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Multiple disassembler errors on vector instructions #2266
This is actually more related to Zydis rather than x64dbg directly nevertheless it's an interesting case. By looking at syntax used in your example code I assume you were using MASM64 to compile that. The problem is that MASM is quite permissive and allows you to specify things like zeroing-mask in places where you should not be allowed to do so, generating invalid instructions as a result.
If you look up VMOVAPS in Intel's manual you can find that following encoding is allowed:
Therefore according to official documentation those instructions
are all INVALID, so Zydis handles them correctly by failing to recognize them.
Were you able to test how those instructions behave on real hardware? Unfortunately I don't have any CPU with AVX-512 support to check this. I would expect that they either cause #UD or silently ignore EVEX.z. In latter case it would mean that there are valid yet undocumented alternative encodings not only for VMOVAPS but for several other AVX-512 instructions with similar semantics.