FORTRANX85-0002

This document provides the Release Notes for VSI Fortran X8.5-0002 for OpenVMS x86 Systems, released on February 23, 2023. Targeted at both system managers and application programmers, it details the initial x86 compiler release, which runs on OpenVMS x86 version 9.2 or later and is based on the OpenVMS I64 version.

Key information includes:

• New Features/Changes: Introduction of /ALIGN=COMMONS-PAD_ALIGN_SIZE qualifier for controlling COMMON block padding, and /ASSUME=64BIT_STRING_PARAMS to enable passing all string variables with 64-bit descriptors (with a caution regarding potential Runtime Library issues). IA64, IA64, X86, and X86_64 predefines are now implemented.
• Floating-Point Arithmetic: The default floating-point datatype is IEEE_FLOAT on x86 systems. VAX floating-point formats are now software-emulated (converted to IEEE for operations) due to lack of hardware support, leading to potential performance and accuracy issues; their use is strongly discouraged. Mixed-mode applications are generally not supported on OpenVMS x86-64.
• Known Issues: Several features are not yet fully implemented or have limitations, including runtime overflow checking, full debug support (may cause assertions), correct printing of VAX floating numbers on V9.2, support for quadruple precision floating point (REAL*16), the /SEPARATE_COMPILATION qualifier, and full functionality of the /OPTIMIZE qualifier. The /MACHINE_CODE qualifier is also ignored.

The document also provides information on getting help via the VSI Support Portal or email (info@vmssoftware.com) and notes that the full VSI Fortran documentation set is available online at https://docs.vmssoftware.com/.