New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

uasm encode xchg eax,eax as nop (0x90) in 64 mode #201

Open

ntysdd opened this issue Apr 16, 2024 · 0 comments

Labels

Milestone

ntysdd commented Apr 16, 2024

I believe this is a bug that's there also in MASM.

In 64 bit mode, xchg r32, r32 generally clear upper half of 64 bit registers. So xchg a 32 bit register with itself is not a nop.

Should be encoded as "87 c0"

john-terraspace added this to the V2.57 milestone

john-terraspace added Scheduled Complete and removed Scheduled labels

john-terraspace added a commit that referenced this issue


          update issue #201

d462c24

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment