println!("cargo:rustc-check-cfg=cfg(reliable_f16)");

println!("cargo:rustc-check-cfg=cfg(reliable_f128)");

// This is a step beyond only having the types and basic functions available. Math functions

// aren't consistently available or correct.

println!("cargo:rustc-check-cfg=cfg(reliable_f16_math)");

println!("cargo:rustc-check-cfg=cfg(reliable_f128_math)");

let has_reliable_f16 = match (target_arch.as_str(), target_os.as_str()) {

// Selection failure until recent LLVM <https://github.com/llvm/llvm-project/issues/93894>

// FIXME(llvm19): can probably be removed at the version bump

_ => false,

};

// These are currently empty, but will fill up as some platforms move from completely

// unreliable to reliable basics but unreliable math.

// LLVM is currenlty adding missing routines, <https://github.com/llvm/llvm-project/issues/93566>

let has_reliable_f16_math = has_reliable_f16

&& match (target_arch.as_str(), target_os.as_str()) {

// Currently nothing special. Hooray!

// This will change as platforms gain better better support for standard ops but math

// lags behind.

_ => true,

};

let has_reliable_f128_math = has_reliable_f128

&& match (target_arch.as_str(), target_os.as_str()) {

// LLVM lowers `fp128` math to `long double` symbols even on platforms where

// `long double` is not IEEE binary128. See

// <https://github.com/llvm/llvm-project/issues/44744>.

//

// This rules out anything that doesn't have `long double` = `binary128`; <= 32 bits

// (ld is `f64`), anything other than Linux (Windows and MacOS use `f64`), and `x86`

// (ld is 80-bit extended precision).

("x86_64", _) => false,

(_, "linux") if target_pointer_width == 64 => true,

_ => false,

};

if has_reliable_f16 {

println!("cargo:rustc-cfg=reliable_f16");

}

if has_reliable_f128 {

println!("cargo:rustc-cfg=reliable_f128");

}

if has_reliable_f16_math {

println!("cargo:rustc-cfg=reliable_f16_math");

}

if has_reliable_f128_math {

println!("cargo:rustc-cfg=reliable_f128_math");

}

}