Differences between EMT64 and AMD64

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LocoDelAssembly
Your code has a bug

Joined: 06 May 2005
Posts: 4624
Location: Argentina

LocoDelAssembly 17 Oct 2005, 13:30

Is there any difference between EMT64 and AMD64? I mean, any code for AMD64 will work for EMT64 and vice versa?

Regards,
LocoDelAssembly

17 Oct 2005, 13:30

Tomasz Grysztar

Joined: 16 Jun 2003
Posts: 8250
Location: Kraków, Poland

Tomasz Grysztar 17 Oct 2005, 13:52

In general, yes. There are some small differences, though. For example EM64T initially didn't include the NX bit feature - I haven't checked whether they added it, but in my opinion they really should. On the other hand, Intel included a few instructions that didn't exist in the AMD64 specification - like 80-bit far jumps and calls or CMPXCHG16B.

17 Oct 2005, 13:52

HyperVista

Joined: 18 Apr 2005
Posts: 691
Location: Virginia, USA

HyperVista 17 Oct 2005, 14:13

NX bit protection is now provided in EM64T. This link provides some documentation http://cache-www.intel.com/cd/00/00/14/93/149307_149307.pdf

17 Oct 2005, 14:13

MazeGen

Joined: 06 Oct 2003
Posts: 977
Location: Czechoslovakia

MazeGen 17 Oct 2005, 14:23

Check also this out.

17 Oct 2005, 14:23

LocoDelAssembly
Your code has a bug

Joined: 06 May 2005
Posts: 4624
Location: Argentina

LocoDelAssembly 18 Oct 2005, 13:00

Well apparently for user code there is no difference except for CMPXCHG16B and, LAHF & SAHF??? I have recently bought a new computer with Athlon64 Venice core (yes, it supports SSE3 Very Happy

) so I will test LAHF & SAHF to see what happend. The problem is I don't have any 64 bit OS yet Sad

Thanks for the data guys!!

18 Oct 2005, 13:00

SDragon

Joined: 13 Sep 2005
Posts: 19
Location: Siberia

SDragon 24 Oct 2005, 09:27

http://www.theregister.co.uk/2005/08/23/intel_fixes_em64t/

24 Oct 2005, 09:27

vid
Verbosity in development

Joined: 05 Sep 2003
Posts: 7105
Location: Slovakia

vid 03 Apr 2007, 22:11

moved from Heap to Main

03 Apr 2007, 22:11

asmfan

Joined: 11 Aug 2006
Posts: 392
Location: Russian

asmfan 04 Apr 2007, 05:39

Wiki x86-64

_________________
Any offers?

04 Apr 2007, 05:39

m

Joined: 28 Dec 2006
Posts: 304
Location: in

m 05 Apr 2007, 10:43

vid wrote:

moved from Heap to Main

Vid how do you do that ?
Can I also move other people's threads ?
Plz !

_________________
Attitude!

05 Apr 2007, 10:43

vid
Verbosity in development

Joined: 05 Sep 2003
Posts: 7105
Location: Slovakia

vid 05 Apr 2007, 10:51

m: no, only moderators can do that

05 Apr 2007, 10:51

m

Joined: 28 Dec 2006
Posts: 304
Location: in

m 05 Apr 2007, 10:56

How to become one ?

05 Apr 2007, 10:56

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