Intel® Fortran Compiler

Developer Guide and Reference

ID 767251
Date 6/30/2025
Public

Visible to Intel only — GUID: GUID-5C971257-3893-46E6-8BA5-0C2C003CA5E5

Document Table of Contents

Overview

This document is for version 2025.2 of the Intel® Fortran Compiler (ifx).

ATTENTION:
The Intel® Fortran Compiler Classic (ifort) was discontinued after the 2024.2 version release. To access past versions of documentation that includes content for the Intel® Fortran Compiler Classic (ifort):

Intel recommends transitioning to the LLVM-based Intel® Fortran Compiler (ifx) for continued Linux* and Windows* support, new language support, new language features, and optimizations. For the latest information on transitioning from ifort to ifx, see the Porting Guide for ifort Users to ifx.

This developer guide provides information about the Intel® Fortran Compiler (ifx), which uses LLVM backend technology.

Refer to the Intel® Fortran Compiler product page and the Release Notes for more information about features, specifications, and downloads.

Use this guide to learn about:

  • Compiler Setup: How to invoke the compiler on the command line or from within an IDE.
  • Compiler Options: Information about options you can use to affect optimization, code generation, and more.
  • Language Reference: Information on language syntax and semantics, on adherence to various Fortran standards, and on extensions to those standards.
  • OpenMP* Support: Details about compiler support for OpenMP 5.2 and some OpenMP Version 6.0 TR12 features.
  • Fortran Language Extensions: Information on using additional implementation features, including creating a Component Object Model server, generating listing and map files, and more.
  • Mixed-Language Programming: Information about Fortran and C interoperable procedures and data types, as well as various specifics of mixed-language programming.
  • Runtime Error Messages: Information about the errors processed by the Intel® Fortran runtime library (RTL).

For more information, refer to the Intel® Fortran Compiler Introduction.

Notices and Important Information

In this document, you may see features labeled as experimental. An experimental feature is one that requires further testing and possible refinement. Depending on testing results, such features may be fully defined and implemented or they may be removed in a future release.

Using the Compiler Documentation

Context Sensitive/F1 Help: To use the Context Sensitive/F1 Help feature, visit the Download Documentation: Intel® Compiler (Current and Previous) page and follow the provided instructions.

NOTE:
For the best search experience, use a Google Chrome* browser to view your downloaded copy of the Intel Fortran Compiler Developer Guide and Reference.

If you use Mozilla Firefox*, you may encounter an issue where the Search tab does not work. As a workaround, you can use the Contents and Index tabs or a third-party search tool to find your content.