"Diffable" constant replacement with false positive

[hopperpl]

The "diffable" 64-bit replacement modifies a constant it shouldn't (false positive).... this is not an address, it's a bit mask (should be 0x0707070707070707)

Maybe check if the to-be-replaced constant is pointing to code? Also doesn't really matter. This may only happen for the pdep instruction anyway.

[Yoticc]

This is an inherent issue with JitDisasm, and it is incredibly difficult to fix within the plugin.

[Yoticc]

I also see that "pdep" is not highlighted in your screenshot.

This strange behavior is something I cannot explain. I tried to recreate your issue and succeeded. However, "pdep" is highlighted in my case. Is it a problem with your local version?

[Yoticc]

Disasm code related to the diffieable feature.
https://github.com/dotnet/runtime/blob/main/src/coreclr/jit/disasm.h#L191

It seems incredibly simple, so in fact any absolute non-zero value will be converted to a diffeable. Here is a clear example:

[hopperpl]

not sure, 5.9.2 should be the latest release.

[Yoticc]

not sure, 5.9.2 should be the latest release.

Hmm, I am not sure, but maybe the plugin did not update properly. Because the AsmSyntax.xshd file contains all these instructions

[hopperpl]

just noticed it was actually me adding those... I have to check, maybe I have some local override messing this up

b1a84c1

[hopperpl]

found the issue:

the last official release in the store was 15/01/2024, 02:54:17, and the PR adding those mnemonics was Jan 18, 2024 or 3 days later...