Suggestion: FFastMath intrinsics in stable

[comex]

@InfernoDeity

It seems like clang supports STDC FENV_ACCESS, so it should be possible, provided the frontend (namely, rustc) emits the right attributes.

Yep; I made a thread about it a few months ago:

Equivalent of `#pragma STDC FENV_ACCESS ON`

I recently wrote some code where I needed to perform floating point calculations in a non-default floating point environment. I wanted to write it in Rust, but Rust doesn't support this, so I ended up having to use C instead. Background The two standard parts of the floating point environment are (1) the rounding mode and (2) exception settings (i.e. whether to raise a signal in various cases like overflow or divide by zero). But there can also be nonstandard, platform-specific parts. In my…

You can either tell LLVM you're using a specific rounding mode other than the standard one, or ask LLVM to produce code that works regardless of the rounding mode (at the cost of killing all floating point optimizations). The latter is what FENV_ACCESS does in C.