[clang] [llvm] [CodeGen][AArch64] Added -mno-va-float to skip FP save in variadic functions (PR #92827)

[Eli Friedman via llvm-commits]

efriedma-quic wrote:

This patch, as proposed, doesn't seem like a good idea: it's very likely to miscompile user code without any diagnostic. Are you sure you don't want one of the following?

- A soft-float ABI (-mabi=aapcs-soft)
- Completely forbidding the use of floating-point values (-mgeneral-regs-only).
- An optimization that opportunistically skips saving float registers if we can prove it isn't necessary. (Not currently implemented, but not something you'd add a compiler option for; you'd just make it work automatically.  I can write up an outline of how to implement this if you're interested.)

https://github.com/llvm/llvm-project/pull/92827