intl/uconv/nsUTF8ToUnicodeSSE2.cpp

   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/. */
   4
   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.
   7
   8 #include <emmintrin.h>
   9 #include "nscore.h"
  10
  11 namespace mozilla {
  12 namespace SSE2 {
  13
  14 void
  15 Convert_ascii_run(const char *&src,
  16                   char16_t  *&dst,
  17                   int32_t      len)
  18 {
  19   if (len > 15) {
  20     __m128i in, out1, out2;
  21     __m128d *outp1, *outp2;
  22     __m128i zeroes;
  23     uint32_t offset;
  24
  25     // align input to 16 bytes
  26     while ((NS_PTR_TO_UINT32(src) & 15) && len > 0) {
  27       if (*src & 0x80U)
  28         return;
  29       *dst++ = (char16_t) *src++;
  30       len--;
  31     }
  32
  33     zeroes = _mm_setzero_si128();
  34
  35     offset = NS_PTR_TO_UINT32(dst) & 15;
  36
  37     // Note: all these inner loops have to break, not return; we need
  38     // to let the single-char loop below catch any leftover
  39     // byte-at-a-time ASCII chars, since this function must consume
  40     // all available ASCII chars before it returns
  41
  42     if (offset == 0) {
  43       while (len > 15) {
  44         in = _mm_load_si128((__m128i *) src);
  45         if (_mm_movemask_epi8(in))
  46           break;
  47         out1 = _mm_unpacklo_epi8(in, zeroes);
  48         out2 = _mm_unpackhi_epi8(in, zeroes);
  49         _mm_stream_si128((__m128i *) dst, out1);
  50         _mm_stream_si128((__m128i *) (dst + 8), out2);
  51         dst += 16;
  52         src += 16;
  53         len -= 16;
  54       }
  55     } else if (offset == 8) {
  56       outp1 = (__m128d *) &out1;
  57       outp2 = (__m128d *) &out2;
  58       while (len > 15) {
  59         in = _mm_load_si128((__m128i *) src);
  60         if (_mm_movemask_epi8(in))
  61           break;
  62         out1 = _mm_unpacklo_epi8(in, zeroes);
  63         out2 = _mm_unpackhi_epi8(in, zeroes);
  64         _mm_storel_epi64((__m128i *) dst, out1);
  65         _mm_storel_epi64((__m128i *) (dst + 8), out2);
  66         _mm_storeh_pd((double *) (dst + 4), *outp1);
  67         _mm_storeh_pd((double *) (dst + 12), *outp2);
  68         src += 16;
  69         dst += 16;
  70         len -= 16;
  71       }
  72     } else {
  73       while (len > 15) {
  74         in = _mm_load_si128((__m128i *) src);
  75         if (_mm_movemask_epi8(in))
  76           break;
  77         out1 = _mm_unpacklo_epi8(in, zeroes);
  78         out2 = _mm_unpackhi_epi8(in, zeroes);
  79         _mm_storeu_si128((__m128i *) dst, out1);
  80         _mm_storeu_si128((__m128i *) (dst + 8), out2);
  81         src += 16;
  82         dst += 16;
  83         len -= 16;
  84       }
  85     }
  86   }
  87
  88   // finish off a byte at a time
  89
  90   while (len-- > 0 && (*src & 0x80U) == 0) {
  91     *dst++ = (char16_t) *src++;
  92   }
  93 }
  94
  95 } // namespace SSE2
  96 } // namespace mozilla