[Bug] rep instruction

[shaynox]

I found a bug, nasm don't detect this error (not mov):

Code: [Select]

            mov     rcx, 1
            rep     vmovups     ymm0, ymm0

In manual of intel it's false but even so by curiosity I run this block of code and it crash (unfortunately x) )

[encryptor256]

I found a bug, nasm don't detect this error (not mov):

Code: [Select]

            mov     rcx, 1
            rep     vmovups     ymm0, ymm0

In manual of intel it's false but even so by curiosity I run this block of code and it crash (unfortunately x) )

Nice catch, shaynox!

I wouldn't call it: "error".
REP is a prefix and looks like - is not affecting rest of the instruction bits n bytes.
But that's right: "nasm don't detect".
But maybe you can find some applications for this permission to add REP prefixes.

I run this block of code and it crash (unfortunately x) )

Interesting... Then what kind of result you were expecting?

[shaynox]

Thanks ^^

Nothing, it just crash, I don't know what kind of error, windows ask to me if I want to debug but no time for that

And if I run this instruction on my OS, I think than it will make a reset of CPU.