x86 Instruction Set Reference

STMXCSR - Store MXCSR Register State

Opcode Mnemonic Description
0F AE /3 STMXCSR m32 Store contents of MXCSR register to m32.
Description

Stores the contents of the MXCSR control and status register to the destination operand. The destination operand is a 32-bit memory location. The reserved bits in the MXCSR register are stored as 0s.
Operation 
m32 = MXCSR;