[petsc-dev] Case TS005062693 - XLF: ICE in xlfentry compiling a module with 358 subroutines

[Satish Balay]

On Wed, 17 Mar 2021, Blaise A Bourdin wrote:

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> On Mar 16, 2021, at 11:17 PM, Barry Smith <bsmith at petsc.dev<mailto:bsmith at petsc.dev>> wrote:
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>   So it actually does not load everything at the call to use but waits until the subroutine definitions and then only loads what you ask to import?
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>   Sorry, this is odd, with C include or python import it immediately loads up everything as soon as it sees the include or import, there is no way later to say "wo hoarsy I didn't really mean you should get everything I asked, for please only load up a subset".
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> But then Fortran was always weird, when I saw presentations of the Fortran standards committee members I always felt like they read every third page of some computer science book but never realized they missed many of the pages.
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> Which proves that they know their target audience ;)
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> >From the standpoint of somebody who also read every third page of a computer science book, fortran modules sounded like a good idea on the paper (I basically think of them as auto-generated header files), but they are miserable in practice, and in particular a major block to cross compiler compatibility since the format of .mod file was left to the discretion of the compiler writers.
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Not just (a)cross compiler - different versions of gfortran are incompatible with each other's .mod format..

Satish

> Blaise
> 
> --
> A.K. & Shirley Barton Professor of  Mathematics
> Adjunct Professor of Mechanical Engineering
> Adjunct of the Center for Computation & Technology
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>