Originally Posted by melgross
Uh, not 30 years ago, it was a bit more recent than that. I've also done other work. But , yes, it's been almost 15 years since I've done anything professional in software development.
Still, you present thing as being easier than they often are. Redoing an app may be easy, on the basic level, but if its anywhere near being big, and complex, they are usually a lot of things that need fixing.
Complexity comes in many forms. A small simple program that uses NEON extensions will require effort. A large, complex program that only uses the SDK is insulated from the issues you describe.
Can there be issues? Yes.
Could they be serious? Yes.
Will that be common? Unlikely given I've already told you that devs compile iOS apps against x86 every day.
That performance differential is important, no matter what you say. And the differences in architecture between the chip lines will mean that not everything will be easily handled by your software, and will need to be done by hand.
Most apps are written in ObjC against Apple SDKs and are completely unaware of architecture differences between ARM and X86 because XCode does all the heavy lifting.
Again most apps run on X86 TODAY. A fact you steadfastly ignore in your presumed expertise.
Even if I never worked with software, I would know that not everything works as smoothly as you assert, in every instance. But then, you probably can't understand why x86 software from Windows worked so poorly using an emulator during the years when the PPC was the more powerful chip. And, yes, this isn't emulation. But there are major differences between the families that the above illustrates, and is why it's not always a straightforward process.
Except that 15 years ago I was responsible for porting C code from the Motorolla 88000 to sparc and part of that effort required writing a 1750A emulator to run on sparc.
So I am quite aware of the differences between emulation and porting.
The reason why window programs was slow on PPC was exactly because of emulation. Windows ported to the Alpha was very performant and my recollection is that it ran well natively on PPC but I personally never saw that. The apps (science data processing...complex but not in a software architecture way) ported to alpha was very fast and although I was never part the development of those apps I didn't hear much screaming and cursing from that team that had to support both x86 and alpha.
Not to mention that the PPC was not that much faster than the equivalent intel chip and not even faster in all respects.
If you just admitted that there are bumps in the road sometimes, this would have been over earlier.
If you didn't arrogantly proclaim that folks who state that something that actually happens every day (iOS apps running on x86) isn't a big problem as "not knowing what they are talking about" you wouldn't be made to look the fool.