dooglius

44 ms·

661.
by dooglius 7y ago
Maybe you have a different definition in mind than I do? I'm using microcode to mean sequences of micro-ops. Wikipedia [0] seems to agree, "the microcode is a layer of hardware-level instructions that implement higher-level machin
662.
by dooglius 7y ago
Okay, you're talking about OoO execution here, and you're right that this can be hard to reason about (in terms of stalls/latencies), however that's orthogonal to microcode translation.
663.
by dooglius 7y ago
Not portably, you could of course use inline assembly in practice, but the normal way of doing it is UB.
664.
by dooglius 7y ago
The micro-architectures are reasonably documented enough (e.g. we know what each the execution ports do, that register renaming is a thing) and if you look at e.g. Agner Fog's instruction tables [0] that map macro-instructions onto lat
665.
by dooglius 7y ago
Can you give an example? The most complicated assembly->microcode examples I can think of are floating-point instructions like FSIN that run CORDIC loops under the hood, and those are still pretty easy to reason about.
666.
by dooglius 7y ago
Not really, assembly language is extremely close to microcode, much much closer than it is to C. C has a whole bunch of baggage like pointer provenance, inability to read uninitialized memory, doesn't understand cache aliasing, etc tha
667.
by dooglius 7y ago
I'm talking mainly about dynamic (switching) power. I'm not sure about overclocking, but I believe it tends to involve also increasing voltage (power does scale quadratically with voltage) and a higher internal temperature (this w
668.
by dooglius 7y ago
>Power consumption grows with the square of frequency You may be thinking of the power of a mechanical wave, which is composed of the kinetic energy of particles in e.g. a vibrating string. A CPU's power consumption is linear with r
669.
by dooglius 7y ago
In fairness, I have hit this exact same problem on Linux
670.
by dooglius 7y ago
Funny, GCC/glibc had this same problem (except you could work around it by detecting the version).
671.
by dooglius 7y ago
I guess it depends on your semantics/mental model of what a pipeline should do. My mental model says that each part should run fully, and the pipeline should emulate sequential behavior, with "yes" being a bit of a hack in th
672.
by dooglius 7y ago
head is just an example, if you pipe rm -vfr (or any program that does more than just output) into _anything_ the reasonable and default behavior should be to run rm to completion. (And from a programmer's POV, the reasonably thing is
673.
by dooglius 7y ago
This is bad advice, if you are doing anything other than output to stdout/stderr (which you almost assuredly are, unless you are doing something very simple like "yes"), you want to switch to /dev/null. For instance
674.
by dooglius 7y ago
> People actually tried to update net-tools ifconfig (one of the two ifconfigs back in 2018). What happened?
675.
by dooglius 7y ago
You could make an artificial min/max of all types object that gets returned on empty lists
676.
by dooglius 7y ago
It's not a boolean whether people become immune or not--maybe some small portion of the population have issues developing immunity and the rest are fine?
677.
by dooglius 7y ago
raises hand The sort of optimizations that compilers abuse UB for aren't that useful, actually, and they don't actually require a compiler anyway; it's more about compiler writers overfitting for benchmarks.
678.
by dooglius 7y ago
I'm not suggesting that the builder finances the R&D itself, NRE costs should be baked into the contract. What I am saying is that the entity doing the cost estimates (which AIUI is also the researcher and builder, though it could
679.
by dooglius 7y ago
I've always wondered why the government doesn't try a payment-on-delivery model. That would put the risk on the supplier and fix the incentive problems. A counter-argument would be that it creates significant barriers to entry, bu
680.
by dooglius 7y ago
Not quite, you can do some stuff that affects the correlation between one output and the other, but that can't be used for communication as each output in isolation looks random.
681.
by dooglius 7y ago
I'll make an attempt, though I am by no means a domain expert. As I said in another comment, Alice doesn't know which column is Bob's column, and Bob doesn't know which row is Alice's row. Bell-like inequalities all
682.
by dooglius 7y ago
> Why not just imagine Alice tells Bob how she's going to choose what to write in the boxes? That works 100% of the time too. Alice doesn't know which column is Bob's column, and Bob doesn't know which row is Alice&#x
683.
by dooglius 7y ago
A post telling people they aren't supposed to run red lights would also be strange, since that is well known. Are you saying that people who don't check fork for errors are doing so knowingly? That is not the impression I got from
684.
by dooglius 7y ago
If I didn't remember how to use a function, I would certainly look at either the documentation or an example, yes.
685.
by dooglius 7y ago
I don't have a problem with the post, I'm just wondering how one gets into a situation where it needs to be said.
686.
by dooglius 7y ago
Posts like this always perplex me, the behavior is clearly documented in the man page and clearly indicated by example demonstration code (e.g. [0]), so how could someone fall under the impression that this wasn't the case? [0] https:
687.
by dooglius 7y ago
It has to be post-implementation, but not necessarily a gate-level sim
688.
by dooglius 7y ago
This is more about making fast short-distance connections.
689.
by dooglius 7y ago
An adversary could compromise the signal server and observe how messages are routed. Applying pressure or coercion to achieve this is well within the capabilities and willingness of state-level adversaries. An adversary could also compromis
690.
by dooglius 7y ago
As a test, I just created a new email via Tor Browser: hn22373017@cock.li It took a few minutes, though admittedly I had to disable noscript. Now, I agree that the average person is going to have a hard time with this, and that's unfor

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