Intel® oneAPI DPC++/C++ Compiler Developer Guide and Reference

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Document Table of Contents
Document Table of Contents x
Intel® oneAPI DPC++/C++ Compiler Developer Guide and Reference
Intel® oneAPI DPC++/C++ Compiler Developer Guide and Reference x
Intel® oneAPI DPC++/C++ Compiler Introduction Compiler Setup Compiler Reference Compilation Optimization and Programming Compatibility and Portability Notices and Disclaimers
Intel® oneAPI DPC++/C++ Compiler Introduction x
Get Help and Support Related Information
Compiler Setup x
Use the Command Line Use Eclipse Use Microsoft Visual Studio
Use the Command Line x
Specify Component Locations Invoke the Compiler Use the Command Line on Windows File Extensions Use Makefiles for Compilation Use CMake with the Compiler Use Compiler Options Specify Compiler Files Convert Projects to Use a Selected Compiler
Use Eclipse x
Add the Compiler to Eclipse Multiversion Compiler Support Use Cheat Sheets Create a Simple Eclipse Project Makefiles Use Intel Libraries with Eclipse
Use Microsoft Visual Studio x
Create a New Project Use the Intel® oneAPI DPC++/C++ Compiler Select the Compiler Version Specify a Base Platform Toolset Use Property Pages Use Intel® Libraries with Microsoft Visual Studio* Include MPI Support Dialog Box Help
Dialog Box Help x
Options: Compilers dialog box Use Intel® oneAPI DPC++/C++ Compiler dialog box Options: Intel Libraries for oneAPI dialog box Options: Converter dialog box
Compiler Reference x
C/C++/SYCL Calling Conventions Compiler Options Floating-Point Operations Attributes Intrinsics Libraries Macros Pragmas Error Handling
Compiler Options x
Alphabetical Option List General Rules for Compiler Options What Appears in the Compiler Option Descriptions Optimization Options Code Generation Options Interprocedural Optimization Options Advanced Optimization Options Optimization Report Options Offload Compilation, OpenMP*, and Parallel Processing Options Floating-Point Options Inlining Options Output, Debug, and Precompiled Header Options Preprocessor Options Component Control Options Language Options Data Options Compiler Diagnostic Options Compatibility Options Linking or Linker Options Miscellaneous Options Deprecated and Removed Compiler Options Display Option Information Alternate Compiler Options Portability and GCC-Compatible Warning Options
Optimization Options x
fast fbuiltin, Oi foptimize-sibling-calls GF nolib-inline O Od Ofast Os Ot Ox
Code Generation Options x
arch ax, Qax EH fasynchronous-unwind-tables fdata-sections, Gw fexceptions ffunction-sections, Gy fomit-frame-pointer Gd GR guard Gv m, Qm m64, Qm64 m80387 march masm mbranches-within-32B-boundaries, Qbranches-within-32B-boundaries mintrinsic-promote, Qintrinsic-promote momit-leaf-frame-pointer mtune, tune regcall, Qregcall x, Qx xHost, QxHost
Interprocedural Optimization Options x
flto ipo, Qipo
Advanced Optimization Options x
ffreestanding, Qfreestanding fjump-tables fvec-peel-loops, Qvec-peel-loops fvec-remainder-loops, Qvec-remainder-loops fvec-with-mask, Qvec-with-mask ipp-link, Qipp-link qactypes, Qactypes qdaal, Qdaal qipp, Qipp qmkl, Qmkl qmkl-ilp64, Qmkl-ilp64 qopt-assume-no-loop-carried-dep, Qopt-assume-no-loop-carried-dep qopt-dynamic-align, Qopt-dynamic-align qopt-for-throughput, Qopt-for-throughput qopt-mem-layout-trans, Qopt-mem-layout-trans qopt-multiple-gather-scatter-by-shuffles, Qopt-multiple-gather-scatter-by-shuffles qopt-streaming-stores, Qopt-streaming-stores qtbb, Qtbb unroll, Qunroll use-intel-optimized-headers, Quse-intel-optimized-headers vec, Qvec vec-threshold, Qvec-threshold
Optimization Report Options x
qopt-report, Qopt-report qopt-report-file, Qopt-report-file
Offload Compilation, OpenMP*, and Parallel Processing Options x
device-math-lib fintelfpga fiopenmp, Qiopenmp fno-sycl-libspirv foffload-static-lib fopenmp fopenmp-declare-target-scalar-defaultmap, Qopenmp-declare-target-scalar-defaultmap fopenmp-device-lib fopenmp-target-buffers, Qopenmp-target-buffers fopenmp-targets, Qopenmp-targets fsycl fsycl-add-targets fsycl-dead-args-optimization fsycl-device-code-split fsycl-device-lib fsycl-device-only fsycl-early-optimizations fsycl-enable-function-pointers fsycl-esimd-force-stateless-mem fsycl-explicit-simd fsycl-force-target fsycl-help fsycl-host-compiler fsycl-host-compiler-options fsycl-id-queries-fit-in-int fsycl-instrument-device-code fsycl-link fsycl-link-huge-device-code fsycl-link-targets fsycl-max-parallel-link-jobs fsycl-rdc fsycl-targets fsycl-unnamed-lambda fsycl-use-bitcode nolibsycl qopenmp, Qopenmp qopenmp-lib, Qopenmp-lib qopenmp-link qopenmp-simd, Qopenmp-simd qopenmp-stubs, Qopenmp-stubs reuse-exe Wno-sycl-strict Xopenmp-target Xs Xsycl-target
Floating-Point Options x
ffp-contract fimf-absolute-error, Qimf-absolute-error fimf-accuracy-bits, Qimf-accuracy-bits fimf-arch-consistency, Qimf-arch-consistency fimf-domain-exclusion, Qimf-domain-exclusion fimf-max-error, Qimf-max-error fimf-precision, Qimf-precision fimf-use-svml, Qimf-use-svml fma, Qfma fp-model, fp fp-speculation, Qfp-speculation pc, Qpc
Inlining Options x
fgnu89-inline finline finline-functions
Output, Debug, and Precompiled Header Options x
c debug (Linux*) debug (Windows*) Fa fasm-blocks Fe Fo Fp ftrapuv, Qtrapuv fverbose-asm g gdwarf grecord-gcc-switches gsplit-dwarf o RTC S use-msasm Y- Yc Yu Zi, Z7, ZI
Preprocessor Options x
B C D dD, QdD dM, QdM E EP FI H, QH I I- idirafter imacros iprefix iquote isystem iwithprefix iwithprefixbefore Kc++, TP M, QM MD, QMD MF, QMF MG, QMG MM, QMM MMD, QMMD MQ MT, QMT nostdinc++ P pragma-optimization-level U undef X
Component Control Options x
Qoption
Language Options x
ansi fno-gnu-keywords fno-operator-names fno-rtti fpermissive fshort-enums fsyntax-only funsigned-char J std, Qstd strict-ansi vd vmg x (type option) Zc Zg Zp Zs
Data Options x
fcommon fkeep-static-consts, Qkeep-static-consts fmath-errno fpack-struct fpic fpie fstack-protector fstack-security-check fvisibility fzero-initialized-in-bss, Qzero-initialized-in-bss GA Gs GS mcmodel Qlong-double
Compiler Diagnostic Options x
w w, W Wabi Wall Wcheck-unicode-security Wcomment Wdeprecated Weffc++, Qeffc++ Werror, WX Werror-all Wextra-tokens Wformat Wformat-security Wmain Wmissing-declarations Wmissing-prototypes Wpointer-arith Wreorder Wreturn-type Wshadow Wsign-compare Wstrict-aliasing Wstrict-prototypes Wtrigraphs Wuninitialized Wunknown-pragmas Wunused-function Wunused-variable Wwrite-strings
Compatibility Options x
gcc-toolchain vmv
Linking or Linker Options x
F (Windows*) fixed fuse-ld l L LD link MD MT no-libgcc nodefaultlibs no-intel-lib, Qno-intel-lib nostartfiles nostdlib pie pthread shared shared-intel shared-libgcc static static-intel static-libgcc static-libstdc++ T u (Linux*) v Wa Wl Wp Xlinker Zl
Miscellaneous Options x
dryrun dumpmachine dumpversion help nologo save-temps, Qsave-temps showIncludes sox, Qsox sysroot Tc TC Tp version watch
Floating-Point Operations x
Programming Tradeoffs in Floating-Point Applications Use the -fp-model, /fp Option Denormal Numbers Set the FTZ and DAZ Flags Tuning Performance IEEE Floating-Point Operations
Attributes x
align align_value allow_cpu_features concurrency_safe const cpu_dispatch, cpu_specific mpx target
Libraries x
Create Libraries Use Intel Shared Libraries on Linux Manage Libraries Redistribute Libraries When Deploying Applications Resolve References to Shared Libraries Intel's Memory Allocator Library SIMD Data Layout Templates Intel® C++ Class Libraries Intel's C++ Asynchronous I/O Extensions for Windows IEEE 754-2008 Binary Floating-Point Conformance Library Intel's Numeric String Conversion Library
SIMD Data Layout Templates x
Function Calls and Containers User-Level Interface Examples
Function Calls and Containers x
Construct an n_container Bounds
User-Level Interface x
SDLT Primitives soa1d_container aos1d_container n_container Bounds Accessors Proxy Objects Number Representation Indexes Convenience and Correctness
aos1d_container x
access_by
n_container x
Layouts Shape make_ n_container template function extent_d template function
Shape x
n_extent_generator
Bounds x
bounds_t sdlt::bounds Template Function n_bounds_t n_bounds_generator bounds_d Template Function
Accessors x
soa1d_container::accessor and aos1d_container::accessor soa1d_container::const_accessor and aos1d_container::const_accessor Accessor Concept
Proxy Objects x
Proxy ConstProxy
Number Representation x
aligned_offset fixed_offset
Indexes x
linear_index n_index_t n_index_generator index_d template function
Convenience and Correctness x
max_val min_val
Examples x
Efficiency with Structure of Arrays Example Complex SDLT Primitive Construction Example Forward Dependency Example Use of Offsets and Methods on a SDLT Primitive Example RGB to YUV Conversion Example
Intel® C++ Class Libraries x
C++ Classes and SIMD Operations Capabilities of C++ SIMD Classes Integer Vector Classes Floating-Point Vector Classes Classes Quick Reference Programming Example Intel's valarray Implementation
Integer Vector Classes x
Terms and Syntax Rules for Operators Assignment Operator Logical Operators Addition and Subtraction Operators Multiplication Operators Shift Operators Comparison Operators Conditional Select Operators Debug Operations Unpack Operators Pack Operators Clear MMX™ State Operator Integer Functions for Intel® Streaming SIMD Extensions Conversions between Fvec and Ivec
Floating-Point Vector Classes x
Fvec Syntax and Notation Data Alignment Conversions Constructors and Initialization Arithmetic Operators Minimum and Maximum Operators Logical Operators Compare Operators Conditional Select Operators for Fvec Classes Cacheability Support Operators Debug Operations Load and Store Operators Unpack Operators Move Mask Operators
Intel's C++ Asynchronous I/O Extensions for Windows x
Intel's C++ Asynchronous I/O Library for Windows Intel's C++ Asynchronous I/O Class for Windows
Intel's C++ Asynchronous I/O Library for Windows x
aio_read aio_write Example for aio_read and aio_write Functions aio_suspend Example for aio_suspend Function aio_error aio_return Example for aio_error and aio_return Functions aio_fsync aio_cancel Example for aio_cancel Function lio_listio Example for lio_listio Function Asynchronous I/O Function Errors
Intel's C++ Asynchronous I/O Class for Windows x
Template Class async_class get_last_operation_id wait get_status get_last_error get_error_operation_id stop_queue resume_queue clear_queue Example for Using async_class Template Class
IEEE 754-2008 Binary Floating-Point Conformance Library x
Intel® IEEE 754-2008 Binary Floating-Point Conformance Library and Usage Function List Homogeneous General-Computational Operations Functions General-Computational Operation Functions Quiet-Computational Operations Functions Signaling-Computational Operations Functions Non-Computational Operations Functions
Intel's Numeric String Conversion Library x
Use Intel's Numeric String Conversion Library Function List
Macros x
ISO Standard Predefined Macros Additional Predefined Macros Use Predefined Macros to Specify Intel® Compilers
Pragmas x
Intel-Specific Pragma Reference Intel-Supported Pragma Reference
Intel-Specific Pragma Reference x
block_loop/noblock_loop distribute_point inline, noinline, forceinline ivdep loop_count nofusion novector omp target variant dispatch ompx prefetch data prefetch/noprefetch unroll/nounroll unroll_and_jam/nounroll_and_jam vector
Compilation x
Compilation Overview Supported Environment Variables Pass Options to the Linker Specify Alternate Tools and Paths Use Configuration Files Use Response Files Global Symbols and Visibility Attributes for Linux* Save Compiler Information in Your Executable Link Debug Information Ahead of Time Compilation Device Offload Compilation Considerations Use a Third-Party Compiler as a Host Compiler for SYCL Code
Optimization and Programming x
Extensions OpenMP* Support Intel® oneAPI Level Zero Vectorization High-Level Optimization Interprocedural Optimization Methods to Optimize Code Size Intel® oneAPI DPC++/C++ Compiler Math Library
OpenMP* Support x
Add OpenMP* Support Parallel Processing Model Worksharing Using OpenMP* Control Thread Allocation OpenMP* Pragmas PARALLEL Pragma TASKING Pragma WORKSHARING Pragmas SYNCHRONIZATION Pragmas Data Environment Pragmas Offload Target Control Pragmas Vectorization Pragmas Cancellation Constructs User-Defined Reduction Pragma Memory Space Allocation Pragma Combined and Composite Pragmas OpenMP* Library Support OpenMP* Advanced Issues OpenMP* Implementation-Defined Behaviors OpenMP* Examples
OpenMP* Library Support x
OpenMP* Runtime Library Routines Intel® Compiler Extension Routines to OpenMP* OpenMP* Support Libraries Use the OpenMP Libraries Thread Affinity Interface OpenMP* Memory Spaces and Allocators
Intel® oneAPI Level Zero x
Intel® oneAPI Level Zero Switch Intel® oneAPI Level Zero Backend Specification Programming with the Intel® oneAPI Level Zero Backend
Vectorization x
Automatic Vectorization Explicit Vector Programming
Automatic Vectorization x
Vectorization Programming Guidelines Use Automatic Vectorization Vectorization and Loops Loop Constructs
Explicit Vector Programming x
User-Mandated or SIMD Vectorization SIMD-Enabled Functions SIMD-Enabled Function Pointers Vectorize a Loop Using the _Simd Keyword Function Annotations and the SIMD Directive for Vectorization Explicit SIMD SYCL Extension
Interprocedural Optimization x
Use Interprocedural Optimization Performance and Large Program Considerations Create a Library from IPO Objects Inline Expansion of Functions
Intel® oneAPI DPC++/C++ Compiler Math Library x
Use the Intel® oneAPI DPC++/C++ Compiler Math Library Math Function List Trigonometric Functions Hyperbolic Functions Exponential Functions Special Functions Nearest Integer Functions Remainder Functions Miscellaneous Functions Complex Functions C99 Macros
Compatibility and Portability x
Standards Conformance GCC Compatibility and Interoperability Microsoft Compatibility Port from Microsoft Visual C++* to the Intel® oneAPI DPC++/C++ Compiler Port from GCC* to the Intel® oneAPI DPC++/C++ Compiler
Port from Microsoft Visual C++* to the Intel® oneAPI DPC++/C++ Compiler x
Modify Your makefile Other Considerations
Port from GCC* to the Intel® oneAPI DPC++/C++ Compiler x
Modify Your makefiledpc Other Considerations
Intel® oneAPI DPC++/C++ Compiler Developer Guide and Reference

OpenMP* Pragmas

This is a summary of the OpenMP* pragmas supported in the Intel® oneAPI DPC++/C++ Compiler. For detailed information about the OpenMP API, see the OpenMP Application Program Interface Version 5.1 specification, which is available from the OpenMP web site.

PARALLEL Pragma

Use this pragma to form a team of threads and execute those threads in parallel.

Pragma

Description

omp parallel

Specifies that a structured block should be run in parallel by a team of threads.

TASKING Pragma

Use these pragmas for deferring execution.

Pragma

Description

omp task

Specifies a code block whose execution may be deferred.

omp taskloop

Specifies that the iterations of one or more associated for loops should be executed using OpenMP tasks. The iterations are distributed across tasks that are created by the construct and scheduled to be executed in parallel by the current team.

WORKSHARING Pragmas

Use these pragmas to share work among a team of threads.

Pragma

Description

omp for

Specifies a work-sharing loop. Iterations of the loop are executed in parallel by the threads in the team.

omp loop

Specifies that the iterations of the associated loops can execute in any order or concurrently.

omp sections

Defines a set of structured blocks that will be distributed among the threads in the team.

omp single

Specifies that a block of code is to be executed by only one thread in the team.

SYNCHRONIZATION Pragmas

Use these pragmas to synchronize between threads.

Pragma

Description

omp atomic

Specifies a computation that must be executed atomically.

omp barrier

Specifies a point in the code where each thread must wait until all threads in the team arrive.

omp critical

Specifies a code block that is restricted to access by only one thread at a time.

omp flush

Identifies a point at which a thread's temporary view of memory becomes consistent with the memory.

omp masked

Specifies a structured block that is executed by a subset of the threads of the current team.

omp master (deprecated, see omp masked)

Specifies a code block that must be executed only once by the primary thread of the team.

omp ordered

Specifies a block of code that the threads in a team must execute in the natural order of the loop iterations, or as a stand-alone directive, specifies cross-iteration dependences in a doacross loop-nest.

The following clauses are available as Intel-specific extensions of the OpenMP* specification:

ompx_monotonic

Specifies a block of code in which the value of the new list item on each iteration of the associated SIMD loop(s) corresponds to the value of the original list item before entering the associated loop, plus the number of the iterations for which the conditional update happens prior to the current iteration, times linear-step. The value corresponding to the sequentially last iteration of the associated loop(s) is assigned to the original list item. Use with the simd clause.

ompx_overlap

Specifies a block of code that has to be executed scalar for overlapping inx values and parallel for different inx values within SIMD loop. Use with the simd clause.

omp taskgroup

Causes the program to wait until the completion of all enclosed and descendant tasks.

omp taskwait

Specifies a wait on the completion of child tasks generated since the beginning of the current task.

omp taskyield

Specifies that the current task can be suspended at this point in favor of execution of a different task.

Data Environment Pragmas

Use these pragmas to affect the data environment.

Pragma

Description

omp threadprivate

Specifies a list of globally-visible variables that will be allocated private to each thread.

Offload Target Control Pragmas

Use these pragmas to control execution on one or more offload targets.

Pragma

Description

omp declare target

Specifies functions and variables that are created or mapped to a device.

omp declare variant

Identifies a variant of a base procedure and specifies the context in which this variant is used.

omp dispatch

Determines if a procedure variant is called for a given procedure.

omp distribute

Specifies that the iterations of one or more loops should be distributed among the initial threads of all thread teams in a league.

omp interop

Identifies a foreign runtime context and identifies runtime characteristics of that context, enabling interoperability with it.

omp requires

Lists the features that an implementation must support so that the program compiles and runs correctly.

omp target enter data

Specifies that variables are mapped to a device data environment.

omp target exit data

Specifies that variables are unmapped from a device data environment.

omp teams

Creates a league of thread teams inside a target region to execute a structured block in the initial thread of each team.

Vectorization Pragmas

Use these pragmas to control execution on vector hardware.

Pragma

Description

omp simd

Transforms the loop into a loop that will be executed concurrently using SIMD instructions.

The following clauses are available as Intel-specific extensions of the OpenMP* specification:

ompx_assert

Specifies that the compiler generates an error message if the loop is not vectorized by whatever reason.

omp declare simd

Creates a version of a function that can process multiple arguments using Single Instruction Multiple Data (SIMD) instructions from a single invocation from a SIMD loop.

Cancellation Constructs

Pragma

Description

omp cancel

Requests cancellation of the innermost enclosing region of the type specified, and causes the encountering task to proceed to the end of the cancelled construct.

omp cancellation point

Defines a point at which implicit or explicit tasks check to see if cancellation has been requested for the innermost enclosing region of the type specified. This construct does not implement a synchronization between threads or tasks.

User-Defined Reduction Pragma

Use this pragma to define reduction identifiers that can be used as reduction operators in a reduction clause.

Pragma

Description

omp declare reduction

Declares User-Defined Reduction (UDR) functions (reduction identifiers) that can be used as reduction operators in a reduction clause.

Memory Space Allocation Pragma

Use this declarative directive to allocate memory space.

Pragma

Description

omp allocate

Specifies memory allocators to use for object allocation and deallocation

Combined and Composite Pragmas

Use these pragmas as shortcuts for multiple pragmas in sequence. A combined construct is a shortcut for specifying one construct immediately nested inside another construct. A combined construct is semantically identical to that of explicitly specifying the first construct containing one instance of the second construct and no other statements.

A composite construct is composed of two constructs but does not have identical semantics to specifying one of the constructs immediately nested inside the other. A composite construct either adds semantics not included in the constructs from which it is composed or the nesting of the one construct inside the other is not conforming.

Pragma

Description

omp distribute parallel for 1

Specifies a loop that can be executed in parallel by multiple threads that are members of multiple teams.

omp distribute parallel for simd1

Specifies a loop that will be executed in parallel by multiple threads that are members of multiple teams. It will be executed concurrently using SIMD instructions.

omp distribute simd 1

Specifies a loop that will be distributed across the primary threads of the teams region. It will be executed concurrently using SIMD instructions.

omp for simd1

Specifies that the iterations of the loop will be distributed across threads in the team. Iterations executed by each thread can also be executed concurrently using SIMD instructions.

omp parallel for

Provides an abbreviated way to specify a parallel region containing only a FOR construct.

omp parallel for simd

Specifies a parallel construct that contains one for simd construct and no other statement.

omp parallel sections

Specifies a parallel construct that contains only a sections construct.

omp target parallel

Creates a device data environment and executes the parallel region on that device.

omp target parallel for

Provides an abbreviated way to specify a target construct that contains an omp target parallel for construct and no other statement between them.

omp target parallel for simd

Specifies a target construct that contains an omp target parallel for simd construct and no other statement between them.

omp target parallel loop

Provides an abbreviated way to specify a target region that contains only a parallel loop construct.

omp target simd

Specifies a target construct that contains an omp simd construct and no other statement between them.

omp target teams

Creates a device data environment and executes the construct on the same device. It also creates a league of thread teams with the primary thread in each team executing the structured block.

omp target teams distribute

Creates a device data environment and then executes the construct on that device. It also specifies that loop iterations will be distributed among the primary threads of all thread teams in a league created by a teams construct.

omp target teams distribute parallel for

Creates a device data environment and then executes the construct on that device. It also specifies a loop that can be executed in parallel by multiple threads that are members of multiple teams created by a teams construct.

omp target teams distribute parallel for simd

Creates a device data environment and then executes the construct on that device. It also specifies a loop that can be executed in parallel by multiple threads that are members of multiple teams created by a teams construct. The loop will be distributed across the teams, which will be executed concurrently using SIMD instructions.

omp target teams distribute simd

Creates a device data environment and then executes the construct on that device. It also specifies that loop iterations will be distributed among the primary threads of all thread teams in a league created by a teams construct. It will be executed concurrently using SIMD instructions.

omp target teams loop

Provides an abbreviated way to specify a target region that contains only a teams loop construct.

omp taskloop simd 1

Specifies a loop that can be executed concurrently using SIMD instructions and that those iterations will also be executed in parallel using OpenMP* tasks.

omp teams distribute

Creates a league of thread teams and specifies that loop iterations will be distributed among the primary threads of all thread teams in the league.

omp teams distribute parallel for

Creates a league of thread teams and specifies that the associated loop can be executed in parallel by multiple threads that are members of multiple teams.

omp teams distribute parallel for simd

Creates a league of thread teams and specifies that the associated loop can be executed concurrently using SIMD instructions in parallel by multiple threads that are members of multiple teams.

omp teams distribute simd

Creates a league of thread teams and specifies that the associated loop will be distributed across the primary threads of the teams and executed concurrently using SIMD instructions.

omp teams loop

Provides an abbreviated way to specify a teams construct that contains only a loop construct.

Footnotes:

1 This directive specifies a composite construct.

Parent topic: OpenMP* Support
Level Two Title