use std::env; fn main() { println!("cargo:rustc-cfg=core_arch_docs"); // Used to tell our `#[assert_instr]` annotations that all simd intrinsics // are available to test their codegen, since some are gated behind an extra // `-Ctarget-feature=+unimplemented-simd128` that doesn't have any // equivalent in `#[target_feature]` right now. println!("cargo:rerun-if-env-changed=RUSTFLAGS"); if env::var("RUSTFLAGS") .unwrap_or_default() .contains("unimplemented-simd128") { println!("cargo:rustc-cfg=all_simd"); } }