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 [off-list ref] wrote:

quoted

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].

quoted

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