Further improvement

src/Common/UTF8Helpers.cpp

@@ -97,6 +97,35 @@ size_t computeWidth(const UInt8 * data, size_t size, size_t prefix) noexcept
     for (size_t i = 0; i < size; ++i)
     {
         /// Quickly skip regular ASCII
+
+#if defined(__SSE2__)
+        const auto lower_bound = _mm_set1_epi8(32);
+        const auto upper_bound = _mm_set1_epi8(126);
+
+        while (i + 15 < size)
+        {
+            __m128i bytes = _mm_loadu_si128(reinterpret_cast<const __m128i *>(&data[i]));
+
+            const uint16_t non_regular_width_mask = _mm_movemask_epi8(
+                _mm_or_si128(
+                    _mm_cmplt_epi8(bytes, lower_bound),
+                    _mm_cmpgt_epi8(bytes, upper_bound)));
+
+            if (non_regular_width_mask)
+            {
+                auto num_regular_chars = __builtin_ctz(non_regular_width_mask);
+                width += num_regular_chars;
+                i += num_regular_chars;
+                break;
+            }
+            else
+            {
+                i += 16;
+                width += 16;
+            }
+        }
+#endif
+
         while (i < size && isPrintableASCII(data[i]))
         {
             ++width;