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* [Bug c/47685] New: Tail call doesn't work for thumb2
@ 2011-02-10 18:30 alexandre.nunes at gmail dot com
2011-02-10 18:43 ` [Bug c/47685] " alexandre.nunes at gmail dot com
` (3 more replies)
0 siblings, 4 replies; 5+ messages in thread
From: alexandre.nunes at gmail dot com @ 2011-02-10 18:30 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47685
Summary: Tail call doesn't work for thumb2
Product: gcc
Version: 4.5.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
AssignedTo: unassigned@gcc.gnu.org
ReportedBy: alexandre.nunes@gmail.com
Created attachment 23298
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=23298
testcase.
When compiling the attached test program for i.e. -mcpu=cortex-a9 -marm the
tail call mechanism works correctly ... if you replace -marm for -mthumb then
the result is a traditional stack frame, for which i couldn't find any switches
to turn it off.
For example, this was taken from the example code for -mthumb:
func_c:
@ args = 0, pretend = 0, frame = 0
@ frame_needed = 0, uses_anonymous_args = 0
push {lr}
movs r3, #33
bl func_a
pop {pc}
.size func_c, .-func_c
And this for -marm:
func_c:
@ args = 0, pretend = 0, frame = 0
@ frame_needed = 0, uses_anonymous_args = 0
@ link register save eliminated.
mov r3, #33
b func_a
.size func_c, .-func_c
This is more relevant for example to -mcpu=cortex-m3 where we have no ram to
waste.
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c/47685] Tail call doesn't work for thumb2
2011-02-10 18:30 [Bug c/47685] New: Tail call doesn't work for thumb2 alexandre.nunes at gmail dot com
@ 2011-02-10 18:43 ` alexandre.nunes at gmail dot com
2011-02-27 23:34 ` [Bug target/47685] " ramana at gcc dot gnu.org
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: alexandre.nunes at gmail dot com @ 2011-02-10 18:43 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47685
--- Comment #1 from Alexandre Pereira Nunes <alexandre.nunes at gmail dot com> 2011-02-10 18:30:48 UTC ---
It also happens on 4.4.5
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug target/47685] Tail call doesn't work for thumb2
2011-02-10 18:30 [Bug c/47685] New: Tail call doesn't work for thumb2 alexandre.nunes at gmail dot com
2011-02-10 18:43 ` [Bug c/47685] " alexandre.nunes at gmail dot com
@ 2011-02-27 23:34 ` ramana at gcc dot gnu.org
2011-02-28 20:28 ` alexandre.nunes at gmail dot com
2011-02-28 20:30 ` alexandre.nunes at gmail dot com
3 siblings, 0 replies; 5+ messages in thread
From: ramana at gcc dot gnu.org @ 2011-02-27 23:34 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47685
Ramana Radhakrishnan <ramana at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
CC| |ramana at gcc dot gnu.org
Resolution| |WONTFIX
--- Comment #2 from Ramana Radhakrishnan <ramana at gcc dot gnu.org> 2011-02-27 23:27:11 UTC ---
This has been fixed on trunk and will be in the 4.6.0 release.
With this commit
http://gcc.gnu.org/ml/gcc-cvs/2010-05/msg00725.html
cheers
Ramana
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug target/47685] Tail call doesn't work for thumb2
2011-02-10 18:30 [Bug c/47685] New: Tail call doesn't work for thumb2 alexandre.nunes at gmail dot com
2011-02-10 18:43 ` [Bug c/47685] " alexandre.nunes at gmail dot com
2011-02-27 23:34 ` [Bug target/47685] " ramana at gcc dot gnu.org
@ 2011-02-28 20:28 ` alexandre.nunes at gmail dot com
2011-02-28 20:30 ` alexandre.nunes at gmail dot com
3 siblings, 0 replies; 5+ messages in thread
From: alexandre.nunes at gmail dot com @ 2011-02-28 20:28 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47685
--- Comment #3 from Alexandre Pereira Nunes <alexandre.nunes at gmail dot com> 2011-02-28 20:25:50 UTC ---
Created attachment 23496
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=23496
Patch from the trunk, which I'm testing against 4.5.x
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug target/47685] Tail call doesn't work for thumb2
2011-02-10 18:30 [Bug c/47685] New: Tail call doesn't work for thumb2 alexandre.nunes at gmail dot com
` (2 preceding siblings ...)
2011-02-28 20:28 ` alexandre.nunes at gmail dot com
@ 2011-02-28 20:30 ` alexandre.nunes at gmail dot com
3 siblings, 0 replies; 5+ messages in thread
From: alexandre.nunes at gmail dot com @ 2011-02-28 20:30 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47685
--- Comment #4 from Alexandre Pereira Nunes <alexandre.nunes at gmail dot com> 2011-02-28 20:27:00 UTC ---
(In reply to comment #2)
> This has been fixed on trunk and will be in the 4.6.0 release.
>
> With this commit
>
> http://gcc.gnu.org/ml/gcc-cvs/2010-05/msg00725.html
>
> cheers
> Ramana
Thanks,
These changes were non-intrusive, so I've applied them to my 4.5.2 toolchain
and it simply "works for me".
Cheers,
Alexandre
^ permalink raw reply [flat|nested] 5+ messages in thread
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2011-02-10 18:30 [Bug c/47685] New: Tail call doesn't work for thumb2 alexandre.nunes at gmail dot com
2011-02-10 18:43 ` [Bug c/47685] " alexandre.nunes at gmail dot com
2011-02-27 23:34 ` [Bug target/47685] " ramana at gcc dot gnu.org
2011-02-28 20:28 ` alexandre.nunes at gmail dot com
2011-02-28 20:30 ` alexandre.nunes at gmail dot com
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