[Info-vax] VMS Software Q1 '23 Update

[Dave Froble]

On 1/25/2023 8:07 PM, bill wrote:
> On 1/25/2023 7:54 PM, Arne Vajhøj wrote:
>>
>>
>> Many years ago I did a lot of Fortran, but it has been some years.
>>
>> As I remember it then good practice was to have the common block itself
>> in an include to ensure consistency and to only initialize once - either
>> in a block data which I think was invented for this purpose or some
>> pre-determined place like the main program.
>>
>
> As did I.  And, at one point I even got to be the front man for support
> for the Fortran Compiler on Primos.
>
> Two interesting things I have run into that are loosely related.
>
> We got a complaint from an "engineer" who claimed the compiler was
> broken because when he compared reals they never equaled each other.
> Prime fixed that one by adding an error message that politely said
> "Don't do that, stupid".
>
> But the better one is still available for viewing today.  The PL/M
> compiler is written in Fortran.  It uses a lot of COMMON.  The version
> I use is somewhat different from the ones you will find on the web.
> Mine has all the variables in the same order in all of the COMMON
> declarations!  And yet it worked for how many years?  Points out
> another flaw.  Obviously all the stuff in COMMON really doesn't need
> to be there.
>
> John, I don't envy your job.
>
> bill
>

I'm guessing (I know very little about how compilers actually work) that one 
reason might be that instead of re-working the compilers to output something 
LLVM can use, they are continuing to output what GEM uses, and then translating 
that to what LLVM can use.  Might sound like a shortcut at first, but, I've got 
to believe there are lots of gators in that swamp.

As for the scale of the job to have the compilers product directly what LLVM can 
use, I don't have any clue.

-- 
David Froble                       Tel: 724-529-0450
Dave Froble Enterprises, Inc.      E-Mail: davef at tsoft-inc.com
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