Table Lookup Compiled -O

vowel:
        sll     %o0,2,%g1
        sethi   %hi(vowels-260),%g2
        add     %g2,%lo(vowels-260),%g2
        retl                    ! Result =  %o0
        ld      [%g1+%g2],%o0   ! volatile

Bottom Line:

switch	46
switch -O	15
Table Lookup	10
Table Lookup -O	5

Table Lookup beats the switch statement in code size and performance; it is also better Software Engineering.