Xavier gcc parameters to turn on neon and fpu

I want to know how to use neon and fpu, I do not know the exactly parameters to turn on the neon and fpu.
And what doc should I read to get this information,or what command in ubuntu can see this information?
Can anyone provide some help , thank you!

I haven’t looked at Neon in a long time, but you might be interested in what ARM says on the topic:

Keep in mind that if you use a compiler option to turn on Neon while in ARMv8-a/arm64/aarch64, then you might get an error since all 64-bit ARM has the Neon hardware. 32-bit ARMv7-a/arm32 made Neon an option, and thus reference to compiler features to enable something in the 32-bit world may not exist on the 64-bit world…options to enable something which is always present were removed when in the 64-bit world.

Note that ARMv8-a 64-bit has ARMv8 (no “-a”) 32-bit compatibility mode. The 32-bit compatibility mode will differ somewhat from the older 32-bit since 64-bit is a superset of 32-bit. All 32-bit code should be compatible with ARMv8 32-bit, but not all ARMv8 32-bit is compatible with ARMv7-a. When you are reading be sure to keep in mind whether you are talking about 64-bit modes, 32-bit ARMv8 superset mode of ARMv7-a, or true ARMv7-a.