Compile time
was measured. My favorite "bug" was the
many minutes it took to compile a constant expression
that involved shifting a constant INT_MAX bits by
performing that many 1-bit shifts.
I don't know if this anecdote is an urban legend or if it really
happened. I was told [a similar] story when I was interning as an operator
at my alma mater, which was an IBM System/360 shop.