# m

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

## Syntax

Linux and macOS: | -m code

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 Equivalent

None

## Alternate Options

Linux and macOS: None

Windows: /arch

Parent topic: Code Generation Options

## See Also

x, Qx compiler option
xHost, QxHost compiler option
ax, Qax compiler option
arch compiler option
march compiler option
m32, m64 compiler option