This document is for version 2021.13 of Intel® Fortran Compiler Classic (ifort) and version 2024.2 of Intel® Fortran Compiler (ifx).
Intel® Fortran Compiler Classic (ifort) is now deprecated and will be discontinued in October 2024. Intel recommends that customers transition now to using the LLVM-based Intel® Fortran Compiler (ifx) for continued Windows* and Linux* 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 Intel® Fortran Compiler Classic (ifort) and its runtime environment, and about Intel® Fortran Compiler (ifx), which is a new compiler based on the Intel Fortran Compiler Classic (ifort) frontend and runtime libraries, 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:
For more information, refer to Introducing the Intel® Fortran Compiler Classic and Intel® Fortran Compiler.
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.
Support for 32-bit targets is deprecated in ifort and may be removed in a future release. ifx does not support 32-bit targets.
macOS is no longer supported for Intel® Fortran Compiler Classic (ifort).
Starting with the 2024.0 release, macOS is no longer supported in Intel® oneAPI Toolkits and components.
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.