Introduce rustversion and use round_ties_even()

.config/topic.dic

@@ -1,4 +1,4 @@
-25
+26
 1G
 1M
 1ns
@@ -13,6 +13,7 @@ io
 JS
 MDN
 MSRV
+MSRVs
 representable
 Serde
 Serde's

.github/upstream-sources.json

@@ -1,7 +1,6 @@
 [
 	{ "owner": "rust-lang", "repo": "libm", "tag": "libm-v0.2.11", "path": "src/math/trunc.rs" },
-	{ "owner": "rust-lang", "repo": "libm", "tag": "libm-v0.2.11", "path": "src/math/copysign.rs" },
-	{ "owner": "rust-lang", "repo": "libm", "tag": "libm-v0.2.11", "path": "src/math/round.rs" },
+	{ "owner": "rust-lang", "repo": "libm", "tag": "libm-v0.2.11", "path": "src/math/rint.rs" },
 	{ "owner": "rust-lang", "repo": "rust", "tag": "1.83.0", "path": "library/core/src/time.rs" },
 	{ "owner": "rust-lang", "repo": "rust", "tag": "1.83.0", "path": "library/std/src/time.rs" },
 	{

.github/workflows/build.yaml

@@ -40,14 +40,25 @@ jobs:
               build-std: true,
             }
         features:
-          - { features: "", no_std: false }
-          - { features: --features serde, no_std: false, description: (`serde`) }
+          - { features: "", description: (`default`) }
+          - { features: --features serde, description: "(`default`, `serde`)" }
+          - { features: --no-default-features --features std, description: (`std`) }
           - { features: --no-default-features, no_std: true, description: (`no_std`) }
+          - {
+              features: --no-default-features --features msrv,
+              no_std: true,
+              description: "(`no_std`, `msrv`)",
+            }
           - {
               features: --no-default-features --features serde,
               no_std: true,
               description: "(`no_std`, `serde`)",
             }
+          - {
+              features: "--no-default-features --features msrv,serde",
+              no_std: true,
+              description: "(`no_std`, `msrv`, `serde`)",
+            }
         exclude:
           - target: { target: x86_64-unknown-linux-gnu, description: Native }
             rust: { version: nightly }
@@ -109,14 +120,25 @@ jobs:
           - { version: stable }
           - { version: nightly }
         features:
-          - { features: "", no_std: false }
-          - { features: --features serde, no_std: false, description: (`serde`) }
+          - { features: "", description: (`default`) }
+          - { features: --features serde, description: "(`default`, `serde`)" }
+          - { features: --no-default-features --features std, description: (`std`) }
           - { features: --no-default-features, no_std: true, description: (`no_std`) }
+          - {
+              features: --no-default-features --features msrv,
+              no_std: true,
+              description: "(`no_std`, `msrv`)",
+            }
           - {
               features: --no-default-features --features serde,
               no_std: true,
               description: "(`no_std`, `serde`)",
             }
+          - {
+              features: "--no-default-features --features msrv,serde",
+              no_std: true,
+              description: "(`no_std`, `msrv`, `serde`)",
+            }
         exclude:
           - target: { target: x86_64-unknown-linux-gnu, description: Native }
             rust: { version: nightly }
@@ -169,14 +191,25 @@ jobs:
           - { version: stable }
           - { version: nightly }
         features:
-          - { features: "", no_std: false }
-          - { features: --features serde, no_std: false, description: (`serde`) }
+          - { features: "", description: (`default`) }
+          - { features: --features serde, description: "(`default`, `serde`)" }
+          - { features: --no-default-features --features std, description: (`std`) }
           - { features: --no-default-features, no_std: true, description: (`no_std`) }
+          - {
+              features: --no-default-features --features msrv,
+              no_std: true,
+              description: "(`no_std`, `msrv`)",
+            }
           - {
               features: --no-default-features --features serde,
               no_std: true,
               description: "(`no_std`, `serde`)",
             }
+          - {
+              features: "--no-default-features --features msrv,serde",
+              no_std: true,
+              description: "(`no_std`, `msrv`, `serde`)",
+            }
         exclude:
           - target: { target: x86_64-unknown-linux-gnu, description: Native }
             rust: { version: nightly }

.github/workflows/lint.yaml

@@ -26,10 +26,8 @@ jobs:
         target:
           - { target: x86_64-unknown-linux-gnu, description: Native }
           - { target: wasm32-unknown-unknown, description: Web }
-          - { target: wasm32v1-none, description: Wasm v1 }
         rust:
           - { version: stable, atomics: false }
-          - { version: nightly, atomics: false }
           - {
               version: nightly,
               description: with Atomics,
@@ -39,8 +37,9 @@ jobs:
               build-std: true,
             }
         features:
-          - { features: "", no_std: false }
-          - { features: --features serde, no_std: false, description: (`serde`) }
+          - { features: "", description: (`default`) }
+          - { features: --features serde, description: (`default` `serde`) }
+          - { features: --no-default-features --features std, no_msrv: true, description: (`std`) }
           - { features: --no-default-features, no_std: true, description: (`no_std`) }
           - {
               features: --no-default-features --features serde,
@@ -49,13 +48,9 @@ jobs:
             }
         exclude:
           - target: { target: x86_64-unknown-linux-gnu, description: Native }
-            rust: { version: nightly }
-          - target: { target: wasm32-unknown-unknown, description: Web }
-            rust: { version: nightly, atomics: false }
-          - target: { target: wasm32v1-none, description: Wasm v1 }
-            rust: { version: stable }
-          - target: { target: wasm32v1-none, description: Wasm v1 }
-            features: { no_std: false }
+            rust: { atomics: true }
+          - target: { target: x86_64-unknown-linux-gnu, description: Native }
+            features: { no_msrv: true }
 
     steps:
       - name: Checkout
@@ -90,7 +85,6 @@ jobs:
         target:
           - { target: x86_64-unknown-linux-gnu, description: Native }
           - { target: wasm32-unknown-unknown, description: Web }
-          - { target: wasm32v1-none, description: Wasm v1 }
         rust:
           - { version: stable, atomics: false }
           - { version: nightly, atomics: false }
@@ -103,8 +97,9 @@ jobs:
               build-std: true,
             }
         features:
-          - { features: "", no_std: false }
-          - { features: --features serde, no_std: false, description: (`serde`) }
+          - { features: "", description: (`default`) }
+          - { features: --features serde, description: (`default` `serde`) }
+          - { features: --no-default-features --features std, no_msrv: true, description: (`std`) }
           - { features: --no-default-features, no_std: true, description: (`no_std`) }
           - {
               features: --no-default-features --features serde,
@@ -115,20 +110,14 @@ jobs:
           - { flags: "", nightly: false }
           - { description: (docs.rs), flags: --cfg=docsrs, nightly: true }
         exclude:
+          - docsrs: { flags: "", nightly: false }
+            rust: { version: nightly }
           - docsrs: { flags: --cfg=docsrs, nightly: true }
             rust: { version: stable }
           - target: { target: x86_64-unknown-linux-gnu, description: Native }
             rust: { atomics: true }
           - target: { target: x86_64-unknown-linux-gnu, description: Native }
-            docsrs: { flags: "", nightly: false }
-            rust: { version: nightly }
-          - target: { target: wasm32-unknown-unknown, description: Web }
-            docsrs: { flags: "", nightly: false }
-            rust: { version: nightly, atomics: false }
-          - target: { target: wasm32v1-none, description: Wasm v1 }
-            rust: { version: stable }
-          - target: { target: wasm32v1-none, description: Wasm v1 }
-            features: { no_std: false }
+            features: { no_msrv: true }
 
     steps:
       - name: Checkout

CHANGELOG.md

@@ -12,6 +12,18 @@ adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 - [`no_std`] support through a `std` crate feature.
 - Support for the [`wasm32v1-none`] target.
 - MSRV policy.
+- A `msrv` crate feature that allows `web-time` to make use of features only available in higher
+  MSRVs. This offers compile-time detection and does not break compilation when enabled with the
+  crates MSRV.
+
+  When used in conjunction with the `std` crate feature and compiling with Rust v1.77 or above, it
+  enables the use of the [`f64.nearest`] instruction. Which will significantly reduce the
+  instruction count for `Instant::now()`.
+
+### Changed
+
+- Improve performance of `Instant::now()` by using `f64::round_ties_even()` instead of
+  `f64::round()` internally.
 
 ### Fixed
 
@@ -20,6 +32,8 @@ adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 [`no_std`]: https://doc.rust-lang.org/1.82.0/reference/names/preludes.html#the-no_std-attribute
 [`wasm32v1-none`]: https://doc.rust-lang.org/nightly/rustc/platform-support/wasm32v1-none.html
+[`f64.nearest`]:
+	https://webassembly.github.io/spec/core/syntax/instructions.html#syntax-instr-numeric
 
 ## [1.1.0] - 2024-03-01
 

Cargo.toml

@@ -17,12 +17,14 @@ rust-version = "1.60"
 version = "1.1.0"
 
 [features]
-default = ["std"]
+default = ["std", "msrv"]
+msrv = ["dep:rustversion"]
 serde = ["dep:serde"]
 std = ["wasm-bindgen-test/std", "getrandom/std", "rand/std", "tests-native/std", "tests-web/std"]
 
 [target.'cfg(all(target_arch = "wasm32", any(target_os = "unknown", target_os = "none")))'.dependencies]
 js-sys = { version = "0.3.75", default-features = false }
+rustversion = { version = "1.0.0", optional = true }
 serde = { version = "1.0.0", optional = true, default-features = false }
 wasm-bindgen = { version = "0.2.98", default-features = false }
 

README.md

@@ -73,6 +73,15 @@ instruction output.
 Without this crate feature compilation the standard library is not included. Has no effect on
 targets other then `wasm32-unknown-unknown` or `wasm32v1-none`.
 
+### `msrv` (enabled by default)
+
+Allows `web-time` to make use of features only available in higher MSRVs. This offers compile-time
+detection and does not break compilation when enabled with the crates MSRV.
+
+When used in conjunction with the `std` crate feature and compiling with Rust v1.77 or above, it
+enables the use of the [`f64.nearest`] instruction. Which will significantly reduce the instruction
+count for [`Instant::now()`].
+
 ### `serde`
 
 Implements [`serde::Deserialize`] and [`serde::Serialize`] for [`SystemTime`].
@@ -140,3 +149,5 @@ additional terms or conditions.
 [`serde::Deserialize`]: https://docs.rs/serde/1/serde/trait.Deserialize.html
 [`serde::Serialize`]: https://docs.rs/serde/1/serde/trait.Serialize.html
 [`wasm-bindgen`]: https://crates.io/crates/wasm-bindgen
+[`f64.nearest`]:
+	https://webassembly.github.io/spec/core/syntax/instructions.html#syntax-instr-numeric

benches/benchmark.rs

@@ -90,7 +90,7 @@ pub fn main() {
 	});
 	benchmark("`Duration::from_millis()` with rounding", |time_stamp| {
 		Duration::from_millis(F64(time_stamp).trunc() as u64)
-			+ Duration::from_nanos(F64(F64(time_stamp).fract() * 1.0e6).round() as u64)
+			+ Duration::from_nanos(F64(F64(time_stamp).fract() * 1.0e6).round_ties_even() as u64)
 	});
 	benchmark("`Duration::from_secs_f64()`", |time_stamp| {
 		Duration::from_secs_f64(time_stamp) / 1000
@@ -155,20 +155,20 @@ impl F64 {
 		self.0 - self.trunc()
 	}
 
-	/// See [`f64::round()`].
+	/// See [`f64::round_ties_even()`].
 	#[cfg(feature = "std")]
 	#[expect(
 		clippy::disallowed_methods,
 		reason = "this is where the abstraction happens"
 	)]
 	#[cfg(feature = "std")]
-	fn round(self) -> f64 {
-		self.0.round()
+	fn round_ties_even(self) -> f64 {
+		self.0.round_ties_even()
 	}
 
 	#[cfg(not(feature = "std"))]
-	fn round(self) -> f64 {
-		libm::round(self.0)
+	fn round_ties_even(self) -> f64 {
+		libm::rint(self.0)
 	}
 }
 

clippy.toml

@@ -5,7 +5,7 @@ disallowed-methods = [
 	{ path = "f64::trunc", reason = "not available on `no_std`" },
 	{ path = "f64::fract", reason = "not available on `no_std`" },
 	{ path = "f64::copysign", reason = "not available on `no_std`" },
-	{ path = "f64::round", reason = "not available on `no_std`" },
+	{ path = "f64::round_ties_even", reason = "not available on `no_std` and MSRV" },
 	{ path = "f64::powi", reason = "not available on `no_std`" },
 ]
 semicolon-outside-block-ignore-multiline = true

src/lib.rs

@@ -76,6 +76,17 @@
 //! Has no effect on targets other then `wasm32-unknown-unknown` or
 //! `wasm32v1-none`.
 //!
+//! ## `msrv` (enabled by default)
+//!
+//! Allows `web-time` to make use of features only available in higher MSRVs.
+//! This offers compile-time detection and does not break compilation when
+//! enabled with the crates MSRV.
+//!
+//! When used in conjunction with the `std` crate feature and compiling with
+//! Rust v1.77 or above, it enables the use of the [`f64.nearest`] instruction.
+//! Which will significantly reduce the instruction
+//! count for [`Instant::now()`].
+//!
 //! ## `serde`
 //!
 //! Implements [`serde::Deserialize`] and [`serde::Serialize`] for
@@ -148,6 +159,7 @@
 	doc = "[`serde::Serialize`]: https://docs.rs/serde/1/serde/trait.Serialize.html"
 )]
 //! [`wasm-bindgen`]: https://crates.io/crates/wasm-bindgen
+//! [`f64.nearest`]: https://webassembly.github.io/spec/core/syntax/instructions.html#syntax-instr-numeric
 
 #![cfg_attr(all(target_arch = "wasm32", not(feature = "std")), no_std)]
 #![cfg_attr(all(test, target_arch = "wasm32"), no_main)]