# _readfsbase_u32(), _readfsbase_u64()

Read the value of the FS base register. Both intrinsics are mapped to `RDFSBASE` instruction.

## Syntax

extern unsigned int _readfsbase_u32();

extern unsigned __int64 _readfsbase_u64();

## Description

These intrinsics read the value of the FS base register.

## Returns

The value of the FS base segment register.

Parent topic: Intrinsics that Allow Reading from and Writing to the FS Base and GS Base Registers