Category
Purpose
Specifies whether external subprograms may be called recursively.
Not recommended.
Syntax
.-norecur-. >>- -q--+-recur---+--------------------------------------------><
@PROCESS:
@PROCESS RECUR | NORECURDefaults
-qnorecur
Usage
For new programs, use the RECURSIVE keyword, which provides a standards-conforming way of using recursive procedures.
If you specify the -qrecur option, the compiler must assume that any procedure could be recursive. Code generation for recursive procedures may be less efficient. With the RECURSIVE keyword, you can specify exactly which procedures are recursive.
When you use the following commands to compile programs
that contain recursive calls, specify -qnosave to
make the default storage class automatic:
- For .f, .F, .f77 and .F77 files: xlf
- For any source files: f77 and fort77
Examples
! The following RECUR recursive function:
@process recur
function factorial (n)
integer factorial
if (n .eq. 0) then
factorial = 1
else
factorial = n * factorial (n-1)
end if
end function factorial
! can be rewritten to use F90/F95 RECURSIVE/RESULT features:
recursive function factorial (n) result (res)
integer res
if (n .eq. 0) then
res = 1
else
res = n * factorial (n-1)
end if
end function factorial