| Who Wrote Fortran IV, Level G? [message #366188] |
Mon, 09 April 2018 13:33  |
Quadibloc
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Registered: June 2012
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I remember it being said that IBM didn't write that compiler itself, but instead
they hired a firm that wrote compilers for computer manufacturers to do that; it
was a firm whose ads I remember seeing in Computerworld, they mentioned that they
used a stack-based technology for their compilers.
But I can't seem to find or remember the name...
John Savard
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| Re: Who Wrote Fortran IV, Level G? [message #366189 is a reply to message #366188] |
Mon, 09 April 2018 14:25  |
Anne & Lynn Wheel
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Quadibloc <jsavard@ecn.ab.ca> writes:
> I remember it being said that IBM didn't write that compiler itself, but instead
> they hired a firm that wrote compilers for computer manufacturers to do that; it
> was a firm whose ads I remember seeing in Computerworld, they mentioned that they
> used a stack-based technology for their compilers.
>
> But I can't seem to find or remember the name...
>
> John Savard
I remember Univ. of Chicago had some amount of the contract for Fort G
.... but don't remember whether it was everything ... or just runtime
libraries.
much later STL started subcontracting lots of compiler stuff out ...
there was some uproar over lots of internal compiler optimization
technology being given to some company.
--
virtualization experience starting Jan1968, online at home since Mar1970
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| Re:Who Wrote Fortran IV, Level G? [message #366190 is a reply to message #366188] |
Mon, 09 April 2018 14:30 |
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Originally posted by: Sarr Blumson
Quadibloc <jsavard@ecn.ab.ca> Wrote in message:
> I remember it being said that IBM didn't write that compiler itself, but instead
> they hired a firm that wrote compilers for computer manufacturers to do that; it
> was a firm whose ads I remember seeing in Computerworld, they mentioned that they
> used a stack-based technology for their compilers.
>
> But I can't seem to find or remember the name...
>
> John Savard
>
Digitek. They actually had a compiler written for a stack oriented
pseudo machine that they then wrote interpreters for to fit on small
machines. I believe the first was the SDS 910 but many small
hardware builders were customers. F4/40 for the PDP 6/10, for example.
They then tried to take on PL/1 and put themselves out of
business. IIRC the survivers started Ryan McFarland.
IBM had more space on G sized machines, so they expanded the
pseudo instructions as macros to speed it up.
sarr
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| Re: Who Wrote Fortran IV, Level G? [message #366193 is a reply to message #366190] |
Mon, 09 April 2018 15:13 |
Peter Flass
Messages: 8402
Registered: December 2011
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Sarr Blumson <sarr.blumson@alum.dartmouth.orgq> wrote:
> Quadibloc <jsavard@ecn.ab.ca> Wrote in message:
>> I remember it being said that IBM didn't write that compiler itself, but instead
>> they hired a firm that wrote compilers for computer manufacturers to do that; it
>> was a firm whose ads I remember seeing in Computerworld, they mentioned that they
>> used a stack-based technology for their compilers.
>>
>> But I can't seem to find or remember the name...
>>
>> John Savard
>>
>
> Digitek. They actually had a compiler written for a stack oriented
> pseudo machine that they then wrote interpreters for to fit on small
> machines. I believe the first was the SDS 910 but many small
> hardware builders were customers. F4/40 for the PDP 6/10, for example.
>
> They then tried to take on PL/1 and put themselves out of
> business. IIRC the survivers started Ryan McFarland.
>
> IBM had more space on G sized machines, so they expanded the
> pseudo instructions as macros to speed it up.
>
Thanks. I believe Digitek was hired to develop PL/I for Multics, but they
failed so spectacularly that the Multics people developed their own
compiler from scratch. It turned out to be one of the best ANSI-standard
PL/I compilers, better than PL/I(F).
--
Pete
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| Re: Who Wrote Fortran IV, Level G? [message #366217 is a reply to message #366190] |
Tue, 10 April 2018 16:56 |
Quadibloc
Messages: 4399
Registered: June 2012
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On Monday, April 9, 2018 at 12:30:17 PM UTC-6, Sarr Blumson wrote:
> Digitek. They actually had a compiler written for a stack oriented
> pseudo machine that they then wrote interpreters for to fit on small
> machines. I believe the first was the SDS 910 but many small
> hardware builders were customers. F4/40 for the PDP 6/10, for example.
Thank you; I couldn't remember the name, but as soon as you said it, it rang a
bell.
John Savard
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| Re: Who Wrote Fortran IV, Level G? [message #366218 is a reply to message #366190] |
Tue, 10 April 2018 17:37 |
John Levine
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Registered: December 2011
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In article <pagbfn$t1o$1@dont-email.me>,
Sarr Blumson <sarr.blumson@alum.dartmouth.orgq> wrote:
> Digitek. They actually had a compiler written for a stack oriented
> pseudo machine that they then wrote interpreters for to fit on small
> machines. I believe the first was the SDS 910 but many small
> hardware builders were customers. F4/40 for the PDP 6/10, for example.
Sounds right. F4/40 generated machine code but it was pretty poor, and
I could easily believe it was macro expanded from a stack pseudomachine.
The code from Fortran G was also pretty poor, largely because it
didn't know anything about the 360's addressing so it was constantly
loading pointers from a literal pool to reference local scalars rather
than keeping a pointer to the base of the scalars in a register and
using the usual base+displacement.
I saw the note about Fortran G generating better code than Fortran H,
and find it hard to believe unless it was for some rather peculiar
code.
--
Regards,
John Levine, johnl@iecc.com, Primary Perpetrator of "The Internet for Dummies",
Please consider the environment before reading this e-mail. https://jl.ly
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| Re: Who Wrote Fortran IV, Level G? [message #366220 is a reply to message #366218] |
Tue, 10 April 2018 20:51 |
Peter Flass
Messages: 8402
Registered: December 2011
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John Levine <johnl@taugh.com> wrote:
> In article <pagbfn$t1o$1@dont-email.me>,
> Sarr Blumson <sarr.blumson@alum.dartmouth.orgq> wrote:
>> Digitek. They actually had a compiler written for a stack oriented
>> pseudo machine that they then wrote interpreters for to fit on small
>> machines. I believe the first was the SDS 910 but many small
>> hardware builders were customers. F4/40 for the PDP 6/10, for example.
>
> Sounds right. F4/40 generated machine code but it was pretty poor, and
> I could easily believe it was macro expanded from a stack pseudomachine.
>
> The code from Fortran G was also pretty poor, largely because it
> didn't know anything about the 360's addressing so it was constantly
> loading pointers from a literal pool to reference local scalars rather
> than keeping a pointer to the base of the scalars in a register and
> using the usual base+displacement.
>
> I saw the note about Fortran G generating better code than Fortran H,
> and find it hard to believe unless it was for some rather peculiar
> code.
>
ISTR that H had problems initially ('67 or so). I recall being warned not
to use it. I would hope that the problems got fixed.
--
Pete
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| Re: Who Wrote Fortran IV, Level G? [message #366225 is a reply to message #366220] |
Wed, 11 April 2018 00:30 |
John Levine
Messages: 1418
Registered: December 2011
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In article <1613292015.545100577.072184.peter_flass-yahoo.com@news.eternal-september.org> you write:
> John Levine <johnl@taugh.com> wrote:
>> I saw the note about Fortran G generating better code than Fortran H,
>> and find it hard to believe unless it was for some rather peculiar
>> code.
>
> ISTR that H had problems initially ('67 or so). I recall being warned not
> to use it. I would hope that the problems got fixed.
I was using Fortran H on production code in about 1973 on Princeton's
360/91 and it worked fine. It was a large (for the time) numerical
economic simulation that took forever to run. Recompiling with H
rather than G and rewriting a couple of subroutines so they didn't
open and close a file every time they read a record from the disk made
a huge difference.
--
Regards,
John Levine, johnl@iecc.com, Primary Perpetrator of "The Internet for Dummies",
Please consider the environment before reading this e-mail. https://jl.ly
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| Re: Who Wrote Fortran IV, Level G? [message #366241 is a reply to message #366218] |
Wed, 11 April 2018 13:50 |
Charles Richmond
Messages: 2754
Registered: December 2011
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On 4/10/2018 4:37 PM, John Levine wrote:
> In article <pagbfn$t1o$1@dont-email.me>,
> Sarr Blumson <sarr.blumson@alum.dartmouth.orgq> wrote:
>> Digitek. They actually had a compiler written for a stack oriented
>> pseudo machine that they then wrote interpreters for to fit on small
>> machines. I believe the first was the SDS 910 but many small
>> hardware builders were customers. F4/40 for the PDP 6/10, for example.
>
> Sounds right. F4/40 generated machine code but it was pretty poor, and
> I could easily believe it was macro expanded from a stack pseudomachine.
>
Thyere is a comment in Don Woods' original Adventure code... that
references a bug in the F40 compiler code generation. Look at he middle
line in the following...
1004 READ(1,1005)LOC,(LINES(J),J=LINUSE+1,LINUSE+14),KK
1005 FORMAT(1G,15A5)
IF(KK.NE.' ')CALL BUG(0)
IF(LOC.EQ.-1)GOTO 1002
DO 1006 K=1,14
KK=LINUSE+15-K
IF(LINES(KK).NE.' ')GOTO 1007
1006 CONTINUE
IF(LOC.EQ.0)GOTO 1004
C ABOVE KLUGE IS TO AVOID F40 BUG IF CRLF BROKEN ACROSS RECORD BOUNDARY
CALL BUG(1)
1007 LINES(LINUSE)=KK+1
IF(LOC.EQ.OLDLOC)GOTO 1020
LINES(LINUSE)=-LINES(LINUSE)
IF(SECT.EQ.12)GOTO 1013
IF(SECT.EQ.10)GOTO 1012
IF(SECT.EQ.6)GOTO 1011
IF(SECT.EQ.5)GOTO 1010
IF(SECT.EQ.1)GOTO 1008
--
numerist at aquaporin4 dot com
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| Re: Who Wrote Fortran IV, Level G? [message #366242 is a reply to message #366241] |
Wed, 11 April 2018 14:13 |
John Levine
Messages: 1418
Registered: December 2011
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In article <palhs0$pfb$1@dont-email.me>,
Charles Richmond <numerist@aquaporin4.com> wrote:
> Thyere is a comment in Don Woods' original Adventure code... that
> references a bug in the F40 compiler code generation. Look at he middle
> line in the following...
That's not a code bug. It's a library bug. For some reason lost in the mists
of time F4/F40 called a lot of its runtime library via user UUOs, which is
so PDP-6/10 specific that I would assume a lot of the library was written at DEC.
R's,
John
> 1004 READ(1,1005)LOC,(LINES(J),J=LINUSE+1,LINUSE+14),KK
> 1005 FORMAT(1G,15A5)
> IF(KK.NE.' ')CALL BUG(0)
> IF(LOC.EQ.-1)GOTO 1002
> DO 1006 K=1,14
> KK=LINUSE+15-K
> IF(LINES(KK).NE.' ')GOTO 1007
> 1006 CONTINUE
> IF(LOC.EQ.0)GOTO 1004
> C ABOVE KLUGE IS TO AVOID F40 BUG IF CRLF BROKEN ACROSS RECORD BOUNDARY
> CALL BUG(1)
> 1007 LINES(LINUSE)=KK+1
> IF(LOC.EQ.OLDLOC)GOTO 1020
> LINES(LINUSE)=-LINES(LINUSE)
> IF(SECT.EQ.12)GOTO 1013
> IF(SECT.EQ.10)GOTO 1012
> IF(SECT.EQ.6)GOTO 1011
> IF(SECT.EQ.5)GOTO 1010
> IF(SECT.EQ.1)GOTO 1008
>
>
> --
> numerist at aquaporin4 dot com
--
Regards,
John Levine, johnl@iecc.com, Primary Perpetrator of "The Internet for Dummies",
Please consider the environment before reading this e-mail. https://jl.ly
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| Re: Who Wrote Fortran IV, Level G? [message #366246 is a reply to message #366218] |
Wed, 11 April 2018 16:48 |
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Originally posted by: Sarr Blumson
John Levine <johnl@taugh.com> Wrote in message:
>
> Sounds right. F4/40 generated machine code but it was pretty poor, and
> I could easily believe it was macro expanded from a stack pseudomachine.
People told me writing was too concise even before tablets. :)
The _compiler_ was written in pseudo code by humans. It generated
real code for the target machine so some serious porting was
required for a new architecture.
F40 was amazingly aggressive, actually. It used all 16 registers
before resorting to temp variables and did common subexpression
reduction within individual statements. Not always correctly,
unfortunately.
Sarr
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