kmillikin@google.com
94a5b82f60
This allows stackmaps with varying lengths in the same function, necessary for the way we plan to support bitmaps for saved live registers. R=vegorov@google.com BUG= Review URL: https://chromiumcodereview.appspot.com//10837303 git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@11019 260f80e4-7a28-3924-810f-c04153c831b5
65 lines
1.8 KiB
C++
65 lines
1.8 KiB
C++
// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
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// for details. All rights reserved. Use of this source code is governed by a
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// BSD-style license that can be found in the LICENSE file.
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#ifndef VM_BITMAP_H_
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#define VM_BITMAP_H_
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#include "vm/allocation.h"
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namespace dart {
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// Forward declarations.
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class RawStackmap;
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class Stackmap;
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// BitmapBuilder is used to build a bitmap. The implementation is optimized for
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// a dense set of small bit maps without an upper bound (e.g: a pointer map
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// description of a stack).
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class BitmapBuilder : public ZoneAllocated {
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public:
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BitmapBuilder() : size_in_bytes_(kInitialSizeInBytes),
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bit_list_(bit_list_data_) {
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memset(bit_list_data_, 0, kInitialSizeInBytes);
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}
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intptr_t SizeInBits() const { return (size_in_bytes_ * kBitsPerByte); }
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intptr_t SizeInBytes() const { return size_in_bytes_; }
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// Get/Set individual bits in the bitmap, set expands the underlying bitmap
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// if needed.
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bool Get(intptr_t bit_offset) const;
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void Set(intptr_t bit_offset, bool value);
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// Return the bit offset of the highest bit set.
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intptr_t Maximum() const;
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// Return the bit offset of the lowest bit set.
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intptr_t Minimum() const;
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// Sets min..max (inclusive) to value.
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void SetRange(intptr_t min, intptr_t max, bool value);
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private:
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static const intptr_t kInitialSizeInBytes = 16;
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static const intptr_t kIncrementSizeInBytes = 16;
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bool InRange(intptr_t offset) const {
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return (offset >= 0) && (offset < SizeInBits());
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}
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bool GetBit(intptr_t bit_offset) const;
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void SetBit(intptr_t bit_offset, bool value);
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intptr_t size_in_bytes_;
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uint8_t bit_list_data_[kInitialSizeInBytes];
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uint8_t* bit_list_;
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DISALLOW_COPY_AND_ASSIGN(BitmapBuilder);
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};
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} // namespace dart
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#endif // VM_BITMAP_H_
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