HP Fortran 90

To generate 32-bit mode code to run on HP-UX 64-bit systems, no new compiler command line options are required.

To compile in 64-bit mode, use the +DA2.0W command line option.

There are no HP Fortran 90 language differences between 32-bit and 64-bit programs. Recompiling should suffice to convert a 32-bit Fortran program to run as a 64-bit program.

HP Fortran 90 and HP C Data Types

Whereas using the +DA2.0W option to compile HP Fortran 90 programs in 64-bit mode has no effect on Fortran data types, the C language has some differences in data type sizes. If your Fortran program calls functions written in C and is compiled in 64-bit mode, the size differences may require promoting data items that are passed to or from the C functions.

Table 2-4 “Size Differences Between HP Fortran 90 and C Data Types” shows the differences between the corresponding data types in HP Fortran 90 and C when compiling in 32-bit mode and in 64-bit mode. Table 2-5 “Size Differences After Compiling with +autodbl” shows the differences when the Fortran program is compiled with the +autodbl option. (The +autodbl option increases the default size of integer, logical, and real items to 8 bytes, and double precision and complex items for 16 bytes.)

Table 2-4 Size Differences Between HP Fortran 90 and C Data Types

HP Fortran 90 Data Types	C Data Types		Sizes (in Bits)
HP Fortran 90 Data Types	32-Bit Mode	64-Bit Mode	Sizes (in Bits)
`INTEGER`	`int` or `long`	`int`	32
`INTEGER*4`	`int` or `long`	`int`	32
`INTEGER*8`	`long long`	`long` or `long long`	64
`REAL`	`float`	`float`	32
`DOUBLE PRECISION`	`double`	`double`	64
`REAL*16`	`long double`	`long double`	128

Table 2-5 Size Differences After Compiling with +autodbl

HP Fortran 90 Data Types	C Data Types		Sizes (in Bits)
HP Fortran 90 Data Types	32-Bit Mode	64-Bit Mode	Sizes (in Bits)
`INTEGER`	`long long`	`long`	64
`INTEGER*4`	`int` or `long`	`int`	32
`INTEGER*8`	`long long`	`long`	64
`REAL`	`double`	`double`	64
`DOUBLE PRECISION`	`long double`	`long double`	128
`REAL*16`	`long double`	`long double`	128

New Fortran 90 Features

The following are new features included in the HP-UX 11.0 release:

Table 2-6 New and Changed HP Fortran 90 Features

Feature	What it Does
`+DA2.0W`	Compiles in 64-bit mode for the PA-RISC 2.0 architecture.
`+DA2.0N`	Compiles in 32-bit mode (narrow mode) for the PA-RISC 2.0 architecture.
`+hugesize`	Lowers the threshold for huge `COMMON` blocks allocated to the huge data space (`.hbss`).
`+hugecommon=``name`	Allocated specific `COMMON` blocks to the huge data space (`.hbss`).

In addition, HP Fortran 90 adds new parallelization directives, library calls, fast math intrinsics, and optimization options.

For More Information:

See the HP Fortran 90 Release Notes for information about huge data.
See the HP Fortran 90 Programmer's Reference for information about command-line options.

HP Fortran 90

Technical documentation

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HP Fortran 90 and HP C Data Types

New Fortran 90 Features

For More Information: