blob: bf181470555da020fb5080d32cb2d8b774e1aab4 [file] [log] [blame]
// 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.
#include "vm/bit_vector.h"
#include "vm/os.h"
namespace dart {
void BitVector::Iterator::Advance() {
++bit_index_;
// Skip zero words.
if (current_word_ == 0) {
do {
++word_index_;
if (Done()) return;
current_word_ = target_->data_[word_index_];
} while (current_word_ == 0);
bit_index_ = word_index_ * kBitsPerWord;
}
// Skip zero bytes.
while ((current_word_ & 0xff) == 0) {
current_word_ >>= 8;
bit_index_ += 8;
}
// Skip zero bits.
while ((current_word_ & 0x1) == 0) {
current_word_ >>= 1;
++bit_index_;
}
current_word_ = current_word_ >> 1;
}
bool BitVector::Equals(const BitVector& other) const {
if (length_ != other.length_) return false;
intptr_t i = 0;
for (; i < data_length_ - 1; i++) {
if (data_[i] != other.data_[i]) return false;
}
if (i < data_length_) {
// Don't compare bits beyond length_.
const intptr_t shift_size = (kBitsPerWord - length_) & (kBitsPerWord - 1);
const uword mask = static_cast<uword>(-1) >> shift_size;
if ((data_[i] & mask) != (other.data_[i] & mask)) return false;
}
return true;
}
bool BitVector::AddAll(const BitVector* from) {
ASSERT(data_length_ == from->data_length_);
bool changed = false;
for (intptr_t i = 0; i < data_length_; i++) {
const uword before = data_[i];
const uword after = data_[i] | from->data_[i];
if (before != after) {
changed = true;
data_[i] = after;
}
}
return changed;
}
bool BitVector::RemoveAll(const BitVector* from) {
ASSERT(data_length_ == from->data_length_);
bool changed = false;
for (intptr_t i = 0; i < data_length_; i++) {
const uword before = data_[i];
const uword after = data_[i] & ~from->data_[i];
if (before != after) {
changed = true;
data_[i] = after;
}
}
return changed;
}
bool BitVector::KillAndAdd(BitVector* kill, BitVector* gen) {
ASSERT(data_length_ == kill->data_length_);
ASSERT(data_length_ == gen->data_length_);
bool changed = false;
for (intptr_t i = 0; i < data_length_; i++) {
const uword before = data_[i];
const uword after = data_[i] | (gen->data_[i] & ~kill->data_[i]);
if (before != after) changed = true;
data_[i] = after;
}
return changed;
}
void BitVector::Intersect(const BitVector* other) {
ASSERT(other->length() == length());
for (intptr_t i = 0; i < data_length_; i++) {
data_[i] = data_[i] & other->data_[i];
}
}
void BitVector::Print() const {
OS::Print("[");
for (intptr_t i = 0; i < length_; i++) {
OS::Print(Contains(i) ? "1" : "0");
}
OS::Print("]");
}
} // namespace dart