Assembly language on mobile phone

This question applies to a Cortex-A76 using arm64-v8a with the latest Android Studio.  When I try to use the SIMD instructions: fcadd or fcmla, I get the build error: "error: instruction requires: complxnum". Is there something unique about the mobile phone arm instruction set (like those instructions were not included in the hardware) or do I not understand how to properly include "complxnum" in the build instructions?  All my other assembly code is working fine.  Thanks in advance!

Bob