[Python-Dev] PEP 393 review (original) (raw)

Antoine Pitrou solipsis at pitrou.net
Sun Aug 28 22:01:06 CEST 2011

- the iobench results are between 2% acceleration (seek operations), 16% slowdown for small-sized reads (4.31MB/s vs. 5.22 MB/s) and 37% for large sized reads (154 MB/s vs. 235 MB/s). The speed difference is probably in the UTF-8 decoder; I have already restored the "runs of ASCII" optimization and am out of ideas for further speedups. Again, having to scan the UTF-8 string twice is probably one cause of slowdown.

I don't think it's the UTF-8 decoder because I see an even larger slowdown with simpler encodings (e.g. "-E latin1" or "-E utf-16le").

Thanks

Antoine.

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