The reason other ISAs have failed to get traction is compatibility. They couldn't run any existing binaries, and everyone wanting to use it would have to develop and adopt new tools. But Apple don't care about interoperability and completely control the entire software tools and distribution stack from top to bottom. They don't have to ask anyone else to do anything at all that they aren't doing already. No previous ISA vendor has even been in that position. Not even IBM with their mainframes. Furthermore the architecture of LLVM decouples it from particular processor architectures in ways that previous compiler architectures didn't, greatly easing the migration process at a technical level.
But what's the benefit? Maybe a few percent speed/power efficiency boost? We've already seen that Apple will go to extraordinary lengths for a few percent improved performance, particularly when it comes to power efficiency. A few percent here, a few more there and soon you're talking an hour+ extra battery life.
I think this is highly plausible. There just doesn't seem to be any particular reason why they wouldn't do it, and plenty of reasons why they would.
> Furthermore the architecture of LLVM decouples it from particular processor architectures in ways that previous compiler architectures didn't, greatly easing the migration process at a technical level.
How is LLVM IR (which I am told is arch specific) different from GCC with RTL?
> No previous ISA vendor has even been in that position.
Remember the transition from VAX to Alpha? And they kept the binary and source compatibility in quite an inventive way (with both binary translation and by making MACRO32 just another high level language).
But what's the benefit? Maybe a few percent speed/power efficiency boost? We've already seen that Apple will go to extraordinary lengths for a few percent improved performance, particularly when it comes to power efficiency. A few percent here, a few more there and soon you're talking an hour+ extra battery life.
I think this is highly plausible. There just doesn't seem to be any particular reason why they wouldn't do it, and plenty of reasons why they would.