Intel® C++ Compiler 19.1 for Windows* Targets Release Notes for Intel® System Studio 2020

ID 788301
Updated 10/29/2020

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This document provides a summary of new and changed features of the Intel® C++ Compiler for applications running on Windows* targets. It also includes notes about features and problems not described in the product documentation.

Intel® C++ Compiler 19.1 in Intel® System Studio 2020 is based on the Intel® C++ Compiler 19.1 in Intel® Parallel Studio XE 2020 for C++ Windows* with some limitations.

Change History

Changes since Intel® C++ Compiler 19.1.2 (New in Intel® C++ Compiler 19.1.3)

  • Corrections to reported problems.

Changes since Intel® C++ Compiler 19.1.1 (New in Intel® C++ Compiler 19.1.2)

  • Corrections to reported problems.

Changes since Intel® C++ Compiler 19.1 (New in Intel® C++ Compiler 19.1.1)

  • Corrections to reported problems.

Changes since Intel® C++ Compiler 19.0 (New in Intel® C++ Compiler 19.1)

  • Access to Intel® C++ Next Generation Technology compiler, aka ICC NextGen
  • New C++20 features supported
  • New features from OpenMP* 5.0

System Requirements

  • A PC based on an Intel® 64 architecture processor supporting the Intel® Streaming SIMD Extensions 2 (Intel® SSE2) instructions (Intel® 2nd Generation or newer Generation of Intel® Core™ i3, i5, or i7 processors and Intel® Xeon® E3 or E5 processor family, or compatible non-Intel processor)
  • 2GB of RAM (4GB recommended)
  • 4GB free disk space for all features
  • Microsoft Windows* 10, Microsoft Windows Server* 2016, 2019 (Intel® 64 only). 
  • To use the Microsoft* Visual Studio development environment or command-line tools to build IA-32 or Intel® 64 architecture applications, one of:
    • Microsoft Visual Studio* 2019 Professional Edition (or higher edition) with 'Visual C++' component installed
    • Microsoft Visual Studio* 2017 Professional Edition (or higher edition) with 'Desktop development with C++' component installed
    • Build Tools for Visual Studio* 2017
    • Build Tools for Visual Studio* 2019
  •  To use command-line tools only to build Intel® 64 architecture applications:
    • Microsoft Build Tools* 2017


  1. This article explains how to use the Intel® C++ Compiler with Microsoft Visual Studio* 2019
  2. This article explains how to use the Intel® C++ Compiler with Microsoft Visual Studio* 2017


Target software requirements

The target platform should be based on one of the following environments:

  • Microsoft Windows* 10, Microsoft Windows Server* 2019

How to use the Intel® C++ Compiler

Intel® System Studio 2020: Getting started with the Intel® C++ Compiler 19.1 for Windows* at <install-dir>\documentation_2020\en\compiler_c\iss2020\get_started_wc.htm contains information on how to use the Intel® C++ Compiler from the command line and from Microsoft Visual Studio*.


Product documentation is linked from <install-dir>\documentation_2020\en. Full documentation for all tool components is available at the Intel System Studio Documentation page.

Offline Core Documentation Removed from the Installed Image

Offline core documentation is removed from the Intel® System Studio installed image. The core documentation for the components of Intel® System Studio is available at the Intel® Software Documentation Library for viewing online.  See this article for additional information and download.


Product samples are now available online at Intel® System Studio Code Samples and Tutorials

Technical Support

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 the support page

Note: If your distributor provides technical support for this product, please contact them for support rather than Intel.

New and Changed Features

The following features are new or significantly enhanced in this version.  For more information on these features, please refer to the documentation.

Access to Intel® C++ Compiler Based on the Modern LLVM* Framework, aka ICC NextGen

  • /Qnextgen compiler option invokes the Early Access ICC NextGen compiler. These options are only available for Windows* or Linux* ICC/ICL/ICPC drivers.  

C++20 features supported

The Intel® C++ Compiler 19.1 supports the following features under the /Qstd=c++20 (Windows*) or -std=c++20 (Linux*/macOS*) options:

  • std::is_constant_evaluated and __builtin_is_constant_evaluated

Features from OpenMP* 5.0

  • IF clause on SIMD directive
  • NONTEMPORAL clause on SIMD directive

Parallel STL for parallel and vector execution of the C++ STL

Intel(R) C++ Compiler is installed with Parallel STL, an implementation of the C++ standard library algorithms with support for execution policies.

Features/API changes

  • More algorithms support parallel and vector execution policies: find_first_of, is_heap, is_heap_until, replace, replace_if.
  • More algorithms support vector execution policies: remove, remove_if.
  • More algorithms support parallel execution policies: partial_sort.

To learn more, please refer to this article

Support Deprecated

Support Removed

  • Support for Android* is removed
  • Intel® Cilk™ Plus support is removed  
  • Microsoft Windows* 7, Windows Server* 2008 R2 SP1, Windows Server* 2012 are not supported
  • Microsoft Windows* 7, Windows Server* 2008 R2 SP1, Windows Server* 2012 are not supported with Intel® C++ Compiler 19.1.
  • Offload support for Intel® Graphics Technology is removed

Known Issues

  • Parallel STL

unseq and par_unseq policies only have effect with compilers that support '#pragma omp simd' or '#pragma simd. Parallel and vector execution is only supported for a subset of algorithms if random access iterators are provided, while for the rest execution will remain serial. Depending on a compiler, zip_iterator may not work with unseq and par_unseq policies.

  • Pointer Checker requires a dynamic runtime library

When using the -check-pointers option, the runtime library must be linked in. When using options like -static or -static-intel with -check-pointers, be aware that this dynamic library will be linked in regardless of your settings. See the article at Pointer Checker in ICC for more information.