Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(706)

Side by Side Diff: vm/bitfield.h

Issue 9021042: Make snapshots 32 or 64 bit compliant by using Write<int64_t> and Read<int64_t> for intptr_t type... (Closed) Base URL: http://dart.googlecode.com/svn/branches/bleeding_edge/dart/runtime/
Patch Set: '' Created 8 years, 11 months ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View unified diff | Download patch | Annotate | Revision Log
« no previous file with comments | « no previous file | vm/raw_object_snapshot.cc » ('j') | vm/snapshot.h » ('J')
Toggle Intra-line Diffs ('i') | Expand Comments ('e') | Collapse Comments ('c') | Show Comments Hide Comments ('s')
OLDNEW
1 // Copyright (c) 2011, the Dart project authors. Please see the AUTHORS file 1 // Copyright (c) 2011, the Dart project authors. Please see the AUTHORS file
2 // for details. All rights reserved. Use of this source code is governed by a 2 // for details. All rights reserved. Use of this source code is governed by a
3 // BSD-style license that can be found in the LICENSE file. 3 // BSD-style license that can be found in the LICENSE file.
4 4
5 #ifndef VM_BITFIELD_H_ 5 #ifndef VM_BITFIELD_H_
6 #define VM_BITFIELD_H_ 6 #define VM_BITFIELD_H_
7 7
8 namespace dart { 8 namespace dart {
9 9
10 // BitField is a template for encoding and decoding a bit field inside 10 // BitField is a template for encoding and decoding a bit field inside
11 // an unsigned machine word. 11 // an unsigned machine word.
12 template<typename T, int position, int size> 12 template<typename T, int position, int size>
13 class BitField { 13 class BitField {
14 public: 14 public:
15 // Tells whether the provided value fits into the bit field. 15 // Tells whether the provided value fits into the bit field.
16 static bool is_valid(T value) { 16 static bool is_valid(T value) {
17 return (static_cast<uword>(value) & ~((1U << size) - 1)) == 0; 17 return (static_cast<uword>(value) & ~((1UL << size) - 1)) == 0;
Ivan Posva 2011/12/27 22:27:59 How about turning 1UL into a static const uword?
siva 2011/12/27 23:47:20 Done.
18 } 18 }
19 19
20 // Returns a uword mask of the bit field. 20 // Returns a uword mask of the bit field.
21 static uword mask() { 21 static uword mask() {
22 return (1U << size) - 1; 22 return (1UL << size) - 1;
23 } 23 }
24 24
25 // Returns a uword mask of the bit field which can be applied directly to 25 // Returns a uword mask of the bit field which can be applied directly to
26 // to the raw unshifted bits. 26 // to the raw unshifted bits.
27 static uword mask_in_place() { 27 static uword mask_in_place() {
28 return ((1U << size) - 1) << position; 28 return ((1UL << size) - 1) << position;
29 } 29 }
30 30
31 // Returns the shift count needed to right-shift the bit field to 31 // Returns the shift count needed to right-shift the bit field to
32 // the least-significant bits. 32 // the least-significant bits.
33 static int shift() { 33 static int shift() {
34 return position; 34 return position;
35 } 35 }
36 36
37 // Returns the size of the bit field. 37 // Returns the size of the bit field.
38 static int bitsize() { 38 static int bitsize() {
39 return size; 39 return size;
40 } 40 }
41 41
42 // Returns a uword with the bit field value encoded. 42 // Returns a uword with the bit field value encoded.
43 static uword encode(T value) { 43 static uword encode(T value) {
44 ASSERT(is_valid(value)); 44 ASSERT(is_valid(value));
45 return static_cast<uword>(value) << position; 45 return static_cast<uword>(value) << position;
46 } 46 }
47 47
48 // Extracts the bit field from the value. 48 // Extracts the bit field from the value.
49 static T decode(uword value) { 49 static T decode(uword value) {
50 return static_cast<T>((value >> position) & ((1U << size) - 1)); 50 return static_cast<T>((value >> position) & ((1UL << size) - 1));
51 } 51 }
52 52
53 // Returns a uword with the bit field value encoded based on the 53 // Returns a uword with the bit field value encoded based on the
54 // original value. Only the bits corresponding to this bit field 54 // original value. Only the bits corresponding to this bit field
55 // will be changed. 55 // will be changed.
56 static uword update(T value, uword original) { 56 static uword update(T value, uword original) {
57 ASSERT(is_valid(value)); 57 ASSERT(is_valid(value));
58 return (static_cast<uword>(value) << position) | 58 return (static_cast<uword>(value) << position) |
59 (~mask_in_place() & original); 59 (~mask_in_place() & original);
60 } 60 }
61 }; 61 };
62 62
63 } // namespace dart 63 } // namespace dart
64 64
65 #endif // VM_BITFIELD_H_ 65 #endif // VM_BITFIELD_H_
OLDNEW
« no previous file with comments | « no previous file | vm/raw_object_snapshot.cc » ('j') | vm/snapshot.h » ('J')

Powered by Google App Engine
This is Rietveld 408576698