subroutine whenxxx(n,array,step,target,index,nindex) integer function isrchxxx(n,array,step,target)The when routines return the indices of all locations in an array that have a ``true relational value'' to the target. See page 4-64 of the Cray ``Library Reference Manual'' for more information. The isrch routines return the first location in an array that has a ``true relational value'' to the target. See page 4-59 of the Cray ``Library Reference Manual''. For both routines, ``xxx'' can be one of ieq, ine, ilt, ile, igt, ige, feq, fne, flt, fle, fgt or fge. These give the type of array (Integer or Floating), and the relation (equal, not equal, less than, etc).
Because these are well optimized routines, these routines should be used in preference to straightforward FORTRAN code that performs an equivalent function.