[Info-vax] C et al (was: Re: Rust as a HS language, was: Re: Quiet?)

[Stephen Hoffman]

On 2022-04-10 02:29:53 +0000, Stephen Hoffman said:

> My usual pointer to just what volatile provides, and doesn't provide:
> 
> http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1152r0.html

For those that believe there is but one write with volatile, there's 
one write per byte yes, but there can be multiple and arbitrary-ordered 
writes involved within that operation.

"...the Standard technically allows an implementation which touched 
each target byte exactly once, one after the other, in an unspecified 
order that could change on each execution."

And this all before we discuss the details of memory accesses and 
"tearing" and caching and multiprocessing, and the rest of how the C 
abstract machine differs from modern machines.



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