Intel® C++ Compiler Classic Developer Guide and Reference

ID 767249
Date 12/16/2022
Public

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Document Table of Contents

align

Directs the compiler to align the variable to a specified boundary and a specified offset.

Syntax

Windows* OS:

__declspec(align(n[,off]))

Linux* OS:

__attribute__((aligned(n[,off])))

__attribute__((align(n[,off])))

For portability on Linux OS, you should use the syntax form __attribute__((aligned(n[, off]))). This form is compatible with the GNU compiler.

Arguments

n

Specifies the alignment. The compiler will align the variable to an n-byte boundary.

off

Optional. Specifies the offset. If this argument is omitted, the value is 0.

Description

This keyword directs the compiler to align the variable to an n-byte boundary with offset off within each n-byte boundary. The address of the variable is address mod n=off.

NOTE:

If you require 8-byte alignment, we recommend you specify 16 for n, instead of 8. When 8 is used, the compiler interprets the value as a suggestion and you may not get the requested 8-byte alignment, depending on various heuristics.