Please see the licenses included in the distribution as well as the Disclaimer and Legal Information section of these release notes for details. Please see the following links for information on this release of the Intel® Fortran Compiler 19.1.
- Change History
- System Requirements
- How to install
- How to Use
- Intel-provided Debug Solutions
- Redistributable Libraries
- Technical Support
- New and Changed Compiler Features
- New and Changed Compiler Options
- Support Deprecated
- Support Removed
- Known Limitations
- Fortran 2008 and Fortran 2018 Feature Summary
- Disclaimer and Legal Information
Changes in Update 4 (Intel® Fortran Compiler 19.1.3)
- Corrections to reported problems.
Changes in Update 3
- Not applicable for macOS
NOTE: Intel® Parallel Studio XE 2020 Composer Edition for Fortran and C++ Linux* contains an update to the Intel® C++ Compiler next generation code generator. This is invoked using the -qnextgen option to the ICC and ICPC compilers. This update to the Intel® C++ Compiler next generation code generator includes our latest updates and features for our C++ next generation compiler invoked with the -qnextgen option.
- There are no new features, bug fixes, or security enhancements for the Intel® Fortran Compiler or the Intel® C++ Compiler without the -qnextgen option.
- Intel® Parallel Studio XE 2020 Update 3 is available for the Intel® Parallel Studio XE 2020 Composer Edition for Fortran and C++ Linux*.
- This is a Linux-only release: there is no Update 3 release for either Windows* or macOS* operating systems.
- In addition, it is only a Composer Edition release: there is no Update 3 release for either Professional or Cluster Editions of Intel® Parallel Studio XE 2020.
- There is no update to the Intel® C++ and Fortran Compilers Redistributable Libraries. The Update 2 versions of these libraries are compatible and should be used.
- There is no update for the Intel® Parallel Studio XE Runtime 2020 YUM* and APT* repository packages. Continue to use the Update 2 packages of this runtime.
Changes in Update 2 (Intel® Fortran Compiler 19.1.2)
- Corrections to reported problems.
Changes in Update 1 (Intel® Fortran Compiler 19.1.1)
- Corrections to reported problems.
- Support for integration with Xcode 11 is removed.
Changes since Intel® Fortran Compiler 19.0 (New in Intel® Fortran Compiler 19.1.0)
- New features from Fortran 2018
- New features from OpenMP 5.0*
- New compiler options:
- Changed compiler behavior
- Corrections to reported problems
- A 64-bit Intel®-based Apple* Mac* system
- 2GB RAM minimum, 4GB RAM recommended
- 14GB free disk space for all features
- One of the following combinations of macOS*, Xcode* and the Xcode SDK:
- macOS* 10.15 and Xcode 11.x -- Note: Fortran Integrations into Xcode is removed. However, Xcode Command Line Tools are needed for command line to function. SEE HERE
- macOS 10.14 and Xcode 10.x
- If doing command line development, the Command Line Tools component of Xcode* is required
- Build Rules Missing: See Known Issues or GO HERE
Note: Advanced optimization options or very large programs may require additional resources such as memory or disk space.
Installation instructions are shipped with all Intel® Software Development Products as part of the documentation.
Note that user should have an administrative authorities to install Intel® Fortran Compiler on macOS*.
Please refer to Installation FAQ for more details on installation questions.
Intel® Parallel Studio XE 2020: Getting Started with the Intel® Fortran Compiler 19.1 for macOS* at <install-dir>/documentation_2020/en/compiler_f/ps2020/get_started_mf.htm contains information on how to use the Intel® Fortran Compiler from the command line and from Xcode*.
This article explains which version of Xcode* is supported by Intel Fortran Compiler release.
Product documentation is linked from
Offline core documentation is removed from the Intel® Parallel Studio XE installed image. The core documentation for the components of Intel® Parallel Studio XE are available at the Intel® Software Documentation Library for viewing online. Offline documentation for older versions is also available from the Intel® Software Development Products Registration Center: Product List > Intel® Parallel Studio XE Documentation and from Download Documentation.
User and Reference Guides, What's New and Release Notes, Installation Guides
Refer to the Intel® Parallel Studio XE Support – Documentation for additional User and Reference Guides, What’s New and Release Notes, and Installation Guides.
Intel®-provided debug solutions are based GNU* GDB. Please see Intel® Parallel Studio 2020 Composer Edition Fortran - Debug Solutions Release Notes for further information.
Product samples are now available online at Intel® Software Product Samples and Tutorials
Refer to the Redistributable Libraries for Intel® Parallel Studio XE for more information.
If you did not register your compiler during installation, please do so at the Intel® Software Development Products Registration Center. Registration entitles you to free technical support, product updates and upgrades for the duration of the support term.
For information about how to find Technical Support, Product Updates, User Forums, FAQs, tips and tricks, and other support information, please visit: http://www.intel.com/software/products/support/
Note: If your distributor provides technical support for this product, please contact them for support rather than Intel.
In general, object code and modules compiled with earlier versions of Intel Fortran Compiler for Linux* (8.0 and later) may be used in a build with version 19.1. Exceptions include:
- Sources that use the CLASS keyword to declare polymorphic variables and which were built with a compiler version earlier than 12.0 must be recompiled.
- Objects built with the multi-file interprocedural optimization (-ipo) option must be recompiled with the current version.
- Objects that use the REAL(16), REAL*16, COMPLEX(16) or COMPLEX*32 datatypes and which were compiled with versions earlier than 12.0 must be recompiled.
- Objects built for the Intel® 64 architecture with a compiler version earlier than 10.0 and that have module variables must be recompiled. If non-Fortran sources reference these variables, the external names may need to be changed to remove an incorrect leading underscore.
- Modules that specified an ATTRIBUTES ALIGN directive outside of a derived type and were compiled with versions earlier than 11.0 must be recompiled. The compiler will notify you if this issue is encountered.
- Modules that specified an ATTRIBUTES ALIGN directive inside a derived type declaration cannot be used by compilers older than 13.0.1.
- The implementation of the Fortran 2008 submodules feature required extensive changes to the internal format of binary .mod files. Therefore module files created by the version 16.0 or newer Fortran compiler cannot be used with version 15.0 or older Fortran compilers.
- Objects built with Intel Fortran Compiler version 18.0 and earlier version of regcall calling convention must be recompiled with 19.0 or newer. Intel library libirng uses regcall. Version of this library shipped with 19.0 compiler version or newer is not compatible with older versions. regcall is implicitly used by following attribute:
!DIR$ ATTRIBUTES [att,] VECTOR [:clause] [, att]... :: routine-name
In versions prior to 12.0, when a REAL(16) or COMPLEX(16) (REAL*16 or COMPLEX*32) item was passed by value, the stack address was aligned at 4 bytes. For improved performance, the version 12 and later compilers align such items at 16 bytes and expects received arguments to be aligned on 16-byte boundaries. This change is also compatible with gcc.
This change primarily affects compiler-generated calls to library routines that do computations on REAL(16) values, including intrinsics. If you have code compiled with earlier versions and link it with the version 12 libraries, or have an application linked to the shared version of the Intel run-time libraries, it may give incorrect results.
In order to avoid errors, you must recompile all Fortran sources that use the REAL(16) and COMPLEX(16) datatypes if they were compiled by compiler versions earlier than 12.0.
- Enhancements to the IMPLICIT statement allow specifying that all external procedures must declared EXTERNAL
- Enhancements to the GENERIC statement permit it to be used to declare generic interfaces
- The locality of variables may now be specified on a DO CONCURRENT statement
- Enhancements to edit descriptor forms E, D, EN, ES, and G allow a field width of zero, analogous to the F edit descriptor
- The exponent width e in a data edit descriptor may now be zero, analogous to a field width of zero
- The RN edit descriptor now rounds to nearest as specified by Fortran 2018 and ISO/IEC/IEEE 60559:2011
- The EX edit descriptor allows for hexadecimal format output of floating point values. Hexadecimal format floating point values are allowed on input.
- SIZE= may be specified for non-advancing I/O
- The values for SIZE= and POS= in an INQUIRE statement for pending asynchronous operations have been standardized
- The value assigned to the RECL= specifier in an INQUIRE statement now has standardized values
- A new form of the intrinsic function CMPLX does not require the KIND= keyword if the first argument is type COMPLEX
- The arguments to the SIGN function may be of different kinds
- INTEGER and LOGICAL arguments to intrinsic procedures are no longer required to be of default kind
- The named constants STAT_FAILED_IMAGE and STAT_UNLOCKED_FAILED_IMAGE have been defined in the intrinsic
- The non-block DO statement and the arithmetic IF statement are now deleted in Fortran 2018. Intel® Fortran fully supports features deleted in the FORTRAN standard
- COMMON, EQUIVALENCE and BLOCKDATA statements are now obsolescent
- The labeled form of DO loops is now obsolescent
- Locality of variables in DO CONCURRENT constructs can now be declared on the DO CONCURRENT statement
- Specific names of intrinsic procedures are now obsolescent
- FAIL IMAGE statement allows debugging recovery code for failed images without having to wait for an actual image failure
- The named constants STAT_FAILED_IMAGE and STAT_UNLOCKED_FAILED_IMAGE have been defined in the intrinsic
- An optional argument STAT= has been added to ATOMIC_REF and ATOMIC_DEFINE intrinsic procedures
- Optional STAT= and ERRMSG= specifiers have been added to the MOVE_ALLOC intrinsic procedure, to image selectors, and to the CRITICAL statement and construct
- Atomic subroutines ATOMIC_ADD, ATOMIC_AND, ATOMIC_CAS, ATOMIC_FETCH_ADD, ATOMIC_FETCH_AND, ATOMIC_FETCH_OR, ATOMIC_FETCH_XOR, ATOMIC_OR, and ATOMIC_XOR have been implemented
- Collective subroutines CO_BROADCAST, CO_MAX, CO_MIN, CO_REDUCE, and CO_SUM have been implemented
- The SELECT RANK construct has been implemented allowing manipulation of assumed rank dummy arguments
- The compiler will now diagnose the use of nonstandard intrinsic procedures and modules as required by Fortran 2018
- Transformational intrinsic functions from the intrinsic modules ISO_C_BINDING, IEEE_ARITHMETIC, and IEEE_EXCEPTIONS are now allowed in specification expressions
- You can now specify the optional argument RADIX for the IEEE_GET_ROUNDING_MODE and IEEE_SET_ROUNDING_MODE intrinsic module procedures
- The optional ROUND argument has been added to the IEEE_RINT function in the intrinsic module IEEE_ARITHMETIC
- The intrinsic module IEEE_ARITHMETIC now includes the functions IEEE_FMA, IEEE_SIGN_BIT, IEEE_NEXT_UP and IEEE_NEXT_DOWN
- The intrinsic module procedures IEEE_MAX, IEEE_MIN, IEEE_MAX_MAG, and IEEE_MIN_MAG have been implemented
- The intrinsic module procedures IEEE_INT and IEEE_REAL have been implemented
- The intrinsic module IEEE_EXCEPTIONS now contains a new derived type, IEEE_MODES_TYPE, which can be used to save and restore the IEEE_MODES using the IEEE_GET_MODES and the IEEE_SET_MODES intrinsic module procedures
- A new rounding mode, IEEE_AWAY has been added
- SUBNORMAL is now synonymous with DENORMAL
- IEEE_QUIET_EQ, IEEE_QUIET_NE, IEEE_QUIET_LT, IEEE_QUIET_LE, IEEE_QUIET_GT, IEEE_QUIET_GE, IEEE_SIGNALING_EQ, IEEE_SIGNALING_NE, IEEE_SIGNALING_GT, IEEE_SIGNALING_GE, IEEE_SIGNALING_LT, and IEEE_SIGNALING_LE intrinsic module procedures have been implemented
- IF clause on SIMD directive
- NONTEMPORAL clause on SIMD directive
- Inclusive/exclusive scan operations in SIMD and TARGET SIMD constructs.
- Previous compiler versions erroneously permitted a PRIVATE or SEQUENCE statement to appear prior to the declaration of any type parameters in a derived type declaration. Intel® Fortran Compiler 19.1 no longer permits this behavior.
- The INQUIRE statement now uses realpath’/’GetFullPathNameA’ and uses the resulting canonicallized file-paths if the calls succeeds. An example of the change is:
Open file as “bar/foo”.
Inquire whether “./bar/foo”, “bar//foo” or “bar/../bar/foo” is open – it is not.
Inquire whether “./bar/foo”, “bar//foo” or “bar/../bar/foo” is open – it is.
- In 19.0 compiler version, all procedures with the exception of C_F_POINTER from the intrinsic module ISO_C_BINDING were made PURE per the Fortran 2018 standard. Interpretation 18/007 declared that making C_F_PROCPOINTER PURE was a mistake. 19.1 complies with this interpretation and makes C_F_PROCPOINTER IMPURE.
Please refer to the compiler documentation for details. Following new compiler options added:
- -assume [no]old_inquire_recl
- -assume [no]old_ldout_zero
- -check [no]udio_iostat
- -warn [no]externals
For a list of deprecated compiler options, see the Compiler Options section of the documentation.
Determines the value of the RECL= specifier on an INQUIRE statement for an unconnected unit or a unit connected for stream access.
Determines the format of a floating-point zero produced by list-directed output. old_ldout_zero uses exponential format, no_old_ldout_zero uses fractional format.
Determines whether standard conformance checking occurs when user defined derived type input/output procedures are executed.-m[no-]branches-within-32B-boundaries
The compiler option -stand f15 will be removed in next update. Use -stand f18 instead.
GNU* DBG support will be removed in the next update.
The Loop Profiler feature is removed in Intel® Fortran Compiler 19.1. The following compiler options related to Loop Profiler are removed: -profile-loops=keyword, -profile-loops-report=value -profile-functions, -guide-profile.
32-bit applications are no longer supported
Starting with the 19.0 release of the Intel® Fortran Compiler, macOS 32-bit applications are no longer supported.
If you want to compile 32-bit applications, you should use an earlier version of the compiler and Xcode* 9.4 or earlier.
Fortran Integration into Xcode removed
Xcode integration capabilities within our Fortran Compiler bundle have been removed. Command line interface remains fully functional for macOS.
Keep in mind that installation of Xcode is still recommended, as command line tools from Xcode are required by the command line compiler. However, you can install just the Xcode Command Line Tools with this command from a terminal window:
macOS Big Sur 11 Not Supported
Intel® Parallel Studio XE 2020 for macOS* and all prior versions of Intel(R) Parallel Studio XE for macOS* are NOT compatible with macOS* 11 Big Sur.
Errors will be missing libraries such as -lSystem not found
More background: New in macOS Big Sur 11.0.1, the system ships with a built-in dynamic linker cache of all system-provided libraries. As part of this change, copies of dynamic libraries are no longer present on the filesystem. Code that attempts to check for dynamic library presence by looking for a file at a path or enumerating a directory will fail.
Slow License Checkout macOS 10.15
The license checkout performance on macOS Catalina 10.15 is roughly 1.1 seconds per source file. This is a 10x slowdown on this OS compared to previous versions of macOS. We are evaluating our license technology for a solution but at this time we have not root caused the issue. If this slowdown is an issue, please revert back to the previous macOS 10.14 where this slowdown does not occur.
Error "no rule to process file" within Xcode* 10 and 11
macOS*’s XCode 10 and 11 come with a new build system and it is configured as the default. Currently, the Intel Fortran Compiler does not support it. You will see the error "no rule to process file" when building an Intel Fortran Compiler project within XCode. Please switch to “Legacy Build System” in Project Settings to build your Fortran project in Xcode.
For more details please find this article.
Keep in mind, support for Xcode Integration is deprecated and will be removed in a future update - SEE THIS NOTE
The Intel® Fortran Compiler supports full Fortran 2008 standard and most features from the Fortran 2018 standard. New Fortran 2018 features supported by the current version are listed in the 'New features from Fortran 2018' section.
INFORMATION IN THIS DOCUMENT IS PROVIDED IN CONNECTION WITH INTEL(R) PRODUCTS. NO LICENSE, EXPRESS OR IMPLIED, BY ESTOPPEL OR OTHERWISE, TO ANY INTELLECTUAL PROPERTY RIGHTS IS GRANTED BY THIS DOCUMENT. EXCEPT AS PROVIDED IN INTEL'S TERMS AND CONDITIONS OF SALE FOR SUCH PRODUCTS, INTEL ASSUMES NO LIABILITY WHATSOEVER, AND INTEL DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY, RELATING TO SALE AND/OR USE OF INTEL PRODUCTS INCLUDING LIABILITY OR WARRANTIES RELATING TO FITNESS FOR A PARTICULAR PURPOSE, MERCHANTABILITY, OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT. UNLESS OTHERWISE AGREED IN WRITING BY INTEL, THE INTEL PRODUCTS ARE NOT DESIGNED NOR INTENDED FOR ANY APPLICATION IN WHICH THE FAILURE OF THE INTEL PRODUCT COULD CREATE A SITUATION WHERE PERSONAL INJURY OR DEATH MAY OCCUR.
Intel may make changes to specifications and product descriptions at any time, without notice. Designers must not rely on the absence or characteristics of any features or instructions marked "reserved" or "undefined." Intel reserves these for future definition and shall have no responsibility whatsoever for conflicts or incompatibilities arising from future changes to them. The information here is subject to change without notice. Do not finalize a design with this information.
The products described in this document may contain design defects or errors known as errata which may cause the product to deviate from published specifications. Current characterized errata are available on request.
Contact your local Intel sales office or your distributor to obtain the latest specifications and before placing your product order.
Copies of documents which have an order number and are referenced in this document, or other Intel literature, may be obtained by calling 1-800-548-4725, or go to: http://www.intel.com/design/literature.htm
Intel processor numbers are not a measure of performance. Processor numbers differentiate features within each processor family, not across different processor families. Go to:
The Intel® Fortran Compiler is provided under Intel’s End User License Agreement (EULA).
Please consult the licenses included in the distribution for details.
Intel, the Intel logo, the Intel Inside logo, Xeon are trademarks of Intel Corporation or its subsidiaries in the U.S. and/or other countries.
* Other names and brands may be claimed as the property of others.
© Intel Corporation. All Rights Reserved.
For more complete information about compiler optimizations, see our Optimization Notice.