" Run this as
"    vim -S fixTailCalls.vim myAssemblerFile.s
"
" Changes
" 	rcall xx/ret 
" to
" 	rjmp xx
" and
" 	rcall xx/.Lyy:/ret 
" to
" 	.Lyy: rjmp xx
"
" and removes doubled ret calls.
"
" save a backup file
w %.bak
" remove comments too; it's easier this way.
g/\/\*.*\*\//d
" condense repeated newlines
1,$s#\n\n#\r#e
" rcall/label/ret => label/rjmp
1,$s#^\(\s\+\)rcall\s\+\(\S\+\)\n\(\s*\.L\d\+:\)\s*\n\s\+ret\s*$#\3\r\1rjmp \2\r#e
" rcall/ret => rjmp
1,$s#^\(\s\+\)rcall\s\+\(\S\+\)\n\s\+ret\s*$#\1rjmp \2\r#e
" ret/ret => ret
1,$s#^\(\s\+\)ret\s*\n\s*ret\s*$#\1ret\r#e
" write changed file
w
" and quit
q