Intel® C++ Compiler Classic Developer Guide and Reference

ID 767249
Date 12/16/2022
Public

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Document Table of Contents

_xgetbv()

Reads the content of an extended control register.

Syntax

extern unsigned __int64 _xgetbv(unsigned int xcr);

Arguments
xcr

An extended control register to be read. Currently, only the value '0' is allowed.

Description

This intrinsic reads from extended control registers. Currently, the only control register allowed/defined is (XCR0) XFEATURE_ENABLED_MASK register. The corresponding constant is defined in the immintrin.h file to refer to this register:

#define _XCR_XFEATURE_ENABLED_MASK 0
This intrinsic maps to XGETBV instruction.

Returns

Returns the content of a specified extended control register.