Hi, On 12/11/2017 00:03, Gabriel Paubert wrote:
I hope that you don't parse /proc/cpuinfo to know the capabilities of your CPU. There is a better way to do this, namely use getauxval(3).
jpeg-turbo was doing exactly that and getauxval() was refused, read the bug discussion.
Speaking of Altivec, there is another library that claims to be compiled for Altivec but is actually compiled for VSX: libx265, which means that I get crashes with "illegal instruction" on my G5. I had a look at the source code, and it's really confusing, many functions have Altivec in the name, but it's actually using vsx instructions. A disassembly of the code reveals it: just grep for "vs[0-9]" patterns.
I don't have a G4 or G5 to test altivec with a free Unix, my PPC development is currently done only on my G3 iBook with Linux and Mac with a G3 (iBook) and G4 (PowerBook).
What uses libx265?Firefox is almost unusable on my iBook: scarce ram and also almost not present video acceleration (old ATI Mach64 is very slow with current X11) limit it do a couple of easier programs and as a test machine more than daily use.
Riccardo