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authorValentin Popov <valentin@popov.link>2024-01-08 00:21:28 +0300
committerValentin Popov <valentin@popov.link>2024-01-08 00:21:28 +0300
commit1b6a04ca5504955c571d1c97504fb45ea0befee4 (patch)
tree7579f518b23313e8a9748a88ab6173d5e030b227 /vendor/crunchy/src
parent5ecd8cf2cba827454317368b68571df0d13d7842 (diff)
downloadfparkan-1b6a04ca5504955c571d1c97504fb45ea0befee4.tar.xz
fparkan-1b6a04ca5504955c571d1c97504fb45ea0befee4.zip
Initial vendor packages
Signed-off-by: Valentin Popov <valentin@popov.link>
Diffstat (limited to 'vendor/crunchy/src')
-rw-r--r--vendor/crunchy/src/lib.rs36
1 files changed, 36 insertions, 0 deletions
diff --git a/vendor/crunchy/src/lib.rs b/vendor/crunchy/src/lib.rs
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+//! The crunchy unroller - deterministically unroll constant loops. For number "crunching".
+//!
+//! The Rust optimizer will unroll constant loops that don't use the loop variable, like this:
+//!
+//! ```ignore
+//! for _ in 0..100 {
+//! println!("Hello!");
+//! }
+//! ```
+//!
+//! However, using the loop variable will cause it to never unroll the loop. This is unfortunate because it means that you can't
+//! constant-fold the loop variable, and if you end up stomping on the registers it will have to do a load for each iteration.
+//! This crate ensures that your code is unrolled and const-folded. It only works on literals,
+//! unfortunately, but there's a work-around:
+//!
+//! ```ignore
+//! debug_assert_eq!(MY_CONSTANT, 100);
+//! unroll! {
+//! for i in 0..100 {
+//! println!("Iteration {}", i);
+//! }
+//! }
+//! ```
+//! This means that your tests will catch if you redefine the constant.
+//!
+//! To default maximum number of loops to unroll is `64`, but that can be easily increased using the cargo features:
+//!
+//! * `limit_128`
+//! * `limit_256`
+//! * `limit_512`
+//! * `limit_1024`
+//! * `limit_2048`
+
+#![cfg_attr(not(feature = "std"), no_std)]
+
+include!(concat!(env!("OUT_DIR"), "/lib.rs"));