I was once debugging some issue with my laptop's multimedia buttons driver. I found some tweak which helped: enable the tweak, reboot - works fine, disable tweak, reboot - no go. Tested repeatedly several times.
I filed a bug report and received an answer that my tweak absolutely cannot work. The tweak was disabled at the time and the button didn't work. I pressed it again after reading this email and boom - it works.
I swear.
I figure my mind must have been believing so much in futility of pressing this button that it didn't even bother pushing it all the way down. Scary stuff.
You don't need logic, set theory, Turing machines or any meta-mathematics to build practical software.
When I was ten, I had no idea about any of this stuff and yet when somebody showed me how to do arithmetic, variable assignments, comparisons and goto in QBasic (pretty much equivalent of Babbage's machine) I was able to write a simple drawing program and tic-tac-toe which checked whether one of the players won.
Add some IO and I would write a program which reads series of transactions and computes your bank account balance. Tell me what a matrix is and I would implement LAPACK for you.
You're invited to a conference that's relevant to your position and your industry.
To a party relevant to your industry.
When you arrive, a number of hired twentysomething men are milling about wearing tight tee-shirts, padded crotches, and skintight jeans. They're dancing, drinking, flirting with you and your coworkers, and subtly drawing attention towards their ample bulges.
I'm pretty sure the dancers were not even allowed to drink and they didn't flirt with female participants, if they flirted with anybody at all.
Some people in the crowd are really getting into this, having their pictures taken with them. The room starts getting sweaty, the music amps up, and the paid gogo boys start thrusting their cocks in rhythm with the music.
And I guess at this point I'm supposed to imagine getting drunk, gang raped by gays and whatnot.
This "analogy" was a severe exaggeration of what really happened.
I have no problem with people using 4 spaces for indentation.
However, damned shall be those who think that tabs are anything but 8 spaces wide and actually use them this way in their code. Tabs really are 8 spaces wide and every terminal will tell you so.
Real world example: just yesterday I've been bitten by Eclipse defaulting to use "4 space wide tabs" for indentation in otherwise space-indented codebase. Everything looked nice and cool until I ran git diff. How could Eclipse developers think that it was a good idea?
Now, some people will claim that having 8-character indentations makes
the code move too far to the right, and makes it hard to read on a
80-character terminal screen. The answer to that is that if you need
more than 3 levels of indentation, you're screwed anyway, and should fix
your program.
AMD AM2/AM3 CPUs support ECC. It will work provided that the motherboard has the extra wiring required and BIOS support is enabled.
Some vendors (notably ASUS) advertise ECC support on many cheap AMD motherboards.
AFAIK to get ECC with Intel you have to pay for the Xeon.
UTM is a dumb and completely impractical model of computation. Thanks to its simplicity it is a handy tool in (un)decidability proofs and some very general computational complexity reasonings.
And that's all. Numeric computations happened on real machines. Graph processing happened on real machines. Text processing happened on real machines. Structured programming, procedures, programming languages, compilers - all happened on real computers.
Using (or even thinking about using) the UTM for any practical application would be a huge PITA and nobody ever does it. We only know that it's "possible" and hence if we want to prove something general about all possible computation, it suffices to do some magic with the UTM.
Without the common mathematical language necessary to reason and talk about computation in the general case, and Babbage-linage programmers would have been at a severe disadvantage.
Not sure about that.
The Analytical Engine was capable of arithmetics and conditional branching. Code and input data were to be read from punched cards.
Such machine was quite practical and if Babbage managed to build it, it would immediately get used for some number crunching - scientists and businesses would love a calculator which can autonomously eat streams of data and perform boring computations on them.
Babbage and Lovelace were aware that AE can be used to process numerically encoded non-numeric data, so it would also find uses in text processing. Sooner or later somebody would invent Fortran and COBOL (after all, early compilers were pretty much string rewriters) and we would be headed to land in same place we actually did.
Only CS PhDs would waste their time on attempts to algorithmically solve the halting problem instead of "wasting" it on the P=NP debate.
Linux defaults to -O2, -Os can be switched with CONFIG_CC_OPTIMIZE_FOR_SIZE. Arch Linux doesn't enable it, dunno about others.
-Os isn't a silver bullet since it enables use of some high level instructions which may be implemented less efficiently on modern CPUs and reduces code alignment possibly causing some short functions or loops to span multiple cache lines.
I was once debugging some issue with my laptop's multimedia buttons driver. I found some tweak which helped: enable the tweak, reboot - works fine, disable tweak, reboot - no go. Tested repeatedly several times.
I filed a bug report and received an answer that my tweak absolutely cannot work. The tweak was disabled at the time and the button didn't work. I pressed it again after reading this email and boom - it works.
I swear.
I figure my mind must have been believing so much in futility of pressing this button that it didn't even bother pushing it all the way down. Scary stuff.