alt Hacker NewsAliasing is no joke and currently the only reason why some arithmetic intensive code-bases still prefer Fortran even nowadays.
While it is possible to remove most aliasing performance issues in a C or C++ codebase, it is a pain to do it properly.
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kryptiskt • today at 1:15 PM
Support for arrays without having to mess with pointers is pretty attractive for number crunchers too.
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.