Intel® C++ Compiler Classic Developer Guide and Reference

ID 767249
Date 12/16/2022
Public

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Document Table of Contents

m

Tells the compiler which features it may target, including which instruction sets it may generate.

Syntax

Linux and macOS:

-mcode

Windows:

None

Arguments

code

Indicates to the compiler a feature set that it may target, including which instruction sets it may generate. Many of the following descriptions refer to Intel® Streaming SIMD Extensions (Intel® SSE) and Supplemental Streaming SIMD Extensions (SSSE). Possible values are:

avx

May generate Intel® Advanced Vector Extensions (Intel® AVX), SSE4.2, SSE4.1, SSE3, SSE2, SSE, and SSSE3 instructions.

sse4.2

May generate Intel® SSE4.2, SSE4.1, SSE3, SSE2, SSE, and SSSE3 instructions.

sse4.1

May generate Intel® SSE4.1, SSE3, SSE2, SSE, and SSSE3 instructions.

ssse3

May generate SSSE3 instructions and Intel® SSE3, SSE2, and SSE instructions.

sse3

May generate Intel® SSE3, SSE2, and SSE instructions.

sse2

May generate Intel® SSE2 and SSE instructions. This value is only available on Linux systems.

sse

This option has been deprecated; it is now the same as specifying ia32.

ia32

Generates x86/x87 generic code that is compatible with IA-32 architecture. Disables any default extended instruction settings, and any previously set extended instruction settings. It also disables all feature-specific optimizations and instructions. This value is only available on Linux* systems using IA-32 architecture.

This compiler option also supports many of the -m option settings available with gcc. For more information on gcc -m settings, see the gcc documentation.

Default

Linux* systems: -msse2
macOS systems: -mssse3

For more information on the default values, see Arguments above.

Description

This option tells the compiler which features it may target, including which instruction sets it may generate.

Code generated with these options should execute on any compatible, non-Intel processor with support for the corresponding instruction set.

Options -x and -m are mutually exclusive. If both are specified, the compiler uses the last one specified and generates a warning.

Linux* systems: For compatibility with gcc, the compiler allows the following options but they have no effect. You will get a warning error, but the instructions associated with the name will not be generated. You should use the suggested replacement options.

gcc Compatibility Option (Linux*)

Suggested Replacement Option

-mfma

-march=core-avx2

-mbmi, -mavx2, -mlzcnt

-march=core-avx2

-mmovbe

-march=atom -minstruction=movbe

-mcrc32, -maes, -mpclmul, -mpopcnt

-march=corei7

-mvzeroupper

-march=corei7-avx

-mfsgsbase, -mrdrnd, -mf16c

-march=core-avx-i

IDE EquivalentNone
Alternate Options

Linux and macOS: None

Windows: /arch

See Also