calindro / emulicious Goto Github PK

Some of the solo notes cut out instead of fading and bending during the menu.

I'm looking at one of the decompressors for Exomizer compression, which uses data to rewrite opcodes depending on whether PC flows into the data byte or jumps into the opcode. For example:

get5    push    hl
        ld      hl, 1
        defb    56
setbit  add     hl, hl
        dec     a
        jr      nz, setbit

In WLA DX form:

get5:
  push hl
    ld hl, 1
.db 56
setbit:
    add hl, hl
    dec a
    jr nz, setbit

Here the 56 converts the opcode to jr c, +$29 which I think is never taken, thereby skipping the add hl,hl in a shorter and faster way than an explicit jump. However in Emulicious' debugger, it seems unable to trace execution when it is at the setbit label and shows this when PC is at setbit:

Source - compilable but not doing anything meaningful: deexoopt_f3_sms.zip