
+      return Utils::IsInt(24, val);
+    }
+    static int32_t update(int32_t val, int32_t orig) {
+      ASSERT(is_valid(val));
+      const int32_t v = val & ((1 << kIndexSize) - 1);
+      return Bits::update(v, orig);
+    }
+    static int32_t decode(int32_t val) {
+      const int32_t v = Bits::decode(val);
+      return (v << kIndexPos) >> kIndexPos;  // Sign-extend.
+    }
+   private:
+    class Bits : public BitField<int32_t, kIndexPos, kIndexSize> {};
+  };
+
+  class KindBits : public BitField<int8_t, kKindPos, kKindSize>{};
+
   struct VarInfo {
-    intptr_t index;      // Slot index on stack or in context.
-    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.
+    int32_t index_kind;  // Bitfield for slot index on stack or in context,
+                         // and Entry kind of type VarInfoKind.
+    int32_t begin_pos;   // Token position of scope start.
+    int32_t end_pos;     // Token position of scope end.
+    int16_t scope_id;    // Scope to which the variable belongs.
+
+    VarInfoKind kind() const {
+      return static_cast<VarInfoKind>(KindBits::decode(index_kind));
+    }
+    void set_kind(VarInfoKind kind) {
+      index_kind = KindBits::update(kind, index_kind);
+    }
+    int32_t index() const {
+      return IndexBits::decode(index_kind);
+    }
+    void set_index(int32_t index) {
+      index_kind = IndexBits::update(index, index_kind);
+    }
   };
 
  private:
   RAW_HEAP_OBJECT_IMPLEMENTATION(LocalVarDescriptors);
-  intptr_t length_;  // Number of descriptors.
   RawArray* names_;  // Array of [length_] variable names.
+  int32_t length_;  // Number of descriptors.
 
   // Variable info with [length_] entries.
-  VarInfo* data() { OPEN_ARRAY_START(VarInfo, intptr_t); }
+  VarInfo* data() { OPEN_ARRAY_START(VarInfo, int32_t); }
 };
 
 
 class RawExceptionHandlers : public RawObject {
  public:
   // The index into the ExceptionHandlers table corresponds to
   // the try_index of the handler.
   struct HandlerInfo {
     intptr_t handler_pc;       // PC value of handler.
     int16_t outer_try_index;   // Try block index of enclosing try block.
     int8_t needs_stacktrace;   // True if a stacktrace is needed.
     int8_t has_catch_all;      // Catches all exceptions.
   };
 
  private:
   RAW_HEAP_OBJECT_IMPLEMENTATION(ExceptionHandlers);
 
   // Number of exception handler entries.
-  intptr_t length_;
+  int32_t length_;
 
   // Array with [length_] entries. Each entry is an array of all handled
   // exception types.
   RawArray* handled_types_data_;
 
   // Exception handler info of length [length_].
   HandlerInfo* data() { OPEN_ARRAY_START(HandlerInfo, intptr_t); }
 };
 
 
 // Contains an array of deoptimization commands, e.g., move a specific register
 // into a specific slot of unoptimized frame.
 class RawDeoptInfo : public RawObject {
   RAW_HEAP_OBJECT_IMPLEMENTATION(DeoptInfo);
 
   RawSmi* length_;  // Number of deoptimization commands
 
   // Variable length data follows here.
   intptr_t* data() { OPEN_ARRAY_START(intptr_t, intptr_t); }
 };
 
 
 class RawContext : public RawObject {
   RAW_HEAP_OBJECT_IMPLEMENTATION(Context);
 
-  intptr_t num_variables_;
+  int32_t num_variables_;
   Isolate* isolate_;
 
   RawObject** from() { return reinterpret_cast<RawObject**>(&ptr()->parent_); }
   RawContext* parent_;
 
   // Variable length data follows here.
   RawInstance** data() { OPEN_ARRAY_START(RawInstance*, RawInstance*); }
   RawObject** to(intptr_t num_vars) {
     return reinterpret_cast<RawObject**>(&ptr()->data()[num_vars - 1]);
   }
 
   friend class SnapshotReader;
 };
 
 
 class RawContextScope : public RawObject {
   RAW_HEAP_OBJECT_IMPLEMENTATION(ContextScope);
 
-  // TODO(iposva): Switch to convential enum offset based structure to avoid
+  // TODO(iposva): Switch to conventional enum offset based structure to avoid
   // alignment mishaps.
   struct VariableDesc {
     RawSmi* token_pos;
     RawString* name;
     RawBool* is_final;
     RawBool* is_const;
     union {
       RawAbstractType* type;
       RawInstance* value;  // iff is_const is true
     };
     RawSmi* context_index;
     RawSmi* context_level;
   };
 
-  intptr_t num_variables_;
+  int32_t num_variables_;
 
   RawObject** from() {
     return reinterpret_cast<RawObject**>(&ptr()->data()[0]);
   }
   // Variable length data follows here.
   RawObject** data() { OPEN_ARRAY_START(RawObject*, RawObject*); }
   RawObject** to(intptr_t num_vars) {
     const intptr_t data_length = num_vars * (sizeof(VariableDesc)/kWordSize);
     return reinterpret_cast<RawObject**>(&ptr()->data()[data_length - 1]);
   }
@@ skipping 248 matching lines @@
   friend class SnapshotReader;
 };
 
 
 class RawBigint : public RawInteger {
   RAW_HEAP_OBJECT_IMPLEMENTATION(Bigint);
 
   // Actual length in chunks at the time of allocation (later we may
   // clamp the operational length but we need to maintain a consistent
   // object length so that the object can be traversed during GC).
-  intptr_t allocated_length_;
+  int32_t allocated_length_;
 
   // Operational length in chunks of the bigint object, clamping can
   // cause this length to be reduced. If the signed_length_ is
   // negative then the number is negative.
-  intptr_t signed_length_;
+  int32_t signed_length_;
 
   // A sequence of Chunks (typedef in Bignum) representing bignum digits.
   // Bignum::Chunk chunks_[Utils::Abs(signed_length_)];
   uint8_t* data() { OPEN_ARRAY_START(uint8_t, uint8_t); }
 
   friend class SnapshotReader;
 };
 
 
 class RawDouble : public RawNumber {
@@ skipping 292 matching lines @@
   RawObject** from() {
     return reinterpret_cast<RawObject**>(&ptr()->data_length_);
   }
   RawSmi* data_length_;
   RawSmi* num_bracket_expressions_;
   RawString* pattern_;  // Pattern to be used for matching.
   RawObject** to() {
     return reinterpret_cast<RawObject**>(&ptr()->pattern_);
   }
 
-  intptr_t type_;  // Uninitialized, simple or complex.
-  intptr_t flags_;  // Represents global/local, case insensitive, multiline.
+  // A bitfield with two fields:
+  // type: Uninitialized, simple or complex.
+  // flags: Represents global/local, case insensitive, multiline.
+  int8_t type_flags_;
 
   // Variable length data follows here.
   uint8_t* data() { OPEN_ARRAY_START(uint8_t, uint8_t); }
 };
 
 
 class RawWeakProperty : public RawInstance {
   RAW_HEAP_OBJECT_IMPLEMENTATION(WeakProperty);
 
   RawObject** from() {
@@ skipping 261 matching lines @@
   COMPILE_ASSERT(kExternalTypedDataInt8ArrayCid ==
                  kTypedDataInt8ArrayViewCid + 15);
   COMPILE_ASSERT(kByteBufferCid == kExternalTypedDataInt8ArrayCid + 14);
   COMPILE_ASSERT(kNullCid == kByteBufferCid + 1);
   return (kNullCid - kTypedDataInt8ArrayCid);
 }
 
 }  // namespace dart
 
 #endif  // VM_RAW_OBJECT_H_