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Diffstat (limited to 'library/compiler-builtins/libm/configure.rs')
| -rw-r--r-- | library/compiler-builtins/libm/configure.rs | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/library/compiler-builtins/libm/configure.rs b/library/compiler-builtins/libm/configure.rs new file mode 100644 index 00000000000..8b8ba981565 --- /dev/null +++ b/library/compiler-builtins/libm/configure.rs @@ -0,0 +1,183 @@ +// Configuration shared with both libm and libm-test + +use std::env; +use std::path::PathBuf; + +#[allow(dead_code)] +pub struct Config { + pub manifest_dir: PathBuf, + pub out_dir: PathBuf, + pub opt_level: String, + pub cargo_features: Vec<String>, + pub target_arch: String, + pub target_env: String, + pub target_family: Option<String>, + pub target_os: String, + pub target_string: String, + pub target_vendor: String, + pub target_features: Vec<String>, +} + +impl Config { + pub fn from_env() -> Self { + let target_features = env::var("CARGO_CFG_TARGET_FEATURE") + .map(|feats| feats.split(',').map(ToOwned::to_owned).collect()) + .unwrap_or_default(); + let cargo_features = env::vars() + .filter_map(|(name, _value)| name.strip_prefix("CARGO_FEATURE_").map(ToOwned::to_owned)) + .map(|s| s.to_lowercase().replace("_", "-")) + .collect(); + + Self { + manifest_dir: PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap()), + out_dir: PathBuf::from(env::var("OUT_DIR").unwrap()), + opt_level: env::var("OPT_LEVEL").unwrap(), + cargo_features, + target_arch: env::var("CARGO_CFG_TARGET_ARCH").unwrap(), + target_env: env::var("CARGO_CFG_TARGET_ENV").unwrap(), + target_family: env::var("CARGO_CFG_TARGET_FAMILY").ok(), + target_os: env::var("CARGO_CFG_TARGET_OS").unwrap(), + target_string: env::var("TARGET").unwrap(), + target_vendor: env::var("CARGO_CFG_TARGET_VENDOR").unwrap(), + target_features, + } + } +} + +/// Libm gets most config options made available. +#[allow(dead_code)] +pub fn emit_libm_config(cfg: &Config) { + emit_intrinsics_cfg(); + emit_arch_cfg(); + emit_optimization_cfg(cfg); + emit_cfg_shorthands(cfg); + emit_cfg_env(cfg); + emit_f16_f128_cfg(cfg); +} + +/// Tests don't need most feature-related config. +#[allow(dead_code)] +pub fn emit_test_config(cfg: &Config) { + emit_optimization_cfg(cfg); + emit_cfg_shorthands(cfg); + emit_cfg_env(cfg); + emit_f16_f128_cfg(cfg); +} + +/// Simplify the feature logic for enabling intrinsics so code only needs to use +/// `cfg(intrinsics_enabled)`. +fn emit_intrinsics_cfg() { + println!("cargo:rustc-check-cfg=cfg(intrinsics_enabled)"); + + // Disabled by default; `unstable-intrinsics` enables again; `force-soft-floats` overrides + // to disable. + if cfg!(feature = "unstable-intrinsics") && !cfg!(feature = "force-soft-floats") { + println!("cargo:rustc-cfg=intrinsics_enabled"); + } +} + +/// Simplify the feature logic for enabling arch-specific features so code only needs to use +/// `cfg(arch_enabled)`. +fn emit_arch_cfg() { + println!("cargo:rustc-check-cfg=cfg(arch_enabled)"); + + // Enabled by default via the "arch" feature, `force-soft-floats` overrides to disable. + if cfg!(feature = "arch") && !cfg!(feature = "force-soft-floats") { + println!("cargo:rustc-cfg=arch_enabled"); + } +} + +/// Some tests are extremely slow. Emit a config option based on optimization level. +fn emit_optimization_cfg(cfg: &Config) { + println!("cargo:rustc-check-cfg=cfg(optimizations_enabled)"); + + if !matches!(cfg.opt_level.as_str(), "0" | "1") { + println!("cargo:rustc-cfg=optimizations_enabled"); + } +} + +/// Provide an alias for common longer config combinations. +fn emit_cfg_shorthands(cfg: &Config) { + println!("cargo:rustc-check-cfg=cfg(x86_no_sse)"); + if cfg.target_arch == "x86" && !cfg.target_features.iter().any(|f| f == "sse") { + // Shorthand to detect i586 targets + println!("cargo:rustc-cfg=x86_no_sse"); + } +} + +/// Reemit config that we make use of for test logging. +fn emit_cfg_env(cfg: &Config) { + println!("cargo:rustc-env=CFG_CARGO_FEATURES={:?}", cfg.cargo_features); + println!("cargo:rustc-env=CFG_OPT_LEVEL={}", cfg.opt_level); + println!("cargo:rustc-env=CFG_TARGET_FEATURES={:?}", cfg.target_features); +} + +/// Configure whether or not `f16` and `f128` support should be enabled. +fn emit_f16_f128_cfg(cfg: &Config) { + println!("cargo:rustc-check-cfg=cfg(f16_enabled)"); + println!("cargo:rustc-check-cfg=cfg(f128_enabled)"); + + // `unstable-float` enables these features. + if !cfg!(feature = "unstable-float") { + return; + } + + // 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 cfg.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 cfg.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 &cfg.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"); + } +} |