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// Configuration that is shared between `compiler_builtins` and `testcrate`.
use std::env;
#[derive(Debug)]
#[allow(dead_code)]
pub struct Target {
pub triple: String,
pub os: String,
pub arch: String,
pub vendor: String,
pub env: String,
pub pointer_width: u8,
pub little_endian: bool,
pub features: Vec<String>,
}
impl Target {
pub fn from_env() -> Self {
let little_endian = match env::var("CARGO_CFG_TARGET_ENDIAN").unwrap().as_str() {
"little" => true,
"big" => false,
x => panic!("unknown endian {x}"),
};
Self {
triple: env::var("TARGET").unwrap(),
os: env::var("CARGO_CFG_TARGET_OS").unwrap(),
arch: env::var("CARGO_CFG_TARGET_ARCH").unwrap(),
vendor: env::var("CARGO_CFG_TARGET_VENDOR").unwrap(),
env: env::var("CARGO_CFG_TARGET_ENV").unwrap(),
pointer_width: env::var("CARGO_CFG_TARGET_POINTER_WIDTH")
.unwrap()
.parse()
.unwrap(),
little_endian,
features: env::var("CARGO_CFG_TARGET_FEATURE")
.unwrap_or_default()
.split(",")
.map(ToOwned::to_owned)
.collect(),
}
}
#[allow(dead_code)]
pub fn has_feature(&self, feature: &str) -> bool {
self.features.iter().any(|f| f == feature)
}
}
/// Configure whether or not `f16` and `f128` support should be enabled.
pub fn configure_f16_f128(target: &Target) {
// Set whether or not `f16` and `f128` are supported at a basic level by LLVM. This only means
// that the backend will not crash when using these types and generates code that can be called
// without crashing (no infinite recursion). This does not mean that the platform doesn't have
// ABI or other bugs.
//
// We do this here rather than in `rust-lang/rust` because configuring via cargo features is
// not straightforward.
//
// Original source of this list:
// <https://github.com/rust-lang/compiler-builtins/pull/652#issuecomment-2266151350>
let f16_enabled = match target.arch.as_str() {
// Unsupported <https://github.com/llvm/llvm-project/issues/94434>
"arm64ec" => false,
// Selection failure <https://github.com/llvm/llvm-project/issues/50374>
"s390x" => false,
// Infinite recursion <https://github.com/llvm/llvm-project/issues/97981>
// FIXME(llvm): loongarch fixed by <https://github.com/llvm/llvm-project/pull/107791>
"csky" => false,
"hexagon" => false,
"loongarch64" => false,
"mips" | "mips64" | "mips32r6" | "mips64r6" => false,
"powerpc" | "powerpc64" => false,
"sparc" | "sparc64" => false,
"wasm32" | "wasm64" => false,
// Most everything else works as of LLVM 19
_ => true,
};
let f128_enabled = match target.arch.as_str() {
// Unsupported (libcall is not supported) <https://github.com/llvm/llvm-project/issues/121122>
"amdgpu" => false,
// Unsupported <https://github.com/llvm/llvm-project/issues/94434>
"arm64ec" => false,
// Selection failure <https://github.com/llvm/llvm-project/issues/96432>
"mips64" | "mips64r6" => false,
// Selection failure <https://github.com/llvm/llvm-project/issues/95471>
"nvptx64" => false,
// Selection failure <https://github.com/llvm/llvm-project/issues/101545>
"powerpc64" if &target.os == "aix" => false,
// Selection failure <https://github.com/llvm/llvm-project/issues/41838>
"sparc" => false,
// Most everything else works as of LLVM 19
_ => true,
};
// If the feature is set, disable these types.
let disable_both = env::var_os("CARGO_FEATURE_NO_F16_F128").is_some();
println!("cargo::rustc-check-cfg=cfg(f16_enabled)");
println!("cargo::rustc-check-cfg=cfg(f128_enabled)");
if f16_enabled && !disable_both {
println!("cargo::rustc-cfg=f16_enabled");
}
if f128_enabled && !disable_both {
println!("cargo::rustc-cfg=f128_enabled");
}
}
|
