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Tag Archives: fast

Ridiculous UTF-8 character counting

So, Colin Percival has posted a UTF-8 strlen which improves on my previous post. While his code runs slightly slower than mine on my PC, I assume that’s because his code is aimed at a 64-bit architecture. With 32-bits (reading 4 bytes at a time, instead of 8 ) it doesn’t quite get the same [...]

Posted 06 June 2008 † Porges § code ‡ Comments (10) ° Also tagged: , , , , , , , ,

Counting Characters in UTF-8 Strings Is Fast(er)

‘Counting Characters in UTF-8 Strings Is Fast’ by Kragen Sitaker shows several ways to count characters UTF-8, using both assembly and C. But, with a few assumptions, we can go faster.
Assumption One: We are dealing with a valid UTF-8 string
Making this assumption means that once we hit the start of a multi-byte character we can [...]

Posted 04 June 2008 † Porges § code ‡ Comments (6) ° Also tagged: , , , , ,