Intel® C++ Compiler Classic Developer Guide and Reference

ID 767249
Date 12/16/2022
Public

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Document Table of Contents

_xrstor64()/xrstors64()

Restores the states of x87 FPU, MMX, XMM, YMM, and MXCSR registers from memory.

Syntax

extern void _xrstor64(void *mem, unsigned __int64 rstor_mask);

extern void _xrstors64(const void *mem, unsigned __int64 rstor_mask);

Arguments
mem

A memory reference to FXSAVE area. The 512-bytes memory addressed by the reference must be 16-bytes aligned.

rstor_mask

A bit mask specifying the extended states to be restored.

Description

Restores the states of x87 FPU, MMX, XMM, YMM, and MXCSR registers from memory. The xrstor64 intrinsic maps to XRSTOR64 instruction, and the xrstors64 intrinsic maps to XRSTORS64 instruction. See the Intel® 64 and IA-32 Architectures Software Developer's Manual for information on how the instructions differ.