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Re: non recursive makefiles
From: |
Pascal J . Bourguignon |
Subject: |
Re: non recursive makefiles |
Date: |
Tue, 11 Jan 2005 19:33:54 +0100 |
Adrian Robert writes:
> >> IMHO precompiled headers support is much more important as the
> >> compilation speed-up is enormous (day to day experience on Mac OS X
> >> using Xcode).
> >
> > ...
> > The ROI (Return On Investment) of working on precompiled headers would
> > be
> > huge compared to other changes we might develop.
>
> Doesn't the compiler still have to parse in the precomp headers so it
> can use the structure information there to help parse the rest of the
> code? (I guess everyone thinks this is much faster than the original
> .h file reading / parsing, but the stated lack of numbers backing it up
> prompts a devil's advocate question.)
Of course. Unless you dump a mmap-able data structure. Which means
you'd replace all pointers with indexes, therefore making every read
access theorically slower (in practice, it may be in cache and not
matter since the I/O is where time will be spent anyway). So the
question is whether the precompiled header are smallers and tighter
than the original ASCII files. Perhaps doing:
ar c precomp.h /usr/include/*.h
is all that would be needed.
> Also, note speedup in Xcode vs. PB is due to more than just PCH:
>
> - switch to 'jam' instead of 'make'
> - extensive use of incremental compilation in background
> - zero-link (whatever that is)
> - if you are using it, distributed compile
--
__Pascal Bourguignon__ http://www.informatimago.com/
You never feed me.
Perhaps I'll sleep on your face.
That will sure show you.
- non recursive makefiles, Rogelio Serrano, 2005/01/09
- Message not available
- Message not available
- Message not available
- Re: non recursive makefiles, Rogelio Serrano, 2005/01/10
- Re: non recursive makefiles, Jeremy Tregunna, 2005/01/10
- Re: non recursive makefiles, Rogelio Serrano, 2005/01/10
- Re: non recursive makefiles, Nicola Pero, 2005/01/10
- Re: non recursive makefiles, Riccardo, 2005/01/11
- Re: non recursive makefiles, Marcus Müller, 2005/01/11
- Re: non recursive makefiles, Nicola Pero, 2005/01/11
- Re: non recursive makefiles, Marcus Müller, 2005/01/11
- Re: non recursive makefiles, Adrian Robert, 2005/01/11
- Re: non recursive makefiles,
Pascal J . Bourguignon <=
- Re: non recursive makefiles, Philippe C . D . Robert, 2005/01/11
- Re: non recursive makefiles, Jeremy Tregunna, 2005/01/10
Re: non recursive makefiles, Nicola Pero, 2005/01/10