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Re: Precompiled headers, etc, on tree-serialize branch


On Sun, Oct 07, 2001 at 03:02:46PM -0400, Daniel Berlin wrote:
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> However, to give you some idea how much faster this would make gcc, 
> here's the current minimum bound on a gcc compilation, as witnessed by 
> just precompiling a file, and generating the assembly from the 
> precompiled file only:
> 
> ./cc1 expr.i
> 24 seconds
> (produces an expr.i.pch, since, as i said, it serializes anything you 
> ask it to compile)
> 
> cp expr.s before.s
> 
> ./cc1 expr.i
> 0.8 seconds
> diff expr.s before.s
> <nothing output>

Hmm.. I wonder what what would be the diffrence if -O2 was used. From my expiriance
in this area it comes up, that for most sources -O2 takes 2-3 times more time to compile.
Of course this is for files with not-so-big includes (I guess Apple is working so hard
on it, since they #include <one-big-file.h> all the time, even for 4-line programs :^).

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