On 06.02.2014 00:39, Jaromír Mikeš wrote: > > Hi all, > > I would like to add some optimization flags for amd64 arch in some > packages (mostly LV2 nad LADSPA plugins). > I found these as candidates for amd64 arch: > > -msse > -msse2 > -mfpmath=sse
this is enabled by default on amd64 > -ffast-math this is dangerous it changes results, sometimes significantly (e.g. for complex numbers), only use if you don't care about correctness or have verified its still correct. > -ftree-vectorize this does sometimes slow programs down, usually only programs doing numeric work profit from it, these usually enable it by themselves. It is enabled by the -O3 optimization level. it is mostly safe to use if you follow the C standard strictly (i.e. no unaligned access of aliased variables) > -mtune=generic should be the default, but you can safely change that to something else. generic in gcc < 4.9 is I think pentium4 which is a very old chip. gcc-4.9 will change the default of it to bulldozer/intel-core btw: http://gcc.gnu.org/gcc-4.9/changes.html -- To UNSUBSCRIBE, email to debian-devel-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/52f2cdaa.4090...@googlemail.com
