DSP is part of the ARM Cortex core instruction set. These are mainly SIMD (vector) instructions and instructions with saturation often based on combinations of add/sub and mul.
CORDIC is a hardware accelerator for speeding-up trigonometric and hyperbolic functions including logarithms. So they both complement each other.
Side note: my first contact with the CORDIC principle was with my HP-41 scientific calculator in the early 80ies 🙂
In most cases, fixed point uses normal register which enables faster computation within and interrupt. Using more math registers from fpu or else will require potential longer latencies to push/pop them even in lazy mode. And interrupt duration is affecting the max RPM of a motor, for example.