Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

ARM chips have an instruction with JavaScript in the name

stackoverflow.com

Post reply on HN
Print view View original

101–110 of 312 posts

Re: ARM chips have an instruction with JavaScript in the name

#101

Post by FullyFunctional »

sterlind wrote: post #82
FullyFunctional wrote: post #73

Earlier quoted context omitted.

Personally I think this would be unfortunate as I don't think JavaScript is the path forward, but computers have always existed to run software (d'oh), which mean the natural selection will obviously make this happen if there is a market advantage. However I see all high performance web computing moving to WASM and JavaScipt will exist just as the glue to tie it together. Adding hardware support for this is naive and…

maybe this will lead to the revival of Transmeta-like architectures? I always had a soft spot for reprogrammable microcode.

WASM is _designed_ to be easily jitted, without the expensive machinery we had to put in place to do this for x86, so the whole point is not require a new architecture.

Because of this I find WASM to be the best direction yet for a "universal ISA" as it's very feasible to translate to most strange new radical architecture (like EDGE, Prodigy, etc). (Introducing a new ISA is almost impossible due to the cost of porting the world. RISC-V might be the last to succeed).

Re: ARM chips have an instruction with JavaScript in the name

#102

Post by throwaway_pdp09 »

matthewmacleod wrote: post #90
throwaway_pdp09 wrote: post #80

Earlier quoted context omitted.

Please No. Let the hardware do best what it's good at, being simple and running fast. Let the interpreter/compiler layer do its thing best, flexibility. There have been attempts to move the hardware 'upwards' to meet the software and it's not generally worked well. No special purpose language supporting hardware exists now that I'm aware of - lisp machines, smalltalk machines, Rekursiv, stretch, that 1980s object ori…

Let the hardware do best what it's good at, being simple and running fast. Let the interpreter/compiler layer do its thing best, flexibility. Yeah, this is pretty much the opposite of what actually works in practice for general-purpose processors though – otherwise we'd all be using VLIW processors.

The complex processors like the PDPs were followed by risc processors because they were simpler. The hardwrae has to run code, I get that, but VLIW didn't work. Risc did. The x86 decompiles its opcodes into micro-ops which are load/store risc-y simple things. Simplicity was always the way to go.

I do take your point about VLIW, but I'm kind of assuming that the CPU has to, you know, actually run real workloads. So move the complexity out of the languages. Or strongly, statically type them. Or just don't use JS for server-side work. Don't make the hardware guys pick up after bad software.

Re: ARM chips have an instruction with JavaScript in the name

#103

Post by goatlover »

tekromancr wrote: post #87
brundolf wrote: post #53

Earlier quoted context omitted.

Seeing as JavaScript was designed and implemented in two weeks, I'm betting this is the answer

Today's JavaScript is so divorced, so radically different from the the original implementation to be considered a different language, though.

Isn’t modern JS backward compatible with 1.1?

Re: ARM chips have an instruction with JavaScript in the name

#104

Post by throwaway_pdp09 »

saagarjha wrote: post #94
throwaway_pdp09 wrote: post #80

Earlier quoted context omitted.

Please No. Let the hardware do best what it's good at, being simple and running fast. Let the interpreter/compiler layer do its thing best, flexibility. There have been attempts to move the hardware 'upwards' to meet the software and it's not generally worked well. No special purpose language supporting hardware exists now that I'm aware of - lisp machines, smalltalk machines, Rekursiv, stretch, that 1980s object ori…

You do understand that current hardware exists to support C, right?

Yep. They have a compiler to bring it down to the metal so IDK what you're saying.

--- EDIT ---

@saagarjha, as I'm being slowposted by HN, here's my response via edit:

OK, sure! You need some agreed semantics for that, at the low level. But the hardware guys aren't likely to add actors in the silicon. And they presumably don't intend to support eg. hardware level malloc, nor hardware level general expression evaluation[0], nor hardware level function calling complete with full argument handling, nor fopen, nor much more.

BTW "The metal which largely respects C's semantics?" C semantics were modelled after real machinery, which is why C has variables which can be assigned to, and arrays which follow very closely actual memory layout, and pointers which are for the hardware's address handling. If the C designers could follow theory rather than hardware, well, look at lisp.

[0] IIRC the PDPs had polynomial evaluation in hardware.

Re: ARM chips have an instruction with JavaScript in the name

#105

Post by FullyFunctional »

mavhc wrote: post #99
FullyFunctional wrote: post #65

Earlier quoted context omitted.

It seems to me people are ignoring that the C stands for Complexity. What's reduced is Complexity of the instruction set, not the size of it (or even the instructions themselves). In the context of the coinage of the term, they almost certainly could have called it "microcode-free ISA", but it wouldn't have sounded as cool.

Doesn't the C stand for Computer?

Oops I'm wrong about the name but not about the spirit. This is the original paper: https://dl.acm.org/doi/pdf/10.1145/641914.641917

Re: ARM chips have an instruction with JavaScript in the name

#106

Post by saagarjha »

throwaway_pdp09 wrote: post #104
saagarjha wrote: post #94

Earlier quoted context omitted.

You do understand that current hardware exists to support C, right?

Yep. They have a compiler to bring it down to the metal so IDK what you're saying. --- EDIT --- @saagarjha, as I'm being slowposted by HN, here's my response via edit: OK, sure! You need some agreed semantics for that , at the low level. But the hardware guys aren't likely to add actors in the silicon. And they presumably don't intend to support eg. hardware level malloc, nor hardware level general expression evaluat…

The metal which largely respects C's semantics? For example, here are some instructions that exist to match C's atomics model: https://developer.arm.com/documentation/den0024/a/Memory-Ord...

Re: ARM chips have an instruction with JavaScript in the name

#107

Post by kps »

saagarjha wrote: post #94
throwaway_pdp09 wrote: post #80

Earlier quoted context omitted.

Please No. Let the hardware do best what it's good at, being simple and running fast. Let the interpreter/compiler layer do its thing best, flexibility. There have been attempts to move the hardware 'upwards' to meet the software and it's not generally worked well. No special purpose language supporting hardware exists now that I'm aware of - lisp machines, smalltalk machines, Rekursiv, stretch, that 1980s object ori…

You do understand that current hardware exists to support C, right?

What aspect of currently popular CPU instruction sets ‘exists to support C’?

Re: ARM chips have an instruction with JavaScript in the name

#108

Post by saagarjha »

offbynull wrote: post #86

Anyone else remember the ARM Jazelle DBX extension? I wonder if they'll end up dumping this in this the same way. I don't remember very many phones supporting DBX, but IIRC the ones that did seemed to run J2ME apps much smoother.

This one is at least documented and in use by major browsers, so I doubt it will go away anytime soon.

Re: ARM chips have an instruction with JavaScript in the name

#109

Post by masklinn »

FullyFunctional wrote: post #73
chubot wrote: post #60

Emery Berger argues that the systems community should be doing exactly this -- improving infrastructure to run JS and Python workloads: https://blog.sigplan.org/2020/10/12/from-heavy-metal-to-irra... We need to incorporate JavaScript and Python workloads into our evaluations. There are already standard benchmark suites for JavaScript performance in the browser, and we can include applications written in node.js (serv…

Personally I think this would be unfortunate as I don't think JavaScript is the path forward, but computers have always existed to run software (d'oh), which mean the natural selection will obviously make this happen if there is a market advantage. However I see all high performance web computing moving to WASM and JavaScipt will exist just as the glue to tie it together. Adding hardware support for this is naive and…

The quote isn't really saying that JS-specific instructions need be added to the ISA though.

Re: ARM chips have an instruction with JavaScript in the name

#110

Post by saagarjha »

kps wrote: post #107
saagarjha wrote: post #94

Earlier quoted context omitted.

You do understand that current hardware exists to support C, right?

What aspect of currently popular CPU instruction sets ‘exists to support C’?

Here's a (doubly-indirected) example: https://news.ycombinator.com/item?id=24813376
Post reply on HN