STMXCSR—Store MXCSR Register State

Opcode*/Instruction	Op/En	64/32 bit Mode Support	CPUID Feature Flag	Description
0F AE /3 STMXCSR m32	M	V/V	SSE	Store contents of MXCSR register to m32.
VEX.LZ.0F.WIG AE /3 VSTMXCSR m32	M	V/V	AVX	Store contents of MXCSR register to m32.

Instruction Operand Encoding

Op/En	Operand 1	Operand 2	Operand 3	Operand 4
M	ModRM:r/m (w)	NA	NA	NA

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.

This instruction’s operation is the same in non-64-bit modes and 64-bit mode. VEX.L must be 0, otherwise instructions will #UD.

Note: In VEX-encoded versions, VEX.vvvv is reserved and must be 1111b, otherwise instructions will #UD.

Operation

m32 ← MXCSR;

Intel C/C++ Compiler Intrinsic Equivalent

_mm_getcsr(void)

SIMD Floating-Point Exceptions

None.

Other Exceptions

See Exceptions Type 5; additionally

#UD	If VEX.L= 1, If VEX.vvvv != 1111B.