vim -u profile.vim

profile.txt

FUNCTION  Profile1()
    Defined: ~/Documents/Source/playground/profile.vim line 2
Called 1 time
Total time:   2.985510
 Self time:   2.985510

count  total (s)   self (s)
    1              0.000020   let a = 'a'
    1              0.000002   let b = 'b'
    1              0.000001   let c = 'c'
1000001              0.771685   for n in range(1, a:1)
1000000              1.552987     silent echo a . b . c
1000001              0.504516   endfor

FUNCTION  Profile2()
    Defined: ~/Documents/Source/playground/profile.vim line 10
Called 1 time
Total time:   3.919718
 Self time:   3.919718

count  total (s)   self (s)
    1              0.000004   let a = 'a'
    1              0.000001   let b = 'b'
    1              0.000000   let c = 'c'
1000001              0.768153   for n in range(1,a:1)
1000000              2.499279     silent echo printf('%s%s%s', a, b, c)
1000001              0.504717   endfor

FUNCTIONS SORTED ON TOTAL TIME
count  total (s)   self (s)  function
    1   3.919718             Profile2()
    1   2.985510             Profile1()

FUNCTIONS SORTED ON SELF TIME
count  total (s)   self (s)  function
    1              3.919718  Profile2()
    1              2.985510  Profile1()

profile.vim

set nocp
function! Profile1(...)
  let a = 'a'
  let b = 'b'
  let c = 'c'
  for n in range(1, a:1)
    silent echo a . b . c
  endfor
endfunction
function! Profile2(...)
  let a = 'a'
  let b = 'b'
  let c = 'c'
  for n in range(1,a:1)
    silent echo printf('%s%s%s', a, b, c)
  endfor
endfunction
profile start /Users/israel/Documents/Source/playground/profile.txt
profile func Profile*
se lazyredraw
let times = 1000000
call Profile1(times)
call Profile2(times)
quit!