diff options
Diffstat (limited to 'library/std/build.rs')
| -rw-r--r-- | library/std/build.rs | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/library/std/build.rs b/library/std/build.rs index 9b58dd53ba2..35a5977b6eb 100644 --- a/library/std/build.rs +++ b/library/std/build.rs @@ -11,6 +11,7 @@ fn main() { .expect("CARGO_CFG_TARGET_POINTER_WIDTH was not set") .parse() .unwrap(); + let is_miri = env::var_os("CARGO_CFG_MIRI").is_some(); println!("cargo:rustc-check-cfg=cfg(netbsd10)"); if target_os == "netbsd" && env::var("RUSTC_STD_NETBSD10").is_ok() { @@ -85,7 +86,14 @@ fn main() { 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()) { + // 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://github.com/llvm/llvm-project/issues/93894> // FIXME(llvm19): can probably be removed at the version bump ("loongarch64", _) => false, @@ -113,6 +121,8 @@ fn main() { }; let has_reliable_f128 = 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, // Unsupported <https://github.com/llvm/llvm-project/issues/94434> ("arm64ec", _) => false, // ABI and precision bugs <https://github.com/rust-lang/rust/issues/125109> @@ -130,10 +140,46 @@ fn main() { _ => 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()) { + // FIXME: Disabled on Miri as the intrinsics are not implemented yet. + _ if is_miri => false, + // 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()) { + // FIXME: Disabled on Miri as the intrinsics are not implemented yet. + _ if is_miri => false, + // 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"); + } } |