diff options
| -rw-r--r-- | src/corelib/json/qjson_p.h | 33 |
1 files changed, 28 insertions, 5 deletions
diff --git a/src/corelib/json/qjson_p.h b/src/corelib/json/qjson_p.h index c2863f41a1..b8430cabf5 100644 --- a/src/corelib/json/qjson_p.h +++ b/src/corelib/json/qjson_p.h @@ -54,6 +54,8 @@ #include <qendian.h> #include <qnumeric.h> +#include "private/qsimd_p.h" + #include <limits.h> #include <limits> @@ -374,13 +376,34 @@ public: inline Latin1String &operator=(const QString &str) { - d->length = str.length(); + int len = d->length = str.length(); uchar *l = (uchar *)d->latin1; const ushort *uc = (const ushort *)str.unicode(); - for (int i = 0; i < str.length(); ++i) - *l++ = uc[i]; - while ((quintptr)l & 0x3) - *l++ = 0; + int i = 0; +#ifdef __SSE2__ + for ( ; i + 16 < len; i += 16) { + __m128i chunk1 = _mm_loadu_si128((__m128i*)&uc[i]); // load + __m128i chunk2 = _mm_loadu_si128((__m128i*)&uc[i + 8]); // load + // pack the two vector to 16 x 8bits elements + const __m128i result = _mm_packus_epi16(chunk1, chunk2); + _mm_storeu_si128((__m128i*)&l[i], result); // store + } +# ifdef Q_PROCESSOR_X86_64 + // we can do one more round, of 8 characters + if (i + 8 < len) { + __m128i chunk = _mm_loadu_si128((__m128i*)&uc[i]); // load + // pack with itself, we'll discard the high part anyway + chunk = _mm_packus_epi16(chunk, chunk); + // unaligned 64-bit store + *(quint64*)&l[i] = _mm_cvtsi128_si64(chunk); + i += 8; + } +# endif +#endif + for ( ; i < len; ++i) + l[i] = uc[i]; + for ( ; (quintptr)(l+i) & 0x3; ++i) + l[i] = 0; return *this; } |