[stcredzero]

This is assembly, not pure Go

Well, if you're going to dip into pedantic mode, couldn't the language maintainers just define Go to include a few relevant Assembly instruction sets? (Not taking a dig at you but rather at the above level of pendantry.)

[MaxBarraclough]

Not without tying Go to one architecture, no.

When C programmers write inline assembly, they don't pretend it's C code.

[sythe2o0]

Go has it's own form of assembly which it compiles to multiple architectures.

[npongratz]

This is interesting. A citation that helps strengthen the explanation:

https://golang.org/doc/asm

"The most important thing to know about Go's assembler is that it is not a direct representation of the underlying machine. Some of the details map precisely to the machine, but some do not... The details vary with architecture, and we apologize for the imprecision; the situation is not well-defined."

[MaxBarraclough]

I followed npongratz's link. Interesting read.

Seems the point of it is to enable easier porting of assembly between architectures, by providing a consistent syntax.

I was expecting something akin to LLVM assembly language, but no, they're come up with their own bizarre high-level assembly-language intended to map fairly directly to various different instruction-sets. It's not an abstraction layer in the usual sense; the exposed register-set and instruction-set are faithful to the target architecture.

It's a finite register machine which isn't just faithfully exposing the underlying architecture. Not something we often see. iirc SPIR and GNU Lightning are both finite register machines, but, to quote Douglas Adams, this has made a lot of people very angry and been widely regarded as a bad move.

How is it compiled? Presumably it doesn't get translated to LLVM as an intermediary.

It strikes me as an awful lot of work. Does their high-level assembler really outperform LLVM? Would've thought a project of that sort would deserve to exist in its own right, not just as an obscure component of Go.

[stcredzero]

It's a finite register machine which isn't just faithfully exposing the underlying architecture. Not something we often see. iirc SPIR and GNU Lightning are both finite register machines, but, to quote Douglas Adams, this has made a lot of people very angry and been widely regarded as a bad move.

TAOS operating system used such a virtual ISA, and was able to achieve around 90% efficiency of native code. The worst case was PowerPC which fell to 80%. That's pretty darn good, IMO.

[MaxBarraclough]

Skimreading http://www.dickpountain.co.uk/home/computing/byte-articles/t... ( linked from https://news.ycombinator.com/item?id=9806607 , where you yourself commented )

Interesting OS. Its 'VP code' looks like a precursor to Java bytecode/HotSpot, but much more low-level and RISC-ey.

Inferno OS's 'Dis' VM took a similar to approach to VP code, if I understand correctly.

I presume that, in 1991 when the article was written, "JIT" wasn't yet in the techies' parlance. It's not used anywhere in the article.

[dbaupp]

It won't when using architecture specific instructions like AVX512.

[pjmlp]

Sure they do, most developers are even't aware that ANSI C does not define any kind of inline Assembly, and ANSI C++ only defines the existance of an asm keyword with implementation defined behavior.

[stcredzero]

Not without tying Go to one architecture, no.

Not trying hard enough to prove the null hypothesis. If you're going full pedantic mode, why stop at one ISA? Just throw in the most relevant dozen. (Heck, I even spelled that out!)

[MaxBarraclough]

That doesn't escape the problem. If you do that, your new definition of the core Go language is no longer cross-platform.

[stcredzero]

It's cross platform enough for most people.