computer puzzle - ‘‘Loopy’’ C loop

What is the smallest number of non-space characters that can be added in order to change the following code into a complete C program that prints  LoopyLoopyLoopyLoopy?

#include
main(){
<-- ^
| @ |
v --> printf("Loopy");}

Starts as: 5 lines with no leading spaces, totaling 52 non-space characters and 5 within-line spaces.

Possible edits (additions that don't move the original characters):
•   Single non-space characters may replace any of the 5 original spaces.
•   Spaces and non-space characters may be added to the ends of lines.

No-nos and pedantry:
•   No commenting.
•   No additional " quotation marks.
•   No new lines. (Intended, but not made explicit, in the original puzzle statement.)
•   All syntax should abide by The C Programming Language, 2nd Edition, Kernighan & Ritchie.
•   If any variables are used before they are initialized, the program should be successful with any initial values for those variables.

_{Notes about the original puzzle statement: The word visible was used instead of instead of non-space. Adding lines was unintentionally allowed as a newline would count as a character added to the end of an existing line. The line #include could have been left out for a more streamlined version of essentially the same puzzle, as mentioned by Arkku.}

Answer

In accordance with the updated rules:

#include
main(){int v=4;for('\
<-- ^\
| @ |';v;)
v --> printf("Loopy");}

The original rules (in effect at the time of posting this) unintentionally permitted adding a newline character to the end of a line, which enabled:

#include
v;
main(){for(;-8
<--v^0;'\
| @ |')
v --> printf("Loopy");}

(16 if adding a newline character to end of line counts as space, 17 if it counts as a non-space.)

Note: The type of the global v defaults to int and is implicitly initialized to zero in ANSI C (the standard at the time of K&R 2nd edition) due to static duration.

If it were permitted to insert a single non-space character between two non-space characters:

#include
main(v){for(;-8
<--v^0;'\
| @ |')

v --> printf("Loopy");}

This with the caveat:

The program must be run without arguments in an environment that passes 1 as the initial argument of main in that case. (As discussed in comments, this is permitted.)