Has anyone tested the efficiency of MERGE function?

REAL::X(100,5)
INTEGER::IS,K
IS=merge(MINLOC(X(:,K)),MAXLOC(X(:,-K)),K>0)

! its equivalent is

IF(K>0)THEN
   IS=MINLOC(X(:,K))
ELSEIF(K<0)THEN
   IS=MAXLOC(X(:,-K))
END IF

! but it seems the later has better efficiency.