The 3DS ARM11 MPCore contains a floating-point coprocessor extension. This extension is called VFP. VFP has several implementation versions which provide different features; the ARM11 MPCore utilizes VFPv2 (also called VFP11 when referring to the ARM11 implementation of it as a whole).
As such, the 3DS is not capable of using floating-point extensions such as NEON (AKA Advanced SIMD).