cfallin

9 ms·

31.
by cfallin 4y ago
> That said, cranelift is still experimental. Echoing everyone else in this thread that Cranelift might work well for this case; just wanted to add: Cranelift is definitely not "experimental" anymore, though it is still young.
32.
by cfallin 4y ago
You're not alone -- I recently had a heck of a time trying to get a T14s AMD 2nd gen to work well in Linux (mostly same CPU/chipset/hardware as your X13). I never got wakeup from S3 suspend to work, it just froze; wakeup from
33.
by cfallin 5y ago
The way this clicked for me (it took some thought!) was to see it as a lever, or at least an analogue to one. Imagine a lever with the fulcrum on one end, attached to the ground. Wind pushes on the middle, and the car is at the other end of
34.
by cfallin 5y ago
The explanation in the book is that neutron-star life is based on nuclear chemistry, whose reactions move much more quickly than our (electron-shell-based) chemistry, so everything happens much more quickly as a result.
35.
by cfallin 5y ago
For anyone looking for a documentary on the Manhattan Project, I'd highly highly recommend The Day After Trinity, a documentary by Jon Else with a bunch of interviews of the original participants (it was made in 1980). Really fantastic
36.
by cfallin 6y ago
Indeed; footnote 3 on the sentence you quoted links to exactly that paper :-) This came up in the Reddit discussion on the post a few days ago. Specifically it works for reducible control flow. In the general case (irreducible control flow)
37.
by cfallin 6y ago
I had sort of the same problem when jumping into Cranelift work -- this stuff is really not well-documented outside of the code itself. Happy to hear you found the posts useful!
38.
Cranelift, Part 3: Correctness in Register Allocation(cfallin.org)
4 points by cfallin 6y ago|2 comments
39.
by cfallin 6y ago
Integrating regalloc with a more streaming approach is something we may want to look at in the future in our backend -- for now we have a more conventional regalloc that extracts live ranges and either does a backtracking allocation or line
40.
by cfallin 6y ago
> I wish there was a nice wrapper dedicated to abstracting hardware support The NetBSD kernel has the ability to be built as a library, letting various drivers be used in other ways -- it's called a "rump kernel" [0]. I&#x
41.
Cranelift, Part 2: Compiler Efficiency, CFGs, and a Branch Peephole Optimizer(cfallin.org)
2 points by cfallin 6y ago|0 comments
42.
by cfallin 6y ago
+1 to Datalog -- it is fantastic for static analysis in particular! There are a bunch of papers from Yannis Smaragdakis' group on this; I built my thesis work on top of their system Doop [1] which is a whole-program points-to analysis
43.
by cfallin 6y ago
Parent comment was correct at time of posting :-) This was a project from last Christmas that I was encouraged to post again; after inspiration from another thread here I added a new version that fits in a single sector.
44.
by cfallin 6y ago
Yup, PC hardware is actually not too bad as a bare-metal platform, and everyone should try writing an OS once! Sounds like a fun senior project.
45.
by cfallin 6y ago
... and now there's a true 512-byte version as well (removing the text and shifting some of the variables to other memory did it) -- `make floppy_1sector.img`. Anyway, thanks for the prompt/challenge!
46.
by cfallin 6y ago
Thanks for working that out -- I had looked into using a JS x86 emulator of some sort to put up a demo when I wrote this, but ran out of time last Christmas :-) Happy to hear it works with that emulator!
47.
by cfallin 6y ago
You're right, it started as an attempt to fit into 512 bytes but right now it's 4 sectors (2KB). Of course, on a modern hard drive with 4KB sectors, we might stretch our definitions a bit :-) (Though the BIOS still only loads 512
48.
Show HN: TreeOS – A 16-bit bootsector Christmas tree demo(github.com)
141 points by cfallin 6y ago|31 comments
49.
by cfallin 6y ago
(author here) that's good feedback; thanks! I tried to make this accessible by at least linking to Wikipedia or elsewhere when introducing new terms (SSA, etc.); that way a curious person could use this as a starting point. A lot of th
50.
A New Backend for Cranelift, Part 1: Instruction Selection(cfallin.org)
3 points by cfallin 6y ago|0 comments
51.
by cfallin 6y ago
Overprovisioning to ensure demand is met in the worst case also sounds like a very early-20th-century sort of design decision; that could be part of it! Here's an interesting article about Spanish flu and radiators: https://
52.
by cfallin 6y ago
This is apparently an artifact of the 1918 flu pandemic: building architects / heating engineers intended for windows to be kept open to ventilate spaces in the winter, and so steam heating systems were over-provisioned. A number of fr
53.
by cfallin 6y ago
Pittsburgh driving taxes one's navigation skills on a good day, to put it mildly. Lived in Squirrel Hill for 8 years and got used to it but it's probably the most local-knowledge-dependent driving I've seen in the US. The fiv
54.
by cfallin 6y ago
Reminds me of this onramp to I-376 in Pittsburgh, where you have a stop sign (!) at the bottom of the onramp (!!), which then dumps you into an exit-only lane with a few hundred feet to merge left (!!!): https://www.google.com&#x
55.
by cfallin 6y ago
Ah, no, probably doesn't do parsing recovery. But `wasm-validate` from the same toolkit will at least tell you the offset at which your wasm file has an error (I just flipped some bits in a wasm file to test this), which may be helpful
56.
by cfallin 6y ago
> reading the binary format ... it'd be nice to do more advanced debugging with a text format. Do you know about `wasm2wat` (from the WebAssembly binary toolkit, "WABT")? It produces a 1-to-1 text representation of the byt
57.
by cfallin 7y ago
Compact / succinct data structures and clever algorithms are still very important when data gets large enough -- consider e.g. a database running complex queries, where a good encoding makes the difference between staying in memory and
58.
by cfallin 7y ago
Soul of a New Machine is fantastic! Also on computer architecture / story of developing a new processor, "The Pentium Chronicles" by Robert Colwell is a really interesting book on the story of the Pentium Pro, the first out-o
59.
by cfallin 7y ago
> What codec would you use for a camera that captures not RGB, but poetry of the soul? I would love to read a collaborative work between you and James Mickens -- this genre of writing seems sadly under-present in the computing world...
60.
by cfallin 7y ago
> But, I can do basically the same thing ... what am I missing about Sandstorm? The big difference, in my mind, is that each app is integrated with a permissions/capabilities model and strongly sandboxed by individual instance or do

More ›