* [Bug bootstrap/34592] useless computation found
2007-12-26 13:46 [Bug bootstrap/34592] New: useless computation found dcb314 at hotmail dot com
@ 2007-12-26 14:01 ` pinskia at gcc dot gnu dot org
2008-01-03 22:02 ` [Bug other/34592] " dcb314 at hotmail dot com
` (5 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2007-12-26 14:01 UTC (permalink / raw)
To: gcc-bugs
------- Comment #1 from pinskia at gcc dot gnu dot org 2007-12-26 14:01 -------
I always hated this warning from the EDG front-end, it sometimes produces a
false warning.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34592
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug other/34592] useless computation found
2007-12-26 13:46 [Bug bootstrap/34592] New: useless computation found dcb314 at hotmail dot com
2007-12-26 14:01 ` [Bug bootstrap/34592] " pinskia at gcc dot gnu dot org
@ 2008-01-03 22:02 ` dcb314 at hotmail dot com
2008-01-03 22:23 ` dcb314 at hotmail dot com
` (4 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: dcb314 at hotmail dot com @ 2008-01-03 22:02 UTC (permalink / raw)
To: gcc-bugs
------- Comment #2 from dcb314 at hotmail dot com 2008-01-03 21:51 -------
Created an attachment (id=14871)
--> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=14871&action=view)
patch for gcc 4.3 20071228
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34592
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug other/34592] useless computation found
2007-12-26 13:46 [Bug bootstrap/34592] New: useless computation found dcb314 at hotmail dot com
2007-12-26 14:01 ` [Bug bootstrap/34592] " pinskia at gcc dot gnu dot org
2008-01-03 22:02 ` [Bug other/34592] " dcb314 at hotmail dot com
@ 2008-01-03 22:23 ` dcb314 at hotmail dot com
2008-01-04 9:33 ` aldot at gcc dot gnu dot org
` (3 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: dcb314 at hotmail dot com @ 2008-01-03 22:23 UTC (permalink / raw)
To: gcc-bugs
------- Comment #3 from dcb314 at hotmail dot com 2008-01-03 21:52 -------
(In reply to comment #1)
> I always hated this warning from the EDG front-end, it sometimes produces a
> false warning.
Feel free to send a bug report to EDG.
Like I said, I checked each one and I agree with Intel C 10.1
I also counted about 300 similar cases where Intel
produced warning #593. I think there is quite a bit
of pointless computation going on.
I attach a patch again 4.3 snapshot 20071228.
Hint: Perhaps if this patch gets into 4.3 it would encourage
me to look at the other 300 cases ?
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34592
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug other/34592] useless computation found
2007-12-26 13:46 [Bug bootstrap/34592] New: useless computation found dcb314 at hotmail dot com
` (2 preceding siblings ...)
2008-01-03 22:23 ` dcb314 at hotmail dot com
@ 2008-01-04 9:33 ` aldot at gcc dot gnu dot org
2008-01-04 19:10 ` dcb314 at hotmail dot com
` (2 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: aldot at gcc dot gnu dot org @ 2008-01-04 9:33 UTC (permalink / raw)
To: gcc-bugs
------- Comment #4 from aldot at gcc dot gnu dot org 2008-01-04 09:15 -------
I'd say that this is blocked by PR18624 (resp. PR30438 for fortran).
dcb, you seem to report these as separate PRs. Previous of this category
include:
PR25547
PR25567
PR26245
PR32948
--
aldot at gcc dot gnu dot org changed:
What |Removed |Added
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CC| |aldot at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34592
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug other/34592] useless computation found
2007-12-26 13:46 [Bug bootstrap/34592] New: useless computation found dcb314 at hotmail dot com
` (3 preceding siblings ...)
2008-01-04 9:33 ` aldot at gcc dot gnu dot org
@ 2008-01-04 19:10 ` dcb314 at hotmail dot com
2008-01-08 17:56 ` manu at gcc dot gnu dot org
2010-05-06 10:59 ` manu at gcc dot gnu dot org
6 siblings, 0 replies; 8+ messages in thread
From: dcb314 at hotmail dot com @ 2008-01-04 19:10 UTC (permalink / raw)
To: gcc-bugs
------- Comment #5 from dcb314 at hotmail dot com 2008-01-04 18:33 -------
(In reply to comment #4)
> I'd say that this is blocked by PR18624 (resp. PR30438 for fortran).
> dcb, you seem to report these as separate PRs. Previous of this category
> include:
> PR25547
> PR25567
> PR26245
> PR32948
I agree I have been reporting this bug for a couple of years.
I have even supplied patches. They have not been applied.
Cleaning up the compiler source code is one thing,
implementing a warning for the users is another.
I don't think putting them together helps.
Mind you, any progress on this issue would be welcome.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34592
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug other/34592] useless computation found
2007-12-26 13:46 [Bug bootstrap/34592] New: useless computation found dcb314 at hotmail dot com
` (4 preceding siblings ...)
2008-01-04 19:10 ` dcb314 at hotmail dot com
@ 2008-01-08 17:56 ` manu at gcc dot gnu dot org
2010-05-06 10:59 ` manu at gcc dot gnu dot org
6 siblings, 0 replies; 8+ messages in thread
From: manu at gcc dot gnu dot org @ 2008-01-08 17:56 UTC (permalink / raw)
To: gcc-bugs
------- Comment #6 from manu at gcc dot gnu dot org 2008-01-08 17:26 -------
(In reply to comment #3)
>
> I also counted about 300 similar cases where Intel
> produced warning #593. I think there is quite a bit
> of pointless computation going on.
>
Thanks. I think optimisers should remove all of them so they should not have
any effect. Nonetheless, if they are not really used, they should be removed
from the code.
> I attach a patch again 4.3 snapshot 20071228.
Unfortunately, GCC 4.3 is open only for regression and documentation fixes.
Your patch would need to wait for GCC 4.4. Yet, you can submit it right now and
there are chances that someone will review. To avoid conflicts between
maintainer of different parts of the compiler, I would suggest one different
submission per component (or if you cannot distinguish the components, one
submission per file).
> Hint: Perhaps if this patch gets into 4.3 it would encourage
> me to look at the other 300 cases ?
Patches must be bootstrapped+regression tested and sent to gcc-patches. Check
http://gcc.gnu.org/contribute.html for further instructions. If you need help
with a particular step, write me an email. Examples of submissions can be found
in the archives of gcc-patches.
--
manu at gcc dot gnu dot org changed:
What |Removed |Added
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CC| |manu at gcc dot gnu dot org
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^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug other/34592] useless computation found
2007-12-26 13:46 [Bug bootstrap/34592] New: useless computation found dcb314 at hotmail dot com
` (5 preceding siblings ...)
2008-01-08 17:56 ` manu at gcc dot gnu dot org
@ 2010-05-06 10:59 ` manu at gcc dot gnu dot org
6 siblings, 0 replies; 8+ messages in thread
From: manu at gcc dot gnu dot org @ 2010-05-06 10:59 UTC (permalink / raw)
To: gcc-bugs
------- Comment #7 from manu at gcc dot gnu dot org 2010-05-06 10:59 -------
Thanks for the report. I think all these have been fixed already in GCC 4.6 and
regressions would be detected by the new -Wunused-but-set flags.
--
manu at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution| |FIXED
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34592
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