dom/base/nsTextFragmentGeneric.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef nsTextFragmentGeneric_h__
   8 #define nsTextFragmentGeneric_h__
   9
  10 #include "nsTextFragmentGenericFwd.h"
  11
  12 #include "nscore.h"
  13 #include "nsTextFragmentImpl.h"
  14 #include <algorithm>
  15
  16 namespace mozilla {
  17
  18 template <class Arch>
  19 int32_t FirstNon8Bit(const char16_t* str, const char16_t* end) {
  20   const uint32_t numUnicharsPerVector = xsimd::batch<int16_t, Arch>::size;
  21   using p = Non8BitParameters<sizeof(size_t)>;
  22   const size_t mask = p::mask();
  23   const uint32_t numUnicharsPerWord = p::numUnicharsPerWord();
  24   const int32_t len = end - str;
  25   int32_t i = 0;
  26
  27   // Align ourselves to the Arch boundary
  28   int32_t alignLen = std::min(
  29       len, int32_t(((-NS_PTR_TO_INT32(str)) & (Arch::alignment() - 1)) /
  30                    sizeof(char16_t)));
  31   for (; i < alignLen; i++) {
  32     if (str[i] > 255) return i;
  33   }
  34
  35   // Check one batch at a time.
  36   const int32_t vectWalkEnd =
  37       ((len - i) / numUnicharsPerVector) * numUnicharsPerVector;
  38   const uint16_t shortMask = 0xff00;
  39   xsimd::batch<int16_t, Arch> vectmask(static_cast<int16_t>(shortMask));
  40   for (; i < vectWalkEnd; i += numUnicharsPerVector) {
  41     const auto vect = xsimd::batch<int16_t, Arch>::load_aligned(str + i);
  42     if (xsimd::any((vect & vectmask) != 0)) return i;
  43   }
  44
  45   // Check one word at a time.
  46   const int32_t wordWalkEnd =
  47       ((len - i) / numUnicharsPerWord) * numUnicharsPerWord;
  48   for (; i < wordWalkEnd; i += numUnicharsPerWord) {
  49     const size_t word = *reinterpret_cast<const size_t*>(str + i);
  50     if (word & mask) return i;
  51   }
  52
  53   // Take care of the remainder one character at a time.
  54   for (; i < len; i++) {
  55     if (str[i] > 255) {
  56       return i;
  57     }
  58   }
  59
  60   return -1;
  61 }
  62
  63 }  // namespace mozilla
  64
  65 #endif