win64 generates SSE instructions even when they are disabled with -sse

[AndrewScull]

Following the advice of rust-lang/rfcs#1364, I tried to avoid using SSE instructions by disabling MMX and SSE, and enabling soft-float with the features field of my tagert "features": "-mmx,-sse,+soft-float". However, when using an extern "win64" function for my UEFI entry point, movaps instructions are still generated to save and restore the xmm6-15 registers.

I have put together a minimal example to demonstate the problem.

[nagisa]

https://llvm.org/bugs/show_bug.cgi?id=30503

[nagisa]

Fixed in LLVM by r282819.

[Mark-Simulacrum]

I'm going to assume we've already backported/migrated to an LLVM with that patch; can someone verify that this is fixed?

[alexcrichton]

We I believe have long since updated LLVM, so closing.