🚀 go-pugleaf

"Robert Myers" <rmyers@rustuck.com> wrote in message
news:iu6fnvch0g09q9f335tt89ogfcj5jm2ovh@4ax.com...
> On Sat, 27 Sep 2003 00:17:13 GMT, "Glen Herrmannsfeldt"
> <gah@ugcs.caltech.edu> wrote:
>
> <snip>
> >
> >PL/I has the MULTIPLY function where one can specify the desired result
> >precision.  At least one compiler I know of expands both operands before
> >doing a double precision multiply when double precision is desired.
> >
> >If someone wanted to comment about other hardware or compilers in use in
the
> >1960's and 1970's, that might also be useful.
> >
>
> When I took numerical methods as a graduate student (mid-seventies), I
> knew only PL/I and 360 Assembler.  Everybody was running on IBM 360
> (or whatever the model was at the time).  My classmates, who all used
> Fortran IV (while I was coding in PL/I), invariably got different
> answers (in the least significant digits) doing the same problem on
> the same machine.  Since I was not majoring in computer science,
> neither the professor nor I had the competence or the interest to
> explore the details, although I might take a different attitude today.

Since my post on Fortran G and H, I have also run the same test on PL/I (F).
That might be the compiler you used.

For   C=C+A*B; single precision A and B, and double precision C, it does the
same thing Fortran did.

It would be interesting to see the results from newer Fortran and PL/I
compilers.

-- glen