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Too bad Arm doesn't allow architectural licenses, because this is exactly the kind of thing Valve and the FEX developers would want to extend the ISA to support
by sitkack 11mo ago
Too bad Arm doesn't allow architectural licenses, because this is exactly the kind of thing Valve and the FEX developers would want to extend the ISA to support. I bet we see a RISC-V backend to FEX in the next 6 months, it probably already exists in a private repo.
FEX is the shootstring, extra special discount budget (not maligning) version of Rosetta. Apple should sell Rosetta to Valve.
- JoshTriplett 11mo ago> Too bad Arm doesn't allow architectural licenses QEMU exists. I doubt they want the bad press of suing an Open Source project everyone is using.
- happymellon 11mo agoARM were perfectly fine getting the bad press for suing Qualcomm for releasing the Snapdragon that was finally performing enough despite these companies paying them a lot of money. They seemed quite happy to destroy their eco system if they won. https://www.rcrwireless.com/20251001/business/qualcomm-arm-2 https://www.rcrwireless.com/20251001/business/qualcomm-arm-2
- anthk 11mo agoAnd GBA emulators. And before that, BBC Accorn ones with Risc OS.
- geerlingguy 11mo agoBox64 already runs on RISC-V. Just, the available processors are so slow it's hard to even play 5-10 year old games.
- snvzz 11mo agoThis means that, when the much faster chips implementing RVA23 arrive next year, they'll be immediately able to run Box64.
- jsheard 11mo agoMy understanding is that Rosetta sidesteps a bunch of tricky memory model issues by using non-standard hardware extensions only present in Apple Silicon, so even if Apple did share Rosetta, which they certainly won't, it wouldn't work properly on Valves hardware anyway.
- fooblaster 11mo agoyeah that is correct. The m series chips can turn on total store ordering memory model solely for Rosetta. There's also some hardware extensions to arm to support x86 condition codes in the hardware because it's way more instruction efficient that way.
- astrange 11mo agoIf you mean FEAT_FlagM, that's standard in ARMv8.4. (There's also FlagM2 and AFP that are optional.) The JavaScript instruction is cooler though. https://developer.arm.com/documentation/dui0801/g/A64-Floating-point-Instructions/FJCVTZS https://developer.arm.com/documentation/dui0801/g/A64-Floati...
- gorkish 11mo agoRISC is dead; long live RISC
- sgerenser 11mo agoThe latter is now an optional feature in the mainstream Arm ISA now (FEAT_FlagM and FEAT_FlagM2). Similarly the “alternate floating point mode” that Apple uses to match nuances of x86 FP semantics is a standard architectural feature as well. The TSO option though is Apples own thing.
- astrange 11mo agoIt's not only present in Apple Silicon, it's just not required by the ARM standard. Fujitsu also has an ARM64 CPU with TSO.
- nullbyte808 11mo agobetter yet, Apple should make it open-source on github.
- scotty79 11mo ago> Apple should sell Rosetta to Valve. Isn't Rosetta kinda bad though? And won't get much better because it's not open source?
- MobiusHorizons 11mo agoRosetta performance is best in class to my knowledge, although they had the benefit of being able to add custom instructions and modes to the cpu to make some parts easier. Meaning Rosetta would not have helped valve unless they built the frame on apple silicon. As for not improving, it is likely that Apple no longer feels the need to invest in Rosetta improvements now that Apple silicon is so dominant and software support is already very strong, but nothing is stopping them from investing in it if they need it for example for gaming
- scotty79 11mo agoRosetta is abandonware: https://developer.apple.com/documentation/apple-silicon/about-the-rosetta-translation-environment https://developer.apple.com/documentation/apple-silicon/abou... Why would a company on its way to the moon, entrust such an important project as translation layer between two major architectures to a single rinky-dinky corp that got rich selling common electronics marketed as luxury fluff, that's on the decline and has head so far stuck up its butt that it thinks it can do whatever it wants, instead of just write it themselves with support of the global developer community? Apple could never do games because there are no luxury games. That's completely out of their zone of comprehensibility.
- dontlaugh 11mo agoI don’t know if the two companies have such different futures. The games industry as a whole is in potentially terminal decline, have you seen all of the redundancies lately?
- kokada 11mo agoThe AAA games industry with their multi-million budgets and "being too big to fail" mentality is on decline. It seems that anything that is not a new Call of Duty is considered not worth by the industry. But smaller games and indie studios are thriving. We got lots of very interesting indie games this year.
- deleted 11mo ago[deleted]
- LeFantome 11mo agoYou are looking for Felix86 https://felix86.com/ https://felix86.com/
- clausecker 11mo agoARM already has most stuff required for this on board. Two proprietary extensions are used by Rosetta: one emulates the parity (rarely used) and half-carry (obsolete) flags, which can also be emulated conventionally. The other implementa TSO memory ordering, which can either be ignored or implemented with explicit barriers; some other chips apparently have a similar setting. The other stuff is all present in ARMv8.5 I think.