# Intrinsics to Read and Write Registers

The prototypes for Intel® Streaming SIMD Extensions (Intel® SSE) intrinsics to read from and write to registers are in the xmmintrin.h header file.

To use these intrinsics, include the immintrin.h file as follows:

    #include <immintrin.h>

Intrinsic Name | Operation | Corresponding Intel® SSE Instruction
--- | --- | ---
_mm_getcsr | Return control register | STMXCSR
_mm_setcsr | Set control register | LDMXCSR

## _mm_getcsr

unsigned int _mm_getcsr(void);

Returns the contents of the control register.

## _mm_setcsr

void _mm_setcsr(unsigned int i);

Sets the control register to the value specified by i.

Parent topic: Intrinsics for Intel® Streaming SIMD Extensions (Intel® SSE)