Line data    Source code

       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             : // This file should only be compiled if you're on x86 or x86_64.  Additionally,
       8             : // you'll need to compile this file with -msse2 if you're using gcc.
       9             : 
      10             : #include <emmintrin.h>
      11             : #include "nscore.h"
      12             : #include "nsAlgorithm.h"
      13             : #include "nsTextFragmentImpl.h"
      14             : #include <algorithm>
      15             : 
      16             : namespace mozilla {
      17             : namespace SSE2 {
      18             : 
      19             : static inline bool
      20        1703 : is_zero (__m128i x)
      21             : {
      22             :   return
      23        5109 :     _mm_movemask_epi8(_mm_cmpeq_epi8(x, _mm_setzero_si128())) == 0xffff;
      24             : }
      25             : 
      26             : int32_t
      27         151 : FirstNon8Bit(const char16_t *str, const char16_t *end)
      28             : {
      29         151 :   const uint32_t numUnicharsPerVector = 8;
      30             :   typedef Non8BitParameters<sizeof(size_t)> p;
      31         151 :   const size_t mask = p::mask();
      32         151 :   const uint32_t numUnicharsPerWord = p::numUnicharsPerWord();
      33         151 :   const int32_t len = end - str;
      34         151 :   int32_t i = 0;
      35             : 
      36             :   // Align ourselves to a 16-byte boundary, as required by _mm_load_si128
      37             :   // (i.e. MOVDQA).
      38             :   int32_t alignLen =
      39         151 :     std::min(len, int32_t(((-NS_PTR_TO_INT32(str)) & 0xf) / sizeof(char16_t)));
      40        1217 :   for (; i < alignLen; i++) {
      41         533 :     if (str[i] > 255)
      42           0 :       return i;
      43             :   }
      44             : 
      45             :   // Check one XMM register (16 bytes) at a time.
      46         151 :   const int32_t vectWalkEnd = ((len - i) / numUnicharsPerVector) * numUnicharsPerVector;
      47         151 :   const uint16_t shortMask = 0xff00;
      48         151 :   __m128i vectmask = _mm_set1_epi16(static_cast<int16_t>(shortMask));
      49        3549 :   for(; i < vectWalkEnd; i += numUnicharsPerVector) {
      50        1703 :     const __m128i vect = *reinterpret_cast<const __m128i*>(str + i);
      51        1703 :     if (!is_zero(_mm_and_si128(vect, vectmask)))
      52           4 :       return i;
      53             :   }
      54             : 
      55             :   // Check one word at a time.
      56         147 :   const int32_t wordWalkEnd = ((len - i) / numUnicharsPerWord) * numUnicharsPerWord;
      57         153 :   for(; i < wordWalkEnd; i += numUnicharsPerWord) {
      58           4 :     const size_t word = *reinterpret_cast<const size_t*>(str + i);
      59           4 :     if (word & mask)
      60           1 :       return i;
      61             :   }
      62             : 
      63             :   // Take care of the remainder one character at a time.
      64        1062 :   for (; i < len; i++) {
      65         461 :     if (str[i] > 255) {
      66           3 :       return i;
      67             :     }
      68             :   }
      69             : 
      70         143 :   return -1;
      71             : }
      72             : 
      73             : } // namespace SSE2
      74             : } // namespace mozilla