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The important players like Samsung/Apple/Huawei are already ARM architecture license holders so they can do their own thing if they don't like the direction th

The important players like Samsung/Apple/Huawei are already ARM architecture license holders so they can do their own thing if they don't like the direction that NVidia is going in. A 128 bit version might be an issue in the future.

ysleepy 6y ago
A 128bit ISA is super unlikely. We're barely using the 48bit implemented in AMD64 of 64 possible address bits. Wider data arguments are already implemented as AVX/2/512.
- akvadrako 6y ago
  Architectures with 128 pointers exist, but the extra bits are used for metadata. I don’t see much indication this’ll become mainstream through. https://www.cl.cam.ac.uk/research/security/ctsrd/cheri/cheri-faq.html https://www.cl.cam.ac.uk/research/security/ctsrd/cheri/cheri...
  - ac934875390 6y ago
    Arm is actually building this: https://developer.arm.com/architectures/cpu-architecture/a-profile/morello https://developer.arm.com/architectures/cpu-architecture/a-p...
xxpor 6y ago
I could imagine we might see an architecture with 128 bit word sizes, but I doubt we'd see 128 bit pointers (aka a 128 bit address space) any time soon. Itd just be more annoying than anything. I personally have even written software where we do pointer path to get 32 bit indexes rather than storing full 64 bit pointers simply because of space constraints (like trying to fit a hot struct into a single cache line) Having a native uint128_t would make dealing with IPv6 addresses a lot nicer though :)
- ip26 6y ago
  Current chips don't even actually support 64 bits of hardware address yet, seeing as few users can afford 2 exbibytes of DRAM and shuffling around a full 64 bits of hardware address is a noticeable tax on the chip.
  - saagarjha 6y ago
    Large address spaces are useful for virtual memory reasons, not because you literally have petabytes of RAM physically attached to your machine.
- DaiPlusPlus 6y ago
  > but I doubt we'd see 128 bit pointers (aka a 128 bit address space) any time soon. I can see 128-bit pointers being a thing: not because of 128-bits of address space, but for the ability to embed type information directly in the pointer - which could improve performance for dynamic-dispatch scenarios or runtime type-safety built-in to the hardware itself. > Having a native uint128_t would make dealing with IPv6 addresses a lot nicer though :) [We're already there](https://stackoverflow.com/questions/34234407/is-there-hardware-support-for-128bit-integers-in-modern-processors https://stackoverflow.com/questions/34234407/is-there-hardwa...)
  - saagarjha 6y ago
    Not type information, but CHERI capabilities: https://www.cl.cam.ac.uk/research/security/ctsrd/cheri/cheri-morello.html https://www.cl.cam.ac.uk/research/security/ctsrd/cheri/cheri...

ysleepy 6y ago

A 128bit ISA is super unlikely. We're barely using the 48bit implemented in AMD64 of 64 possible address bits. Wider data arguments are already implemented as AVX/2/512.

akvadrako 6y ago
Architectures with 128 pointers exist, but the extra bits are used for metadata. I don’t see much indication this’ll become mainstream through. https://www.cl.cam.ac.uk/research/security/ctsrd/cheri/cheri-faq.html https://www.cl.cam.ac.uk/research/security/ctsrd/cheri/cheri...
- ac934875390 6y ago
  Arm is actually building this: https://developer.arm.com/architectures/cpu-architecture/a-profile/morello https://developer.arm.com/architectures/cpu-architecture/a-p...

xxpor 6y ago

I could imagine we might see an architecture with 128 bit word sizes, but I doubt we'd see 128 bit pointers (aka a 128 bit address space) any time soon. Itd just be more annoying than anything. I personally have even written software where we do pointer path to get 32 bit indexes rather than storing full 64 bit pointers simply because of space constraints (like trying to fit a hot struct into a single cache line) Having a native uint128_t would make dealing with IPv6 addresses a lot nicer though :)

ip26 6y ago
Current chips don't even actually support 64 bits of hardware address yet, seeing as few users can afford 2 exbibytes of DRAM and shuffling around a full 64 bits of hardware address is a noticeable tax on the chip.
- saagarjha 6y ago
  Large address spaces are useful for virtual memory reasons, not because you literally have petabytes of RAM physically attached to your machine.
DaiPlusPlus 6y ago
> but I doubt we'd see 128 bit pointers (aka a 128 bit address space) any time soon. I can see 128-bit pointers being a thing: not because of 128-bits of address space, but for the ability to embed type information directly in the pointer - which could improve performance for dynamic-dispatch scenarios or runtime type-safety built-in to the hardware itself. > Having a native uint128_t would make dealing with IPv6 addresses a lot nicer though :) [We're already there](https://stackoverflow.com/questions/34234407/is-there-hardware-support-for-128bit-integers-in-modern-processors https://stackoverflow.com/questions/34234407/is-there-hardwa...)
- saagarjha 6y ago
  Not type information, but CHERI capabilities: https://www.cl.cam.ac.uk/research/security/ctsrd/cheri/cheri-morello.html https://www.cl.cam.ac.uk/research/security/ctsrd/cheri/cheri...