Auto merge of rust-lang#129385 - tgross35:more-platforms-enable-f16, …

…r=<try>

Enable `f16` tests on platforms that were missing conversion symbols

The only requirement for `f16` support, aside from LLVM not crashing and no ABI issues, is that symbols to convert to and from `f32` are available. Since the update to compiler-builtins in rust-lang#125016, we now provide these on all platforms.

This also enables `f16` math since there are no further requirements.

try-job: arm-android
try-job: test-various
try-job: x86_64-fuchsia

library/std/build.rs

@@ -96,9 +96,6 @@ fn main() {
  let has_reliable_f16 = match (target_arch.as_str(), target_os.as_str()) {
  // We can always enable these in Miri as that is not affected by codegen bugs.
  _ if is_miri => true,
- // Selection failure until recent LLVM <https:/llvm/llvm-project/issues/93894>
- // FIXME(llvm19): can probably be removed at the version bump
- ("loongarch64", _) => false,
  // Selection failure <https:/llvm/llvm-project/issues/50374>
  ("s390x", _) => false,
  // Unsupported <https:/llvm/llvm-project/issues/94434>
@@ -108,18 +105,18 @@ fn main() {
  // Apple has a special ABI for `f16` that we do not yet support
  // FIXME(builtins): fixed by <https:/rust-lang/compiler-builtins/pull/675>
  ("x86" | "x86_64", _) if target_vendor == "apple" => false,
- // Missing `__gnu_h2f_ieee` and `__gnu_f2h_ieee`
+ // Infinite recursion <https:/llvm/llvm-project/issues/97981>
+ ("csky", _) => false,
+ ("hexagon", _) => false,
+ ("loongarch64", _) => false,
+ ("mips" | "mips64" | "mips32r6" | "mips64r6", _) => false,
  ("powerpc" | "powerpc64", _) => false,
- // Missing `__gnu_h2f_ieee` and `__gnu_f2h_ieee`
- ("mips" | "mips32r6" | "mips64" | "mips64r6", _) => false,
- // Missing `__extendhfsf` and `__truncsfhf`
- ("riscv32" | "riscv64", _) => false,
- // Most OSs are missing `__extendhfsf` and `__truncsfhf`
- (_, "linux" | "macos") => true,
- // Almost all OSs besides Linux and MacOS are missing symbols until compiler-builtins can
- // be updated. <https:/rust-lang/rust/pull/125016> will get some of these, the
- // next CB update should get the rest.
- _ => false,
+ ("sparc" | "sparc64", _) => false,
+ ("wasm32" | "wasm64", _) => false,
+ // `f16` support only requires that symbols converting to and from `f32` are available. We
+ // provide these in `compiler-builtins`, so `f16` should be available on all platforms that
+ // do not have other ABI issues or LLVM crashes.
+ _ => true,
  };
 
  let has_reliable_f128 = match (target_arch.as_str(), target_os.as_str()) {