El Dijous, 10 de setembre de 2015, a les 12:35:55, Simon McVittie va escriure: > On 10/09/15 12:25, Leopold Palomo-Avellaneda wrote: > > That bug made a reference about that, in lower hardware (32 bits) ode is > > too slow. > > That's not how it works. On a few less-powerful CPUs (in particular > older generations of 32-bit ARM, or other platforms lacking hardware > floating-point units), float is significantly faster than double. On > mainstream CPUs with a FPU (such as i386), there's little difference. > > That means > > that with 32 bit platforms, if we use floats (4 bytes = 32 bits), every > > operation is done with one cpu step (?), but if we uses doubles (8 bytes = > > 64 bits), every operation needs two, so it becomes slooow. > > i386 can do double-precision floating-point operations perfectly well. > The fact that it only has a 32-bit address space is not relevant. Well, reviewing my old studies and investigating a bit further about this topic I must admit that Steve are right. On moderns 32 bits CPU platforms, with FPU, this kind on double calculations are done by the math coprocessor and, in general it has 64 bits register to operate. However, after, I think that some kind of penalty must be occurs. > > > I think that we can have the same package in debian, but with the > > platforms > > with 32 bits using single precision and with 64 double. With this solution > > I think that all the needs would be covered. It's more simple to maintain > > and we don't have duplication of packages. > > You could consider using float on armel and maybe mips(el), and double > on everything else... but it's certainly unnecessary to restrict > yourself to single-precision floating point on i386 or armhf, for > instance. Those architectures are 32-bit but are guaranteed[1] to have > hardware floating-point. To me it's ok then. If nobody has any mention about the contrary I follow the Steve advice and put armel and mips(el) as single precision and the others double. All the changes are done in git. Now the packages has a copyright file updated. Lintian is error clean and it shows minors warnings. Please, someone could review it and upload if it's ok? Best regards, Leopold -- -- Linux User 152692 GPG: 05F4A7A949A2D9AA Catalonia ------------------------------------- A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?
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