Can someone tell me what "mov ebx,[edi+edx]" does in this program and if there is another to do what it does? In debugger it advances EIP from 004036E5 to 004036E7 NO other registers are effected. I got this to work in my program by trial and error but would like to know how? (Assembly x86 MASM)

mov ecx,LENGTHOF arrayQ/4 ;// ecx counter set to 3

mov edi,OFFSET arrayQ ;// first element of arrayQ moved to edi

L3: ;// destination label for loop L3

sub edx,TYPE arrayQ ;// decrement edx by TYPE of arrayQ which is DWORD=4

mov eax,[edi] ;// moves element stored in eax into dereference edi

mov ebx,[edi+edx] ;//

mov [edi],ebx ;//

add edi,edx ;//

mov [edi],eax ;//

sub edi,edx ;//

add edi,TYPE arrayQ ;//

sub edx,TYPE arrayQ ;//

Loop L3 ;//