Platform Development • Re: Building fails on current master branch

Well, it's worth bearing in mind that there was a fairly long period where we had mostly 32-bit binaries running on 64-bit CPUs. A lot of applications for the longest time only provided 32-bit x86 versions of themselves even if they were expected to run on 64-bit machines. So in some cases, supporting newer CPU instructions while still compiling a 32-bit binary would have possibly made sense for people targeting a newer CPU who hadn't bothered to write an application in such a way that it could be compiled as 64-bit to start with, maybe too dependent on 32-bit assumptions, but still wanted to take advantage of AVX.

Not saying this was a super common edge case, but I do recall there were a lot of applications that took forever to start providing a 64-bit version, or which would still push the 32-bit version as default because of various incompatibilities introduced by 64-bit, and that this was going on (less and less admittedly) until probably at least 2014 or so. AVX would likely be among the last new instruction sets to be introduced while people were still in the weird "32-bit binaries, 64-bit CPU" transitional mindset. I seem to recall vaguely that weird period persisted a lot longer on older 64-bit architectures where RAM was at a premium, like on Solaris SPARC for instance. Linux is the odd one out here, it generally expected most of the binaries to be 64-bit if you were running 64-bit Linux, or 32-bit if you were running 32-bit Linux. There were 32-bit compatibility libraries for third-party binaries for a while, but they were not recommended and distros tended to avoid using that in their repos where possible.

I remember this precisely because I didn't want to buy a 64-bit CPU that would "go to waste" if all the applications were still 32-bit for a long time. If I didn't have enough RAM to make use of additional address space or 64-bit applications, it seemed a bit pointless until the late 2000s when I started seeing enough 64-bit applications to not feel like a 64-bit machine was a waste.