diff options
Diffstat (limited to 'vendor/memchr/build.rs')
-rw-r--r-- | vendor/memchr/build.rs | 88 |
1 files changed, 0 insertions, 88 deletions
diff --git a/vendor/memchr/build.rs b/vendor/memchr/build.rs deleted file mode 100644 index 584a60856..000000000 --- a/vendor/memchr/build.rs +++ /dev/null @@ -1,88 +0,0 @@ -use std::env; - -fn main() { - enable_simd_optimizations(); - enable_libc(); -} - -// This adds various simd cfgs if this compiler and target support it. -// -// This can be disabled with RUSTFLAGS="--cfg memchr_disable_auto_simd", but -// this is generally only intended for testing. -// -// On targets which don't feature SSE2, this is disabled, as LLVM wouln't know -// how to work with SSE2 operands. Enabling SSE4.2 and AVX on SSE2-only targets -// is not a problem. In that case, the fastest option will be chosen at -// runtime. -fn enable_simd_optimizations() { - if is_env_set("CARGO_CFG_MEMCHR_DISABLE_AUTO_SIMD") { - return; - } - let arch = env::var("CARGO_CFG_TARGET_ARCH").unwrap(); - match &arch[..] { - "x86_64" => { - if !target_has_feature("sse2") { - return; - } - println!("cargo:rustc-cfg=memchr_runtime_simd"); - println!("cargo:rustc-cfg=memchr_runtime_sse2"); - println!("cargo:rustc-cfg=memchr_runtime_sse42"); - println!("cargo:rustc-cfg=memchr_runtime_avx"); - } - "wasm32" | "wasm64" => { - if !target_has_feature("simd128") { - return; - } - println!("cargo:rustc-cfg=memchr_runtime_simd"); - println!("cargo:rustc-cfg=memchr_runtime_wasm128"); - } - _ => {} - } -} - -// This adds a `memchr_libc` cfg if and only if libc can be used, if no other -// better option is available. -// -// This could be performed in the source code, but it's simpler to do it once -// here and consolidate it into one cfg knob. -// -// Basically, we use libc only if its enabled and if we aren't targeting a -// known bad platform. For example, wasm32 doesn't have a libc and the -// performance of memchr on Windows is seemingly worse than the fallback -// implementation. -fn enable_libc() { - const NO_ARCH: &'static [&'static str] = &["wasm32", "windows"]; - const NO_ENV: &'static [&'static str] = &["sgx"]; - - if !is_feature_set("LIBC") { - return; - } - - let arch = match env::var("CARGO_CFG_TARGET_ARCH") { - Err(_) => return, - Ok(arch) => arch, - }; - let env = match env::var("CARGO_CFG_TARGET_ENV") { - Err(_) => return, - Ok(env) => env, - }; - if NO_ARCH.contains(&&*arch) || NO_ENV.contains(&&*env) { - return; - } - - println!("cargo:rustc-cfg=memchr_libc"); -} - -fn is_feature_set(name: &str) -> bool { - is_env_set(&format!("CARGO_FEATURE_{}", name)) -} - -fn is_env_set(name: &str) -> bool { - env::var_os(name).is_some() -} - -fn target_has_feature(feature: &str) -> bool { - env::var("CARGO_CFG_TARGET_FEATURE") - .map(|features| features.contains(feature)) - .unwrap_or(false) -} |