/in/foo.c: In function 'main':
/in/foo.c:7:45: warning: 'origy' may be used uninitialized in this function [-Wmaybe-uninitialized]
     return sqrt((ax - bx) * (ax - bx) + (by - ay) * (by - ay));
                                         ~~~~^~~~~
/in/foo.c:15:41: note: 'origy' was declared here
     double prex = -1, prey = -1, origx, origy;
                                         ^~~~~
/in/foo.c:7:21: warning: 'origx' may be used uninitialized in this function [-Wmaybe-uninitialized]
     return sqrt((ax - bx) * (ax - bx) + (by - ay) * (by - ay));
                 ~~~~^~~~~
/in/foo.c:15:34: note: 'origx' was declared here
     double prex = -1, prey = -1, origx, origy;
                                  ^~~~~