+ # extract "reverse gear" for mapreduce mode
+ with m.If((~is_ldst) & # not for LD/ST
+ (mode2 == 0) & # first 2 bits == 0
+ mode[SVP64MODE.REDUCE] & # bit 2 == 1
+ (~mode[SVP64MODE.PARALLEL])): # not parallel mapreduce
+ comb += self.reverse_gear.eq(mode[SVP64MODE.RG]) # finally, whew
+