The Tor Browser: content/base/src/nsTextFragmentSSE2.cpp@deefc01c0e14

Integrate friendly tips from Tor colleagues to make (or not) 4.5 alpha 3;
This includes removal of overloaded (but unused) methods, and addition of
a overlooked call to DataStruct::SetData(nsISupports, uint32_t, bool.)

     1 /* This Source Code Form is subject to the terms of the Mozilla Public

     2  * License, v. 2.0. If a copy of the MPL was not distributed with this

     3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

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

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

     8 #include <emmintrin.h>

     9 #include "nscore.h"

    10 #include "nsAlgorithm.h"

    11 #include "nsTextFragmentImpl.h"

    12 #include <algorithm>

    14 namespace mozilla {

    15 namespace SSE2 {

    17 static inline bool

    18 is_zero (__m128i x)

    19 {

    20   return

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

    22 }

    24 int32_t

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

    26 {

    27   const uint32_t numUnicharsPerVector = 8;

    28   typedef Non8BitParameters<sizeof(size_t)> p;

    29   const size_t mask = p::mask();

    30   const uint32_t numUnicharsPerWord = p::numUnicharsPerWord();

    31   const int32_t len = end - str;

    32   int32_t i = 0;

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

    35   // (i.e. MOVDQA).

    36   int32_t alignLen =

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

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

    39     if (str[i] > 255)

    40       return i;

    41   }

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

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

    45   const uint16_t shortMask = 0xff00;

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

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

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

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

    50       return i;

    51   }

    53   // Check one word at a time.

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

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

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

    57     if (word & mask)

    58       return i;

    59   }

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

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

    63     if (str[i] > 255) {

    64       return i;

    65     }

    66   }

    68   return -1;

    69 }

    71 } // namespace SSE2

    72 } // namespace mozilla

The Tor Browser / file revision

content/base/src/nsTextFragmentSSE2.cpp@deefc01c0e14

content/base/src/nsTextFragmentSSE2.cpp