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* [Bug fortran/104483] New: Multiplication of huge and small numbers
@ 2022-02-10 9:37 shaydin at ktu dot edu.tr
2022-02-10 9:43 ` [Bug fortran/104483] " pinskia at gcc dot gnu.org
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: shaydin at ktu dot edu.tr @ 2022-02-10 9:37 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104483
Bug ID: 104483
Summary: Multiplication of huge and small numbers
Product: gcc
Version: 11.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: shaydin at ktu dot edu.tr
Target Milestone: ---
Created attachment 52402
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52402&action=edit
Simple Fortran Code
As in the attached file, I am testing the multiplication of very large and
small decimal placed numbers for different real kinds. But the results are
different and the most strange point is the decimal part is lost for the quad
(real*16) version. I want to learn what is the problem and where is my mistake.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug fortran/104483] Multiplication of huge and small numbers
2022-02-10 9:37 [Bug fortran/104483] New: Multiplication of huge and small numbers shaydin at ktu dot edu.tr
@ 2022-02-10 9:43 ` pinskia at gcc dot gnu.org
2022-02-10 10:04 ` shaydin at ktu dot edu.tr
2022-02-10 10:11 ` rguenth at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: pinskia at gcc dot gnu.org @ 2022-02-10 9:43 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104483
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Resolution|--- |INVALID
Status|UNCONFIRMED |RESOLVED
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
https://docs.oracle.com/cd/E19957-01/806-3568/ncg_goldberg.html
Basically floating point has a fixed precision so multiplying will cause
truncation due to that.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug fortran/104483] Multiplication of huge and small numbers
2022-02-10 9:37 [Bug fortran/104483] New: Multiplication of huge and small numbers shaydin at ktu dot edu.tr
2022-02-10 9:43 ` [Bug fortran/104483] " pinskia at gcc dot gnu.org
@ 2022-02-10 10:04 ` shaydin at ktu dot edu.tr
2022-02-10 10:11 ` rguenth at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: shaydin at ktu dot edu.tr @ 2022-02-10 10:04 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104483
--- Comment #2 from Prof.Dr. Selçuk Han AYDIN <shaydin at ktu dot edu.tr> ---
In this case, non of the precision gives correct answer when compared with
wxMaxima, Maple, Mathematica or some other wide range precision calculator. Is
there any solution for the fortran side.
Best regards
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug fortran/104483] Multiplication of huge and small numbers
2022-02-10 9:37 [Bug fortran/104483] New: Multiplication of huge and small numbers shaydin at ktu dot edu.tr
2022-02-10 9:43 ` [Bug fortran/104483] " pinskia at gcc dot gnu.org
2022-02-10 10:04 ` shaydin at ktu dot edu.tr
@ 2022-02-10 10:11 ` rguenth at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: rguenth at gcc dot gnu.org @ 2022-02-10 10:11 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104483
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Prof.Dr. Selçuk Han AYDIN from comment #2)
> In this case, non of the precision gives correct answer when compared with
> wxMaxima, Maple, Mathematica or some other wide range precision calculator.
> Is there any solution for the fortran side.
No.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2022-02-10 10:11 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2022-02-10 9:37 [Bug fortran/104483] New: Multiplication of huge and small numbers shaydin at ktu dot edu.tr
2022-02-10 9:43 ` [Bug fortran/104483] " pinskia at gcc dot gnu.org
2022-02-10 10:04 ` shaydin at ktu dot edu.tr
2022-02-10 10:11 ` rguenth at gcc dot gnu.org
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