Elimination of if-else for improving performance in pipelined architecture

My professor insists on writing code which is "truly sequential" by omitting use of "if-else" constructs or "looping" constructs.
His argument is that any branch instruction causes a pipeline flush and is inefficient.
He suggested use of signals and exception handling.
Also use certain flags viz, Overflow flag, sign flag, carry flag to replace if-else conditions.
My question is whether such a program is feasible. If YES is it really efficient?
Examples would be helpful.