How can i use the gcc create the instruction what i want ?

just create the simple instruction, just like add cal and so on.
do not rely on the platform.

or i want to know where i can find help ,what i should learn~~in that manual i was lost~~

i just wanna make a simple system in a simple machine,it has the require condition.


cal int/byte/flo mul/sub/add/div A,B
jmp S
jpz N (condition)
cmp
ret
call
ld (load)
pop
push

and some others

it has a 4m flat memory 32bit

so how can i do it?