On Mon, Feb 3, 2014 at 10:56 AM, Reinhard Tartler <siret...@gmail.com> wrote: > On Mon, Feb 3, 2014 at 10:43 AM, Felipe Sateler <fsate...@debian.org> wrote:
>>> Please be careful with adding those flags. They instruct gcc to emit >>> code that does not work on some machines. The admitedlyonly way to use >>> them correctly is to ensure that the emitted code is only used on >>> machines that actually supports that. >> >> The mtune flag instructs the compiler to optimize for a certain >> instruction set, but still provide a fallback for when the instrucions >> are not available. I don't know if this includes the use of SSE or >> other coprocessor. >> >> http://stackoverflow.com/questions/10559275/gcc-how-is-march-different-from-mtune > > OK, then we will only see performance impact on machines not matching > the optimization target. Which seems OK to me, if the benefit for the > targeted architectures justify this. Sorry for the noise. Please note that Jaromir proposed to use the following flags: ifeq ($(DEB_HOST_ARCH_CPU),amd64) CFLAGS += -msse -msse2 -mfpmath=sse endif None of them fall in the "mtune" category, that is, none of them are "safe" to use without further precaution measures! -- regards, Reinhard _______________________________________________ pkg-multimedia-maintainers mailing list pkg-multimedia-maintainers@lists.alioth.debian.org http://lists.alioth.debian.org/cgi-bin/mailman/listinfo/pkg-multimedia-maintainers
