Return-Path: Message-ID: <1327320346.32646.71.camel@novo.hadess.net> Subject: Re: 4.98 fails to build with newer gcc From: Bastien Nocera To: Johan Hedberg Cc: Siarhei Siamashka , linux-bluetooth@vger.kernel.org Date: Mon, 23 Jan 2012 12:05:46 +0000 In-Reply-To: <20120123115456.GA19251@x220> References: <1326460244.2112.48.camel@novo.hadess.net> <20120123115456.GA19251@x220> Content-Type: text/plain; charset="ISO-8859-1" Mime-Version: 1.0 Sender: linux-bluetooth-owner@vger.kernel.org List-ID: 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 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 :)