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1 // Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file | 1 // Copyright (c) 2012, 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_BITMAP_H_ | 5 #ifndef VM_BITMAP_H_ |
6 #define VM_BITMAP_H_ | 6 #define VM_BITMAP_H_ |
7 | 7 |
8 #include "vm/allocation.h" | 8 #include "vm/allocation.h" |
| 9 #include "vm/isolate.h" |
| 10 #include "vm/zone.h" |
9 | 11 |
10 namespace dart { | 12 namespace dart { |
11 | 13 |
12 // Forward declarations. | 14 // Forward declarations. |
13 class RawStackmap; | 15 class RawStackmap; |
14 class Stackmap; | 16 class Stackmap; |
15 | 17 |
16 | 18 |
17 // BitmapBuilder is used to build a bitmap. The implementation is optimized for | 19 // BitmapBuilder is used to build a bitmap. The implementation is optimized |
18 // a dense set of small bit maps without an upper bound (e.g: a pointer map | 20 // for a dense set of small bit maps without a fixed upper bound (e.g: a |
19 // description of a stack). | 21 // pointer map description of a stack). |
20 class BitmapBuilder : public ZoneAllocated { | 22 class BitmapBuilder : public ZoneAllocated { |
21 public: | 23 public: |
22 BitmapBuilder() : size_in_bytes_(kInitialSizeInBytes), | 24 BitmapBuilder() |
23 bit_list_(bit_list_data_) { | 25 : length_(0), |
24 memset(bit_list_data_, 0, kInitialSizeInBytes); | 26 data_size_in_bytes_(kInitialSizeInBytes), |
| 27 data_(Isolate::Current()->current_zone()->Alloc<uint8_t>( |
| 28 kInitialSizeInBytes)) { |
| 29 memset(data_, 0, kInitialSizeInBytes); |
25 } | 30 } |
26 | 31 |
27 intptr_t SizeInBits() const { return (size_in_bytes_ * kBitsPerByte); } | 32 intptr_t Length() const { return length_; } |
28 intptr_t SizeInBytes() const { return size_in_bytes_; } | 33 void SetLength(intptr_t length); |
29 | 34 |
30 // Get/Set individual bits in the bitmap, set expands the underlying bitmap | 35 // Get/Set individual bits in the bitmap, setting bits beyond the bitmap's |
31 // if needed. | 36 // length increases the length and expands the underlying bitmap if |
| 37 // needed. |
32 bool Get(intptr_t bit_offset) const; | 38 bool Get(intptr_t bit_offset) const; |
33 void Set(intptr_t bit_offset, bool value); | 39 void Set(intptr_t bit_offset, bool value); |
34 | 40 |
35 // Return the bit offset of the highest bit set. | 41 // Return the bit offset of the highest bit set. |
36 intptr_t Maximum() const; | 42 intptr_t Maximum() const; |
37 | 43 |
38 // Return the bit offset of the lowest bit set. | 44 // Return the bit offset of the lowest bit set. |
39 intptr_t Minimum() const; | 45 intptr_t Minimum() const; |
40 | 46 |
41 // Sets min..max (inclusive) to value. | 47 // Sets min..max (inclusive) to value. |
42 void SetRange(intptr_t min, intptr_t max, bool value); | 48 void SetRange(intptr_t min, intptr_t max, bool value); |
43 | 49 |
44 private: | 50 private: |
45 static const intptr_t kInitialSizeInBytes = 16; | 51 static const intptr_t kInitialSizeInBytes = 16; |
46 static const intptr_t kIncrementSizeInBytes = 16; | 52 static const intptr_t kIncrementSizeInBytes = 16; |
47 | 53 |
48 bool InRange(intptr_t offset) const { | 54 bool InRange(intptr_t offset) const { |
49 return (offset >= 0) && (offset < SizeInBits()); | 55 return (offset >= 0) && (offset < length_); |
50 } | 56 } |
51 | 57 |
| 58 // Get/Set a bit that is known to be covered by the backing store. |
52 bool GetBit(intptr_t bit_offset) const; | 59 bool GetBit(intptr_t bit_offset) const; |
53 void SetBit(intptr_t bit_offset, bool value); | 60 void SetBit(intptr_t bit_offset, bool value); |
54 | 61 |
55 intptr_t size_in_bytes_; | 62 intptr_t length_; |
56 uint8_t bit_list_data_[kInitialSizeInBytes]; | 63 |
57 uint8_t* bit_list_; | 64 // Backing store for the bitmap. Reading bits beyond the backing store |
| 65 // (up to length_) is allowed and they are assumed to be false. |
| 66 intptr_t data_size_in_bytes_; |
| 67 uint8_t* data_; |
58 | 68 |
59 DISALLOW_COPY_AND_ASSIGN(BitmapBuilder); | 69 DISALLOW_COPY_AND_ASSIGN(BitmapBuilder); |
60 }; | 70 }; |
61 | 71 |
62 } // namespace dart | 72 } // namespace dart |
63 | 73 |
64 #endif // VM_BITMAP_H_ | 74 #endif // VM_BITMAP_H_ |
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