🚀 go-pugleaf

In article <1992Aug31.034803.27829@unixg.ubc.ca> ochealth@unixg.ubc.ca (ochealth) writes:
>
>
>This is pure speculation, as I haven't checked out the 386/7 or 486 instructions
>but couldn't some PM applications seem faster because OS/2 can shove several
>instructions at the coprocessor, and then continue with another task?
>
>I thought that the CPU and the FPU worked more-or-less independently of

As far as I know, the O/S makes no difference -- it is entirely possible
to have the 80x86 chip do some non-dependent ** calculations while the
80x87 chip is doing it's thing. There is an instruction that is the 
equivalent of a "join" -- it forces the 80x86 to wait for the 80x87 to
complete its work before the program procedes further. But if there is
something else that the 80x86 can do in the meantime [typical example:
index or pointer arithmetic], the the only limitation is that of the
programmer's or compiler's intelligence. 

** A  non-dependent calculation is one that can be done using input
data that is not being produced by the co-processor.

It is poor programming practice to leave out the "wait" instruction --
even if the timing works out alright now, a future version of the
80x87 or 80x86 [or combined equivalent] might have different cycle times
for the two parallel execution threads and the program might fail on those
processors.

orville

--------------------------------------       **********************************
Orville R. Weyrich, Jr.                          Weyrich Computer Consulting
Certified Data Processor                       POB 5782, Scottsdale, AZ 85261
Certified Systems Professional                      Voice: (602) 391-0821
Certified Computer Programmer                Internet: orville%weyrich@tnet.com
--------------------------------------       **********************************
>each other. Under DOS anyway, I thought the CPU had to wait for the FPU
>to finish to get results back.
>
>jpm
>
>-- 
>______________________________________________________________________________
>jpm: ochealth@unixg.ubc.ca         
>                            Happily using OS/2 2.0 because MS Windows isNT ___
>                                                      Insert VapourFeature ^^^