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bregmatoday at 11:23 AM1 replyview on HN

Aliasing can be a problem in Fortran too.

Decades ago I was a Fortran developer and encountered a very odd bug in which the wrong values were being calculated. After a lot of investigation I tracked it down to a subroutine call in which a hard-coded zero was being passed as an argument. It turned out that in the body of that subroutine the value 4 was being assigned to that parameter for some reason. The side effect was that the value of zero because 4 for the rest of the program execution because Fortran aliases all parameters since it passes by descriptor (or at least DEC FORTRAN IV did so on RSX/11). As you can imagine, hilarity ensued.


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pklauslertoday at 2:21 PM

How does this bug concern aliasing?

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