sir my confusion is you are saying
1. g(xi) is being computed,and after that f(()).
lets say the above is line no 1. This above line is happening precisely 5 times from x1 to x5 in one instance(assuming both instances are running simultenously,I am considering this instance only).
so g(xi) 5 times and f(()) 5 times.That means i am considering g(xi) and f() as 2 phases in 1 instruction,one is 5ns and another is 3ns,so max taking 5ns,and so 5 instructions in 1 instance.Now i dont know the stages but i can say only at the execution stage of g(xi) i can get the Operand fetch phase of f(),so for 5 instruction it should be (1*2 + (5-1)*1)*5ns =30 ns?
so my confusion is one functional unit equivalent to one phase of an instruction? (the instruction being f(g(xi))) ?