HP Fortran v2.9 for HP-UX 11i v2 Release Note5991-0697

HP Fortran for HP-UX v2.9

What’s in This Version

Chapter 18

Additionally, the following defaults for Tru64 mode were changed:

• +U77 always on

•localsonstack(+save)

• +nopadsrc

• -altparam

For a complete list of the Tru64 options, please refer to the f90(1) man page.

Other new or revised directives/options

The following reflects recent changes/additions to directives and options:

+O[no]failsafe

• This option is now supported for the Itanium

processor family.

• The f90 manpage has been updated to correctly reflect that for the +O[no]failsafe

directive, +Ofailsafe is the default.

+allow_ivdep

The f90 manpage has been updated to include the IVDEP directive.

The IVDEP directive assists the compiler’s dependence analysis. It can only be applied to

iterative DO loops and is only honored when the +allow_ivdep compiler flag is used.

The IVDEP directive takes the following form:

C$DIR IVDEP

Rules and behavior:

The IVDEP directive is an assertion to the compiler’s optimizer about the order of memory

references inside a DO loop.

The IVDEP directive tells the compiler to begin dependence analysis by assuming all

dependences occur in the same forward direction as their appearance in the normal scalar

execution order. This contrasts with normal compiler behavior, which is for the dependence

analysis to make no initial assumptions about the direction of a dependence.

The IVDEP directive must precede the DO statement for each DO loop it affects. No source code

lines, other than the following.