It amazed me, and annoyed me at the same time, that Fortran 90 et seq. eschewed the ubiquitous REAL8 for all this KIND nonsense. The reason that CDC didn't have REAL8 is that they ran 60-bit words. You could therefore have 60 bit REAL or 120 bit DOUBLE PRECISION, but not 64 bit anything. When computers were word-based instead of being byte-based, there were all sorts of native precisions, for example, 36-bit or 24-bit words etc.
Although there are a few constructs in Fortran 90 that have no equivalent in Fortran 77, mostly the new features duplicate things you could already do. The 9x standards simply ignore such things as graphics, user interfaces and so on, as a result of which the language went nowhere at a time it could have been rejuvenated. To get all those things, one has to tie oneself to a specific compiler, e.g. FTNxx with ClearWin+. I imagine that this makes commercial developers nervous. However, Salford/Silverfrost's FTN proved more durable than Microsoft's Fortran! Tying oneself to Windows is less of an issue, given the proportion of machines that use it.
I recently spent some time pondering Hatton's 'safe subset' idea (i.e. that there is a subset of a language that programmers make fewest mistakes with - in his case he considered Fortran 77). The safe subset of Fortran 9x is, of course, Fortran 77. Not only is this true of user code, but based on what gets fixed release by release, it is true of FTN95 itself (forgetting 'reversions' - of which there are few).
In my view, it is sad that we don't have REAL6, as this is for many uses REAL4 is grossly inadequate, and REAL*8 is overkill. We had this precision on ICL computers, and also on the BBC micro.
KIND might be of more use if one could trade off range and precision, but in practice, one can't. There is one model for how the bits are shared out, and that is that.
A similar argument could be adduced for the introduction of 'short' INTEGERs. I never got integer overflow on a machine where the INTEGER and REAL were the same length - it was a problem I first encountered (but only once) on a PC when I used short (INTEGER2) integers to save space on my first PC back in 1983. I realise that few people get integer overflow with INTEGER4, but that small number becomes even smaller with INTEGER*6.
Eddie
