Re: Rounding timings

Robert,
It seems pretty easy for me to find what you originally said - and contrary to
what you say below, you DID claim to "but the myth" for ROUNDED. Here are your
original words,

"Proposition: "Do not use the REMAINDER, ROUNDED, ON SIZE ERROR or CORRESPONDING
phrases if
you want the fastest performance. No optimization is done on arithmetic
statements if the
ON SIZE ERROR phrase is used. For this reason, we recommend you do not use this
phrase if
high performance is required. The ROUNDED phrase impacts performance, but it is
generally
faster to use ROUNDED than try to round the result using your own routine. "

Test:
compute binary-number rounded = binary-number + 1 *> 1 us (no penalty)
add 1 to binary-number *>
15 us
on size error display 'overflow'
end-add

Finding: busted for rounded, confirmed for size error."

***

Obviously, the test itself has changed, but you have never retracted your
original claim to have "busted" the myth for ROUNDED>

--
Bill Klein
wmklein <at> ix.netcom.com
"Robert" <no@xxxxxx> wrote in message
news:j3p8f3d4g88pdf4ld48bhuc722bbkd2es3@xxxxxxxxxx
On Fri, 21 Sep 2007 04:40:03 GMT, "William M. Klein"
<wmklein@xxxxxxxxxxxxxxxxx> wrote:

and in all cases confirm that using the ROUNDED phrase is faster (no matter
how
much) than doing the arithmetic yourself.

Now, can you admit it, that was what the original recommendation said?

How much impact this could have on an application would depend upon how much
rounding (and in what constructs) there were, but the original recommendation
("myth") certainly seems confirmed.

Correct. I didn't say the test results busted a myth. I don't recall the
conversation that
prompted my running this test. People keep starting new threads for no good
reason,
thereby making it difficult to trace a thread backward.


.

Relevant Pages

  • Re: Rounding timings
    ... you DID claim to "but the myth" for ROUNDED. ... ON SIZE ERROR phrase is used. ... faster to use ROUNDED than try to round the result using your own routine. ...
    (comp.lang.cobol)
  • Re: Rounding timings
    ... you DID claim to "but the myth" for ROUNDED. ... ON SIZE ERROR phrase is used. ... faster to use ROUNDED than try to round the result using your own routine. ...
    (comp.lang.cobol)