Preprocessor symbols (macros) let you substitute values in a program before it is compiled. The substitution is performed in the preprocessing phase.
Some preprocessor symbols are predefined by the compiler system and are available to compiler directives and to fpp. If you want to use others, you need to specify them on the command line.
You can use the -D (Linux* and Mac OS*) or /D (Windows*) option to define the symbol names to be used during preprocessing. This option performs the same function as the #define preprocessor directive.
Preprocessing replaces every occurrence of the defined symbol name with the specified value.
For more information, see the following topic:
D compiler option
You can use the -U (Linux and Mac OS) or /U (Windows) option to suppress an automatic definition of a preprocessor symbol. This option suppresses any symbol definition currently in effect for the specified name. This option performs the same function as an #undef preprocessor directive.
For more information, see the following topic:
U compiler option
Windows Systems:
The following information applies to Windows systems.
In addition to specifying preprocessor symbols on the command line, you can also specify them in the Visual Studio* integrated development environment (IDE). To do this, select Project>Properties and use the Preprocessor Definitions item in the General Options or Preprocessor Options category.
The following preprocessor symbols are available:
| Predefined Symbol Name and Value | Conditions When this Symbol is Defined |
|---|---|
|
__INTEL_COMPILER=910 |
Identifies the Intel Fortran compiler |
|
__INTEL_COMPILER_BUILD_DATE=YYYYMMDD |
Identifies the Intel Fortran compiler build date |
|
_DLL=1 |
Only if /libs:dll, /MDs, /MD, /dll, or /LD is specified, but not when /libs:static is specified |
|
_MT=1 |
Only if /threads or /MT is specified |
|
_M_IX86=n00 |
Only for systems based on IA-32 architecture; n is the number specified for /G (for example, _M_IX86=700 for /G7) |
|
_M_IA64=64n00 |
Only for IA-64 architecture based systems; n is the number specified for /G (for example, _M_IA64=64100 for /G1) |
|
_M_X64 |
Only for systems based on Intel® 64 architecture. For use in conditionalizing applications for the Intel® 64 platform. |
|
_M_AMD64 |
Only for systems based on Intel® 64 architecture. This symbol is set by default. |
|
_OPENMP=200505 |
Valid when OpenMP processing has been requested (that is, when /Qopenmp is specified) Takes the form YYYYMM where YYYY is the year and MM is the month of the OpenMP Fortran specification supported. This symbol can be used in both fpp and the Fortran compiler conditional compilations. |
|
_PGO_INSTRUMENT |
Defined if /Qprof_gen is specified |
|
_WIN32 |
Always defined |
|
_WIN64 |
Only for systems based on Intel® 64 architecture and systems based on IA-64 architecture |
|
_VF_VER=910 |
Valid when Compaq* Visual Fortran-compatible compile commands (df or f90) are used |
When using the non-native IA-64 architecture based compiler, platform-specific symbols are set for the target platform of the executable, not for the system in use.
Linux and Mac OS systems:
The following information applies to Linux and Mac OS systems.
| Symbol Name | Default | Architecture (IA-32, Intel® 64, IA-64) | Description |
|---|---|---|---|
|
__INTEL_COMPILER=n |
On, n=910 |
All |
Identifies the Intel Fortran Compiler |
|
__INTEL_COMPILER_BUILD_DATE |
|
All |
Identifies the Intel Fortran Compiler build date |
|
__linux__ (Linux only) |
|
All |
Defined at the start of compilation |
|
__APPLE__ (Mac OS only |
|
IA-32 |
Defined at the start of compilation |
|
__i386__ |
|
IA-32 |
Identifies the architecture for the target hardware for which programs are being compiled |
|
__ia64__ (Linux only) |
|
IA-64 |
Identifies the architecture for the target hardware for which programs are being compiled |
|
__x86_64 |
|
Intel® 64 |
Identifies the architecture for the target hardware for which programs are being compiled. |
|
_OPENMP=n |
n=200505 |
All |
Takes the form YYYYMM, where YYYY is the year and MM is the month of the OpenMP Fortran specification supported. This preprocessor symbol can be used in both fpp and the Fortran compiler conditional compilation. It is available only when -openmp is specified. |
|
_PGO_INSTRUMENT |
Off |
All |
Defined when -prof_gen is specified. |
|
__PIC__ |
Off (Linux), |
All |
Set if the code was requested to be compiled as position independent code. On Mac OS systems, these symbols are always set. |