The compilers generate code for IA-32 and Intel 64 processors and certain non-Intel but compatible processors, such as certain AMD processors. A specific release of the compiler (11.1) remains available for development of Linux-based applications for IA-64 (Itanium 2) processors. On Windows, it is known as Intel Visual Fortran.[2] On macOS and Linux, it is known as Intel Fortran. In 2020 the existing compiler was renamed “Intel Fortran Compiler Classic” (ifort) and a new Intel Fortran Compiler for oneAPI (ifx) supporting GPU offload was introduced.
The 2021 release of the Classic compiler adds full Fortran support through the 2018 standard, full OpenMP* 4.5, and Initial Open MP 5.1 for CPU only. The 2021 beta compiler focuses on OpenMP for GPU Offload. When used with the Intel OneAPI HPC toolkit (see the "Description of Packaging" below) the compiler can also automatically generate Message Passing Interface calls for distributed memory multiprocessing from OpenMP directives.
For more information on Fortran standards, a number or resources are available, such as the Wikipedia Fortran entry or the Fortran wiki page.
The Intel Fortran package included the Intel Array Visualizer, a visualization tool for scientific formats such as FITS and netCDF, which can produce x-y plots, contour plots, and image plots, and save them to other formats.[3][4]
Optimizations
Intel compilers are optimized[5] for computer systems using processors that support Intel architectures. They are designed to minimize stalls and to produce code that executes in the fewest possible number of cycles. Intel Fortran Compilers support three separate high-level techniques for optimizing the compiled program: interprocedural optimization (IPO), profile-guided optimization (PGO), and other high-level optimizations (HLO).
Interprocedural optimization applies typical compiler optimizations (such as constant propagation) but uses a broader scope that may include multiple procedures, multiple files, or the entire program.[6]
Regarding profile-guided optimization, the compiler generates a dataset of performance-related information from using the application with representative workloads, which it then analyzes to find which parts of the application are executed more and less frequently. The compiler uses these data to organize application execution to optimize performance based on how the application is actually used. This is in contrast to IPO which optimizes applications according to the logical flow of the application independent of workloads. The two can be combined to provide workload-based optimizations within which the logical-flow is optimized. Thus, all optimizations can benefit from profile-guided feedback because they are less reliant on heuristics when making compilation decisions.
The Intel Fortran Compiler Classic fully supports Fortran through the 2018 standard. The Intel Fortran Compiler (Beta) supports full Fortran 77/90/95 and has partial support of the Fortran 2003 standard.
The compilers are available standalone from Intel and from APT and Yum repositories. They are also available in the Intel oneAPI HPC Toolkit which includes other build tools, such as libraries, and analysis tools for error checking and performance analysis. Containers with the compilers are on Docker Hub.
Improved parallelizer and vectorizer, Streaming SIMD Extensions 4 (SSE4), new and enhanced optimization reports for advanced loop transformations, new optimized exception handling implementation.
Intel Fortran Compiler 10.1
November 7, 2007
New OpenMP* compatibility runtime library. To use the new libraries, you need to use the new option "-Qopenmp /Qopenmp-lib:compat" on Windows, and "-openmp -openmp-lib:compat" on Linux. This version of the Intel compiler supports more intrinsics from Microsoft Visual Studio 2005. VS2008 support - command line only in this release.
Intel Fortran Compiler 11.0
November 2008
More Fortran 2003 support. Support for OpenMP 3.0. Source Checker for static memory/parallel diagnostics. Commercial licenses for Windows version include Microsoft Visual Studio 2005 Premier Partner Edition.
Intel Fortran Compiler 11.1
June 23, 2009
Support for latest Intel SSE, AVX and AES instructions. More Fortran 2003 support. Support for latest Intel MKL release (included in compiler products). Commercial licenses for Windows version include Microsoft Visual Studio 2008 Shell and libraries.
Intel Fortran Composer XE 2011 up to Update 5 (compiler 12.0)
OpenMP 3.1, additional 2003 (ALLOCATE with SOURCE=, polymorphic source) and 2008 standards support, Windows version ships with Visual Studio 2010 Shell.
Intel Fortran Composer XE 2013 (compiler 13.0)
September 5, 2012
Linux-based support for Intel Xeon Phi coprocessors, support for Microsoft Visual Studio 12 (Desktop), support for gcc 4.7, support for Intel AVX 2 instructions, updates to existing functionality focused on delivering improved application performance. Continued availability of the Visual Studio 2010 Shell for Windows versions.
Japanese localization of 14.0; Windows 8.1 and Xcode 5.0 support
Intel Fortran Composer XE 2015 (compiler 15.0)
August 5, 2014
Full support for Fortran 2003; BLOCK from Fortran 2008; EXECUTE_COMMAND_LINE from Fortran 2008; New optimization report annotates the source from within Visual Studio[8]
The Intel compiler provides debugging information that is standard for the common debuggers (DWARF 2 on Linux, similar to gdb, and COFF for Windows). The flags to compile with debugging information are /Zi on Windows and -g on Linux. Debugging is done on Windows using the Visual Studio debugger, and on Linux using gdb.
While the Intel compiler can generate a gprof-compatible profiling output, Intel also provides a kernel-level, system-wide statistical profiler as a separate product called VTune. VTune features an easy-to-use GUI (integrated into Visual Studio for Windows, Eclipse for Linux) as well as a command-line interface. In addition to the VTune profiler, there is Intel Advisor that specializes in vectorization optimization and tools for threading design and prototyping.
Intel also offers a tool for memory and threading error detection called Intel Inspector XE. Regarding memory errors, it helps detect memory leaks, memory corruption, allocation/de-allocation of API mismatches and inconsistent memory API usage. Regarding threading errors, it helps detect data races (both heap and stack), deadlocks and thread and synch API errors.
^The Software Optimization Cookbook, High-Performance Recipes for IA-32 Platforms, Richard Gerber, Aart J.C. Bik, Kevin B. Smith, and Xinmin Tian, Intel Press, 2006
