Improve cpuid-bool efficiency#86

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newpavlov merged 5 commits into from
Nov 29, 2020
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Improve cpuid-bool efficiency #86

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0ff06a0
improve cpuid-bool efficiency
newpavlov Nov 28, 2020
316b021
update changelog
newpavlov Nov 28, 2020
7d78bf1
fmt fix
newpavlov Nov 28, 2020
599d251
update docs
newpavlov Nov 28, 2020
81691bd
update Cargo.lock
newpavlov Nov 28, 2020
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2 changes: 1 addition & 1 deletion Cargo.lock
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6 changes: 6 additions & 0 deletions cpuid-bool/CHANGELOG.md
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Original file line numberDiff line numberDiff line change
Expand Up@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

## 0.2.0 (2020-12-01)
### Changed
- Macro now creates a module with several function and the `InitToken` type ([#86])

[#86]: https://github.com/RustCrypto/utils/pull/86

## 0.1.2 (2020-07-20)
### Added
- LICENSE files ([#70])
Expand Down
4 changes: 2 additions & 2 deletions cpuid-bool/Cargo.toml
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Original file line numberDiff line numberDiff line change
@@ -1,9 +1,9 @@
[package]
name = "cpuid-bool"
version = "0.1.2"
version = "0.2.0"
authors = ["RustCrypto Developers"]
license = "MIT OR Apache-2.0"
description = "A lightweight no-std compatible alternative to is_x86_feature_detected"
description = "A lightweight and efficient no-std compatible alternative to the is_x86_feature_detected macro"
documentation = "https://docs.rs/cpuid-bool"
repository = "https://github.com/RustCrypto/utils"
keywords = ["cpuid", "target-feature"]
Expand Down
157 changes: 94 additions & 63 deletions cpuid-bool/src/lib.rs
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Original file line numberDiff line numberDiff line change
@@ -1,51 +1,118 @@
//! Macro for checking CPU capabilities at runtime.
//!
//! # Usage example
//! # Example
//! ```
//! if cpuid_bool::cpuid_bool!("sha", "aes") {
//! // This macro creates `cpuid_aes_sha` module
//! cpuid_bool::new!(cpuid_aes_sha, "aes", "sha");
//!
//! // `token` is a Zero Sized Type value, which guarantees
//! // that underlying static storage got properly initialized,
//! // which allows to omit initialization branch
//! let token: cpuid_aes_sha::InitToken = cpuid_aes_sha::init();
//! if token.get() {
//! println!("CPU supports both SHA and AES extensions");
//! } else {
//! println!("SHA and AES extensions are not supported");
//! }
//!
//! // If stored value needed only once you can get stored value
//! // omitting the token
//! let val = cpuid_aes_sha::get();
//! assert_eq!(val, token.get());
//!
//! // Additionally you can get both token and value
//! let (token, val) = cpuid_aes_sha::init_get();
//! assert_eq!(val, token.get());
//! ```
//! Note that if all tested target features are enabled via compiler options
//! (e.g. by using `RUSTFLAGS`), `cpuid_bool!` macro immideatly will expand
//! to `true` and will not use CPUID instruction. Such behavior allows
//! compiler to eliminate fallback code.
//! (e.g. by using `RUSTFLAGS`), the `get` method will always return `true`
//! and `init` will not use CPUID instruction. Such behavior allows
//! compiler to completely eliminate fallback code.
Comment thread
tarcieri marked this conversation as resolved.
//!
//! After first call macro caches result and returns it in subsequent
//! calls, thus runtime overhead for them is minimal.
#![no_std]
#[cfg(not(any(target_arch = "x86", target_arch = "x86_64")))]
compile_error!("This crate works only on x86 and x86-64 targets.");

use core::sync::atomic::{AtomicU8, Ordering::Relaxed};
/// Create module with CPUID bool code.
#[macro_export]
macro_rules! new {
($mod_name:ident, $($tf:tt),+ $(,)? ) => {
mod $mod_name {
use core::sync::atomic::{AtomicU8, Ordering::Relaxed};

const UNINIT: u8 = u8::max_value();
static STORAGE: AtomicU8 = AtomicU8::new(UNINIT);

/// This structure represents a lazily initialized static boolean value.
///
/// Useful when it is preferable to just rerun initialization instead of
/// locking. Used internally by the `cpuid_bool` macro.
pub struct LazyBool(AtomicU8);
/// Initialization token
#[derive(Copy, Clone, Debug)]
pub struct InitToken(());

impl InitToken {
/// Get initialized value
#[inline(always)]
pub fn get(&self) -> bool {
// CPUID is not available on SGX targets
#[cfg(all(not(target_env = "sgx"), not(all($(target_feature=$tf, )*))))]
let res = STORAGE.load(Relaxed) == 1;
#[cfg(all(target_env = "sgx", not(all($(target_feature=$tf, )*))))]
let res = false;
#[cfg(all($(target_feature=$tf, )*))]
let res = true;
res
}
}

/// Initialize underlying storage if needed and get
/// stored value and initialization token.
#[inline]
pub fn init_get() -> (InitToken, bool) {
// CPUID is not available on SGX targets
#[cfg(all(not(target_env = "sgx"), not(all($(target_feature=$tf, )*))))]
let res = {
#[cfg(target_arch = "x86")]
use core::arch::x86::{__cpuid, __cpuid_count};
#[cfg(target_arch = "x86_64")]
use core::arch::x86_64::{__cpuid, __cpuid_count};

// Relaxed ordering is fine, as we only have a single atomic variable.
let val = STORAGE.load(Relaxed);
if val == UNINIT {
#[allow(unused_variables)]
let cr = unsafe {
[__cpuid(1), __cpuid_count(7, 0)]
};
let res = $(cpuid_bool::check!(cr, $tf) & )+ true;
STORAGE.store(res as u8, Relaxed);
res
} else {
val == 1
}
};
#[cfg(all(target_env = "sgx", not(all($(target_feature=$tf, )*))))]
let res = false;
#[cfg(all($(target_feature=$tf, )*))]
let res = true;

impl LazyBool {
const UNINIT: u8 = u8::max_value();
(InitToken(()), res)
}

pub const fn new() -> Self {
Self(AtomicU8::new(Self::UNINIT))
}
/// Initialize underlying storage if needed and get
/// initialization token.
#[inline]
pub fn init() -> InitToken {
init_get().0
}

// Runs the init() function at least once, returning the value of some run
// of init(). Multiple callers can run their init() functions in parallel.
// init() should always return the same value, if it succeeds.
pub fn unsync_init(&self, init: impl FnOnce() -> bool) -> bool {
// Relaxed ordering is fine, as we only have a single atomic variable.
let mut val = self.0.load(Relaxed);
if val == Self::UNINIT {
val = init() as u8;
self.0.store(val as u8, Relaxed);
/// Initialize underlying storage if needed and get
/// stored value.
#[inline]
pub fn get() -> bool {
init_get().1
}
}
val != 0
}
};
}

// TODO: find how to define private macro usable inside a public one
Expand DownExpand Up@@ -83,39 +150,3 @@ expand_check_macro! {
("adx", 1, ebx, 19),
("sha", 1, ebx, 29),
}

/// Check at runtime if CPU supports sequence of target features.
///
/// During first execution this macro will use CPUID to check requested
/// target features, results will be cached and further calls will return
/// it instead.
#[macro_export]
macro_rules! cpuid_bool {
($($tf:tt),+ $(,)? ) => {{
// CPUID is not available on SGX targets
#[cfg(all(not(target_env = "sgx"), not(all($(target_feature=$tf, )*))))]
let res = {
#[cfg(target_arch = "x86")]
use core::arch::x86::{__cpuid, __cpuid_count};
#[cfg(target_arch = "x86_64")]
use core::arch::x86_64::{__cpuid, __cpuid_count};

static CPUID_BOOL: cpuid_bool::LazyBool = cpuid_bool::LazyBool::new();
CPUID_BOOL.unsync_init(|| {
#[allow(unused_variables)]
let cr = unsafe {
[__cpuid(1), __cpuid_count(7, 0)]
};
// TODO: find how to remove `true`
$(cpuid_bool::check!(cr, $tf) & )+ true
})
};

#[cfg(all(target_env = "sgx", not(all($(target_feature=$tf, )*))))]
let res = false;
#[cfg(all($(target_feature=$tf, )*))]
let res = true;

res
}};
}
, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all 
 blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks");
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '

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Improve cpuid-bool efficiency#86

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 Merged

newpavlov
merged 5 commits into

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Nov 29, 2020
 Merged


Improve cpuid-bool efficiency
#86
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improve cpuid-bool efficiency


newpavlov Nov 28, 2020
316b021

update changelog


newpavlov Nov 28, 2020
7d78bf1

fmt fix


newpavlov Nov 28, 2020
599d251

update docs


newpavlov Nov 28, 2020
81691bd

update Cargo.lock


newpavlov Nov 28, 2020

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cpuid-bool/CHANGELOG.md

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Original file line numberDiff line numberDiff line change
Expand Up@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

## 0.2.0 (2020-12-01)
### Changed
- Macro now creates a module with several function and the `InitToken` type ([#86])

[#86]: https://github.com/RustCrypto/utils/pull/86

## 0.1.2 (2020-07-20)
### Added
- LICENSE files ([#70])
Expand Down

4 changes: 2 additions & 2 deletions
cpuid-bool/Cargo.toml

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Original file line numberDiff line numberDiff line change
@@ -1,9 +1,9 @@
[package]
name = "cpuid-bool"
version = "0.1.2"
version = "0.2.0"
authors = ["RustCrypto Developers"]
license = "MIT OR Apache-2.0"
description = "A lightweight no-std compatible alternative to is_x86_feature_detected"
description = "A lightweight and efficient no-std compatible alternative to the is_x86_feature_detected macro"
documentation = "https://docs.rs/cpuid-bool"
repository = "https://github.com/RustCrypto/utils"
keywords = ["cpuid", "target-feature"]
Expand Down

157 changes: 94 additions & 63 deletions
cpuid-bool/src/lib.rs

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Original file line numberDiff line numberDiff line change
@@ -1,51 +1,118 @@
//! Macro for checking CPU capabilities at runtime.
//!
//! # Usage example
//! # Example
//! ```
//! if cpuid_bool::cpuid_bool!("sha", "aes") {
//! // This macro creates `cpuid_aes_sha` module
//! cpuid_bool::new!(cpuid_aes_sha, "aes", "sha");
//!
//! // `token` is a Zero Sized Type value, which guarantees
//! // that underlying static storage got properly initialized,
//! // which allows to omit initialization branch
//! let token: cpuid_aes_sha::InitToken = cpuid_aes_sha::init();
//! if token.get() {
//! println!("CPU supports both SHA and AES extensions");
//! } else {
//! println!("SHA and AES extensions are not supported");
//! }
//!
//! // If stored value needed only once you can get stored value
//! // omitting the token
//! let val = cpuid_aes_sha::get();
//! assert_eq!(val, token.get());
//!
//! // Additionally you can get both token and value
//! let (token, val) = cpuid_aes_sha::init_get();
//! assert_eq!(val, token.get());
//! ```
//! Note that if all tested target features are enabled via compiler options
//! (e.g. by using `RUSTFLAGS`), `cpuid_bool!` macro immideatly will expand
//! to `true` and will not use CPUID instruction. Such behavior allows
//! compiler to eliminate fallback code.
//! (e.g. by using `RUSTFLAGS`), the `get` method will always return `true`
//! and `init` will not use CPUID instruction. Such behavior allows
//! compiler to completely eliminate fallback code.
Comment thread
tarcieri marked this conversation as resolved.

//!
//! After first call macro caches result and returns it in subsequent
//! calls, thus runtime overhead for them is minimal.
#![no_std]
#[cfg(not(any(target_arch = "x86", target_arch = "x86_64")))]
compile_error!("This crate works only on x86 and x86-64 targets.");

use core::sync::atomic::{AtomicU8, Ordering::Relaxed};
/// Create module with CPUID bool code.
#[macro_export]
macro_rules! new {
 ($mod_name:ident, $($tf:tt),+ $(,)? ) => {
 mod $mod_name {
 use core::sync::atomic::{AtomicU8, Ordering::Relaxed};

 const UNINIT: u8 = u8::max_value();
 static STORAGE: AtomicU8 = AtomicU8::new(UNINIT);

/// This structure represents a lazily initialized static boolean value.
///
/// Useful when it is preferable to just rerun initialization instead of
/// locking. Used internally by the `cpuid_bool` macro.
pub struct LazyBool(AtomicU8);
 /// Initialization token
 #[derive(Copy, Clone, Debug)]
 pub struct InitToken(());

 impl InitToken {
 /// Get initialized value
 #[inline(always)]
 pub fn get(&self) -> bool {
 // CPUID is not available on SGX targets
 #[cfg(all(not(target_env = "sgx"), not(all($(target_feature=$tf, )*))))]
 let res = STORAGE.load(Relaxed) == 1;
 #[cfg(all(target_env = "sgx", not(all($(target_feature=$tf, )*))))]
 let res = false;
 #[cfg(all($(target_feature=$tf, )*))]
 let res = true;
 res
 }
 }

 /// Initialize underlying storage if needed and get
 /// stored value and initialization token.
 #[inline]
 pub fn init_get() -> (InitToken, bool) {
 // CPUID is not available on SGX targets
 #[cfg(all(not(target_env = "sgx"), not(all($(target_feature=$tf, )*))))]
 let res = {
 #[cfg(target_arch = "x86")]
 use core::arch::x86::{__cpuid, __cpuid_count};
 #[cfg(target_arch = "x86_64")]
 use core::arch::x86_64::{__cpuid, __cpuid_count};

 // Relaxed ordering is fine, as we only have a single atomic variable.
 let val = STORAGE.load(Relaxed);
 if val == UNINIT {
 #[allow(unused_variables)]
 let cr = unsafe {
 [__cpuid(1), __cpuid_count(7, 0)]
 };
 let res = $(cpuid_bool::check!(cr, $tf) & )+ true;
 STORAGE.store(res as u8, Relaxed);
 res
 } else {
 val == 1
 }
 };
 #[cfg(all(target_env = "sgx", not(all($(target_feature=$tf, )*))))]
 let res = false;
 #[cfg(all($(target_feature=$tf, )*))]
 let res = true;

impl LazyBool {
const UNINIT: u8 = u8::max_value();
 (InitToken(()), res)
 }

 pub const fn new() -> Self {
 Self(AtomicU8::new(Self::UNINIT))
 }
 /// Initialize underlying storage if needed and get
 /// initialization token.
 #[inline]
 pub fn init() -> InitToken {
 init_get().0
 }

 // Runs the init() function at least once, returning the value of some run
 // of init(). Multiple callers can run their init() functions in parallel.
 // init() should always return the same value, if it succeeds.
 pub fn unsync_init(&self, init: impl FnOnce() -> bool) -> bool {
 // Relaxed ordering is fine, as we only have a single atomic variable.
 let mut val = self.0.load(Relaxed);
 if val == Self::UNINIT {
 val = init() as u8;
 self.0.store(val as u8, Relaxed);
 /// Initialize underlying storage if needed and get
 /// stored value.
 #[inline]
 pub fn get() -> bool {
 init_get().1
 }
 }
 val != 0
 }
 };
}

// TODO: find how to define private macro usable inside a public one
Expand DownExpand Up@@ -83,39 +150,3 @@ expand_check_macro! {
 ("adx", 1, ebx, 19),
 ("sha", 1, ebx, 29),
}

/// Check at runtime if CPU supports sequence of target features.
///
/// During first execution this macro will use CPUID to check requested
/// target features, results will be cached and further calls will return
/// it instead.
#[macro_export]
macro_rules! cpuid_bool {
 ($($tf:tt),+ $(,)? ) => {{
 // CPUID is not available on SGX targets
 #[cfg(all(not(target_env = "sgx"), not(all($(target_feature=$tf, )*))))]
 let res = {
 #[cfg(target_arch = "x86")]
 use core::arch::x86::{__cpuid, __cpuid_count};
 #[cfg(target_arch = "x86_64")]
 use core::arch::x86_64::{__cpuid, __cpuid_count};

 static CPUID_BOOL: cpuid_bool::LazyBool = cpuid_bool::LazyBool::new();
 CPUID_BOOL.unsync_init(|| {
 #[allow(unused_variables)]
 let cr = unsafe {
 [__cpuid(1), __cpuid_count(7, 0)]
 };
 // TODO: find how to remove `true`
 $(cpuid_bool::check!(cr, $tf) & )+ true
 })
 };

 #[cfg(all(target_env = "sgx", not(all($(target_feature=$tf, )*))))]
 let res = false;
 #[cfg(all($(target_feature=$tf, )*))]
 let res = true;

 res
 }};
}

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Force GitHub README to respect dark mode\n(function() {\n var style = document.createElement('style');\n style.textContent = '\n .markdown-body {\n color-scheme: dark light;\n }\n .markdown-body pre { background: #161b22 !important; }\n .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }\n .markdown-body table th, .markdown-body table td { border-color: #30363d !important; }\n .markdown-body img { background: #0d1117; }\n .markdown-body blockquote { border-left-color: #8b949e; }\n .markdown-body hr { border-color: #30363d; }\n ';\n document.head.appendChild(style);\n})();", "GitHub Dark Mode README Fix");
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

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Improve cpuid-bool efficiency#86

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 Merged

newpavlov
merged 5 commits into

from

Nov 29, 2020
 Merged


Improve cpuid-bool efficiency
#86
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0ff06a0

improve cpuid-bool efficiency


newpavlov Nov 28, 2020
316b021

update changelog


newpavlov Nov 28, 2020
7d78bf1

fmt fix


newpavlov Nov 28, 2020
599d251

update docs


newpavlov Nov 28, 2020
81691bd

update Cargo.lock


newpavlov Nov 28, 2020

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6 changes: 6 additions & 0 deletions
cpuid-bool/CHANGELOG.md

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Original file line numberDiff line numberDiff line change
Expand Up@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

## 0.2.0 (2020-12-01)
### Changed
- Macro now creates a module with several function and the `InitToken` type ([#86])

[#86]: https://github.com/RustCrypto/utils/pull/86

## 0.1.2 (2020-07-20)
### Added
- LICENSE files ([#70])
Expand Down

4 changes: 2 additions & 2 deletions
cpuid-bool/Cargo.toml

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Open in desktop

Original file line numberDiff line numberDiff line change
@@ -1,9 +1,9 @@
[package]
name = "cpuid-bool"
version = "0.1.2"
version = "0.2.0"
authors = ["RustCrypto Developers"]
license = "MIT OR Apache-2.0"
description = "A lightweight no-std compatible alternative to is_x86_feature_detected"
description = "A lightweight and efficient no-std compatible alternative to the is_x86_feature_detected macro"
documentation = "https://docs.rs/cpuid-bool"
repository = "https://github.com/RustCrypto/utils"
keywords = ["cpuid", "target-feature"]
Expand Down

157 changes: 94 additions & 63 deletions
cpuid-bool/src/lib.rs

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Open in desktop

Original file line numberDiff line numberDiff line change
@@ -1,51 +1,118 @@
//! Macro for checking CPU capabilities at runtime.
//!
//! # Usage example
//! # Example
//! ```
//! if cpuid_bool::cpuid_bool!("sha", "aes") {
//! // This macro creates `cpuid_aes_sha` module
//! cpuid_bool::new!(cpuid_aes_sha, "aes", "sha");
//!
//! // `token` is a Zero Sized Type value, which guarantees
//! // that underlying static storage got properly initialized,
//! // which allows to omit initialization branch
//! let token: cpuid_aes_sha::InitToken = cpuid_aes_sha::init();
//! if token.get() {
//! println!("CPU supports both SHA and AES extensions");
//! } else {
//! println!("SHA and AES extensions are not supported");
//! }
//!
//! // If stored value needed only once you can get stored value
//! // omitting the token
//! let val = cpuid_aes_sha::get();
//! assert_eq!(val, token.get());
//!
//! // Additionally you can get both token and value
//! let (token, val) = cpuid_aes_sha::init_get();
//! assert_eq!(val, token.get());
//! ```
//! Note that if all tested target features are enabled via compiler options
//! (e.g. by using `RUSTFLAGS`), `cpuid_bool!` macro immideatly will expand
//! to `true` and will not use CPUID instruction. Such behavior allows
//! compiler to eliminate fallback code.
//! (e.g. by using `RUSTFLAGS`), the `get` method will always return `true`
//! and `init` will not use CPUID instruction. Such behavior allows
//! compiler to completely eliminate fallback code.
Comment thread
tarcieri marked this conversation as resolved.

//!
//! After first call macro caches result and returns it in subsequent
//! calls, thus runtime overhead for them is minimal.
#![no_std]
#[cfg(not(any(target_arch = "x86", target_arch = "x86_64")))]
compile_error!("This crate works only on x86 and x86-64 targets.");

use core::sync::atomic::{AtomicU8, Ordering::Relaxed};
/// Create module with CPUID bool code.
#[macro_export]
macro_rules! new {
 ($mod_name:ident, $($tf:tt),+ $(,)? ) => {
 mod $mod_name {
 use core::sync::atomic::{AtomicU8, Ordering::Relaxed};

 const UNINIT: u8 = u8::max_value();
 static STORAGE: AtomicU8 = AtomicU8::new(UNINIT);

/// This structure represents a lazily initialized static boolean value.
///
/// Useful when it is preferable to just rerun initialization instead of
/// locking. Used internally by the `cpuid_bool` macro.
pub struct LazyBool(AtomicU8);
 /// Initialization token
 #[derive(Copy, Clone, Debug)]
 pub struct InitToken(());

 impl InitToken {
 /// Get initialized value
 #[inline(always)]
 pub fn get(&self) -> bool {
 // CPUID is not available on SGX targets
 #[cfg(all(not(target_env = "sgx"), not(all($(target_feature=$tf, )*))))]
 let res = STORAGE.load(Relaxed) == 1;
 #[cfg(all(target_env = "sgx", not(all($(target_feature=$tf, )*))))]
 let res = false;
 #[cfg(all($(target_feature=$tf, )*))]
 let res = true;
 res
 }
 }

 /// Initialize underlying storage if needed and get
 /// stored value and initialization token.
 #[inline]
 pub fn init_get() -> (InitToken, bool) {
 // CPUID is not available on SGX targets
 #[cfg(all(not(target_env = "sgx"), not(all($(target_feature=$tf, )*))))]
 let res = {
 #[cfg(target_arch = "x86")]
 use core::arch::x86::{__cpuid, __cpuid_count};
 #[cfg(target_arch = "x86_64")]
 use core::arch::x86_64::{__cpuid, __cpuid_count};

 // Relaxed ordering is fine, as we only have a single atomic variable.
 let val = STORAGE.load(Relaxed);
 if val == UNINIT {
 #[allow(unused_variables)]
 let cr = unsafe {
 [__cpuid(1), __cpuid_count(7, 0)]
 };
 let res = $(cpuid_bool::check!(cr, $tf) & )+ true;
 STORAGE.store(res as u8, Relaxed);
 res
 } else {
 val == 1
 }
 };
 #[cfg(all(target_env = "sgx", not(all($(target_feature=$tf, )*))))]
 let res = false;
 #[cfg(all($(target_feature=$tf, )*))]
 let res = true;

impl LazyBool {
const UNINIT: u8 = u8::max_value();
 (InitToken(()), res)
 }

 pub const fn new() -> Self {
 Self(AtomicU8::new(Self::UNINIT))
 }
 /// Initialize underlying storage if needed and get
 /// initialization token.
 #[inline]
 pub fn init() -> InitToken {
 init_get().0
 }

 // Runs the init() function at least once, returning the value of some run
 // of init(). Multiple callers can run their init() functions in parallel.
 // init() should always return the same value, if it succeeds.
 pub fn unsync_init(&self, init: impl FnOnce() -> bool) -> bool {
 // Relaxed ordering is fine, as we only have a single atomic variable.
 let mut val = self.0.load(Relaxed);
 if val == Self::UNINIT {
 val = init() as u8;
 self.0.store(val as u8, Relaxed);
 /// Initialize underlying storage if needed and get
 /// stored value.
 #[inline]
 pub fn get() -> bool {
 init_get().1
 }
 }
 val != 0
 }
 };
}

// TODO: find how to define private macro usable inside a public one
Expand DownExpand Up@@ -83,39 +150,3 @@ expand_check_macro! {
 ("adx", 1, ebx, 19),
 ("sha", 1, ebx, 29),
}

/// Check at runtime if CPU supports sequence of target features.
///
/// During first execution this macro will use CPUID to check requested
/// target features, results will be cached and further calls will return
/// it instead.
#[macro_export]
macro_rules! cpuid_bool {
 ($($tf:tt),+ $(,)? ) => {{
 // CPUID is not available on SGX targets
 #[cfg(all(not(target_env = "sgx"), not(all($(target_feature=$tf, )*))))]
 let res = {
 #[cfg(target_arch = "x86")]
 use core::arch::x86::{__cpuid, __cpuid_count};
 #[cfg(target_arch = "x86_64")]
 use core::arch::x86_64::{__cpuid, __cpuid_count};

 static CPUID_BOOL: cpuid_bool::LazyBool = cpuid_bool::LazyBool::new();
 CPUID_BOOL.unsync_init(|| {
 #[allow(unused_variables)]
 let cr = unsafe {
 [__cpuid(1), __cpuid_count(7, 0)]
 };
 // TODO: find how to remove `true`
 $(cpuid_bool::check!(cr, $tf) & )+ true
 })
 };

 #[cfg(all(target_env = "sgx", not(all($(target_feature=$tf, )*))))]
 let res = false;
 #[cfg(all($(target_feature=$tf, )*))]
 let res = true;

 res
 }};
}

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Highlight search terms from Google/DuckDuckGo/Bing referrer\n(function() {\n var ref = document.referrer;\n var terms = [];\n \n if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {\n var url = new URL(ref);\n var q = url.searchParams.get('q') || url.searchParams.get('p');\n if (q) {\n terms = q.split(/\\s+/).filter(function(t) { return t.length > 2; });\n }\n }\n \n if (terms.length === 0) return;\n \n var style = document.createElement('style');\n style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';\n document.head.appendChild(style);\n \n function highlight(node) {\n if (node.nodeType === 3) { // text node\n var text = node.textContent;\n var found = false;\n terms.forEach(function(term) {\n var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\') + ')', 'gi');\n if (regex.test(text)) {\n found = true;\n var frag = document.createDocumentFragment();\n var parts = text.split(regex);\n parts.forEach(function(part, i) {\n if (i % 2 === 0) {\n frag.appendChild(document.createTextNode(part));\n } else {\n var span = document.createElement('span');\n span.className = 'userscript-highlight';\n span.textContent = part;\n frag.appendChild(span);\n }\n });\n node.parentNode.replaceChild(frag, node);\n }\n });\n } else if (node.nodeType === 1 && node.childNodes) { // element\n var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];\n if (!skipTags.includes(node.tagName)) {\n Array.from(node.childNodes).forEach(highlight);\n }\n }\n }\n \n highlight(document.body);\n \n // Re-highlight on dynamic content\n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1 || node.nodeType === 3) highlight(node);\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Highlight Search Terms");
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

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#86
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0ff06a0

improve cpuid-bool efficiency


newpavlov Nov 28, 2020
316b021

update changelog


newpavlov Nov 28, 2020
7d78bf1

fmt fix


newpavlov Nov 28, 2020
599d251

update docs


newpavlov Nov 28, 2020
81691bd

update Cargo.lock


newpavlov Nov 28, 2020

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cpuid-bool/CHANGELOG.md

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Original file line numberDiff line numberDiff line change
Expand Up@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

## 0.2.0 (2020-12-01)
### Changed
- Macro now creates a module with several function and the `InitToken` type ([#86])

[#86]: https://github.com/RustCrypto/utils/pull/86

## 0.1.2 (2020-07-20)
### Added
- LICENSE files ([#70])
Expand Down

4 changes: 2 additions & 2 deletions
cpuid-bool/Cargo.toml

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Original file line numberDiff line numberDiff line change
@@ -1,9 +1,9 @@
[package]
name = "cpuid-bool"
version = "0.1.2"
version = "0.2.0"
authors = ["RustCrypto Developers"]
license = "MIT OR Apache-2.0"
description = "A lightweight no-std compatible alternative to is_x86_feature_detected"
description = "A lightweight and efficient no-std compatible alternative to the is_x86_feature_detected macro"
documentation = "https://docs.rs/cpuid-bool"
repository = "https://github.com/RustCrypto/utils"
keywords = ["cpuid", "target-feature"]
Expand Down

157 changes: 94 additions & 63 deletions
cpuid-bool/src/lib.rs

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Original file line numberDiff line numberDiff line change
@@ -1,51 +1,118 @@
//! Macro for checking CPU capabilities at runtime.
//!
//! # Usage example
//! # Example
//! ```
//! if cpuid_bool::cpuid_bool!("sha", "aes") {
//! // This macro creates `cpuid_aes_sha` module
//! cpuid_bool::new!(cpuid_aes_sha, "aes", "sha");
//!
//! // `token` is a Zero Sized Type value, which guarantees
//! // that underlying static storage got properly initialized,
//! // which allows to omit initialization branch
//! let token: cpuid_aes_sha::InitToken = cpuid_aes_sha::init();
//! if token.get() {
//! println!("CPU supports both SHA and AES extensions");
//! } else {
//! println!("SHA and AES extensions are not supported");
//! }
//!
//! // If stored value needed only once you can get stored value
//! // omitting the token
//! let val = cpuid_aes_sha::get();
//! assert_eq!(val, token.get());
//!
//! // Additionally you can get both token and value
//! let (token, val) = cpuid_aes_sha::init_get();
//! assert_eq!(val, token.get());
//! ```
//! Note that if all tested target features are enabled via compiler options
//! (e.g. by using `RUSTFLAGS`), `cpuid_bool!` macro immideatly will expand
//! to `true` and will not use CPUID instruction. Such behavior allows
//! compiler to eliminate fallback code.
//! (e.g. by using `RUSTFLAGS`), the `get` method will always return `true`
//! and `init` will not use CPUID instruction. Such behavior allows
//! compiler to completely eliminate fallback code.
Comment thread
tarcieri marked this conversation as resolved.

//!
//! After first call macro caches result and returns it in subsequent
//! calls, thus runtime overhead for them is minimal.
#![no_std]
#[cfg(not(any(target_arch = "x86", target_arch = "x86_64")))]
compile_error!("This crate works only on x86 and x86-64 targets.");

use core::sync::atomic::{AtomicU8, Ordering::Relaxed};
/// Create module with CPUID bool code.
#[macro_export]
macro_rules! new {
 ($mod_name:ident, $($tf:tt),+ $(,)? ) => {
 mod $mod_name {
 use core::sync::atomic::{AtomicU8, Ordering::Relaxed};

 const UNINIT: u8 = u8::max_value();
 static STORAGE: AtomicU8 = AtomicU8::new(UNINIT);

/// This structure represents a lazily initialized static boolean value.
///
/// Useful when it is preferable to just rerun initialization instead of
/// locking. Used internally by the `cpuid_bool` macro.
pub struct LazyBool(AtomicU8);
 /// Initialization token
 #[derive(Copy, Clone, Debug)]
 pub struct InitToken(());

 impl InitToken {
 /// Get initialized value
 #[inline(always)]
 pub fn get(&self) -> bool {
 // CPUID is not available on SGX targets
 #[cfg(all(not(target_env = "sgx"), not(all($(target_feature=$tf, )*))))]
 let res = STORAGE.load(Relaxed) == 1;
 #[cfg(all(target_env = "sgx", not(all($(target_feature=$tf, )*))))]
 let res = false;
 #[cfg(all($(target_feature=$tf, )*))]
 let res = true;
 res
 }
 }

 /// Initialize underlying storage if needed and get
 /// stored value and initialization token.
 #[inline]
 pub fn init_get() -> (InitToken, bool) {
 // CPUID is not available on SGX targets
 #[cfg(all(not(target_env = "sgx"), not(all($(target_feature=$tf, )*))))]
 let res = {
 #[cfg(target_arch = "x86")]
 use core::arch::x86::{__cpuid, __cpuid_count};
 #[cfg(target_arch = "x86_64")]
 use core::arch::x86_64::{__cpuid, __cpuid_count};

 // Relaxed ordering is fine, as we only have a single atomic variable.
 let val = STORAGE.load(Relaxed);
 if val == UNINIT {
 #[allow(unused_variables)]
 let cr = unsafe {
 [__cpuid(1), __cpuid_count(7, 0)]
 };
 let res = $(cpuid_bool::check!(cr, $tf) & )+ true;
 STORAGE.store(res as u8, Relaxed);
 res
 } else {
 val == 1
 }
 };
 #[cfg(all(target_env = "sgx", not(all($(target_feature=$tf, )*))))]
 let res = false;
 #[cfg(all($(target_feature=$tf, )*))]
 let res = true;

impl LazyBool {
const UNINIT: u8 = u8::max_value();
 (InitToken(()), res)
 }

 pub const fn new() -> Self {
 Self(AtomicU8::new(Self::UNINIT))
 }
 /// Initialize underlying storage if needed and get
 /// initialization token.
 #[inline]
 pub fn init() -> InitToken {
 init_get().0
 }

 // Runs the init() function at least once, returning the value of some run
 // of init(). Multiple callers can run their init() functions in parallel.
 // init() should always return the same value, if it succeeds.
 pub fn unsync_init(&self, init: impl FnOnce() -> bool) -> bool {
 // Relaxed ordering is fine, as we only have a single atomic variable.
 let mut val = self.0.load(Relaxed);
 if val == Self::UNINIT {
 val = init() as u8;
 self.0.store(val as u8, Relaxed);
 /// Initialize underlying storage if needed and get
 /// stored value.
 #[inline]
 pub fn get() -> bool {
 init_get().1
 }
 }
 val != 0
 }
 };
}

// TODO: find how to define private macro usable inside a public one
Expand DownExpand Up@@ -83,39 +150,3 @@ expand_check_macro! {
 ("adx", 1, ebx, 19),
 ("sha", 1, ebx, 29),
}

/// Check at runtime if CPU supports sequence of target features.
///
/// During first execution this macro will use CPUID to check requested
/// target features, results will be cached and further calls will return
/// it instead.
#[macro_export]
macro_rules! cpuid_bool {
 ($($tf:tt),+ $(,)? ) => {{
 // CPUID is not available on SGX targets
 #[cfg(all(not(target_env = "sgx"), not(all($(target_feature=$tf, )*))))]
 let res = {
 #[cfg(target_arch = "x86")]
 use core::arch::x86::{__cpuid, __cpuid_count};
 #[cfg(target_arch = "x86_64")]
 use core::arch::x86_64::{__cpuid, __cpuid_count};

 static CPUID_BOOL: cpuid_bool::LazyBool = cpuid_bool::LazyBool::new();
 CPUID_BOOL.unsync_init(|| {
 #[allow(unused_variables)]
 let cr = unsafe {
 [__cpuid(1), __cpuid_count(7, 0)]
 };
 // TODO: find how to remove `true`
 $(cpuid_bool::check!(cr, $tf) & )+ true
 })
 };

 #[cfg(all(target_env = "sgx", not(all($(target_feature=$tf, )*))))]
 let res = false;
 #[cfg(all($(target_feature=$tf, )*))]
 let res = true;

 res
 }};
}

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links");
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '

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 Merged

newpavlov
merged 5 commits into

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Nov 29, 2020
 Merged


Improve cpuid-bool efficiency
#86
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0ff06a0

improve cpuid-bool efficiency


newpavlov Nov 28, 2020
316b021

update changelog


newpavlov Nov 28, 2020
7d78bf1

fmt fix


newpavlov Nov 28, 2020
599d251

update docs


newpavlov Nov 28, 2020
81691bd

update Cargo.lock


newpavlov Nov 28, 2020

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cpuid-bool/CHANGELOG.md

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Original file line numberDiff line numberDiff line change
Expand Up@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

## 0.2.0 (2020-12-01)
### Changed
- Macro now creates a module with several function and the `InitToken` type ([#86])

[#86]: https://github.com/RustCrypto/utils/pull/86

## 0.1.2 (2020-07-20)
### Added
- LICENSE files ([#70])
Expand Down

4 changes: 2 additions & 2 deletions
cpuid-bool/Cargo.toml

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -1,9 +1,9 @@
[package]
name = "cpuid-bool"
version = "0.1.2"
version = "0.2.0"
authors = ["RustCrypto Developers"]
license = "MIT OR Apache-2.0"
description = "A lightweight no-std compatible alternative to is_x86_feature_detected"
description = "A lightweight and efficient no-std compatible alternative to the is_x86_feature_detected macro"
documentation = "https://docs.rs/cpuid-bool"
repository = "https://github.com/RustCrypto/utils"
keywords = ["cpuid", "target-feature"]
Expand Down

157 changes: 94 additions & 63 deletions
cpuid-bool/src/lib.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -1,51 +1,118 @@
//! Macro for checking CPU capabilities at runtime.
//!
//! # Usage example
//! # Example
//! ```
//! if cpuid_bool::cpuid_bool!("sha", "aes") {
//! // This macro creates `cpuid_aes_sha` module
//! cpuid_bool::new!(cpuid_aes_sha, "aes", "sha");
//!
//! // `token` is a Zero Sized Type value, which guarantees
//! // that underlying static storage got properly initialized,
//! // which allows to omit initialization branch
//! let token: cpuid_aes_sha::InitToken = cpuid_aes_sha::init();
//! if token.get() {
//! println!("CPU supports both SHA and AES extensions");
//! } else {
//! println!("SHA and AES extensions are not supported");
//! }
//!
//! // If stored value needed only once you can get stored value
//! // omitting the token
//! let val = cpuid_aes_sha::get();
//! assert_eq!(val, token.get());
//!
//! // Additionally you can get both token and value
//! let (token, val) = cpuid_aes_sha::init_get();
//! assert_eq!(val, token.get());
//! ```
//! Note that if all tested target features are enabled via compiler options
//! (e.g. by using `RUSTFLAGS`), `cpuid_bool!` macro immideatly will expand
//! to `true` and will not use CPUID instruction. Such behavior allows
//! compiler to eliminate fallback code.
//! (e.g. by using `RUSTFLAGS`), the `get` method will always return `true`
//! and `init` will not use CPUID instruction. Such behavior allows
//! compiler to completely eliminate fallback code.
Comment thread
tarcieri marked this conversation as resolved.

//!
//! After first call macro caches result and returns it in subsequent
//! calls, thus runtime overhead for them is minimal.
#![no_std]
#[cfg(not(any(target_arch = "x86", target_arch = "x86_64")))]
compile_error!("This crate works only on x86 and x86-64 targets.");

use core::sync::atomic::{AtomicU8, Ordering::Relaxed};
/// Create module with CPUID bool code.
#[macro_export]
macro_rules! new {
 ($mod_name:ident, $($tf:tt),+ $(,)? ) => {
 mod $mod_name {
 use core::sync::atomic::{AtomicU8, Ordering::Relaxed};

 const UNINIT: u8 = u8::max_value();
 static STORAGE: AtomicU8 = AtomicU8::new(UNINIT);

/// This structure represents a lazily initialized static boolean value.
///
/// Useful when it is preferable to just rerun initialization instead of
/// locking. Used internally by the `cpuid_bool` macro.
pub struct LazyBool(AtomicU8);
 /// Initialization token
 #[derive(Copy, Clone, Debug)]
 pub struct InitToken(());

 impl InitToken {
 /// Get initialized value
 #[inline(always)]
 pub fn get(&self) -> bool {
 // CPUID is not available on SGX targets
 #[cfg(all(not(target_env = "sgx"), not(all($(target_feature=$tf, )*))))]
 let res = STORAGE.load(Relaxed) == 1;
 #[cfg(all(target_env = "sgx", not(all($(target_feature=$tf, )*))))]
 let res = false;
 #[cfg(all($(target_feature=$tf, )*))]
 let res = true;
 res
 }
 }

 /// Initialize underlying storage if needed and get
 /// stored value and initialization token.
 #[inline]
 pub fn init_get() -> (InitToken, bool) {
 // CPUID is not available on SGX targets
 #[cfg(all(not(target_env = "sgx"), not(all($(target_feature=$tf, )*))))]
 let res = {
 #[cfg(target_arch = "x86")]
 use core::arch::x86::{__cpuid, __cpuid_count};
 #[cfg(target_arch = "x86_64")]
 use core::arch::x86_64::{__cpuid, __cpuid_count};

 // Relaxed ordering is fine, as we only have a single atomic variable.
 let val = STORAGE.load(Relaxed);
 if val == UNINIT {
 #[allow(unused_variables)]
 let cr = unsafe {
 [__cpuid(1), __cpuid_count(7, 0)]
 };
 let res = $(cpuid_bool::check!(cr, $tf) & )+ true;
 STORAGE.store(res as u8, Relaxed);
 res
 } else {
 val == 1
 }
 };
 #[cfg(all(target_env = "sgx", not(all($(target_feature=$tf, )*))))]
 let res = false;
 #[cfg(all($(target_feature=$tf, )*))]
 let res = true;

impl LazyBool {
const UNINIT: u8 = u8::max_value();
 (InitToken(()), res)
 }

 pub const fn new() -> Self {
 Self(AtomicU8::new(Self::UNINIT))
 }
 /// Initialize underlying storage if needed and get
 /// initialization token.
 #[inline]
 pub fn init() -> InitToken {
 init_get().0
 }

 // Runs the init() function at least once, returning the value of some run
 // of init(). Multiple callers can run their init() functions in parallel.
 // init() should always return the same value, if it succeeds.
 pub fn unsync_init(&self, init: impl FnOnce() -> bool) -> bool {
 // Relaxed ordering is fine, as we only have a single atomic variable.
 let mut val = self.0.load(Relaxed);
 if val == Self::UNINIT {
 val = init() as u8;
 self.0.store(val as u8, Relaxed);
 /// Initialize underlying storage if needed and get
 /// stored value.
 #[inline]
 pub fn get() -> bool {
 init_get().1
 }
 }
 val != 0
 }
 };
}

// TODO: find how to define private macro usable inside a public one
Expand DownExpand Up@@ -83,39 +150,3 @@ expand_check_macro! {
 ("adx", 1, ebx, 19),
 ("sha", 1, ebx, 29),
}

/// Check at runtime if CPU supports sequence of target features.
///
/// During first execution this macro will use CPUID to check requested
/// target features, results will be cached and further calls will return
/// it instead.
#[macro_export]
macro_rules! cpuid_bool {
 ($($tf:tt),+ $(,)? ) => {{
 // CPUID is not available on SGX targets
 #[cfg(all(not(target_env = "sgx"), not(all($(target_feature=$tf, )*))))]
 let res = {
 #[cfg(target_arch = "x86")]
 use core::arch::x86::{__cpuid, __cpuid_count};
 #[cfg(target_arch = "x86_64")]
 use core::arch::x86_64::{__cpuid, __cpuid_count};

 static CPUID_BOOL: cpuid_bool::LazyBool = cpuid_bool::LazyBool::new();
 CPUID_BOOL.unsync_init(|| {
 #[allow(unused_variables)]
 let cr = unsafe {
 [__cpuid(1), __cpuid_count(7, 0)]
 };
 // TODO: find how to remove `true`
 $(cpuid_bool::check!(cr, $tf) & )+ true
 })
 };

 #[cfg(all(target_env = "sgx", not(all($(target_feature=$tf, )*))))]
 let res = false;
 #[cfg(all($(target_feature=$tf, )*))]
 let res = true;

 res
 }};
}

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default");
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

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#86
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0ff06a0

improve cpuid-bool efficiency


newpavlov Nov 28, 2020
316b021

update changelog


newpavlov Nov 28, 2020
7d78bf1

fmt fix


newpavlov Nov 28, 2020
599d251

update docs


newpavlov Nov 28, 2020
81691bd

update Cargo.lock


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cpuid-bool/CHANGELOG.md

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Original file line numberDiff line numberDiff line change
Expand Up@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

## 0.2.0 (2020-12-01)
### Changed
- Macro now creates a module with several function and the `InitToken` type ([#86])

[#86]: https://github.com/RustCrypto/utils/pull/86

## 0.1.2 (2020-07-20)
### Added
- LICENSE files ([#70])
Expand Down

4 changes: 2 additions & 2 deletions
cpuid-bool/Cargo.toml

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Original file line numberDiff line numberDiff line change
@@ -1,9 +1,9 @@
[package]
name = "cpuid-bool"
version = "0.1.2"
version = "0.2.0"
authors = ["RustCrypto Developers"]
license = "MIT OR Apache-2.0"
description = "A lightweight no-std compatible alternative to is_x86_feature_detected"
description = "A lightweight and efficient no-std compatible alternative to the is_x86_feature_detected macro"
documentation = "https://docs.rs/cpuid-bool"
repository = "https://github.com/RustCrypto/utils"
keywords = ["cpuid", "target-feature"]
Expand Down

157 changes: 94 additions & 63 deletions
cpuid-bool/src/lib.rs

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Original file line numberDiff line numberDiff line change
@@ -1,51 +1,118 @@
//! Macro for checking CPU capabilities at runtime.
//!
//! # Usage example
//! # Example
//! ```
//! if cpuid_bool::cpuid_bool!("sha", "aes") {
//! // This macro creates `cpuid_aes_sha` module
//! cpuid_bool::new!(cpuid_aes_sha, "aes", "sha");
//!
//! // `token` is a Zero Sized Type value, which guarantees
//! // that underlying static storage got properly initialized,
//! // which allows to omit initialization branch
//! let token: cpuid_aes_sha::InitToken = cpuid_aes_sha::init();
//! if token.get() {
//! println!("CPU supports both SHA and AES extensions");
//! } else {
//! println!("SHA and AES extensions are not supported");
//! }
//!
//! // If stored value needed only once you can get stored value
//! // omitting the token
//! let val = cpuid_aes_sha::get();
//! assert_eq!(val, token.get());
//!
//! // Additionally you can get both token and value
//! let (token, val) = cpuid_aes_sha::init_get();
//! assert_eq!(val, token.get());
//! ```
//! Note that if all tested target features are enabled via compiler options
//! (e.g. by using `RUSTFLAGS`), `cpuid_bool!` macro immideatly will expand
//! to `true` and will not use CPUID instruction. Such behavior allows
//! compiler to eliminate fallback code.
//! (e.g. by using `RUSTFLAGS`), the `get` method will always return `true`
//! and `init` will not use CPUID instruction. Such behavior allows
//! compiler to completely eliminate fallback code.
Comment thread
tarcieri marked this conversation as resolved.

//!
//! After first call macro caches result and returns it in subsequent
//! calls, thus runtime overhead for them is minimal.
#![no_std]
#[cfg(not(any(target_arch = "x86", target_arch = "x86_64")))]
compile_error!("This crate works only on x86 and x86-64 targets.");

use core::sync::atomic::{AtomicU8, Ordering::Relaxed};
/// Create module with CPUID bool code.
#[macro_export]
macro_rules! new {
 ($mod_name:ident, $($tf:tt),+ $(,)? ) => {
 mod $mod_name {
 use core::sync::atomic::{AtomicU8, Ordering::Relaxed};

 const UNINIT: u8 = u8::max_value();
 static STORAGE: AtomicU8 = AtomicU8::new(UNINIT);

/// This structure represents a lazily initialized static boolean value.
///
/// Useful when it is preferable to just rerun initialization instead of
/// locking. Used internally by the `cpuid_bool` macro.
pub struct LazyBool(AtomicU8);
 /// Initialization token
 #[derive(Copy, Clone, Debug)]
 pub struct InitToken(());

 impl InitToken {
 /// Get initialized value
 #[inline(always)]
 pub fn get(&self) -> bool {
 // CPUID is not available on SGX targets
 #[cfg(all(not(target_env = "sgx"), not(all($(target_feature=$tf, )*))))]
 let res = STORAGE.load(Relaxed) == 1;
 #[cfg(all(target_env = "sgx", not(all($(target_feature=$tf, )*))))]
 let res = false;
 #[cfg(all($(target_feature=$tf, )*))]
 let res = true;
 res
 }
 }

 /// Initialize underlying storage if needed and get
 /// stored value and initialization token.
 #[inline]
 pub fn init_get() -> (InitToken, bool) {
 // CPUID is not available on SGX targets
 #[cfg(all(not(target_env = "sgx"), not(all($(target_feature=$tf, )*))))]
 let res = {
 #[cfg(target_arch = "x86")]
 use core::arch::x86::{__cpuid, __cpuid_count};
 #[cfg(target_arch = "x86_64")]
 use core::arch::x86_64::{__cpuid, __cpuid_count};

 // Relaxed ordering is fine, as we only have a single atomic variable.
 let val = STORAGE.load(Relaxed);
 if val == UNINIT {
 #[allow(unused_variables)]
 let cr = unsafe {
 [__cpuid(1), __cpuid_count(7, 0)]
 };
 let res = $(cpuid_bool::check!(cr, $tf) & )+ true;
 STORAGE.store(res as u8, Relaxed);
 res
 } else {
 val == 1
 }
 };
 #[cfg(all(target_env = "sgx", not(all($(target_feature=$tf, )*))))]
 let res = false;
 #[cfg(all($(target_feature=$tf, )*))]
 let res = true;

impl LazyBool {
const UNINIT: u8 = u8::max_value();
 (InitToken(()), res)
 }

 pub const fn new() -> Self {
 Self(AtomicU8::new(Self::UNINIT))
 }
 /// Initialize underlying storage if needed and get
 /// initialization token.
 #[inline]
 pub fn init() -> InitToken {
 init_get().0
 }

 // Runs the init() function at least once, returning the value of some run
 // of init(). Multiple callers can run their init() functions in parallel.
 // init() should always return the same value, if it succeeds.
 pub fn unsync_init(&self, init: impl FnOnce() -> bool) -> bool {
 // Relaxed ordering is fine, as we only have a single atomic variable.
 let mut val = self.0.load(Relaxed);
 if val == Self::UNINIT {
 val = init() as u8;
 self.0.store(val as u8, Relaxed);
 /// Initialize underlying storage if needed and get
 /// stored value.
 #[inline]
 pub fn get() -> bool {
 init_get().1
 }
 }
 val != 0
 }
 };
}

// TODO: find how to define private macro usable inside a public one
Expand DownExpand Up@@ -83,39 +150,3 @@ expand_check_macro! {
 ("adx", 1, ebx, 19),
 ("sha", 1, ebx, 29),
}

/// Check at runtime if CPU supports sequence of target features.
///
/// During first execution this macro will use CPUID to check requested
/// target features, results will be cached and further calls will return
/// it instead.
#[macro_export]
macro_rules! cpuid_bool {
 ($($tf:tt),+ $(,)? ) => {{
 // CPUID is not available on SGX targets
 #[cfg(all(not(target_env = "sgx"), not(all($(target_feature=$tf, )*))))]
 let res = {
 #[cfg(target_arch = "x86")]
 use core::arch::x86::{__cpuid, __cpuid_count};
 #[cfg(target_arch = "x86_64")]
 use core::arch::x86_64::{__cpuid, __cpuid_count};

 static CPUID_BOOL: cpuid_bool::LazyBool = cpuid_bool::LazyBool::new();
 CPUID_BOOL.unsync_init(|| {
 #[allow(unused_variables)]
 let cr = unsafe {
 [__cpuid(1), __cpuid_count(7, 0)]
 };
 // TODO: find how to remove `true`
 $(cpuid_bool::check!(cr, $tf) & )+ true
 })
 };

 #[cfg(all(target_env = "sgx", not(all($(target_feature=$tf, )*))))]
 let res = false;
 #[cfg(all($(target_feature=$tf, )*))]
 let res = true;

 res
 }};
}

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers");
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

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Improve cpuid-bool efficiency#86

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 Merged

newpavlov
merged 5 commits into

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Nov 29, 2020
 Merged


Improve cpuid-bool efficiency
#86
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0ff06a0

improve cpuid-bool efficiency


newpavlov Nov 28, 2020
316b021

update changelog


newpavlov Nov 28, 2020
7d78bf1

fmt fix


newpavlov Nov 28, 2020
599d251

update docs


newpavlov Nov 28, 2020
81691bd

update Cargo.lock


newpavlov Nov 28, 2020

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cpuid-bool/CHANGELOG.md

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Original file line numberDiff line numberDiff line change
Expand Up@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

## 0.2.0 (2020-12-01)
### Changed
- Macro now creates a module with several function and the `InitToken` type ([#86])

[#86]: https://github.com/RustCrypto/utils/pull/86

## 0.1.2 (2020-07-20)
### Added
- LICENSE files ([#70])
Expand Down

4 changes: 2 additions & 2 deletions
cpuid-bool/Cargo.toml

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Original file line numberDiff line numberDiff line change
@@ -1,9 +1,9 @@
[package]
name = "cpuid-bool"
version = "0.1.2"
version = "0.2.0"
authors = ["RustCrypto Developers"]
license = "MIT OR Apache-2.0"
description = "A lightweight no-std compatible alternative to is_x86_feature_detected"
description = "A lightweight and efficient no-std compatible alternative to the is_x86_feature_detected macro"
documentation = "https://docs.rs/cpuid-bool"
repository = "https://github.com/RustCrypto/utils"
keywords = ["cpuid", "target-feature"]
Expand Down

157 changes: 94 additions & 63 deletions
cpuid-bool/src/lib.rs

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Open in desktop

Original file line numberDiff line numberDiff line change
@@ -1,51 +1,118 @@
//! Macro for checking CPU capabilities at runtime.
//!
//! # Usage example
//! # Example
//! ```
//! if cpuid_bool::cpuid_bool!("sha", "aes") {
//! // This macro creates `cpuid_aes_sha` module
//! cpuid_bool::new!(cpuid_aes_sha, "aes", "sha");
//!
//! // `token` is a Zero Sized Type value, which guarantees
//! // that underlying static storage got properly initialized,
//! // which allows to omit initialization branch
//! let token: cpuid_aes_sha::InitToken = cpuid_aes_sha::init();
//! if token.get() {
//! println!("CPU supports both SHA and AES extensions");
//! } else {
//! println!("SHA and AES extensions are not supported");
//! }
//!
//! // If stored value needed only once you can get stored value
//! // omitting the token
//! let val = cpuid_aes_sha::get();
//! assert_eq!(val, token.get());
//!
//! // Additionally you can get both token and value
//! let (token, val) = cpuid_aes_sha::init_get();
//! assert_eq!(val, token.get());
//! ```
//! Note that if all tested target features are enabled via compiler options
//! (e.g. by using `RUSTFLAGS`), `cpuid_bool!` macro immideatly will expand
//! to `true` and will not use CPUID instruction. Such behavior allows
//! compiler to eliminate fallback code.
//! (e.g. by using `RUSTFLAGS`), the `get` method will always return `true`
//! and `init` will not use CPUID instruction. Such behavior allows
//! compiler to completely eliminate fallback code.
Comment thread
tarcieri marked this conversation as resolved.

//!
//! After first call macro caches result and returns it in subsequent
//! calls, thus runtime overhead for them is minimal.
#![no_std]
#[cfg(not(any(target_arch = "x86", target_arch = "x86_64")))]
compile_error!("This crate works only on x86 and x86-64 targets.");

use core::sync::atomic::{AtomicU8, Ordering::Relaxed};
/// Create module with CPUID bool code.
#[macro_export]
macro_rules! new {
 ($mod_name:ident, $($tf:tt),+ $(,)? ) => {
 mod $mod_name {
 use core::sync::atomic::{AtomicU8, Ordering::Relaxed};

 const UNINIT: u8 = u8::max_value();
 static STORAGE: AtomicU8 = AtomicU8::new(UNINIT);

/// This structure represents a lazily initialized static boolean value.
///
/// Useful when it is preferable to just rerun initialization instead of
/// locking. Used internally by the `cpuid_bool` macro.
pub struct LazyBool(AtomicU8);
 /// Initialization token
 #[derive(Copy, Clone, Debug)]
 pub struct InitToken(());

 impl InitToken {
 /// Get initialized value
 #[inline(always)]
 pub fn get(&self) -> bool {
 // CPUID is not available on SGX targets
 #[cfg(all(not(target_env = "sgx"), not(all($(target_feature=$tf, )*))))]
 let res = STORAGE.load(Relaxed) == 1;
 #[cfg(all(target_env = "sgx", not(all($(target_feature=$tf, )*))))]
 let res = false;
 #[cfg(all($(target_feature=$tf, )*))]
 let res = true;
 res
 }
 }

 /// Initialize underlying storage if needed and get
 /// stored value and initialization token.
 #[inline]
 pub fn init_get() -> (InitToken, bool) {
 // CPUID is not available on SGX targets
 #[cfg(all(not(target_env = "sgx"), not(all($(target_feature=$tf, )*))))]
 let res = {
 #[cfg(target_arch = "x86")]
 use core::arch::x86::{__cpuid, __cpuid_count};
 #[cfg(target_arch = "x86_64")]
 use core::arch::x86_64::{__cpuid, __cpuid_count};

 // Relaxed ordering is fine, as we only have a single atomic variable.
 let val = STORAGE.load(Relaxed);
 if val == UNINIT {
 #[allow(unused_variables)]
 let cr = unsafe {
 [__cpuid(1), __cpuid_count(7, 0)]
 };
 let res = $(cpuid_bool::check!(cr, $tf) & )+ true;
 STORAGE.store(res as u8, Relaxed);
 res
 } else {
 val == 1
 }
 };
 #[cfg(all(target_env = "sgx", not(all($(target_feature=$tf, )*))))]
 let res = false;
 #[cfg(all($(target_feature=$tf, )*))]
 let res = true;

impl LazyBool {
const UNINIT: u8 = u8::max_value();
 (InitToken(()), res)
 }

 pub const fn new() -> Self {
 Self(AtomicU8::new(Self::UNINIT))
 }
 /// Initialize underlying storage if needed and get
 /// initialization token.
 #[inline]
 pub fn init() -> InitToken {
 init_get().0
 }

 // Runs the init() function at least once, returning the value of some run
 // of init(). Multiple callers can run their init() functions in parallel.
 // init() should always return the same value, if it succeeds.
 pub fn unsync_init(&self, init: impl FnOnce() -> bool) -> bool {
 // Relaxed ordering is fine, as we only have a single atomic variable.
 let mut val = self.0.load(Relaxed);
 if val == Self::UNINIT {
 val = init() as u8;
 self.0.store(val as u8, Relaxed);
 /// Initialize underlying storage if needed and get
 /// stored value.
 #[inline]
 pub fn get() -> bool {
 init_get().1
 }
 }
 val != 0
 }
 };
}

// TODO: find how to define private macro usable inside a public one
Expand DownExpand Up@@ -83,39 +150,3 @@ expand_check_macro! {
 ("adx", 1, ebx, 19),
 ("sha", 1, ebx, 29),
}

/// Check at runtime if CPU supports sequence of target features.
///
/// During first execution this macro will use CPUID to check requested
/// target features, results will be cached and further calls will return
/// it instead.
#[macro_export]
macro_rules! cpuid_bool {
 ($($tf:tt),+ $(,)? ) => {{
 // CPUID is not available on SGX targets
 #[cfg(all(not(target_env = "sgx"), not(all($(target_feature=$tf, )*))))]
 let res = {
 #[cfg(target_arch = "x86")]
 use core::arch::x86::{__cpuid, __cpuid_count};
 #[cfg(target_arch = "x86_64")]
 use core::arch::x86_64::{__cpuid, __cpuid_count};

 static CPUID_BOOL: cpuid_bool::LazyBool = cpuid_bool::LazyBool::new();
 CPUID_BOOL.unsync_init(|| {
 #[allow(unused_variables)]
 let cr = unsafe {
 [__cpuid(1), __cpuid_count(7, 0)]
 };
 // TODO: find how to remove `true`
 $(cpuid_bool::check!(cr, $tf) & )+ true
 })
 };

 #[cfg(all(target_env = "sgx", not(all($(target_feature=$tf, )*))))]
 let res = false;
 #[cfg(all($(target_feature=$tf, )*))]
 let res = true;

 res
 }};
}

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Universal Dark Mode - works on any site\n(function() {\n var enabled = true;\n \n function applyDarkMode() {\n if (!enabled) return;\n \n // Create style element if it doesn't exist\n var style = document.getElementById('universal-dark-mode-style');\n if (!style) {\n style = document.createElement('style');\n style.id = 'universal-dark-mode-style';\n document.head.appendChild(style);\n }\n \n // Dark mode CSS - inverts colors but preserves images/video\n style.textContent = '\n /* Invert everything except media */\n html {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #1a1a2e !important;\n }\n \n /* Restore images, videos, iframes, canvas */\n img, video, iframe, canvas, svg, picture, [style*=\"background-image\"] {\n filter: invert(1) hue-rotate(180deg) !important;\n }\n \n /* Preserve specific elements that should not be inverted */\n .no-dark-mode, .no-dark-mode *,\n [data-theme=\"light\"], [data-theme=\"light\"],\n .ace_editor, .ace_editor *,\n .CodeMirror, .CodeMirror *,\n .monaco-editor, .monaco-editor *,\n .markdown-body pre, .markdown-body pre *,\n .highlight, .highlight *,\n pre code, pre code * {\n filter: none !important;\n }\n \n /* Fix common UI elements */\n .modal, .popup, .dropdown-menu, .tooltip, .popover {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #2d2d44 !important;\n border-color: #444 !important;\n }\n \n /* Scrollbars */\n ::-webkit-scrollbar { background: #1a1a2e !important; }\n ::-webkit-scrollbar-thumb { background: #444 !important; }\n ::-webkit-scrollbar-thumb:hover { background: #555 !important; }\n \n /* Selection */\n ::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ';\n }\n \n function removeDarkMode() {\n var style = document.getElementById('universal-dark-mode-style');\n if (style) style.remove();\n }\n \n // Toggle with Alt+Shift+D\n document.addEventListener('keydown', function(e) {\n if (e.altKey && e.shiftKey && e.key === 'D') {\n e.preventDefault();\n enabled = !enabled;\n if (enabled) {\n applyDarkMode();\n console.log('[Universal Dark Mode] Enabled');\n } else {\n removeDarkMode();\n console.log('[Universal Dark Mode] Disabled');\n }\n }\n });\n \n // Apply on load\n applyDarkMode();\n \n // Re-apply on dynamic content\n var observer = new MutationObserver(function(mutations) {\n if (enabled && !document.getElementById('universal-dark-mode-style')) {\n applyDarkMode();\n }\n });\n observer.observe(document.head, { childList: true });\n \n console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');\n})();", "Universal Dark Mode");
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();

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Nov 29, 2020
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Improve cpuid-bool efficiency
#86
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0ff06a0

improve cpuid-bool efficiency


newpavlov Nov 28, 2020
316b021

update changelog


newpavlov Nov 28, 2020
7d78bf1

fmt fix


newpavlov Nov 28, 2020
599d251

update docs


newpavlov Nov 28, 2020
81691bd

update Cargo.lock


newpavlov Nov 28, 2020

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2 changes: 1 addition & 1 deletion
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cpuid-bool/CHANGELOG.md

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Original file line numberDiff line numberDiff line change
Expand Up@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

## 0.2.0 (2020-12-01)
### Changed
- Macro now creates a module with several function and the `InitToken` type ([#86])

[#86]: https://github.com/RustCrypto/utils/pull/86

## 0.1.2 (2020-07-20)
### Added
- LICENSE files ([#70])
Expand Down

4 changes: 2 additions & 2 deletions
cpuid-bool/Cargo.toml

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Original file line numberDiff line numberDiff line change
@@ -1,9 +1,9 @@
[package]
name = "cpuid-bool"
version = "0.1.2"
version = "0.2.0"
authors = ["RustCrypto Developers"]
license = "MIT OR Apache-2.0"
description = "A lightweight no-std compatible alternative to is_x86_feature_detected"
description = "A lightweight and efficient no-std compatible alternative to the is_x86_feature_detected macro"
documentation = "https://docs.rs/cpuid-bool"
repository = "https://github.com/RustCrypto/utils"
keywords = ["cpuid", "target-feature"]
Expand Down

157 changes: 94 additions & 63 deletions
cpuid-bool/src/lib.rs

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Original file line numberDiff line numberDiff line change
@@ -1,51 +1,118 @@
//! Macro for checking CPU capabilities at runtime.
//!
//! # Usage example
//! # Example
//! ```
//! if cpuid_bool::cpuid_bool!("sha", "aes") {
//! // This macro creates `cpuid_aes_sha` module
//! cpuid_bool::new!(cpuid_aes_sha, "aes", "sha");
//!
//! // `token` is a Zero Sized Type value, which guarantees
//! // that underlying static storage got properly initialized,
//! // which allows to omit initialization branch
//! let token: cpuid_aes_sha::InitToken = cpuid_aes_sha::init();
//! if token.get() {
//! println!("CPU supports both SHA and AES extensions");
//! } else {
//! println!("SHA and AES extensions are not supported");
//! }
//!
//! // If stored value needed only once you can get stored value
//! // omitting the token
//! let val = cpuid_aes_sha::get();
//! assert_eq!(val, token.get());
//!
//! // Additionally you can get both token and value
//! let (token, val) = cpuid_aes_sha::init_get();
//! assert_eq!(val, token.get());
//! ```
//! Note that if all tested target features are enabled via compiler options
//! (e.g. by using `RUSTFLAGS`), `cpuid_bool!` macro immideatly will expand
//! to `true` and will not use CPUID instruction. Such behavior allows
//! compiler to eliminate fallback code.
//! (e.g. by using `RUSTFLAGS`), the `get` method will always return `true`
//! and `init` will not use CPUID instruction. Such behavior allows
//! compiler to completely eliminate fallback code.
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//!
//! After first call macro caches result and returns it in subsequent
//! calls, thus runtime overhead for them is minimal.
#![no_std]
#[cfg(not(any(target_arch = "x86", target_arch = "x86_64")))]
compile_error!("This crate works only on x86 and x86-64 targets.");

use core::sync::atomic::{AtomicU8, Ordering::Relaxed};
/// Create module with CPUID bool code.
#[macro_export]
macro_rules! new {
 ($mod_name:ident, $($tf:tt),+ $(,)? ) => {
 mod $mod_name {
 use core::sync::atomic::{AtomicU8, Ordering::Relaxed};

 const UNINIT: u8 = u8::max_value();
 static STORAGE: AtomicU8 = AtomicU8::new(UNINIT);

/// This structure represents a lazily initialized static boolean value.
///
/// Useful when it is preferable to just rerun initialization instead of
/// locking. Used internally by the `cpuid_bool` macro.
pub struct LazyBool(AtomicU8);
 /// Initialization token
 #[derive(Copy, Clone, Debug)]
 pub struct InitToken(());

 impl InitToken {
 /// Get initialized value
 #[inline(always)]
 pub fn get(&self) -> bool {
 // CPUID is not available on SGX targets
 #[cfg(all(not(target_env = "sgx"), not(all($(target_feature=$tf, )*))))]
 let res = STORAGE.load(Relaxed) == 1;
 #[cfg(all(target_env = "sgx", not(all($(target_feature=$tf, )*))))]
 let res = false;
 #[cfg(all($(target_feature=$tf, )*))]
 let res = true;
 res
 }
 }

 /// Initialize underlying storage if needed and get
 /// stored value and initialization token.
 #[inline]
 pub fn init_get() -> (InitToken, bool) {
 // CPUID is not available on SGX targets
 #[cfg(all(not(target_env = "sgx"), not(all($(target_feature=$tf, )*))))]
 let res = {
 #[cfg(target_arch = "x86")]
 use core::arch::x86::{__cpuid, __cpuid_count};
 #[cfg(target_arch = "x86_64")]
 use core::arch::x86_64::{__cpuid, __cpuid_count};

 // Relaxed ordering is fine, as we only have a single atomic variable.
 let val = STORAGE.load(Relaxed);
 if val == UNINIT {
 #[allow(unused_variables)]
 let cr = unsafe {
 [__cpuid(1), __cpuid_count(7, 0)]
 };
 let res = $(cpuid_bool::check!(cr, $tf) & )+ true;
 STORAGE.store(res as u8, Relaxed);
 res
 } else {
 val == 1
 }
 };
 #[cfg(all(target_env = "sgx", not(all($(target_feature=$tf, )*))))]
 let res = false;
 #[cfg(all($(target_feature=$tf, )*))]
 let res = true;

impl LazyBool {
const UNINIT: u8 = u8::max_value();
 (InitToken(()), res)
 }

 pub const fn new() -> Self {
 Self(AtomicU8::new(Self::UNINIT))
 }
 /// Initialize underlying storage if needed and get
 /// initialization token.
 #[inline]
 pub fn init() -> InitToken {
 init_get().0
 }

 // Runs the init() function at least once, returning the value of some run
 // of init(). Multiple callers can run their init() functions in parallel.
 // init() should always return the same value, if it succeeds.
 pub fn unsync_init(&self, init: impl FnOnce() -> bool) -> bool {
 // Relaxed ordering is fine, as we only have a single atomic variable.
 let mut val = self.0.load(Relaxed);
 if val == Self::UNINIT {
 val = init() as u8;
 self.0.store(val as u8, Relaxed);
 /// Initialize underlying storage if needed and get
 /// stored value.
 #[inline]
 pub fn get() -> bool {
 init_get().1
 }
 }
 val != 0
 }
 };
}

// TODO: find how to define private macro usable inside a public one
Expand DownExpand Up@@ -83,39 +150,3 @@ expand_check_macro! {
 ("adx", 1, ebx, 19),
 ("sha", 1, ebx, 29),
}

/// Check at runtime if CPU supports sequence of target features.
///
/// During first execution this macro will use CPUID to check requested
/// target features, results will be cached and further calls will return
/// it instead.
#[macro_export]
macro_rules! cpuid_bool {
 ($($tf:tt),+ $(,)? ) => {{
 // CPUID is not available on SGX targets
 #[cfg(all(not(target_env = "sgx"), not(all($(target_feature=$tf, )*))))]
 let res = {
 #[cfg(target_arch = "x86")]
 use core::arch::x86::{__cpuid, __cpuid_count};
 #[cfg(target_arch = "x86_64")]
 use core::arch::x86_64::{__cpuid, __cpuid_count};

 static CPUID_BOOL: cpuid_bool::LazyBool = cpuid_bool::LazyBool::new();
 CPUID_BOOL.unsync_init(|| {
 #[allow(unused_variables)]
 let cr = unsafe {
 [__cpuid(1), __cpuid_count(7, 0)]
 };
 // TODO: find how to remove `true`
 $(cpuid_bool::check!(cr, $tf) & )+ true
 })
 };

 #[cfg(all(target_env = "sgx", not(all($(target_feature=$tf, )*))))]
 let res = false;
 #[cfg(all($(target_feature=$tf, )*))]
 let res = true;

 res
 }};
}