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Re: Preprocessor performance analysis
- To: gcc at gcc dot gnu dot org
- Subject: Re: Preprocessor performance analysis
- From: Neil Booth <neil at daikokuya dot demon dot co dot uk>
- Date: Mon, 1 Oct 2001 23:06:00 +0100
- References: <20011001223311.A18202@daikokuya.demon.co.uk>
> When considering the above, note that the 3.x preprocessor has greater
> functionality than 2.95.x, e.g. _Pragma (a small but non-trivial
> bottleneck, since every identifier token has to be checked to see if
> it is _Pragma), better diagnostics, and fixes numerous minor bugs in
> the former. Producing preprocessed output is an extra step for 3.0.x,
> but a natural by-product of preprocessing for 2.95.x, which isn't
> performed with integrated CPP, that on this machine takes roughly
> 25-40% of execution time, depending on the file.
I should also mention that 2.95.x leaks almost all the memory it uses.
Also, stand-alone 3.1-CURRENT takes the effort to free() all allocated
memory, and has no memory leaks [I think it may have leaks with
-remap, but who cares about that].