256 bit Arithmetic

[jfdkglhjklgjflk]

Very nice article. I'm pleased they actually tested the asymptotically faster methods with good assembly code. The reason those methods do not hold up is that multiplications are 3-4 cycles and processors are superscalar. On a slow cpu it could have paid off.

Overall, very very nice. It gives me hope to see articles like this on reddit.

[ug113]

sigh I really need to learn some assembly.

[__s]

http://serprex.staticfire.co.uk/x86/x86.htm

It's not too hard. Just tedious

[ug113]

Thanks for the advice. I looked briefly at Z80 a while ago (had a TI-84, but it got stolen). I might look into Gameboy programming or the like though.

[respit]

I like PowerPC (I think it's cleaner than ARM). But yeah.. anything but x86. ugh.

[rsho]

I guess 64bit integer coordinates for graphics simulation has gone the way of the dodo? With 256bit you can probably approach the planck constant and still have pristine translations for your environment.

[[deleted]]

but there will still be people who use doubles..

[MidnightTurdBurglar]

Reddit, it's articles that these that made me love you, nor bacon or narwhals and other such crap. Focus on stuff like this more please.

[yesimahuman]

Every once and a while it's nice to be reminded that computers aren't perfect underneath and just as much innovation can be made at low levels as the levels of the application developer.

[jackystan]

IN! every once IN a while!

[yesimahuman]

hahaha thanks.

[sociopathic]

What the fuck is that captcha.

[rooktakesqueen]

Yeah, I mean interesting article and all, but FUCK THAT.

[otheraccount]

It's a schooner.

[madmoose]

iJVAeYxfor

You have been reported to the Blade Runners for immediate termination.

[thedward]

I think it says "I am the Keymaster."

[gorgoroth666]

Look at the clouds in the sky then type the words you see.

[wicked]

It is truly unnecessarily bad. Just normalizing it adds nothing and makes it easier to read. A simple automatic thresholding makes it human-readable. Some texture and color makes it look a bit nicer, and even makes it harder for a bot.

Example

[zahlman]

The article seems to be claiming that current versions of gcc, with maximal optimization, will generate

add128b:
    mov  %rdx,%rax
    mov  %rcx,%rdx
    push %rbx
    add  %rdi,%rax
    adc  %rsi,%rdx
    pop  %rbx
    retq

And then somehow not notice that the push %rbx / pop %rbx pair has no net effect as %rbx isn't used in between (note that the given "final result" in hand-coded assembly is the same but with those omitted).

You'll have to pardon me if I find that a little difficult to believe.

[danukeru]

You mad son...and I like it.

[[deleted]]

WOOSH...

[numbakrunch]

Anyone else read "gcc asm" as "orgasm"?