c950963be3
If the data to be stored in a BitVector is small enough (less than the pointer size), it can be stored directly on the BitVector instead of the pointer. This patch makes the data field of the BitVector a union between a pointer and uintptr_t, and uses the latter is the data length is 0. Change-Id: I24c1920f2c16373c883cf69b123bf59812fef28e Reviewed-on: https://chromium-review.googlesource.com/541307 Commit-Queue: Leszek Swirski <leszeks@chromium.org> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org> Cr-Commit-Position: refs/heads/master@{#46209}
59 lines
1.2 KiB
C++
59 lines
1.2 KiB
C++
// Copyright 2010 the V8 project authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#include "src/bit-vector.h"
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#include "src/base/bits.h"
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#include "src/utils.h"
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namespace v8 {
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namespace internal {
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#ifdef DEBUG
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void BitVector::Print() {
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bool first = true;
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PrintF("{");
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for (int i = 0; i < length(); i++) {
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if (Contains(i)) {
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if (!first) PrintF(",");
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first = false;
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PrintF("%d", i);
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}
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}
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PrintF("}\n");
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}
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#endif
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void BitVector::Iterator::Advance() {
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current_++;
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uintptr_t val = current_value_;
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while (val == 0) {
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current_index_++;
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if (Done()) return;
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DCHECK(!target_->is_inline());
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val = target_->data_.ptr_[current_index_];
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current_ = current_index_ << kDataBitShift;
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}
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val = SkipZeroBytes(val);
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val = SkipZeroBits(val);
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current_value_ = val >> 1;
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}
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int BitVector::Count() const {
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if (data_length_ == 0) {
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return base::bits::CountPopulation(data_.inline_);
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} else {
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int count = 0;
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for (int i = 0; i < data_length_; i++) {
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count += base::bits::CountPopulation(data_.ptr_[i]);
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}
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return count;
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}
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}
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} // namespace internal
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} // namespace v8
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