2012-01-13 13:10:44

by Bastien Nocera

[permalink] [raw]
Subject: 4.98 fails to build with newer gcc

A few warnings:

sbc/sbc.c:766:34: warning: always_inline function might not be inlinable [-Wattributes]
sbc/sbc.c:558:34: warning: always_inline function might not be inlinable [-Wattributes]
sbc/sbc.c:163:31: warning: always_inline function might not be inlinable [-Wattributes]

and an error

sbc/sbc_primitives_mmx.c: In function 'sbc_calc_scalefactors_mmx':
sbc/sbc_primitives_mmx.c:294:4: warning: asm operand 2 probably doesn't match constraints [enabled by default]
sbc/sbc_primitives_mmx.c:294:4: error: impossible constraint in 'asm'

Full build log:
http://koji.fedoraproject.org/koji/getfile?taskID=3657376&name=build.log
Using gcc 4.7.0 as mentioned in root log:
http://koji.fedoraproject.org/koji/getfile?taskID=3657376&name=root.log

The same build works correctly with gcc 4.6.1 on Fedora 16.

Any ideas?



2012-01-23 12:05:46

by Bastien Nocera

[permalink] [raw]
Subject: Re: 4.98 fails to build with newer gcc

On Mon, 2012-01-23 at 13:54 +0200, Johan Hedberg wrote:
> Hi,
>
> On Fri, Jan 13, 2012, Siarhei Siamashka wrote:
> > On Fri, Jan 13, 2012 at 3:10 PM, Bastien Nocera <[email protected]> wrote:
> > > A few warnings:
> > >
> > > sbc/sbc.c:766:34: warning: always_inline function might not be inlinable [-Wattributes]
> > > sbc/sbc.c:558:34: warning: always_inline function might not be inlinable [-Wattributes]
> > > sbc/sbc.c:163:31: warning: always_inline function might not be inlinable [-Wattributes]
> >
> > Looks like the new version of gcc requires both "inline" and
> > "__attribute__((always_inline))" to be used in SBC_ALWAYS_INLINE
> > according to [1].
> >
> > > and an error
> > >
> > > sbc/sbc_primitives_mmx.c: In function 'sbc_calc_scalefactors_mmx':
> > > sbc/sbc_primitives_mmx.c:294:4: warning: asm operand 2 probably doesn't match constraints [enabled by default]
> > > sbc/sbc_primitives_mmx.c:294:4: error: impossible constraint in 'asm'
> >
> > Here gcc 4.7 thinks that
> > "i" ((char *) &sb_sample_f[1][0][0] -
> > (char *) &sb_sample_f[0][0][0]),
> > is an impossible constraint. According to [2], "i" means "An immediate
> > integer operand (one with constant value) is allowed. This includes
> > symbolic constants whose values will be known only at assembly time or
> > later".
> > Earlier versions of gcc could see that this expression is a compile
> > time constant, but gcc 4.7 can't. As a workaround, "i" can be changed
> > to "r" here. The downside is that this needs one more register for
> > inline assembly and the number of available registers is really
> > limited for 32-bit x86 systems. As a test, it is possible to try "gcc
> > -O2 -mmmx -c -m32 -fno-omit-frame-pointer -fPIC sbc_primitives_mmx.c".
> > Both "-fno-omit-frame-pointer" and "-fPIC" options reduce the number
> > of available registers.
>
> So is someone going to send a patch for this? I think we should try to
> have it fixed before doing the next BlueZ release.

I won't be. I'm expecting upstream to come up with one :)


2012-01-23 11:54:56

by Johan Hedberg

[permalink] [raw]
Subject: Re: 4.98 fails to build with newer gcc

Hi,

On Fri, Jan 13, 2012, Siarhei Siamashka wrote:
> On Fri, Jan 13, 2012 at 3:10 PM, Bastien Nocera <[email protected]> wrote:
> > A few warnings:
> >
> > sbc/sbc.c:766:34: warning: always_inline function might not be inlinable [-Wattributes]
> > sbc/sbc.c:558:34: warning: always_inline function might not be inlinable [-Wattributes]
> > sbc/sbc.c:163:31: warning: always_inline function might not be inlinable [-Wattributes]
>
> Looks like the new version of gcc requires both "inline" and
> "__attribute__((always_inline))" to be used in SBC_ALWAYS_INLINE
> according to [1].
>
> > and an error
> >
> > sbc/sbc_primitives_mmx.c: In function 'sbc_calc_scalefactors_mmx':
> > sbc/sbc_primitives_mmx.c:294:4: warning: asm operand 2 probably doesn't match constraints [enabled by default]
> > sbc/sbc_primitives_mmx.c:294:4: error: impossible constraint in 'asm'
>
> Here gcc 4.7 thinks that
> "i" ((char *) &sb_sample_f[1][0][0] -
> (char *) &sb_sample_f[0][0][0]),
> is an impossible constraint. According to [2], "i" means "An immediate
> integer operand (one with constant value) is allowed. This includes
> symbolic constants whose values will be known only at assembly time or
> later".
> Earlier versions of gcc could see that this expression is a compile
> time constant, but gcc 4.7 can't. As a workaround, "i" can be changed
> to "r" here. The downside is that this needs one more register for
> inline assembly and the number of available registers is really
> limited for 32-bit x86 systems. As a test, it is possible to try "gcc
> -O2 -mmmx -c -m32 -fno-omit-frame-pointer -fPIC sbc_primitives_mmx.c".
> Both "-fno-omit-frame-pointer" and "-fPIC" options reduce the number
> of available registers.

So is someone going to send a patch for this? I think we should try to
have it fixed before doing the next BlueZ release.

Johan

2012-01-13 16:26:57

by Siarhei Siamashka

[permalink] [raw]
Subject: Re: 4.98 fails to build with newer gcc

On Fri, Jan 13, 2012 at 3:10 PM, Bastien Nocera <[email protected]> wrote:
> A few warnings:
>
> sbc/sbc.c:766:34: warning: always_inline function might not be inlinable [-Wattributes]
> sbc/sbc.c:558:34: warning: always_inline function might not be inlinable [-Wattributes]
> sbc/sbc.c:163:31: warning: always_inline function might not be inlinable [-Wattributes]

Looks like the new version of gcc requires both "inline" and
"__attribute__((always_inline))" to be used in SBC_ALWAYS_INLINE
according to [1].

> and an error
>
> sbc/sbc_primitives_mmx.c: In function 'sbc_calc_scalefactors_mmx':
> sbc/sbc_primitives_mmx.c:294:4: warning: asm operand 2 probably doesn't match constraints [enabled by default]
> sbc/sbc_primitives_mmx.c:294:4: error: impossible constraint in 'asm'

Here gcc 4.7 thinks that
"i" ((char *) &sb_sample_f[1][0][0] -
(char *) &sb_sample_f[0][0][0]),
is an impossible constraint. According to [2], "i" means "An immediate
integer operand (one with constant value) is allowed. This includes
symbolic constants whose values will be known only at assembly time or
later".
Earlier versions of gcc could see that this expression is a compile
time constant, but gcc 4.7 can't. As a workaround, "i" can be changed
to "r" here. The downside is that this needs one more register for
inline assembly and the number of available registers is really
limited for 32-bit x86 systems. As a test, it is possible to try "gcc
-O2 -mmmx -c -m32 -fno-omit-frame-pointer -fPIC sbc_primitives_mmx.c".
Both "-fno-omit-frame-pointer" and "-fPIC" options reduce the number
of available registers.

> Full build log:
> http://koji.fedoraproject.org/koji/getfile?taskID=3657376&name=build.log
> Using gcc 4.7.0 as mentioned in root log:
> http://koji.fedoraproject.org/koji/getfile?taskID=3657376&name=root.log
>
> The same build works correctly with gcc 4.6.1 on Fedora 16.
>
> Any ideas?
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in
> the body of a message to [email protected]
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

1. http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49139#c1
2. http://gcc.gnu.org/onlinedocs/gcc-4.6.2/gcc/Simple-Constraints.html#Simple-Constraints

--
Best regards,
Siarhei Siamashka

2012-02-24 12:16:15

by Siarhei Siamashka

[permalink] [raw]
Subject: Re: 4.98 fails to build with newer gcc

On Mon, Jan 23, 2012 at 1:54 PM, Johan Hedberg <[email protected]> wrote:
> Hi,
>
> On Fri, Jan 13, 2012, Siarhei Siamashka wrote:
>> On Fri, Jan 13, 2012 at 3:10 PM, Bastien Nocera <[email protected]> wrote:
>> > A few warnings:
>> >
>> > sbc/sbc.c:766:34: warning: always_inline function might not be inlinable [-Wattributes]
>> > sbc/sbc.c:558:34: warning: always_inline function might not be inlinable [-Wattributes]
>> > sbc/sbc.c:163:31: warning: always_inline function might not be inlinable [-Wattributes]
>>
>> Looks like the new version of gcc requires both "inline" and
>> "__attribute__((always_inline))" to be used in SBC_ALWAYS_INLINE
>> according to [1].
>>
>> > and an error
>> >
>> > sbc/sbc_primitives_mmx.c: In function 'sbc_calc_scalefactors_mmx':
>> > sbc/sbc_primitives_mmx.c:294:4: warning: asm operand 2 probably doesn't match constraints [enabled by default]
>> > sbc/sbc_primitives_mmx.c:294:4: error: impossible constraint in 'asm'
>>
>> Here gcc 4.7 thinks that
>>                               "i" ((char *) &sb_sample_f[1][0][0] -
>>                                       (char *) &sb_sample_f[0][0][0]),
>> is an impossible constraint. According to [2], "i" means "An immediate
>> integer operand (one with constant value) is allowed. This includes
>> symbolic constants whose values will be known only at assembly time or
>> later".
>> Earlier versions of gcc could see that this expression is a compile
>> time constant, but gcc 4.7 can't. As a workaround, "i" can be changed
>> to "r" here. The downside is that this needs one more register for
>> inline assembly and the number of available registers is really
>> limited for 32-bit x86 systems. As a test, it is possible to try "gcc
>> -O2 -mmmx -c -m32 -fno-omit-frame-pointer -fPIC sbc_primitives_mmx.c".
>> Both "-fno-omit-frame-pointer" and "-fPIC" options reduce the number
>> of available registers.
>
> So is someone going to send a patch for this? I think we should try to
> have it fixed before doing the next BlueZ release.

Sorry for the slow follow up.

I reported the build error problem to gcc bugzilla (where it actually
belongs), and now this should be fixed in gcc 4.7:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52355

A simple patch for the inlining warning fix is sent as a separate e-mail.

--
Best regards,
Siarhei Siamashka