[Arech]

In most cases (and this was the case of Mozilla I referred to) it's only a matter of compiling code that already have all support necessary. They are using some upstream component that works perfectly fine on my architecture. They just decided to drop it, because they could.

[sparkie]

It's not only your own software, but also its dependencies. The link above is for glibc, and is specifically addressing incompatibliy issues between different software. Unless you are going to compile your own glibc (for example, doing Linux From Scratch), you're going to depend on features shipped by someone else. In this case that means either baseline, with no SIMD support at all, or level A, which includes SSE4.1. It makes no sense for developers to keep maintaining software for 20 year old CPUs when they can't test it.

[johnklos]

> It makes no sense for developers to keep maintaining software for 20 year old CPUs when they can't test it.

This is horribly inaccurate. You can compile software for 20 year old CPUs and run that software on a modern CPU. You can run that software inside of qemu.

FYI, there are plenty of methods of selecting code at run time, too.

If we take what you're saying at face value, then we should give up on portable software, because nobody can possibly test code on all those non-x86 and/or non-modern processors. A bit ridiculous, don't you think?

[yjftsjthsd-h]

> Unless you are going to compile your own glibc (for example, doing Linux From Scratch),

It's not that hard to use gentoo.