Developer Guide and Reference

Contents

_xrstor()/xrstors()

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

Syntax

extern void _xrstor(void *mem, unsigned __int64 rstor_mask);
extern void _xrstors(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
xrstor
intrinsic maps to
XRSTOR
instruction, and the
xrstors
intrinsic maps to
XRSTORS
instruction. See the Intel® 64 and IA-32 Architectures Software Developer's Manual for information on how the instructions differ.