Re: announce: my very first disassembler now available (GPL)

On Aug 20, 10:59 pm, "H. Peter Anvin" <h...@xxxxxxxxx> wrote:
Alexei A. Frounze wrote:

48 90 = rex.w nop = xchg rax,rax

Should be a NOP effectively.

49 90 = rex.wb nop = xchg rax,r8

Same here.

Not a NOP, certainly...

Oops, sorry, missed B. So, it's an XCHG,

So, did you do the last two under a debugger? If you did, on what CPU
brand? Intel, AMD or both?

Not under a debugger, but yes, I executed them (inside a small C
program). AMD Athlon X2 4200+ (socket 939).

Then what? The AMD doc confirmed and opcode 0x90 can indeed represent
either NOP or XCHG?

Alex
.

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