From ddff2ed649340fc07d3f6a3357c85b61d4b22b5f Mon Sep 17 00:00:00 2001 From: Shotaro Yamada Date: Sun, 6 Jan 2019 15:33:11 +0900 Subject: Remove unnecessary adapter --- src/libcore/fmt/mod.rs | 25 ++----------------------- 1 file changed, 2 insertions(+), 23 deletions(-) (limited to 'src/libcore') diff --git a/src/libcore/fmt/mod.rs b/src/libcore/fmt/mod.rs index ec1aeb8a7d1..bb6f511acf7 100644 --- a/src/libcore/fmt/mod.rs +++ b/src/libcore/fmt/mod.rs @@ -191,29 +191,8 @@ pub trait Write { /// assert_eq!(&buf, "world"); /// ``` #[stable(feature = "rust1", since = "1.0.0")] - fn write_fmt(&mut self, args: Arguments) -> Result { - // This Adapter is needed to allow `self` (of type `&mut - // Self`) to be cast to a Write (below) without - // requiring a `Sized` bound. - struct Adapter<'a,T: ?Sized +'a>(&'a mut T); - - impl Write for Adapter<'_, T> - where T: Write - { - fn write_str(&mut self, s: &str) -> Result { - self.0.write_str(s) - } - - fn write_char(&mut self, c: char) -> Result { - self.0.write_char(c) - } - - fn write_fmt(&mut self, args: Arguments) -> Result { - self.0.write_fmt(args) - } - } - - write(&mut Adapter(self), args) + fn write_fmt(mut self: &mut Self, args: Arguments) -> Result { + write(&mut self, args) } } -- cgit 1.4.1-3-g733a5 From f67124245cc24babd0345347a77089ba698acd14 Mon Sep 17 00:00:00 2001 From: Shotaro Yamada Date: Sun, 6 Jan 2019 15:33:42 +0900 Subject: Derive Clone for ArgumentV1 manual impl was a workaround for #28229. --- src/libcore/fmt/mod.rs | 10 +--------- 1 file changed, 1 insertion(+), 9 deletions(-) (limited to 'src/libcore') diff --git a/src/libcore/fmt/mod.rs b/src/libcore/fmt/mod.rs index bb6f511acf7..0127277d9cf 100644 --- a/src/libcore/fmt/mod.rs +++ b/src/libcore/fmt/mod.rs @@ -247,7 +247,7 @@ struct Void { /// family of functions. It contains a function to format the given value. At /// compile time it is ensured that the function and the value have the correct /// types, and then this struct is used to canonicalize arguments to one type. -#[derive(Copy)] +#[derive(Copy, Clone)] #[allow(missing_debug_implementations)] #[unstable(feature = "fmt_internals", reason = "internal to format_args!", issue = "0")] @@ -257,14 +257,6 @@ pub struct ArgumentV1<'a> { formatter: fn(&Void, &mut Formatter) -> Result, } -#[unstable(feature = "fmt_internals", reason = "internal to format_args!", - issue = "0")] -impl Clone for ArgumentV1<'_> { - fn clone(&self) -> Self { - *self - } -} - impl<'a> ArgumentV1<'a> { #[inline(never)] fn show_usize(x: &usize, f: &mut Formatter) -> Result { -- cgit 1.4.1-3-g733a5 From 6e742dbb3f5f9dde10dda8ba1930e03a0f057b5e Mon Sep 17 00:00:00 2001 From: Huon Wilson Date: Sun, 6 Jan 2019 01:02:55 +1100 Subject: Optimise floating point `is_finite` (2x) and `is_infinite` (1.6x). These can both rely on IEEE754 semantics to be made faster, by folding away the sign with an abs (left private for now), and then comparing to infinity, letting the NaN semantics of a direct float comparison handle NaN input properly. The `abs` bit-fiddling is simple (a single and), and so these new forms compile down to a few instructions, without branches, e.g. for f32: ```asm is_infinite: andps xmm0, xmmword ptr [rip + .LCPI2_0] ; 0x7FFF_FFFF ucomiss xmm0, dword ptr [rip + .LCPI2_1] ; 0x7F80_0000 setae al ret is_finite: andps xmm0, xmmword ptr [rip + .LCPI1_0] ; 0x7FFF_FFFF movss xmm1, dword ptr [rip + .LCPI1_1] ; 0x7F80_0000 ucomiss xmm1, xmm0 seta al ret ``` When used in loops/repeatedly, they get even better: the memory operations (loading the mask 0x7FFFFFFF for abs, and infinity 0x7F80_0000) are likely to be hoisted out of the individual calls, to be shared, and the `seta`/`setae` are likely to be collapsed into conditional jumps or moves (or similar). The old `is_infinite` did two comparisons, and the old `is_finite` did three (with a branch), and both of them had to check the flags after every one of those comparison. These functions have had that old implementation since they were added in https://github.com/rust-lang/rust/commit/6284190ef9918e05cb9147a2a81100ddcb06fea8 7 years ago. Benchmark (`abs` is the new form, `std` is the old): ``` test f32_is_finite_abs ... bench: 55 ns/iter (+/- 10) test f32_is_finite_std ... bench: 118 ns/iter (+/- 5) test f32_is_infinite_abs ... bench: 53 ns/iter (+/- 1) test f32_is_infinite_std ... bench: 84 ns/iter (+/- 6) test f64_is_finite_abs ... bench: 52 ns/iter (+/- 12) test f64_is_finite_std ... bench: 128 ns/iter (+/- 25) test f64_is_infinite_abs ... bench: 54 ns/iter (+/- 5) test f64_is_infinite_std ... bench: 93 ns/iter (+/- 23) ``` ```rust #![feature(test)] extern crate test; use std::{f32, f64}; use test::Bencher; const VALUES_F32: &[f32] = &[0.910, 0.135, 0.735, -0.874, 0.518, 0.150, -0.527, -0.418, 0.449, -0.158, -0.064, -0.144, -0.948, -0.103, 0.225, -0.104, -0.795, 0.435, 0.860, 0.027, 0.625, -0.848, -0.454, 0.359, -0.930, 0.067, 0.642, 0.976, -0.682, -0.035, 0.750, 0.005, -0.825, 0.731, -0.850, -0.740, -0.118, -0.972, 0.888, -0.958, 0.086, 0.237, -0.580, 0.488, 0.028, -0.552, 0.302, 0.058, -0.229, -0.166, -0.248, -0.430, 0.789, -0.122, 0.120, -0.934, -0.911, -0.976, 0.882, -0.410, 0.311, -0.611, -0.758, 0.786, -0.711, 0.378, 0.803, -0.068, 0.932, 0.483, 0.085, 0.247, -0.128, -0.839, -0.737, -0.605, 0.637, -0.230, -0.502, 0.231, -0.694, -0.400, -0.441, 0.142, 0.174, 0.681, -0.763, -0.608, 0.848, -0.550, 0.883, -0.212, 0.876, 0.186, -0.909, 0.401, -0.533, -0.961, 0.539, -0.298, -0.448, 0.223, -0.307, -0.594, 0.629, -0.534, 0.959, 0.349, -0.926, -0.523, -0.895, -0.157, -0.074, -0.060, 0.513, -0.647, -0.649, 0.428, 0.401, 0.391, 0.426, 0.700, 0.880, -0.101, 0.862, 0.493, 0.819, -0.597]; #[bench] fn f32_is_infinite_std(b: &mut Bencher) { b.iter(|| test::black_box(VALUES_F32).iter().any(|x| x.is_infinite())); } #[bench] fn f32_is_infinite_abs(b: &mut Bencher) { b.iter(|| test::black_box(VALUES_F32).iter().any(|x| x.abs()== f32::INFINITY)); } #[bench] fn f32_is_finite_std(b: &mut Bencher) { b.iter(|| test::black_box(VALUES_F32).iter().all(|x| x.is_finite())); } #[bench] fn f32_is_finite_abs(b: &mut Bencher) { b.iter(|| test::black_box(VALUES_F32).iter().all(|x| x.abs() < f32::INFINITY)); } const VALUES_F64: &[f64] = &[0.910, 0.135, 0.735, -0.874, 0.518, 0.150, -0.527, -0.418, 0.449, -0.158, -0.064, -0.144, -0.948, -0.103, 0.225, -0.104, -0.795, 0.435, 0.860, 0.027, 0.625, -0.848, -0.454, 0.359, -0.930, 0.067, 0.642, 0.976, -0.682, -0.035, 0.750, 0.005, -0.825, 0.731, -0.850, -0.740, -0.118, -0.972, 0.888, -0.958, 0.086, 0.237, -0.580, 0.488, 0.028, -0.552, 0.302, 0.058, -0.229, -0.166, -0.248, -0.430, 0.789, -0.122, 0.120, -0.934, -0.911, -0.976, 0.882, -0.410, 0.311, -0.611, -0.758, 0.786, -0.711, 0.378, 0.803, -0.068, 0.932, 0.483, 0.085, 0.247, -0.128, -0.839, -0.737, -0.605, 0.637, -0.230, -0.502, 0.231, -0.694, -0.400, -0.441, 0.142, 0.174, 0.681, -0.763, -0.608, 0.848, -0.550, 0.883, -0.212, 0.876, 0.186, -0.909, 0.401, -0.533, -0.961, 0.539, -0.298, -0.448, 0.223, -0.307, -0.594, 0.629, -0.534, 0.959, 0.349, -0.926, -0.523, -0.895, -0.157, -0.074, -0.060, 0.513, -0.647, -0.649, 0.428, 0.401, 0.391, 0.426, 0.700, 0.880, -0.101, 0.862, 0.493, 0.819, -0.597]; #[bench] fn f64_is_infinite_std(b: &mut Bencher) { b.iter(|| test::black_box(VALUES_F64).iter().any(|x| x.is_infinite())); } #[bench] fn f64_is_infinite_abs(b: &mut Bencher) { b.iter(|| test::black_box(VALUES_F64).iter().any(|x| x.abs() == f64::INFINITY)); } #[bench] fn f64_is_finite_std(b: &mut Bencher) { b.iter(|| test::black_box(VALUES_F64).iter().all(|x| x.is_finite())); } #[bench] fn f64_is_finite_abs(b: &mut Bencher) { b.iter(|| test::black_box(VALUES_F64).iter().all(|x| x.abs() < f64::INFINITY)); } ``` --- src/libcore/num/f32.rs | 14 ++++++++++++-- src/libcore/num/f64.rs | 14 ++++++++++++-- 2 files changed, 24 insertions(+), 4 deletions(-) (limited to 'src/libcore') diff --git a/src/libcore/num/f32.rs b/src/libcore/num/f32.rs index d1bd9755202..68da79135d3 100644 --- a/src/libcore/num/f32.rs +++ b/src/libcore/num/f32.rs @@ -161,6 +161,14 @@ impl f32 { self != self } + // FIXME(#50145): `abs` is publicly unavailable in libcore due to + // concerns about portability, so this implementation is for + // private use internally. + #[inline] + fn abs_private(self) -> f32 { + f32::from_bits(self.to_bits() & 0x7fff_ffff) + } + /// Returns `true` if this value is positive infinity or negative infinity and /// false otherwise. /// @@ -181,7 +189,7 @@ impl f32 { #[stable(feature = "rust1", since = "1.0.0")] #[inline] pub fn is_infinite(self) -> bool { - self == INFINITY || self == NEG_INFINITY + self.abs_private() == INFINITY } /// Returns `true` if this number is neither infinite nor `NaN`. @@ -203,7 +211,9 @@ impl f32 { #[stable(feature = "rust1", since = "1.0.0")] #[inline] pub fn is_finite(self) -> bool { - !(self.is_nan() || self.is_infinite()) + // There's no need to handle NaN separately: if self is NaN, + // the comparison is not true, exactly as desired. + self.abs_private() < INFINITY } /// Returns `true` if the number is neither zero, infinite, diff --git a/src/libcore/num/f64.rs b/src/libcore/num/f64.rs index 8ada5b6756c..b6773915481 100644 --- a/src/libcore/num/f64.rs +++ b/src/libcore/num/f64.rs @@ -161,6 +161,14 @@ impl f64 { self != self } + // FIXME(#50145): `abs` is publicly unavailable in libcore due to + // concerns about portability, so this implementation is for + // private use internally. + #[inline] + fn abs_private(self) -> f64 { + f64::from_bits(self.to_bits() & 0x7fff_ffff_ffff_ffff) + } + /// Returns `true` if this value is positive infinity or negative infinity and /// false otherwise. /// @@ -181,7 +189,7 @@ impl f64 { #[stable(feature = "rust1", since = "1.0.0")] #[inline] pub fn is_infinite(self) -> bool { - self == INFINITY || self == NEG_INFINITY + self.abs_private() == INFINITY } /// Returns `true` if this number is neither infinite nor `NaN`. @@ -203,7 +211,9 @@ impl f64 { #[stable(feature = "rust1", since = "1.0.0")] #[inline] pub fn is_finite(self) -> bool { - !(self.is_nan() || self.is_infinite()) + // There's no need to handle NaN separately: if self is NaN, + // the comparison is not true, exactly as desired. + self.abs_private() < INFINITY } /// Returns `true` if the number is neither zero, infinite, -- cgit 1.4.1-3-g733a5 From 12ae3651f891d22f804c67923d02cbdfa10fa60d Mon Sep 17 00:00:00 2001 From: Shotaro Yamada Date: Sun, 6 Jan 2019 15:36:14 +0900 Subject: Misc cleanups --- src/libcore/fmt/mod.rs | 12 ++++++------ src/libcore/str/pattern.rs | 3 +-- 2 files changed, 7 insertions(+), 8 deletions(-) (limited to 'src/libcore') diff --git a/src/libcore/fmt/mod.rs b/src/libcore/fmt/mod.rs index 0127277d9cf..214b5d3a84f 100644 --- a/src/libcore/fmt/mod.rs +++ b/src/libcore/fmt/mod.rs @@ -1076,7 +1076,7 @@ impl<'a> Formatter<'a> { self.args[i].as_usize() } rt::v1::Count::NextParam => { - self.curarg.next().and_then(|arg| arg.as_usize()) + self.curarg.next()?.as_usize() } } } @@ -1142,15 +1142,15 @@ impl<'a> Formatter<'a> { sign = Some('+'); width += 1; } - let mut prefixed = false; - if self.alternate() { - prefixed = true; width += prefix.chars().count(); + let prefixed = self.alternate(); + if prefixed { + width += prefix.chars().count(); } // Writes the sign if it exists, and then the prefix if it was requested let write_prefix = |f: &mut Formatter| { if let Some(c) = sign { - f.buf.write_str(c.encode_utf8(&mut [0; 4]))?; + f.buf.write_char(c)?; } if prefixed { f.buf.write_str(prefix) } else { Ok(()) } @@ -1312,7 +1312,7 @@ impl<'a> Formatter<'a> { // remove the sign from the formatted parts formatted.sign = b""; - width = if width < sign.len() { 0 } else { width - sign.len() }; + width = width.saturating_sub(sign.len()); align = rt::v1::Alignment::Right; self.fill = '0'; self.align = rt::v1::Alignment::Right; diff --git a/src/libcore/str/pattern.rs b/src/libcore/str/pattern.rs index b4eae4d1bb7..55a7ba181e5 100644 --- a/src/libcore/str/pattern.rs +++ b/src/libcore/str/pattern.rs @@ -425,8 +425,7 @@ impl<'a> Pattern<'a> for char { #[inline] fn into_searcher(self, haystack: &'a str) -> Self::Searcher { let mut utf8_encoded = [0; 4]; - self.encode_utf8(&mut utf8_encoded); - let utf8_size = self.len_utf8(); + let utf8_size = self.encode_utf8(&mut utf8_encoded).len(); CharSearcher { haystack, finger: 0, -- cgit 1.4.1-3-g733a5 From 186d5d7fd4de3ffeb06503134477fd453a185936 Mon Sep 17 00:00:00 2001 From: Steve Klabnik Date: Thu, 10 Jan 2019 15:21:01 -0500 Subject: re-do docs for core::cmp Fixes #32934 --- src/libcore/cmp.rs | 35 +++++++++++++++-------------------- 1 file changed, 15 insertions(+), 20 deletions(-) (limited to 'src/libcore') diff --git a/src/libcore/cmp.rs b/src/libcore/cmp.rs index f420d0d00a4..86f28a957cd 100644 --- a/src/libcore/cmp.rs +++ b/src/libcore/cmp.rs @@ -1,27 +1,22 @@ //! Functionality for ordering and comparison. //! -//! This module defines both [`PartialOrd`] and [`PartialEq`] traits which are used -//! by the compiler to implement comparison operators. Rust programs may -//! implement [`PartialOrd`] to overload the `<`, `<=`, `>`, and `>=` operators, -//! and may implement [`PartialEq`] to overload the `==` and `!=` operators. +//! This module contains various tools for ordering and comparing values. In +//! summary: //! -//! [`PartialOrd`]: trait.PartialOrd.html -//! [`PartialEq`]: trait.PartialEq.html +//! * [`Eq`] and [`PartialEq`] are traits that allow you to define total and +//! partial equality between values, respectively. Implementing them overloads +//! the `==` and `!=` operators. +//! * [`Ord`] and [`PartialOrd`] are traits that allow you to define total and +//! partial orderings between values, respectively. Implementing them overloads +//! the `<`, `<=`, `>`, and `>=` operators. +//! * [`Ordering`][cmp::Ordering] is an enum returned by the +//! main functions of [`Ord`] and [`PartialOrd`], and describes an ordering. +//! * [`Reverse`][cmp::Reverse] is a struct that allows you to easily reverse +//! an ordering. +//! * [`max`][cmp::max] and [`min`][cmp::min] are functions that build off of +//! [`Ord`] and allow you to find the maximum or minimum of two values. //! -//! # Examples -//! -//! ``` -//! let x: u32 = 0; -//! let y: u32 = 1; -//! -//! // these two lines are equivalent -//! assert_eq!(x < y, true); -//! assert_eq!(x.lt(&y), true); -//! -//! // these two lines are also equivalent -//! assert_eq!(x == y, false); -//! assert_eq!(x.eq(&y), false); -//! ``` +//! For more details, see the respective documentation of each item in the list. #![stable(feature = "rust1", since = "1.0.0")] -- cgit 1.4.1-3-g733a5