fetch mul input for inst - 1 < accumulate inst - 3
fetch x regs < fetch y regs < update last z regs < update x regs
update x regs < fetch y regs 
update x reg < fetch z regs
fetch z reg < update y reg
fetch x reg < fetch y reg < last ireg fetch < fetch z reg
last ireg fetch < update x regs
store ireg == fetch last y reg (conflict)
store ireg < store inst-4 zreg
fetch dau flags < accumulate inst-3 or set dau flags == accumlate

fetch & update x & y regs or i regs & flags
fetch x mem for inst - 1 or fetch mem for inst - 1
fetch y mem for inst - 1 or store to mem
update last z reg
fetch z regs
fetch next inst??
store z addr for inst - 4
mul for inst - 2
accumulate or special op && update flags for inst - 3
pc leads by 8