vecabi, Qvecabi

Syntax

Linux and macOS:

-vecabi=keyword

Windows:

/Qvecabi:keyword

Arguments

keyword

Specifies which vector function ABI to use. Possible values are:

compat	Tells the compiler to use the compatibility vector function ABI. This ABI includes Intel®-specific features.
cmdtarget	Tells the compiler to generate an extended set of vector functions. The option is very similar to setting compat. However, for compat, only one vector function is created, while for cmdtarget, several vector functions are created for each vector specification. Vector variants are created for targets specified by compiler options [Q]x and/or [Q]ax. No change is made to the source code.
gcc	Tells the compiler to use the gcc vector function ABI. Use this setting only in cases when you want to link with modules compiled by gcc. This setting is not available on Windows* systems.
legacy	Tells the compiler to use the legacy vector function ABI. Use this setting if you need to keep the generated vector function binary backward compatible with the vectorized binary generated by older versions of the Intel® compilers (V13.1 or older).

Default

compat

The compiler uses the compatibility vector function ABI.

Description

This option determines which vector function application binary interface (ABI) the compiler uses to create or call vector functions.

Note

To avoid possible link-time and run-time errors, use identical [Q]vecabi settings when compiling all files in an application that define or use vector functions, including libraries. If setting cmdtarget is specified, options [Q]x and/or [Q]ax must have identical values.

Be careful using setting cmdtarget with libraries or program modules/routines with vector function definitions that cannot be recompiled. In such cases, setting cmdtarget may cause link errors.

On Linux* systems, since the default is compat, you must specify legacy if you need to keep the generated vector function binary backward compatible with the vectorized binary generated by the previous version of Intel® compilers.

When cmdtarget is specified, the additional vector function versions are created by copying each vector specification and changing target processor in the copy. The number of vector functions is determined by the settings specified in options [Q]x and/or [Q]ax.

For example, suppose we have the following function declaration:

interface
integer function foo(a)
!dir$ attributes vector:(processor(core_2_duo_sse4_1)) :: foo
    integer a
end function
end interface

and the following options are specified: -axAVX,CORE-AVX2

The following table shows the different results for the above declaration and option specifications when setting compat or setting cmdtarget is used:

compat	cmdtarget
One vector version is created for Intel® SSE4.1 (by vector function specification).	Four vector versions are created for the following targets: Intel® SSE2 (default because no -x option is used) Intel® SSE4.1 (by vector function specification) Intel® AVX (by the first -ax option value) Intel® AVX2 (by the second -ax option value)

compat

cmdtarget

One vector version is created for Intel® SSE4.1 (by vector function specification).

Four vector versions are created for the following targets:

Intel® SSE2 (default because no -x option is used)
Intel® SSE4.1 (by vector function specification)
Intel® AVX (by the first -ax option value)
Intel® AVX2 (by the second -ax option value)

For more information about the Intel®-compatible vector functions ABI, see the Vector Function ABI document available in the Open Specifications section at cilkplus.org.

For more information about the GCC vector functions ABI, see the item Libmvec - vector math library document in the GLIBC wiki at sourceware.org.

Optimization Notice
Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice. Notice revision #20110804

Optimization Notice

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804

IDE Equivalent

None

Alternate Options

None