owlbite · HackerTrans

il y a 10 joursdiscuss

At least with LG TVs you can just not give them the internet and nothing of value is lost (at least assuming you have an Apple TV or other trusted smart tv capability). Much more difficult to not give the windows PC internet and have it be useful (at least mine is only used for gaming).

owlbite

il y a 25 joursdiscuss

I'm still astounded my Ford's infotainment system takes 5-10 seconds after opening the radio "app" to present me with the station selection UI. Most of that seems to be some sort of startup delay. The mind boggles.

owlbite

le mois dernierdiscuss

I'm somewhat dubious about anything talking about low level performance programming at the instruction level that doesn't distinguish between latency and throughput, never mind mention the incredibly out-of-order nature of modern desktop/server class CPU cores.

owlbite

il y a 2 moisdiscuss

Or economies of liability and buck passing. I suspect managers and businesses will still want to be in the game of "not my fault, supplier is working on it, we can sue them if they don't meet SLA".

owlbite

il y a 4 moisdiscuss

It will be interesting to see if this solves any issues that aren't already addressed by the likes of matlab / SciPy / Julia. Reading the paper it sounds a lot like "SciPy but with MLIR"?

owlbite

il y a 5 moisdiscuss

Not just for speed, Horner can also be essential for numerical stability.

owlbite

il y a 5 moisdiscuss

FORmula TRANslation, the clue is in the name. It's great at math, but yeah, strings and OS stuff is a PITA. The modern vector-based syntax is still really nice and I've yet to come across a C++ library quite as slick.

But I think what it was really missing last time I looked at it was good access to compiler intrinsics (or otherwise) to hit vectorizations and math optimization instructions. The OpenMP simd pragmas weren't really doing a fantastic job. I hope that's better now it's in LLVM.

owlbite

il y a 5 moisdiscuss

I suspect main benefits are they have no need to maintain the hardware or software for any longer than it makes sense for their own needs, and don't have to handhold users through a constantly evolving minefield of performance and technical capabilities.

owlbite

il y a 5 moisdiscuss

I think the current generation of tools have a long way to go before I trust any numerical algorithm they implement, based on our recent experiments trying to make it implement some linear algebra by calling LAPACK. When we asked it to write some sparse linear algebra code based on some more obscure graph algorithms it produced some ugly stepchild of dijkstra's algorithm instead, which needless to say did not achieve the desired aim.

owlbite

il y a 6 moisdiscuss

Have meetings to figure out how to interact with the other 9990 employees. Then try and make the skeleton app left behind by the team of transient engineers who left after 18 months before moving on to their next gig work, before throwing it out and starting again from scratch.

owlbite

il y a 6 moisdiscuss

Transmission is pretty expensive, lots of infrastructure and maintenance.

owlbite

il y a 6 moisdiscuss

I think calling VLIW "an adandoned design" is somewhat of an exaggeration, such architectures are pretty common for embedded audio processing.

owlbite

il y a 8 moisdiscuss

This book provides a high level overview of many methods without (on a quick skim) really hinting at the practical usage. Basically this reads as a encyclopedia to me, whereas Nocedal and Wright is more of an introductory graduate course going into significantly more detail on a smaller selection of algorithms (generally those that are more commonly used).

Picking on what I'd consider one of the major workhorse methods of continous constrained optimization, Interior Point Methods get a 2-3 page super high level summary in this book. Nocedal and Wright give an entire chapter on the topic (~25 pages) (which of course still is probably insufficient detail to implement anything like a competitive solver).

owlbite

il y a 9 moisdiscuss

But it can be even worse than that. It's "we assassinated the phone", "algorithm says vehicle has suspicious travel history and must die". There's no real thinking human in the loop for some of this stuff, just some model decided the metadata has a high probability of being associate with an opponent of some flavor and then everyone in the vicinity is blown to bits as computer said kill.

owlbite

il y a 9 moisdiscuss

Very true, but a lot of stuff builds on a few core optimized libraries like BLAS/LAPACK, and picking up a build of those targeted at a modern microarchitecture can give you 10x or more compared to a non-targeted build.

That said, most of those packages will just read the hardware capability from the OS and dispatch an appropriate codepath anyway. You maybe save some code footprint by restricting the number of codepaths it needs to compile.

owlbite

il y a 9 moisdiscuss

They just label such people as Applied Mathematicians, or worse: Physicists and Engineers; and then get back to sensible business such as algebraic geometry, complex analysis and group theory.

owlbite

il y a 9 moisdiscuss

Introduction to PhD study: "How hard can it be, I'm sure I could write that in a week"

owlbite

il y a 9 moisdiscuss

I thought GPLv3 adoption by GCC was what really lit the flames on moving to llvm by commercial entities?

owlbite

il y a 10 moisdiscuss

Oh yes, from an actual implementation POV you can just apply some transpose and ordering transforms to convert from row major to column major or vice-versa. cblas is pretty universal though I don't think any LAPACK C API ever gained as wide support for non column-major usage (and actually has some routines where you can't just pull transpose tricks for the transformation).

Certain layouts have performance advantages for certain operations on certain microarchitectures due to data access patterns (especially for level 2 BLAS), but that's largely irrelevant to historical discussion of the API's evolution.

owlbite

il y a 10 moisdiscuss

What I suspect he really means is that FORTRAN lays out its arrays column-major, whilst C choose row-major. Historically most math software was written in the former, including the de facto standard BLAS and LAPACK APIs used for most linear algebra. Mix-and-matching memory layouts is a recipe for confusion and bugs, so "mathematicians" (which I'll read as people writing a lot of non-ML matrix-related code) tend to prefer to stick with column major.

Of course things have moved on since then and a lot of software these days is written in languages that inherited their array ordering from C, leading to much fun and confusion.

The other gotcha with a lot of these APIs is of course 0 vs 1-based array numbering.

comments