cfallin

21 ms·

151.
by cfallin 10y ago
The optimizer recognizes that the variable `condition` and the condition with the guard's if-statement are the same (edit: inverses actually), so within the if-statement's body, it can assume that `condition` is false. But when ot
152.
by cfallin 10y ago
Ah hah -- I had missed your `Ref` and channel types. Thanks for the detailed explanation!
153.
by cfallin 10y ago
This is an impressive effort! It seems that Gluon has taken inspiration from Haskell right down to the monadic solution to mutable state: https://github.com/Marwes/gluon/blob/master/std/state.glu I
154.
by cfallin 10y ago
The muddy marsh/salt ponds surprised me too! But there are a few spots where the actual Bay (open water) is visible... e.g. Baylands Nature Preserve in Palo Alto. Also nearby hills have views -- I used to take walks to the top of the h
155.
by cfallin 10y ago
It can get even more fun! If instead of two brothers marrying two sisters, you have two brothers marrying two first cousins, like so... b1 and b2 are brothers c1 and c2 are first cousins b1 and c1 marry and have child x b2
156.
by cfallin 10y ago
Fair point -- I forgot about MOSIS. Agreed, pretty reasonable for small test runs. I guess I've mostly heard of tapeouts when proving out a full design though, e.g. TRIPS from UT-Austin (and they had a team of ~20 students, so that was
157.
by cfallin 10y ago
You definitely wouldn't want to use Verilog to iterate quickly on a simulation model. It's a lot more work: in a software model, you can (for example) say the equivalent of "this instruction is a divide and takes 32 cycles&qu
158.
by cfallin 10y ago
From their MICRO'15 paper (section 5): "We use an in-house microarchitectural, event-driven, sequential simulator based on Pin". This is fairly standard for computer architecture research in academia: the results are based on
159.
by cfallin 10y ago
I'm curious, what sorts of issues arise with complex types that Haskell-like syntax handles better? (Genuinely curious here -- I've written a little Haskell but am by no means an expert...) IMHO a Rust-style type `Option<HashMa
160.
by cfallin 10y ago
I wonder if anyone is working on a full rework of Haskell's syntax, a la Facebook's Reason for OCaml? I'm a big fan of the semantics but not as much the syntax of Haskell, too, and it would be interesting to see what a more..
161.
by cfallin 10y ago
That's how the Unix History Repository was built, at least (a really cool project that reconstructed a synthetic git commit history for Unix from the initial Bell Labs source onward): https://github.com/dspinellis/
162.
by cfallin 10y ago
Ah, yes, sorry, I missed your "of a single non-repeating atom" :-) I'm also curious -- but I wonder, would this allow for imaging anything that a scanning electron microscope can't?
163.
by cfallin 10y ago
Isn't that basically what X-ray crystallography is (taking the liberty to include X-rays as "light")? Though with the (significant) restriction that it only works for repeating crystal structures, not unique individual target
164.
by cfallin 10y ago
I thought so too at first, but the thing about the limits imposed by the borrow rules is that they completely avoid the bugs that, in my experience, take the longest to track down in e.g. C++. It's the pain-up-front vs. more-pain-durin
165.
by cfallin 10y ago
> The problem is our entire generation doesn't care about privacy. Yup -- law follows culture, not the other way around. IMHO this (cultural priorities) is at the root of other ills too, e.g. educational system and criminal justice
166.
by cfallin 10y ago
I have a little bit of experience with this... I think that almost certainly, no single human understands the whole chip down to the gate level. The complexity is managed by layers of abstraction. The core architects understand the pipeline
167.
by cfallin 10y ago
This is just a branch predictor! It would be interesting to play with more modern branch prediction algorithms (e.g., Andre Seznec's recent work) with the same interactive interface. I haven't seen anyone do this before...
168.
by cfallin 10y ago
I like to compare it to the "comma error" idiom in Go, i.e., `result, err = doStuff(...)`. The Rust prelude's Result enum is a less ad-hoc version of that.
169.
by cfallin 10y ago
The ALU performs an operation on half of the machine word (16 of the 32 bits) each half-cycle, i.e., one on the rising edge and one on the falling edge of the clock. Basically they split the carry chain across two (half-)pipe stages and the
170.
by cfallin 10y ago
> @Intel: how about thinking about 10GHz single core CPUs? They tried that -- the Pentium 4. The key design goal was to push clock speed as high as possible, and they used some crazy tricks, like 30-some-stage pipelines, a really long in
171.
by cfallin 10y ago
> Also, I hear Portland is nice. As someone who grew up in Portland [1], I could write a post just like yours, and I'm sympathetic to the frustration... But I still side with the pro-housing crowd. What are people who seek to move u
172.
by cfallin 10y ago
I'm pretty sure it was plug-and-play. It's actually kind of cool how many USB peripherals Android natively supports -- keyboards, mice, flash drives, etc...
173.
by cfallin 10y ago
> Can smartphones even be plugged directly into an Ethernet socket? Yup. I've done this with my Nexus 5. You need a USB OTG cable and a USB Ethernet adapter. Dorkiest thing ever, walking around the apartment trailing an Ethernet cab
174.
by cfallin 10y ago
Great list! I recently visited Cook Forest [1] in northwest Pennsylvania and it is breathtakingly beautiful. It's not just quantitatively different (bigger trees) but also qualitatively -- all towering evergreens in a very deciduous st
175.
by cfallin 10y ago
Ooh, a chance to plug a toy side-project! I wrote "pingd" [1] to ping an address continuously and dump (timestamp, latency, dropped) tuples to a SQLite database, and also report results (tables only, no plots) via a web interface.
176.
by cfallin 10y ago
Boston is in the next tier, I agree, but from a CS perspective, I would take Pittsburgh over Philly, RTP, or Baltimore in a heartbeat. We're the only city outside of SF/NYC/Boston/Seattle to have a top-five CS school and
177.
by cfallin 10y ago
> EVERY "up and coming" city [ ... ] Detroit, Baltimore, Philly, Raleigh, New Orleans, St. Louis, Indianapolis, Kansas City, Omaha, Miami [ ... ] One unique factor about Pittsburgh is its academic presence, in both CS/engi
178.
by cfallin 10y ago
If flying to warm places is your metric, PIT has direct flights to LAX, SFO, Las Vegas, Atlanta, and four airports in Florida. I don't think travel connectivity is a good argument against Pittsburgh. It's also really easy to get
179.
by cfallin 10y ago
Wasn't the Bakery Square building itself an old Nabisco factory? I agree that all the new apartment buildings around it are pretty out-of-place, but I do think there are plenty of reasonable attempts at keeping historical bits around..
180.
by cfallin 10y ago
I just got exactly the same setup working this past week, after deciding to move from ad-hoc setup to a clean Dockerized setup with minimal custom config. It's great! The thing I like about this setup is that it seamlessly supports mul

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