splitnets - split up multi-bit nets

yosys> help splitnets
splitnets [options] [selection]
This command splits multi-bit nets into single-bit nets.
-format char1[char2[char3]]
the first char is inserted between the net name and the bit index, the
second char is appended to the netname. e.g. -format () creates net
names like 'mysignal(42)'. the 3rd character is the range separation
character when creating multi-bit wires. the default is '[]:'.
also split module ports. per default only internal signals are split.
don't blindly split nets in individual bits. instead look at the driver
and split nets so that no driver drives only part of a net.