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

Alexei A. Frounze wrote:
On Aug 16, 10:08 pm, "Alexei A. Frounze" <alexfrun...@xxxxxxxxx>
wrote:
There's also a special case in 64-bit mode. Depending on the rex
prefix (AFAIR, bit B) it can be either NOP or XCHG.

I meant to say, if both operands are rAX, then it's NOP. This is
controlled by mod, REX.R (if REX is present), reg, REX.B (if REX is
present) and r/m.

Except, it's not.

Plain 90h, which would normally be XCHG EAX,EAX (and therefore zero-extend EAX into RAX) is actually NOP.

-hpa
.

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