My impression is that projects which still use FORTRAN, mostly do so because they rely on large bodies of existing code that have been well-tested, and they don't want to bother re-implementing all that code...
On Sun, Oct 19, 2014 at 5:24 AM, Steve Richfield via AGI <[email protected]> wrote: > John, > > On Sat, Oct 18, 2014 at 6:33 AM, John Rose via AGI <[email protected]> > wrote: > >> Here's an idea - let's re-spec Fortran to do better 3D graphics rendering >> and real-time physics simulation so people can use it to write video games. >> The question is why? Perhaps to migrate existing developers? Better to >> create a whole new language IMO. >> > > OK, on the way to answering this question, I'll ask and answer the > following question: > > Q: Why do most supercomputers STILL program in FORTRAN?!!! > > A1: Because it has carefully conceived language impediments that make it > much easier (than C, Java, etc.) to write code in ways that are > automatically vectorizeable. This started for different reasons, e.g. the > motivation to use the TIX (conditional Transfer and Increment an indeX > register) instructions on the early IBM 70X computers, later to become 70XX > computers. However, the requirements to write code as efficient loops are > nearly the same in vector machines. > > A2: The complexity of an optimizing and vectorizing compiler tends to > grow as the square of the number of elements in the language, so compilers > for "modern" languages tend to do a bad job of optimization, and a horrible > job of vectorization, unless you write in a minimal subset of the languages > that strongly resembles FORTRAN. > > Of course if your problem is SO simple it can be run on an Intel > processor, which clearly does NOT include AGI, then there is no need for > executional efficiency. > > You mentioned rendering. Have you looked at the execution times for > rendering programs? These days, they must schedule planned movie releases > around the expected rendering times. Is it REALLY worth such costs to > implement more convenient language constructs? > > Language impediments were carefully studied when FORTRAN was created, but > this art has been lost to time. Perhaps you remember the early restriction > that subscripts had to be of the form aX+b? This restriction was soon > removed, but expert programmers learned to abide by the removed > restrictions, because doing so made their code run faster. > > In implementing something like COBOL, the issue of language restrictions > should be carefully revisited. > > Steve > >> ------------------------------------------- >> AGI >> Archives: https://www.listbox.com/member/archive/303/=now >> RSS Feed: >> https://www.listbox.com/member/archive/rss/303/10443978-6f4c28ac >> Modify Your Subscription: https://www.listbox.com/member/?&; >> Powered by Listbox: http://www.listbox.com >> > > > > -- > Full employment can be had with the stoke of a pen. Simply institute a six > hour workday. That will easily create enough new jobs to bring back full > employment. > > *AGI* | Archives <https://www.listbox.com/member/archive/303/=now> > <https://www.listbox.com/member/archive/rss/303/212726-deec6279> | Modify > <https://www.listbox.com/member/?&;> > Your Subscription <http://www.listbox.com> > -- Ben Goertzel, PhD http://goertzel.org "The reasonable man adapts himself to the world: the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man." -- George Bernard Shaw ------------------------------------------- AGI Archives: https://www.listbox.com/member/archive/303/=now RSS Feed: https://www.listbox.com/member/archive/rss/303/21088071-f452e424 Modify Your Subscription: https://www.listbox.com/member/?member_id=21088071&id_secret=21088071-58d57657 Powered by Listbox: http://www.listbox.com
