ive started studying reverse engineering, and in a binary i am trying to reverse i stumbled upon an unusual(to me) line of assembly in IDA PRO. and it looks like this
.text:00000000008A1C21 mov r8d, ds:(off_8A40FC - 400000h)[rcx+rax*4]
so i know that it moves something into the r8 register which is the size of a dword, but i do not understand what it moves into it ? something from the data segment, but im clueless as of how to interpret it, any help would be great.