Hello. It's seem that the use of an undefined symbol in an dup expression + the use of scaleof trigger a segfault (linux & freebsd).

Hope this help.

Thank you! It's fixed now.

What about
vpsrlq reg, mem, imm
assembling just fine when the processor says #UD on what FASM generates.

You got me a bit confused, as this seems to be completely unrelated to this thread.

Anyway: VPSRLQ reg,mem,imm is a variant only present in AVX-512. You can test this with fasmg, where the instruction does not assemble with AVX2.INC, but assembles with AVX512.INC.

Sorry, you are right - 256 bit shift from memory only in avx 512 . I am getting confused by all of the avx variants, and to make matters worse, my computer runs surprisingly few of them. 52 bit -> 104 bit multiplication sounds good, but, guess what? #UD