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It's interesting what this tells us about Apple's approach to the Intel to Arm transition. They must have performed deep analysis of the requirements of Rosett
by klelatti 4y ago
It's interesting what this tells us about Apple's approach to the Intel to Arm transition.
They must have performed deep analysis of the requirements of Rosetta down to the level of individual instruction emulation before they finalised the design of the M1.
Also the Rosetta team had enough influence to get the hardware team to build it. Not necessarily a given in all organisations.
What would be interesting - and perhaps not surprising - is if Arm added this to the standard Arm ISA in order to facilitate x86 to Arm translation elsewhere. After all they added the infamous FJCVTZS instruction which speeds up x86 derived floating point conversions in JS.
- hedgehog 4y agoIt's useful to think of the transition as starting close to 15 years ago with Apple buying PA Semi and Intrinsity, shaping ARMv8, doing test ports of macOS, etc. Of course deep analysis too, but some pretty empirical evaluation of multiple generations of running prototypes to find the gaps that mattered (product and performance). They telegraphed the plan pretty plainly when they announced the A7 as "desktop class."
- klelatti 4y agoAbsolutely. I suspect that someone has had 'develop Rosetta 2' on their job description since c2011 at the latest.
- hedgehog 4y agoVery possible. I think of their approach as "experiment and remix," that is they test a lot of the technical and supply chain ingredients for new products years in advance, then combine at the last moment to create a widget for the public to buy. I've been watching the pieces of their VR/AR effort come together and my guess is they will do surprisingly large volume for how expensive the headsets will be. Collaboration, but done well.
- klelatti 4y agoThat's really interesting. Anything interesting on the processor / SoC side on their VR/AR work?
- hedgehog 4y agoNot that I've seen, though I expect it'll be like phones where they err on the side of more compute not less. If you look around on the software side there are pieces of a headset collaboration experience all over though, even beyond the obvious stuff in ARKit. Memojis, FaceTime spatial audio, AR Spaces in the Clips app, Freeform, App Clips, Metal variable rate shading, etc. It'll be interesting to see what actually ships.
- CharlesW 4y agoYou can even see Apple developing their XR marketing in public: https://www.apple.com/augmented-reality/ https://www.apple.com/augmented-reality/
- smoldesu 4y ago> my guess is they will do surprisingly large volume for how expensive the headsets will be. Bloomberg estimates that Apple intends to ship less than a half-million headsets it's debut year. By comparison, the Meta Quest 2 sold 10 million units in it's first year at sale.
- chipotle_coyote 4y agoBloomberg also estimates that Apple's headset is going to cost $2000 or more, as opposed to the Quest 2 which debuted at $299. Your definition may vary, but I'd consider moving a half-million headsets at that price to be surprisingly large volume. (Also, surely anything at that price point is going to be positioned against the Quest Pro, right?)
- smoldesu 4y ago
- bcrl 4y agoIt started even further back almost 34 years ago. The first PowerPC Macs shipped with Motorola 68000 emulation in 1994, but development was being investigated back in 1988 or so. Apple has successfully made this kind of transition before, and it's entirely possible they will do so again in the future!
- MikeRichardson 4y agoThe first version of 68K emulation they shipped was not great. At least one third party (Connectix) sold a faster version that replaced the OS provided routines with their own.
- acdha 4y agoI think that highlights the different incentives for an OS vendor and a third-party: Apple needed to be compatible but they didn’t want to be in that business long-term and focused more on getting developers to port their apps. Connectix arrived a year later and they had to deliver speed since nobody would buy it unless they did.
- hedgehog 4y agoIn defense of the original emulation strategy it shipped on time, fit in the ROM, and worked reliably with good compatibility. The first round of PowerPC Macs were so much faster than the 68k Macs than even emulated apps worked better. I don't remember the history any more but Apple did eventually do a new emulator, while Connectix made some other emulation products (PlayStation, PC) and eventually sold to Microsoft. I've read that Connectix people helped seed Microsoft's virtualization efforts.
- vbezhenar 4y agoWhy is it important to keep some particular quirk of floating point conversion in JS? JS breaks stuff all the time. Nobody would notice if some floating point conversion will change its lowest bit.
- nfriedly 4y ago> JS breaks stuff all the time. JS libraries break all the time. APIs and experimental language features break sometimes. But the low-level core fundamentals of the language, such as the way math works, have never changed in it's entire existence. Even the fairly minor changes in strict mode require explicitly opting-in.
- MikeRichardson 4y agoThis adds to my ongoing theory that "Notarization" (the process where you have to send your binaries to Apple) really has nothing to do with security. Instead, they really just wanted a deeper selection of binaries to analyze for other various reasons.
- rockdoe 4y agoPreviously people pointed out that a lot of the extra M1 stuff (like TSO, x87 FP) is already standardized and/or has shipped in other ARM chips.
- stephencanon 4y agox87 FP hasn’t been standardized or added to any ARM cpu. What was added is a mode where underflow is detected “after rounding” (as x86 SSE/AVX instructions use) rather than “before rounding” (what all ARM FP instructions default to).