diff options
Diffstat (limited to 'src/corelib/tools/qstring.cpp')
| -rw-r--r-- | src/corelib/tools/qstring.cpp | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/src/corelib/tools/qstring.cpp b/src/corelib/tools/qstring.cpp index 269b592f62..cf85807888 100644 --- a/src/corelib/tools/qstring.cpp +++ b/src/corelib/tools/qstring.cpp @@ -347,14 +347,32 @@ static int findChar(const QChar *str, int len, QChar ch, int from, if (from < 0) from = qMax(from + len, 0); if (from < len) { - const ushort *n = s + from - 1; + const ushort *n = s + from; const ushort *e = s + len; if (cs == Qt::CaseSensitive) { +#ifdef __SSE2__ + __m128i mch = _mm_set1_epi32(c | (c << 16)); + + // we're going to read n[0..7] (16 bytes) + for (const ushort *next = n + 8; next <= e; n = next, next += 8) { + __m128i data = _mm_loadu_si128((__m128i*)n); + __m128i result = _mm_cmpeq_epi16(data, mch); + uint mask = _mm_movemask_epi8(result); + if (ushort(mask)) { + // found a match + // same as: return n - s + _bit_scan_forward(mask) / 2 + return (reinterpret_cast<const char *>(n) - reinterpret_cast<const char *>(s) + + _bit_scan_forward(mask)) >> 1; + } + } +#endif + --n; while (++n != e) if (*n == c) return n - s; } else { c = foldCase(c); + --n; while (++n != e) if (foldCase(*n) == c) return n - s; |