# Intel® C++ Compiler Classic Developer Guide and Reference

This guide contains information for version 2021.7 of the compiler.

Intel® C++ Compiler Classic (icc) is deprecated and will be removed in a oneAPI release in the second half of 2023. Intel recommends that customers transition now to using the LLVM-based Intel® oneAPI DPC++/C++ Compiler (icx) for continued Windows* and Linux* support, new language support, new language features, and optimizations. Note that starting with release 2021.7, macOS* support is limited to Mac* computers with Intel® Processors.

This document contains information about the Intel® C++ Compiler Classic (icc for Linux* and icl for Windows*) compiler and runtime environment. The Intel® C++ Compiler Classic can be found in the Intel® oneAPI HPC Toolkit, Intel® oneAPI IoT Toolkit, or as a standalone compiler. More information and specifications about Intel C/C++ compilers can be found on the Intel® oneAPI DPC++/C++ Compiler product page and in the Release Notes.

The following are some important sections of the compiler developer guide:

Compiler Setup | Compiler Setup explains how to invoke the compiler on the command line or from within an IDE.
OpenMP* Support | The compiler supports many OpenMP* features, including most of OpenMP* Version TR4: Version 5.0.
Compiler Options | Compiler Options provides information about options you can use to affect optimization, code generation, and more.
Intrinsics | Intrinsics let you generate more readable code, simplify instruction scheduling, reduce debugging, access the instructions that cannot be generated using the standard constructs of the C and C++ languages, and more.
Pragmas | Pragmas provide the compiler with the instructions for specific tasks, such as splitting large loops into smaller ones, enabling or disabling optimization for code, or offloading computation to the target.
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 instructions provided there.
Download Previous Versions of the Developer Guide and Reference | Visit the Download Documentation: Intel® Compiler (Current and Previous) page to download PDF or FAR HTML versions of previous compiler documentation. ### Note For the best search experience, use a Google Chrome* or Internet Explorer* browser to view your downloaded copy of the 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.