/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 * vim: set ts=8 sts=2 et sw=2 tw=80:
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "jit/BitSet.h"

#include <string.h>

#include "jit/JitAllocPolicy.h"

using namespace js;
using namespace js::jit;

bool BitSet::init(TempAllocator& alloc) {
  size_t sizeRequired = numWords() * sizeof(*bits_);

  bits_ = (uint32_t*)alloc.allocate(sizeRequired);
  if (!bits_) {
    return false;
  }

  memset(bits_, 0, sizeRequired);

  return true;
}

bool BitSet::empty() const {
  MOZ_ASSERT(bits_);
  const uint32_t* bits = bits_;
  for (unsigned int i = 0, e = numWords(); i < e; i++) {
    if (bits[i]) {
      return false;
    }
  }
  return true;
}

void BitSet::insertAll(const BitSet& other) {
  MOZ_ASSERT(bits_);
  MOZ_ASSERT(other.numBits_ == numBits_);
  MOZ_ASSERT(other.bits_);

  uint32_t* bits = bits_;
  const uint32_t* otherBits = other.bits_;
  for (unsigned int i = 0, e = numWords(); i < e; i++) {
    bits[i] |= otherBits[i];
  }
}

void BitSet::removeAll(const BitSet& other) {
  MOZ_ASSERT(bits_);
  MOZ_ASSERT(other.numBits_ == numBits_);
  MOZ_ASSERT(other.bits_);

  uint32_t* bits = bits_;
  const uint32_t* otherBits = other.bits_;
  for (unsigned int i = 0, e = numWords(); i < e; i++) {
    bits[i] &= ~otherBits[i];
  }
}

void BitSet::intersect(const BitSet& other) {
  MOZ_ASSERT(bits_);
  MOZ_ASSERT(other.numBits_ == numBits_);
  MOZ_ASSERT(other.bits_);

  uint32_t* bits = bits_;
  const uint32_t* otherBits = other.bits_;
  for (unsigned int i = 0, e = numWords(); i < e; i++) {
    bits[i] &= otherBits[i];
  }
}

// returns true if the intersection caused the contents of the set to change.
bool BitSet::fixedPointIntersect(const BitSet& other) {
  MOZ_ASSERT(bits_);
  MOZ_ASSERT(other.numBits_ == numBits_);
  MOZ_ASSERT(other.bits_);

  bool changed = false;

  uint32_t* bits = bits_;
  const uint32_t* otherBits = other.bits_;
  for (unsigned int i = 0, e = numWords(); i < e; i++) {
    uint32_t old = bits[i];
    bits[i] &= otherBits[i];

    if (!changed && old != bits[i]) {
      changed = true;
    }
  }
  return changed;
}

void BitSet::complement() {
  MOZ_ASSERT(bits_);
  uint32_t* bits = bits_;
  for (unsigned int i = 0, e = numWords(); i < e; i++) {
    bits[i] = ~bits[i];
  }
}

void BitSet::clear() {
  MOZ_ASSERT(bits_);
  uint32_t* bits = bits_;
  for (unsigned int i = 0, e = numWords(); i < e; i++) {
    bits[i] = 0;
  }
}