ARM or x86? ISA Doesn’t Matter

Re:ARM or x86? ISA Doesn’t Matter by MBCook on Sunday May 14, 2023 @11:33PM (#35943614)

Yes I did, thanks. It’s also kind of reminiscent of the Transmeta Crusoe.

The problem I think multi-ISA would run into is the “master of none” issue. Intel can tune for how x86-64 works, Apple and Samsung for ARM.

But if one chip runs it all, it can’t tune for anything too specific.

It must not be worth it. I wonder if Apple would have done something like that for the M series to let it keep running Intel software. They must have tried to figure out if it was worth it right? I know they added a few instructions or an addressing mode or something to help. But they must have determined it wasn’t worth it and it could be done well enough in software.

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Re:ARM or x86? ISA Doesn’t Matter by audunw on Monday May 15, 2023 @08:08AM (#35946913)

Exactly, they added an flag to enable total store ordering to help x86 instructions map cleanly to ARM instruction.

https://twitter.com/ErrataRob/status/1331735383193903104

Considering how fast Apple M series can emulate x86 it's clearly not worth adding much more hardware than what they have now.

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