/* -*- 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/. */

// This file should only be compiled if you're on x86 or x86_64.  Additionally,

// you'll need to compile this file with -msse2 if you're using gcc.

#include <emmintrin.h>

#include "nscore.h"

#include "nsAlgorithm.h"

#include "nsTextFragmentImpl.h"

#include <algorithm>

namespace mozilla {

namespace SSE2 {

static inline bool

is_zero (__m128i x)

{

  return

    _mm_movemask_epi8(_mm_cmpeq_epi8(x, _mm_setzero_si128())) == 0xffff;

}

int32_t

FirstNon8Bit(const char16_t *str, const char16_t *end)

{

  const uint32_t numUnicharsPerVector = 8;

  typedef Non8BitParameters<sizeof(size_t)> p;

  const size_t mask = p::mask();

  const uint32_t numUnicharsPerWord = p::numUnicharsPerWord();

  const int32_t len = end - str;

  int32_t i = 0;

  // Align ourselves to a 16-byte boundary, as required by _mm_load_si128

  // (i.e. MOVDQA).

  int32_t alignLen =

    std::min(len, int32_t(((-NS_PTR_TO_INT32(str)) & 0xf) / sizeof(char16_t)));

  for (; i < alignLen; i++) {

    if (str[i] > 255)

      return i;

  }

  // Check one XMM register (16 bytes) at a time.

  const int32_t vectWalkEnd = ((len - i) / numUnicharsPerVector) * numUnicharsPerVector;

  const uint16_t shortMask = 0xff00;

  __m128i vectmask = _mm_set1_epi16(static_cast<int16_t>(shortMask));

  for(; i < vectWalkEnd; i += numUnicharsPerVector) {

    const __m128i vect = *reinterpret_cast<const __m128i*>(str + i);

    if (!is_zero(_mm_and_si128(vect, vectmask)))

      return i;

  }

  // Check one word at a time.

  const int32_t wordWalkEnd = ((len - i) / numUnicharsPerWord) * numUnicharsPerWord;

  for(; i < wordWalkEnd; i += numUnicharsPerWord) {

    const size_t word = *reinterpret_cast<const size_t*>(str + i);

    if (word & mask)

      return i;

  }

  // Take care of the remainder one character at a time.

  for (; i < len; i++) {

    if (str[i] > 255) {

      return i;

    }

  }

  return -1;

}

} // namespace SSE2

} // namespace mozilla