AMD Releases Hammer documentation

Jonathan Graham writes: "Last Thursday AMD posted the five volume architectural manual to their new x86-64 processor on their website. The tomes are as follows: Application Programming, System Programming,General Purpose and System Instructions,128-bit Media Instructions and 64-bit Media and x87 Floating Point Instructions. Gentlemen...start your compilers! (or start writing them!)"

Comments

What a waste

[Demona]

gcc for Linux has those -i486, 586 and 686 flags, but no -amd flag, so it would seem that your spiffy Duron or Athlon doesn't take advantage of any of the chip's special features, essentially running it like a dumb fast legacy chip. That ain't my idea of efficiency. How many years did it take for the Pentium optimizations to make their way from an IBM lab into egcs and finally the mainstream gcc? By that time, AMD's were selling like hotcakes, especially among the build-your-own crowd. And this was when the dot com bubble was still growing, so it's a real shame AMD didn't stick a few developers on the necessary gcc work for that platform -- now that they're currently releasing the XP's and working on Hammer while phasing out Durons, the timing would have been perfect to release what they had for the older chips and work with the community on integrating it.

But as the roommate said, if you bothered trying to optimize your software for PC hardware it'll take you at least a year or two, by which time the hardware will be 'hopelessly outdated'. In the meantime, we get laptops that are nothing more than gigahertz crotch-warmers and desktops that are 2 gigahertz room-warmers, effectively dropping jet engines into lawnmowers and seeing a lot of energy diappear into a black hole called FALSE PROGRESS.

Re:What a waste

[droidix]

gcc does have -march=athlon though

Re:What a waste

[leviramsey]

gcc for Linux has those -i486, 586 and 686 flags, but no -amd flag

You're not using gcc-3.2, are you?

gcc-3.2 has both -mcpu=athlon and -march=athlon flags.

Yeah, gcc-2.95 won't optimize for athlon, but the only excuse for using an outdated compiler like that is if you're a debian user, in which case you don't give a shit about keeping up with the joneses, anyway.

Re:What a waste

[Demona]

Obviously, I wasn't aware of that, or I wouldn't have said what I said. I stand corrected. However, I use Debian, and a whole lot of other Linuxes, and BSD, and Windows, and other OS's where appropriate, so your attempt at being witty comes across as dismissive, juvenile and rude. Big fat surprise, eh? I'll just invoke Godwin's Law now and note that if Hitler used Linux, the Slashbots would have helped write software to send Jews to the gas chambers...

Re:What a waste

[leviramsey]

My apologies for the gratuitous distro flame. Many/most of the debian users I talk to (especially those who are still running potato), when I start talking about how great the latest GNOME/KDE/mozilla/XFree/kernel versions are essentially take the attitude of "so what, kernel 2.2.17 is working fine for me." From this, I deduce that debian users don't necessarily care about having the latest versions of software. I'm not knocking this mindset, but the vaunted stability of Debian has its counterpoints, and this is one of them. OTOH, I run Mandrake's development branch (Cooker being somewhere between Sid and Sarge), and get the latest and greatest (or only a few steps from the edge) versions and damn fine stability to boot... diff'rent strokes for diff'rent folks.

Re:What a waste

[Demona]

My thoughts precisely, and thanks for your clarification and gracious apology. My first thought on hearing mention of gcc3.2 was, "How many distros use it as default?" I know Gentoo's working on it for their next version, but they're already notorious for being bleeding-edge. As you see, for both my personal use and in various work settings I prefer a mix of current, recent and older software; but of course there are tons of institutions out there who move far slower, and rely far more heavily on things staying the same. (Witness the infinite COBOL, mainframe and assorted other discussions that always come up when someone assumes that history started with the PC...) As you say, the right tool for the right job.

More to the point, now that I know about -march for Athlons, I'll search it out and give it a try on a test machine. Thanks for the information.

Re:What a waste

[Lars T.]

Uh-oh, a new wave for the trolls: first apology.

Oh, of course...

[Demona]

...the Slashbot consensus now is, not only do cool people use only Linux, but cool people only use PC-compatibles. Sort of like the riceboys who get a big kick out of their souped-up piece of crap that a real engineered vehicle leaves in the dust. (Note: By piece of crap, I am referring to PC hardware, not Linux. If you don't see this as a contradiction, you may have two brain cells to rub together.)

Re:Oh, of course...

[HughsOnFirst]

>4cyl engines that red-line at 3500rpm (totally
>guessing...
I had an old 1986 Civic that I gave to one of my coders ( cheaper than junking it ) that was quite happy to rev to 6500 rpm for minutes at a time.
7000 between shifts. I could not blow it up if I tried, and I _did_ try. I heard he drove it from NYC to Maine every weekend for a couple years after I gave it to him.
Some new Hondas go up to 9000 rpm.

I however am quite happy with my Volvo turbo wagon. The only thing faster than the Honda engine was the rust on my Honda.

Re:Oh, of course...

[cant_get_a_good_nick]

I think you need to differentiate between "souped up" and "I want it to look like this is souped up". Most souped up cars are fairly subtle, don't want to catch any unwanted attention from the cops.

The "rice boyz", the dorks who trick their cars out, do stupid stuff:

• Add a huge exhaust pipe when their engine isn't modded. This decreases performance from the increased back pressure. But it he heh, looks cool. Heh... dooood.
  
• Huge spoked rims on drum brakes. No real racer would have drum brakes, too fade prone. Worse is when they paint the drums body color, which infinitessibly hurts performance (more unsprung weight, more rotational inertia) and makes heat dissipation not as efficient, so slightly adds to fading.
  
• The wings, all they do is add drag. Why have on a front wheeel drive car? Pressure is friction, but in a front driver, they don't help much. You'll bite at the back. I guess in some respects it is good, cause it will slow the morons down and give them understeer, so they won't be idiots and fishtail into oncoming traffic.
  
• Super low sidewall tires. They help cornering, but do shit to ride quality. Hope they jar their fillings out.
  
• High colored interiors. Saw one car with a bright yellow interior. Imagine the reflections off that? There's a reason everything in a real car is boring flat black, nothing to distract you.
  

GCC already supports x86-64

[vojtech]

Why talk about athlon optimizations? GCC already supports the x86-64 arch, and Linux runs on it, see http://www.x86-64.org

Virtualization?

[phr2]

I looked at the table of contents for the system programming manual and don't see any features for supporting self-virtualization beyond what's in the Pentium etc. I wonder what kinds of hoops it will take to make something like Plex86 virtualize the 86-64. I wish they'd add some hardware virtualization features since with these big processors, running multiple 'partitions' becomes more and more important.

I also notice that cycle counts aren't specified for the fancier arithmetic instructions like MUL and the multimedia instructions. Those make a big difference in the performance of graphics and signal processing applications including audio compression and so forth. So I guess we'll have to wait to see benchmarks.

Re:Old news.

[Phosphor3k]

Guess I should have hit the links first. Didnt realize they link to pdfs. If you go to amds order page, you can get any documentation they offer (so they say) in book form, for free.Here's a link to the x86-64 5 volume order page:

http://sausmaps.amd.com/AMDeMA/www/cpg_tech_manu al_order_form.jsp

Personally, I perfer my documentation in book, not electronic form.

80's Has-been Joke

[Mignon]

AMD Releases Hammer documentation

So what they're saying is, "You can touch this," right?

gcc already supports the amd x86-64

[Per Abrahamsen]

See gcc news.

Sheer sexism

[The_Guv'na]

Gentlemen...start your compilers! (or start writing them!)"

What, so no females use/develop linux? Maybe it seems like that...

Ali

Re:Sheer sexism

[oliverthered]

Ok seeing as you failed your English (like me)...

him/man is the indefinite neuter
her/she is the definite neuter.

Gentlemen is correctish just like
Fire man, post man, She's your man, There are twelve men in the all woman team. take you men...

America and her army,
She sailed today (referring to a ship).
She's a beauty....

Another tip on -march/-mcpu

[devphil]

Current development sources recognize athlon* as a cpu type. So instead of i686-pc-linux-gnu, I tell build gcc for athlon_mp-pc-linux-gnu, and by default it uses the -march and -mcpu options that turn on the Athlon MP extensions like SSE and whatever.

Use "gcc -v" to see what triplet you're using.

This is /not/ in 3.2. I'm not even certain if it's in 3.3.

SMP threading and process management

[oliverthered]

Did you spot any improvements to threading and SMP? More fine grained cache management, read-write states. easier state switching between processes/threads. etc.... Why do you think Intel is hyperthreading there core? so that next time round they can realy put two processers in there and sort out the threading men from the boys.

My 2x2.5Ghz beats your 1x5Ghz