* [Bug c++/28718] Call to -lgcc added prior to user libraries
2006-08-14 12:13 [Bug c++/28718] New: Call to -lgcc added prior to user libraries j at uriah dot heep dot sax dot de
@ 2006-08-14 13:18 ` pinskia at gcc dot gnu dot org
2006-08-14 14:13 ` j at uriah dot heep dot sax dot de
` (7 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2006-08-14 13:18 UTC (permalink / raw)
To: gcc-bugs
------- Comment #1 from pinskia at gcc dot gnu dot org 2006-08-14 13:18 -------
Wait the user did say to link against -lm anyways. This comes from the specs.
What kind of wrong math functions are being used anyways? If soft-fp, then you
are to think you can override them in libm.a because that is not the job of
libm.a.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28718
^ permalink raw reply [flat|nested] 10+ messages in thread* [Bug c++/28718] Call to -lgcc added prior to user libraries
2006-08-14 12:13 [Bug c++/28718] New: Call to -lgcc added prior to user libraries j at uriah dot heep dot sax dot de
2006-08-14 13:18 ` [Bug c++/28718] " pinskia at gcc dot gnu dot org
@ 2006-08-14 14:13 ` j at uriah dot heep dot sax dot de
2006-08-14 14:15 ` pinskia at gcc dot gnu dot org
` (6 subsequent siblings)
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From: j at uriah dot heep dot sax dot de @ 2006-08-14 14:13 UTC (permalink / raw)
To: gcc-bugs
------- Comment #2 from j at uriah dot heep dot sax dot de 2006-08-14 14:13 -------
I know that the current situation for the AVR is suboptimal, there really
are overrides in libm.a for functions that are already present in libgcc.a.
However, this is not so easy to change for a number of logistical reasons
(the functions in question are highly tied into the remaining FP library
framework, but they offer much more optimal code for the user).
However, the main question here is: shouldn't all user-supplied -lXXX options
*always* be processed before any internally added -lgcc options, and why is
the behaviour different when the user calls the compiler "avr-g++" rather
than "avr-gcc"?
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28718
^ permalink raw reply [flat|nested] 10+ messages in thread* [Bug c++/28718] Call to -lgcc added prior to user libraries
2006-08-14 12:13 [Bug c++/28718] New: Call to -lgcc added prior to user libraries j at uriah dot heep dot sax dot de
2006-08-14 13:18 ` [Bug c++/28718] " pinskia at gcc dot gnu dot org
2006-08-14 14:13 ` j at uriah dot heep dot sax dot de
@ 2006-08-14 14:15 ` pinskia at gcc dot gnu dot org
2006-08-14 14:28 ` j at uriah dot heep dot sax dot de
` (5 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2006-08-14 14:15 UTC (permalink / raw)
To: gcc-bugs
------- Comment #3 from pinskia at gcc dot gnu dot org 2006-08-14 14:15 -------
-lm was not an user supplied option as shown by your commands.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28718
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2006-08-14 12:13 [Bug c++/28718] New: Call to -lgcc added prior to user libraries j at uriah dot heep dot sax dot de
` (2 preceding siblings ...)
2006-08-14 14:15 ` pinskia at gcc dot gnu dot org
@ 2006-08-14 14:28 ` j at uriah dot heep dot sax dot de
2006-08-15 18:24 ` pinskia at gcc dot gnu dot org
` (4 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: j at uriah dot heep dot sax dot de @ 2006-08-14 14:28 UTC (permalink / raw)
To: gcc-bugs
------- Comment #4 from j at uriah dot heep dot sax dot de 2006-08-14 14:28 -------
(In reply to comment #3)
> -lm was not an user supplied option as shown by your commands.
>
Oh no, sorry for the confusion: it *is* a user-supplied library.
Sorry, I now see that I somehow copy&pasted the wrong sequence. :-(
OK, here's the essence again, now with the correct commands:
% avr-gcc -v foo.cc -lm
...
/tools/i686/lib/gcc/avr/4.1.0/../../../../avr/bin/ld [...] /tmp/cc6mvtc6.o -lm
-lgcc -lc -lgcc
% avr-g++ -v foo.cc -lm
...
/tools/i686/lib/gcc/avr/4.1.0/../../../../avr/bin/ld [...] /tmp/cck5jSBR.o
-lgcc -lm -lgcc -lc -lgcc
I hope that makes my question clearer now.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28718
^ permalink raw reply [flat|nested] 10+ messages in thread* [Bug c++/28718] Call to -lgcc added prior to user libraries
2006-08-14 12:13 [Bug c++/28718] New: Call to -lgcc added prior to user libraries j at uriah dot heep dot sax dot de
` (3 preceding siblings ...)
2006-08-14 14:28 ` j at uriah dot heep dot sax dot de
@ 2006-08-15 18:24 ` pinskia at gcc dot gnu dot org
2006-09-06 16:51 ` bjoern dot m dot haase at web dot de
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From: pinskia at gcc dot gnu dot org @ 2006-08-15 18:24 UTC (permalink / raw)
To: gcc-bugs
------- Comment #5 from pinskia at gcc dot gnu dot org 2006-08-15 18:24 -------
Also libm is not supposed to be overriding stuff in libgcc really, it is only
supposed to be including the C math functions.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28718
^ permalink raw reply [flat|nested] 10+ messages in thread* [Bug c++/28718] Call to -lgcc added prior to user libraries
2006-08-14 12:13 [Bug c++/28718] New: Call to -lgcc added prior to user libraries j at uriah dot heep dot sax dot de
` (4 preceding siblings ...)
2006-08-15 18:24 ` pinskia at gcc dot gnu dot org
@ 2006-09-06 16:51 ` bjoern dot m dot haase at web dot de
2006-09-12 8:06 ` pinskia at gcc dot gnu dot org
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From: bjoern dot m dot haase at web dot de @ 2006-09-06 16:51 UTC (permalink / raw)
To: gcc-bugs
------- Comment #6 from bjoern dot m dot haase at web dot de 2006-09-06 16:51 -------
To clear up the issues.
1.) libgcc provides a fp emulation based on compiled c functions that is to my
very best knowledge untested for avr and extremely inefficient.
2.) avr-libc provides fp emulation that is hand-tuned assembly and on a less
restrictive license than GPL. IIRC, the person who wrote them is no longer
active in the field.
3.) the functions supplied by avr-libc are as basic as "single float add 3",
"single float multiply 3", "single float convert to integer 2" ...
4.) the hand-tuned assembly routines should really replace the libgcc ones, but
that's not easily feasible. Partly due to licensing issues (modified free bsd
for avr-libc), partly because it is very very difficult for us developers to
get code integrated into mainline gcc.
5.) the externally supplied functions in libm need the hand-tuned assembly
versions in order to operate properly and will failed with the untested libgcc
variants.
5.) There is only one single libc and libm implementation available for avr
that cooperates with gcc: avr-libc.
The suggestion of Joerg Wunsch is, thus, in line with the needs of gcc users
for the avr target.
Bjoern.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28718
^ permalink raw reply [flat|nested] 10+ messages in thread* [Bug c++/28718] Call to -lgcc added prior to user libraries
2006-08-14 12:13 [Bug c++/28718] New: Call to -lgcc added prior to user libraries j at uriah dot heep dot sax dot de
` (5 preceding siblings ...)
2006-09-06 16:51 ` bjoern dot m dot haase at web dot de
@ 2006-09-12 8:06 ` pinskia at gcc dot gnu dot org
2006-09-12 8:52 ` j at uriah dot heep dot sax dot de
2009-08-19 15:32 ` [Bug driver/28718] " abnikant dot singh at atmel dot com
8 siblings, 0 replies; 10+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2006-09-12 8:06 UTC (permalink / raw)
To: gcc-bugs
------- Comment #7 from pinskia at gcc dot gnu dot org 2006-09-12 08:06 -------
(In reply to comment #6)
> The suggestion of Joerg Wunsch is, thus, in line with the needs of gcc users
> for the avr target.
But not in the line with the rest of GCC. Really if you cannot get a patch
applied to GCC, there is a maintainer problem with the avr target inside GCC.
And second GCC's soft-fp should be correct indepdent of the libc.
So this is not a bug. Also if libm is only the normal math library and should
not include the soft-fp but those should be in libgcc as they are support
functions needed for GCC to work even without a libc.
--
pinskia at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution| |INVALID
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28718
^ permalink raw reply [flat|nested] 10+ messages in thread* [Bug c++/28718] Call to -lgcc added prior to user libraries
2006-08-14 12:13 [Bug c++/28718] New: Call to -lgcc added prior to user libraries j at uriah dot heep dot sax dot de
` (6 preceding siblings ...)
2006-09-12 8:06 ` pinskia at gcc dot gnu dot org
@ 2006-09-12 8:52 ` j at uriah dot heep dot sax dot de
2009-08-19 15:32 ` [Bug driver/28718] " abnikant dot singh at atmel dot com
8 siblings, 0 replies; 10+ messages in thread
From: j at uriah dot heep dot sax dot de @ 2006-09-12 8:52 UTC (permalink / raw)
To: gcc-bugs
------- Comment #8 from j at uriah dot heep dot sax dot de 2006-09-12 08:52 -------
(In reply to comment #7)
> So this is not a bug. Also if libm is only the normal math library and should
> not include the soft-fp but those should be in libgcc as they are support
> functions needed for GCC to work even without a libc.
The bug is that libstdc++ (in our case: libgcc, as the AVR implementation
doesn't have a libstdc++) and libm are linked *before* any user-supplied
-l options in C++ mode. This doesn't happen in C mode. This also happens
for non-AVR targets, so it appears to be a generic bug to me.
This is violating the principle of least astonishment at least.
The AVR user can for sure live (by now) with the artefacts caused by there
not-really-GCC-standard libm.a implementation, as long as they've got
reasonable control about when the GCC-internal libraries are getting
linked in (so the user always gets a chance to override).
--
j at uriah dot heep dot sax dot de changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|RESOLVED |UNCONFIRMED
Resolution|INVALID |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28718
^ permalink raw reply [flat|nested] 10+ messages in thread* [Bug driver/28718] Call to -lgcc added prior to user libraries
2006-08-14 12:13 [Bug c++/28718] New: Call to -lgcc added prior to user libraries j at uriah dot heep dot sax dot de
` (7 preceding siblings ...)
2006-09-12 8:52 ` j at uriah dot heep dot sax dot de
@ 2009-08-19 15:32 ` abnikant dot singh at atmel dot com
8 siblings, 0 replies; 10+ messages in thread
From: abnikant dot singh at atmel dot com @ 2009-08-19 15:32 UTC (permalink / raw)
To: gcc-bugs
------- Comment #9 from abnikant dot singh at atmel dot com 2009-08-19 15:32 -------
This is because libstdc++ is not build in case of avr(8 bit),I did check it in
avr32 there I get flags in the sequence : -lstdc++ -lm -lgcc
--
abnikant dot singh at atmel dot com changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |abnikant dot singh at atmel
| |dot com
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28718
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