FORTRAN Language Compiler Options

-C

Generates code that checks for correct array subscripting at run-time. This option slows program execution.

-bigswitch

Allows large computed GOTO statements by forcing the compiler to use a 32-bit offset. The default is a 16-bit offset, which is smaller and faster but fails if any of the labels is too far away.

-nobigswitch

Uses a 16-bit offset which does not allow large computed GOTO statements.[default]

-d_line

Compiles lines starting with d, D, x, or X. The default is to treat them as comments. This option enables debugging statements.

-dod

Enables the DoD FORTRAN extensions. This is implied by -vms.

-nodod

Disables recognition of the DoD FORTRAN extensions. The DoD extensions are also part of the VMS FORTRAN extensions enabled by -vms.

-extend_source

Extends source to interpret columns 1 through 132 instead of 1 through 72.

-i2

Sets the type for INTEGER to INTEGER*2. The default is INTEGER*4.

-i4

Sets the type for INTEGER to INTEGER*4.[default]

-namelist

Enables the IBM and VMS compatible NAMELIST extensions in FORTRAN. These extensions are enabled by the -vms option, and so this option is only needed when -novms is active.

-nonamelist

Disables the IBM and VMS compatible NAMELIST extensions in FORTRAN. These extensions are enabled by default by the -vms option.

-onetrip

Executes at least one iteration of every DO loop. By default, when the lower bound index of a DO loop is greater than the upper bound index, the compiler does not execute the DO loop, for compatibility with the ANSI FORTRAN-77 standard. This option is required for some older FORTRAN-66 programs to operate properly.

-save

Allocates all local variables to permanent memory, equivalent to coding SAVE at the start of every subroutine or function for compatibility with older FORTRAN compilers. With this option, variables retain their values between calls to subroutines or functions. [default]

-nosave

Allocates local variables to registers or stack, equivalent to coding IMPLICIT AUTOMATIC (A-Z) at the start of every subroutine or function. Programs compiled with this option are compliant with ANSI FORTRAN-77 and in some cases execute more quickly.

-U

Does not convert uppercase user-supplied variables to lowercase. By default, FORTRAN is not case sensitive and all FORTRAN names are converted to lowercase. The compiler and library both assume that this translation is performed. This option accesses variables defined in C as uppercase. However when you use this option, all FORTRAN keywords must be in lowercase, making the compiler incompatible with the ANSI FORTRAN-77 standard.

-u

Makes "undefined" the default data type for undeclared variables, equivalent to coding IMPLICIT UNDEFINED(A-Z) at the top of the source file.

-vms

Selects VMS compatibility mode.[default]

-novms

Selects UNIX F77 FORTRAN compatibility mode.


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