Compressed MOD files?

[Jerry DeLisle]

Steve Kargl wrote:
> On Mon, Oct 30, 2006 at 09:06:24PM +0200, Erik Edelmann wrote:
>> On Mon, 30 Oct 2006, FX Coudert wrote:
>>
>>>>> ssed or not when reading, which is pretty easy) It increases CPU
>>>>> usage, but it gets the disk space used by module files by a factor 5
>>>>> to 6 on my own codes.
>>>> This sounds interesting, but how much real space usage reduction do you 
>>>> see?
>>> a factor of 5 to 6? e.g., from 27 megabytes to 5.2 megabytes on the 
>>> real-life F95 code I currently use for my work.
>> My first reaction when I saw your first message in this thread was "Does it
>> really matter?".  But if there are real life code that prdoces 27 MB of
>> *.mod files, I guess compression would be nice.  Not of huge importance
>> perhaps, with the hard disk sizes of today, but nice.  Since it shouldn't
>> add much complexity to the compiler, my vote is "yes".
>>
>>
> 
> gfortran doesn't cache a previously read module.
> 
> module foo
>   contains
>     subroutine A
>        use B
>     end subroutine A
>     subroutine C
>        use B
>     end subroutine C
> end module 
>     
> 
> Module B will be read twice, and hence, it would be decompressed
> twice.  How much overhead is added by the decompression phase?

I think it would be better to fix this multiple reading first before bothering 
with compression.

Jerry