The techniques in the Dragon Book are scientific and let the run-of-the-mill systems programmers build compilers consistently. Before that the field was fragmented, formal grammar not well understood, and compilers faced difficult hardware constraints. So each compiler was hand built, often by exceptional developers, and techniques used were all over the place.
which is sliced into a huge number of passes so the compiler could fit inside a tiny memory footprint (e.g. a "mainframe" with the memory capacity of an Altair)
Another interesting if not so high performance compiler was the first FORTRAN IV compiler for the PDP-11 which used a stack machine instead of register allocation . DEC wasn't interested in making the best possible FORTRAN but instead in making a product that was competitive on the market so they started out with that, then developed a floating point processor designed specifically for that compiler, and then evolved from there.
Although machines from the IBM 360 were broadly competitive they varied from 4k of 16M of RAM and core and had very different implementations which varied in performance by orders of magnitude. Back then it was common for a hardware vendor to publish several compilers for a machine aimed at different balances of compile time and run time. It's not like we don't have some of that now, but anybody who was developing compilers in 1970 was flying on a wing and a prayer.
>In the middle 1970's, the IBM corporation did (and perhaps still does) most of their in-house programming in a computer language called FORTRAN.
Sorry, I doubt that. In the middle 70s it was COBOL, when COBOL'74 came out it became king of in-house programming for IBM and many other companies.
Now if you said the 60s or science based programming, I would agree with you about FORTRAN. But in-house usually means running the business, that is where COBOL rules.
Now, in-house is SAP ABAP, I think that took over at IBM in the mid to late 90s and early 00s. But IBM is moving to the next release of SAP and from what I heard from people there, ABAP is being phased out for something new that SAP came up with.
> Computer programming is still a black art. It's less than fifty years old, and nobody is very good at it yet. We can make better tools than we know how to use.
Before the Dragon Book some commercial compilers used heroic techniques that got superior performance along various axes.
Which? And do you mean compilers stopped using those approaches?
The techniques in the Dragon Book are scientific and let the run-of-the-mill systems programmers build compilers consistently. Before that the field was fragmented, formal grammar not well understood, and compilers faced difficult hardware constraints. So each compiler was hand built, often by exceptional developers, and techniques used were all over the place.
This one is legendary
https://ibm-1401.info/1401-IBM-Systems-Journal-FORTRAN.html
which is sliced into a huge number of passes so the compiler could fit inside a tiny memory footprint (e.g. a "mainframe" with the memory capacity of an Altair)
Another interesting if not so high performance compiler was the first FORTRAN IV compiler for the PDP-11 which used a stack machine instead of register allocation . DEC wasn't interested in making the best possible FORTRAN but instead in making a product that was competitive on the market so they started out with that, then developed a floating point processor designed specifically for that compiler, and then evolved from there.
Although machines from the IBM 360 were broadly competitive they varied from 4k of 16M of RAM and core and had very different implementations which varied in performance by orders of magnitude. Back then it was common for a hardware vendor to publish several compilers for a machine aimed at different balances of compile time and run time. It's not like we don't have some of that now, but anybody who was developing compilers in 1970 was flying on a wing and a prayer.
>In the middle 1970's, the IBM corporation did (and perhaps still does) most of their in-house programming in a computer language called FORTRAN.
Sorry, I doubt that. In the middle 70s it was COBOL, when COBOL'74 came out it became king of in-house programming for IBM and many other companies.
Now if you said the 60s or science based programming, I would agree with you about FORTRAN. But in-house usually means running the business, that is where COBOL rules.
Now, in-house is SAP ABAP, I think that took over at IBM in the mid to late 90s and early 00s. But IBM is moving to the next release of SAP and from what I heard from people there, ABAP is being phased out for something new that SAP came up with.
> Sorry, I doubt that. In the middle 70s it was COBOL, when COBOL'74 came out it became king of in-house programming for IBM and many other companies.
Depends very much on what the house did. Business programming ? COBOL. Scientific programming (data analysis, prediction, math) ? FORTAN.
> In the middle 70s it was COBOL, when COBOL'74 came out it became king of in-house programming for IBM
I thought IBM were still focused on APL in the 70s…
In the mid-1970s Alan k. Was working at Xerox Parc creating Smalltalk and the future.
Sadly, it didn't sell paper.
> Computer programming is still a black art. It's less than fifty years old, and nobody is very good at it yet. We can make better tools than we know how to use.