110 lines
3.3 KiB
Rust
110 lines
3.3 KiB
Rust
#![no_std]
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#![doc = include_str!("../README.md")]
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#![doc(
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html_logo_url = "https://raw.githubusercontent.com/RustCrypto/media/6ee8e381/logo.svg",
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html_favicon_url = "https://raw.githubusercontent.com/RustCrypto/media/6ee8e381/logo.svg"
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)]
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#[cfg(not(miri))]
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#[cfg(target_arch = "aarch64")]
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#[doc(hidden)]
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pub mod aarch64;
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#[cfg(not(miri))]
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#[cfg(target_arch = "loongarch64")]
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#[doc(hidden)]
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pub mod loongarch64;
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#[cfg(not(miri))]
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#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
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mod x86;
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#[cfg(miri)]
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mod miri;
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#[cfg(not(any(
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target_arch = "aarch64",
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target_arch = "loongarch64",
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target_arch = "x86",
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target_arch = "x86_64"
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)))]
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compile_error!("This crate works only on `aarch64`, `loongarch64`, `x86`, and `x86-64` targets.");
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/// Create module with CPU feature detection code.
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#[macro_export]
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macro_rules! new {
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($mod_name:ident, $($tf:tt),+ $(,)?) => {
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mod $mod_name {
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use core::sync::atomic::{AtomicU8, Ordering::Relaxed};
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const UNINIT: u8 = u8::max_value();
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static STORAGE: AtomicU8 = AtomicU8::new(UNINIT);
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/// Initialization token
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#[derive(Copy, Clone, Debug)]
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pub struct InitToken(());
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impl InitToken {
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/// Initialize token, performing CPU feature detection.
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pub fn init() -> Self {
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init()
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}
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/// Initialize token and return a `bool` indicating if the feature is supported.
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pub fn init_get() -> (Self, bool) {
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init_get()
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}
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/// Get initialized value.
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#[inline(always)]
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pub fn get(&self) -> bool {
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$crate::__unless_target_features! {
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$($tf),+ => {
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STORAGE.load(Relaxed) == 1
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}
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}
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}
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}
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/// Get stored value and initialization token,
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/// initializing underlying storage if needed.
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#[inline]
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pub fn init_get() -> (InitToken, bool) {
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let res = $crate::__unless_target_features! {
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$($tf),+ => {
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#[cold]
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fn init_inner() -> bool {
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let res = $crate::__detect_target_features!($($tf),+);
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STORAGE.store(res as u8, Relaxed);
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res
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}
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// Relaxed ordering is fine, as we only have a single atomic variable.
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let val = STORAGE.load(Relaxed);
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if val == UNINIT {
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init_inner()
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} else {
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val == 1
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}
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}
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};
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(InitToken(()), res)
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}
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/// Initialize underlying storage if needed and get initialization token.
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#[inline]
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pub fn init() -> InitToken {
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init_get().0
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}
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/// Initialize underlying storage if needed and get stored value.
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#[inline]
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pub fn get() -> bool {
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init_get().1
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}
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}
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};
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}
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