[Python-Dev] Tagged integers (original) (raw)

Brian Quinlan brian at sweetapp.com
Wed Jul 14 11:40:40 CEST 2004

James Y Knight wrote:

So I was saying to someone the other day "Gee, I wonder why Python doesn't use tagged integers, it seems like it would be a lot faster than allocating new objects all the time.", and they said "Cause you'd have to change everything, too much work!" and I said "Nah, you only need to change a few things to use macros, it'd only take a few hours, mostly query-replace".

So, of course, I had to do it then, and it only took a couple hours, and appears to be at least somewhat faster.

It made integer-heavy things 20% faster. How much slower did it make everything else? Did you try running a complete benchmark (e.g. pystone) before and after?

And the lack of portability is a real problem - it means that every code path must be tested twice AND there might be architectures and problems were tagged integers work but it actually makes things slower.

I'm skeptical until I see a complete system benchmark but it's great that you tried this!

Cheers, Brian

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