On Mar 31, 2016, at 8:34 AM, Lennart Sorensen <lsore...@csclub.uwaterloo.ca> wrote:
> On Thu, Mar 31, 2016 at 01:18:53AM -0700, Rick Thomas wrote: >> The altivec instructions and other optimizations speed-up significantly >> certain kinds of programs on CPUs that can use them. It would be a shame to >> loose the optimized versions by dropping back to the lowest common >> denominator CPU architecture. Would it be possible to create and support a >> sub-architecture that provided altivec optimized versions of packages? > > No idea, but certainly in the past i386 did not have sub architectures for > sse or mmx or anything else. There were some programs and libraries that > did have optimizations when they detected such support, and I believe > that is also true with powerpc already. libc does do cpu specific > optimizations at runtime for strcpy and such. > > Any examples of programs where altivec makes a measurable improvement? > > -- > Len Sorensen > The main beneficiaries of vector instruction extensions are users of scientific, cryptographic, and audio/visual libraries. Basically anything that wants to do simple, repetitive operations on long strings of data at memory speed. Rick
