From 6839ec5efd2b8aa97524e0b4bc774daf2c394c01 Mon Sep 17 00:00:00 2001 From: Trevor Gross Date: Sun, 16 Jun 2024 03:09:58 -0500 Subject: [PATCH 01/16] Extract repeated constants from `f32` and `f64` source This will make it easier to keep `f16` and `f128` consistent as their implementations get added. --- core/src/num/f32.rs | 45 +++++++++++++----------- core/src/num/f64.rs | 51 ++++++++++++++------------- std/src/f32/tests.rs | 82 +++++++++++++++++++++++++++++-------------- std/src/f64/tests.rs | 83 +++++++++++++++++++++++++++++--------------- 4 files changed, 160 insertions(+), 101 deletions(-) diff --git a/core/src/num/f32.rs b/core/src/num/f32.rs index 9d34d3da9e955..271965c28840a 100644 --- a/core/src/num/f32.rs +++ b/core/src/num/f32.rs @@ -490,6 +490,21 @@ impl f32 { #[stable(feature = "assoc_int_consts", since = "1.43.0")] pub const NEG_INFINITY: f32 = -1.0_f32 / 0.0_f32; + /// Sign bit + const SIGN_MASK: u32 = 0x8000_0000; + + /// Exponent mask + const EXP_MASK: u32 = 0x7f80_0000; + + /// Mantissa mask + const MAN_MASK: u32 = 0x007f_ffff; + + /// Minimum representable positive value (min subnormal) + const TINY_BITS: u32 = 0x1; + + /// Minimum representable negative value (min negative subnormal) + const NEG_TINY_BITS: u32 = Self::TINY_BITS | Self::SIGN_MASK; + /// Returns `true` if this value is NaN. /// /// ``` @@ -515,7 +530,7 @@ impl f32 { #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")] pub(crate) const fn abs_private(self) -> f32 { // SAFETY: This transmutation is fine. Probably. For the reasons std is using it. - unsafe { mem::transmute::(mem::transmute::(self) & 0x7fff_ffff) } + unsafe { mem::transmute::(mem::transmute::(self) & !Self::SIGN_MASK) } } /// Returns `true` if this value is positive infinity or negative infinity, and @@ -682,12 +697,9 @@ impl f32 { // runtime-deviating logic which may or may not be acceptable. #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")] const unsafe fn partial_classify(self) -> FpCategory { - const EXP_MASK: u32 = 0x7f800000; - const MAN_MASK: u32 = 0x007fffff; - // SAFETY: The caller is not asking questions for which this will tell lies. let b = unsafe { mem::transmute::(self) }; - match (b & MAN_MASK, b & EXP_MASK) { + match (b & Self::MAN_MASK, b & Self::EXP_MASK) { (0, 0) => FpCategory::Zero, (_, 0) => FpCategory::Subnormal, _ => FpCategory::Normal, @@ -699,12 +711,9 @@ impl f32 { // plus a transmute. We do not live in a just world, but we can make it more so. #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")] const fn classify_bits(b: u32) -> FpCategory { - const EXP_MASK: u32 = 0x7f800000; - const MAN_MASK: u32 = 0x007fffff; - - match (b & MAN_MASK, b & EXP_MASK) { - (0, EXP_MASK) => FpCategory::Infinite, - (_, EXP_MASK) => FpCategory::Nan, + match (b & Self::MAN_MASK, b & Self::EXP_MASK) { + (0, Self::EXP_MASK) => FpCategory::Infinite, + (_, Self::EXP_MASK) => FpCategory::Nan, (0, 0) => FpCategory::Zero, (_, 0) => FpCategory::Subnormal, _ => FpCategory::Normal, @@ -789,17 +798,14 @@ impl f32 { pub const fn next_up(self) -> Self { // We must use strictly integer arithmetic to prevent denormals from // flushing to zero after an arithmetic operation on some platforms. - const TINY_BITS: u32 = 0x1; // Smallest positive f32. - const CLEAR_SIGN_MASK: u32 = 0x7fff_ffff; - let bits = self.to_bits(); if self.is_nan() || bits == Self::INFINITY.to_bits() { return self; } - let abs = bits & CLEAR_SIGN_MASK; + let abs = bits & !Self::SIGN_MASK; let next_bits = if abs == 0 { - TINY_BITS + Self::TINY_BITS } else if bits == abs { bits + 1 } else { @@ -839,17 +845,14 @@ impl f32 { pub const fn next_down(self) -> Self { // We must use strictly integer arithmetic to prevent denormals from // flushing to zero after an arithmetic operation on some platforms. - const NEG_TINY_BITS: u32 = 0x8000_0001; // Smallest (in magnitude) negative f32. - const CLEAR_SIGN_MASK: u32 = 0x7fff_ffff; - let bits = self.to_bits(); if self.is_nan() || bits == Self::NEG_INFINITY.to_bits() { return self; } - let abs = bits & CLEAR_SIGN_MASK; + let abs = bits & !Self::SIGN_MASK; let next_bits = if abs == 0 { - NEG_TINY_BITS + Self::NEG_TINY_BITS } else if bits == abs { bits - 1 } else { diff --git a/core/src/num/f64.rs b/core/src/num/f64.rs index 95f021b2541ab..bccd39f605941 100644 --- a/core/src/num/f64.rs +++ b/core/src/num/f64.rs @@ -489,6 +489,21 @@ impl f64 { #[stable(feature = "assoc_int_consts", since = "1.43.0")] pub const NEG_INFINITY: f64 = -1.0_f64 / 0.0_f64; + /// Sign bit + const SIGN_MASK: u64 = 0x8000_0000_0000_0000; + + /// Exponent mask + const EXP_MASK: u64 = 0x7ff0_0000_0000_0000; + + /// Mantissa mask + const MAN_MASK: u64 = 0x000f_ffff_ffff_ffff; + + /// Minimum representable positive value (min subnormal) + const TINY_BITS: u64 = 0x1; + + /// Minimum representable negative value (min negative subnormal) + const NEG_TINY_BITS: u64 = Self::TINY_BITS | Self::SIGN_MASK; + /// Returns `true` if this value is NaN. /// /// ``` @@ -514,9 +529,7 @@ impl f64 { #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")] pub(crate) const fn abs_private(self) -> f64 { // SAFETY: This transmutation is fine. Probably. For the reasons std is using it. - unsafe { - mem::transmute::(mem::transmute::(self) & 0x7fff_ffff_ffff_ffff) - } + unsafe { mem::transmute::(mem::transmute::(self) & !Self::SIGN_MASK) } } /// Returns `true` if this value is positive infinity or negative infinity, and @@ -673,13 +686,10 @@ impl f64 { // and some normal floating point numbers truncated from an x87 FPU. #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")] const unsafe fn partial_classify(self) -> FpCategory { - const EXP_MASK: u64 = 0x7ff0000000000000; - const MAN_MASK: u64 = 0x000fffffffffffff; - // SAFETY: The caller is not asking questions for which this will tell lies. let b = unsafe { mem::transmute::(self) }; - match (b & MAN_MASK, b & EXP_MASK) { - (0, EXP_MASK) => FpCategory::Infinite, + match (b & Self::MAN_MASK, b & Self::EXP_MASK) { + (0, Self::EXP_MASK) => FpCategory::Infinite, (0, 0) => FpCategory::Zero, (_, 0) => FpCategory::Subnormal, _ => FpCategory::Normal, @@ -691,12 +701,9 @@ impl f64 { // plus a transmute. We do not live in a just world, but we can make it more so. #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")] const fn classify_bits(b: u64) -> FpCategory { - const EXP_MASK: u64 = 0x7ff0000000000000; - const MAN_MASK: u64 = 0x000fffffffffffff; - - match (b & MAN_MASK, b & EXP_MASK) { - (0, EXP_MASK) => FpCategory::Infinite, - (_, EXP_MASK) => FpCategory::Nan, + match (b & Self::MAN_MASK, b & Self::EXP_MASK) { + (0, Self::EXP_MASK) => FpCategory::Infinite, + (_, Self::EXP_MASK) => FpCategory::Nan, (0, 0) => FpCategory::Zero, (_, 0) => FpCategory::Subnormal, _ => FpCategory::Normal, @@ -756,7 +763,7 @@ impl f64 { // IEEE754 says: isSignMinus(x) is true if and only if x has negative sign. isSignMinus // applies to zeros and NaNs as well. // SAFETY: This is just transmuting to get the sign bit, it's fine. - unsafe { mem::transmute::(self) & 0x8000_0000_0000_0000 != 0 } + unsafe { mem::transmute::(self) & Self::SIGN_MASK != 0 } } #[must_use] @@ -799,17 +806,14 @@ impl f64 { pub const fn next_up(self) -> Self { // We must use strictly integer arithmetic to prevent denormals from // flushing to zero after an arithmetic operation on some platforms. - const TINY_BITS: u64 = 0x1; // Smallest positive f64. - const CLEAR_SIGN_MASK: u64 = 0x7fff_ffff_ffff_ffff; - let bits = self.to_bits(); if self.is_nan() || bits == Self::INFINITY.to_bits() { return self; } - let abs = bits & CLEAR_SIGN_MASK; + let abs = bits & !Self::SIGN_MASK; let next_bits = if abs == 0 { - TINY_BITS + Self::TINY_BITS } else if bits == abs { bits + 1 } else { @@ -849,17 +853,14 @@ impl f64 { pub const fn next_down(self) -> Self { // We must use strictly integer arithmetic to prevent denormals from // flushing to zero after an arithmetic operation on some platforms. - const NEG_TINY_BITS: u64 = 0x8000_0000_0000_0001; // Smallest (in magnitude) negative f64. - const CLEAR_SIGN_MASK: u64 = 0x7fff_ffff_ffff_ffff; - let bits = self.to_bits(); if self.is_nan() || bits == Self::NEG_INFINITY.to_bits() { return self; } - let abs = bits & CLEAR_SIGN_MASK; + let abs = bits & !Self::SIGN_MASK; let next_bits = if abs == 0 { - NEG_TINY_BITS + Self::NEG_TINY_BITS } else if bits == abs { bits - 1 } else { diff --git a/std/src/f32/tests.rs b/std/src/f32/tests.rs index 9ca4e8f2f45fe..63e65698374c8 100644 --- a/std/src/f32/tests.rs +++ b/std/src/f32/tests.rs @@ -2,6 +2,45 @@ use crate::f32::consts; use crate::num::FpCategory as Fp; use crate::num::*; +/// Smallest number +#[allow(dead_code)] // unused on x86 +const TINY_BITS: u32 = 0x1; + +/// Next smallest number +#[allow(dead_code)] // unused on x86 +const TINY_UP_BITS: u32 = 0x2; + +/// Exponent = 0b11...10, Sifnificand 0b1111..10. Min val > 0 +#[allow(dead_code)] // unused on x86 +const MAX_DOWN_BITS: u32 = 0x7f7f_fffe; + +/// Zeroed exponent, full significant +#[allow(dead_code)] // unused on x86 +const LARGEST_SUBNORMAL_BITS: u32 = 0x007f_ffff; + +/// Exponent = 0b1, zeroed significand +#[allow(dead_code)] // unused on x86 +const SMALLEST_NORMAL_BITS: u32 = 0x0080_0000; + +/// First pattern over the mantissa +#[allow(dead_code)] // unused on x86 +const NAN_MASK1: u32 = 0x002a_aaaa; + +/// Second pattern over the mantissa +#[allow(dead_code)] // unused on x86 +const NAN_MASK2: u32 = 0x0055_5555; + +#[allow(unused_macros)] +macro_rules! assert_f32_biteq { + ($left : expr, $right : expr) => { + let l: &f32 = &$left; + let r: &f32 = &$right; + let lb = l.to_bits(); + let rb = r.to_bits(); + assert_eq!(lb, rb, "float {l} ({lb:#010x}) is not bitequal to {r} ({rb:#010x})"); + }; +} + #[test] fn test_num_f32() { test_num(10f32, 2f32); @@ -315,27 +354,16 @@ fn test_is_sign_negative() { assert!((-f32::NAN).is_sign_negative()); } -#[allow(unused_macros)] -macro_rules! assert_f32_biteq { - ($left : expr, $right : expr) => { - let l: &f32 = &$left; - let r: &f32 = &$right; - let lb = l.to_bits(); - let rb = r.to_bits(); - assert_eq!(lb, rb, "float {} ({:#x}) is not equal to {} ({:#x})", *l, lb, *r, rb); - }; -} - // Ignore test on x87 floating point, these platforms do not guarantee NaN // payloads are preserved and flush denormals to zero, failing the tests. #[cfg(not(target_arch = "x86"))] #[test] fn test_next_up() { - let tiny = f32::from_bits(1); - let tiny_up = f32::from_bits(2); - let max_down = f32::from_bits(0x7f7f_fffe); - let largest_subnormal = f32::from_bits(0x007f_ffff); - let smallest_normal = f32::from_bits(0x0080_0000); + let tiny = f32::from_bits(TINY_BITS); + let tiny_up = f32::from_bits(TINY_UP_BITS); + let max_down = f32::from_bits(MAX_DOWN_BITS); + let largest_subnormal = f32::from_bits(LARGEST_SUBNORMAL_BITS); + let smallest_normal = f32::from_bits(SMALLEST_NORMAL_BITS); assert_f32_biteq!(f32::NEG_INFINITY.next_up(), f32::MIN); assert_f32_biteq!(f32::MIN.next_up(), -max_down); assert_f32_biteq!((-1.0 - f32::EPSILON).next_up(), -1.0); @@ -352,8 +380,8 @@ fn test_next_up() { // Check that NaNs roundtrip. let nan0 = f32::NAN; - let nan1 = f32::from_bits(f32::NAN.to_bits() ^ 0x002a_aaaa); - let nan2 = f32::from_bits(f32::NAN.to_bits() ^ 0x0055_5555); + let nan1 = f32::from_bits(f32::NAN.to_bits() ^ NAN_MASK1); + let nan2 = f32::from_bits(f32::NAN.to_bits() ^ NAN_MASK2); assert_f32_biteq!(nan0.next_up(), nan0); assert_f32_biteq!(nan1.next_up(), nan1); assert_f32_biteq!(nan2.next_up(), nan2); @@ -364,11 +392,11 @@ fn test_next_up() { #[cfg(not(target_arch = "x86"))] #[test] fn test_next_down() { - let tiny = f32::from_bits(1); - let tiny_up = f32::from_bits(2); - let max_down = f32::from_bits(0x7f7f_fffe); - let largest_subnormal = f32::from_bits(0x007f_ffff); - let smallest_normal = f32::from_bits(0x0080_0000); + let tiny = f32::from_bits(TINY_BITS); + let tiny_up = f32::from_bits(TINY_UP_BITS); + let max_down = f32::from_bits(MAX_DOWN_BITS); + let largest_subnormal = f32::from_bits(LARGEST_SUBNORMAL_BITS); + let smallest_normal = f32::from_bits(SMALLEST_NORMAL_BITS); assert_f32_biteq!(f32::NEG_INFINITY.next_down(), f32::NEG_INFINITY); assert_f32_biteq!(f32::MIN.next_down(), f32::NEG_INFINITY); assert_f32_biteq!((-max_down).next_down(), f32::MIN); @@ -386,8 +414,8 @@ fn test_next_down() { // Check that NaNs roundtrip. let nan0 = f32::NAN; - let nan1 = f32::from_bits(f32::NAN.to_bits() ^ 0x002a_aaaa); - let nan2 = f32::from_bits(f32::NAN.to_bits() ^ 0x0055_5555); + let nan1 = f32::from_bits(f32::NAN.to_bits() ^ NAN_MASK1); + let nan2 = f32::from_bits(f32::NAN.to_bits() ^ NAN_MASK2); assert_f32_biteq!(nan0.next_down(), nan0); assert_f32_biteq!(nan1.next_down(), nan1); assert_f32_biteq!(nan2.next_down(), nan2); @@ -734,8 +762,8 @@ fn test_float_bits_conv() { // Check that NaNs roundtrip their bits regardless of signaling-ness // 0xA is 0b1010; 0x5 is 0b0101 -- so these two together clobbers all the mantissa bits - let masked_nan1 = f32::NAN.to_bits() ^ 0x002A_AAAA; - let masked_nan2 = f32::NAN.to_bits() ^ 0x0055_5555; + let masked_nan1 = f32::NAN.to_bits() ^ NAN_MASK1; + let masked_nan2 = f32::NAN.to_bits() ^ NAN_MASK2; assert!(f32::from_bits(masked_nan1).is_nan()); assert!(f32::from_bits(masked_nan2).is_nan()); diff --git a/std/src/f64/tests.rs b/std/src/f64/tests.rs index f88d01593b5e4..d9e17fd601d2d 100644 --- a/std/src/f64/tests.rs +++ b/std/src/f64/tests.rs @@ -2,6 +2,45 @@ use crate::f64::consts; use crate::num::FpCategory as Fp; use crate::num::*; +/// Smallest number +#[allow(dead_code)] // unused on x86 +const TINY_BITS: u64 = 0x1; + +/// Next smallest number +#[allow(dead_code)] // unused on x86 +const TINY_UP_BITS: u64 = 0x2; + +/// Exponent = 0b11...10, Sifnificand 0b1111..10. Min val > 0 +#[allow(dead_code)] // unused on x86 +const MAX_DOWN_BITS: u64 = 0x7fef_ffff_ffff_fffe; + +/// Zeroed exponent, full significant +#[allow(dead_code)] // unused on x86 +const LARGEST_SUBNORMAL_BITS: u64 = 0x000f_ffff_ffff_ffff; + +/// Exponent = 0b1, zeroed significand +#[allow(dead_code)] // unused on x86 +const SMALLEST_NORMAL_BITS: u64 = 0x0010_0000_0000_0000; + +/// First pattern over the mantissa +#[allow(dead_code)] // unused on x86 +const NAN_MASK1: u64 = 0x000a_aaaa_aaaa_aaaa; + +/// Second pattern over the mantissa +#[allow(dead_code)] // unused on x86 +const NAN_MASK2: u64 = 0x0005_5555_5555_5555; + +#[allow(unused_macros)] +macro_rules! assert_f64_biteq { + ($left : expr, $right : expr) => { + let l: &f64 = &$left; + let r: &f64 = &$right; + let lb = l.to_bits(); + let rb = r.to_bits(); + assert_eq!(lb, rb, "float {l} ({lb:#018x}) is not bitequal to {r} ({rb:#018x})"); + }; +} + #[test] fn test_num_f64() { test_num(10f64, 2f64); @@ -305,27 +344,16 @@ fn test_is_sign_negative() { assert!((-f64::NAN).is_sign_negative()); } -#[allow(unused_macros)] -macro_rules! assert_f64_biteq { - ($left : expr, $right : expr) => { - let l: &f64 = &$left; - let r: &f64 = &$right; - let lb = l.to_bits(); - let rb = r.to_bits(); - assert_eq!(lb, rb, "float {} ({:#x}) is not equal to {} ({:#x})", *l, lb, *r, rb); - }; -} - // Ignore test on x87 floating point, these platforms do not guarantee NaN // payloads are preserved and flush denormals to zero, failing the tests. #[cfg(not(target_arch = "x86"))] #[test] fn test_next_up() { - let tiny = f64::from_bits(1); - let tiny_up = f64::from_bits(2); - let max_down = f64::from_bits(0x7fef_ffff_ffff_fffe); - let largest_subnormal = f64::from_bits(0x000f_ffff_ffff_ffff); - let smallest_normal = f64::from_bits(0x0010_0000_0000_0000); + let tiny = f64::from_bits(TINY_BITS); + let tiny_up = f64::from_bits(TINY_UP_BITS); + let max_down = f64::from_bits(MAX_DOWN_BITS); + let largest_subnormal = f64::from_bits(LARGEST_SUBNORMAL_BITS); + let smallest_normal = f64::from_bits(SMALLEST_NORMAL_BITS); assert_f64_biteq!(f64::NEG_INFINITY.next_up(), f64::MIN); assert_f64_biteq!(f64::MIN.next_up(), -max_down); assert_f64_biteq!((-1.0 - f64::EPSILON).next_up(), -1.0); @@ -341,8 +369,8 @@ fn test_next_up() { assert_f64_biteq!(f64::INFINITY.next_up(), f64::INFINITY); let nan0 = f64::NAN; - let nan1 = f64::from_bits(f64::NAN.to_bits() ^ 0x000a_aaaa_aaaa_aaaa); - let nan2 = f64::from_bits(f64::NAN.to_bits() ^ 0x0005_5555_5555_5555); + let nan1 = f64::from_bits(f64::NAN.to_bits() ^ NAN_MASK1); + let nan2 = f64::from_bits(f64::NAN.to_bits() ^ NAN_MASK2); assert_f64_biteq!(nan0.next_up(), nan0); assert_f64_biteq!(nan1.next_up(), nan1); assert_f64_biteq!(nan2.next_up(), nan2); @@ -353,11 +381,11 @@ fn test_next_up() { #[cfg(not(target_arch = "x86"))] #[test] fn test_next_down() { - let tiny = f64::from_bits(1); - let tiny_up = f64::from_bits(2); - let max_down = f64::from_bits(0x7fef_ffff_ffff_fffe); - let largest_subnormal = f64::from_bits(0x000f_ffff_ffff_ffff); - let smallest_normal = f64::from_bits(0x0010_0000_0000_0000); + let tiny = f64::from_bits(TINY_BITS); + let tiny_up = f64::from_bits(TINY_UP_BITS); + let max_down = f64::from_bits(MAX_DOWN_BITS); + let largest_subnormal = f64::from_bits(LARGEST_SUBNORMAL_BITS); + let smallest_normal = f64::from_bits(SMALLEST_NORMAL_BITS); assert_f64_biteq!(f64::NEG_INFINITY.next_down(), f64::NEG_INFINITY); assert_f64_biteq!(f64::MIN.next_down(), f64::NEG_INFINITY); assert_f64_biteq!((-max_down).next_down(), f64::MIN); @@ -374,8 +402,8 @@ fn test_next_down() { assert_f64_biteq!(f64::INFINITY.next_down(), f64::MAX); let nan0 = f64::NAN; - let nan1 = f64::from_bits(f64::NAN.to_bits() ^ 0x000a_aaaa_aaaa_aaaa); - let nan2 = f64::from_bits(f64::NAN.to_bits() ^ 0x0005_5555_5555_5555); + let nan1 = f64::from_bits(f64::NAN.to_bits() ^ NAN_MASK1); + let nan2 = f64::from_bits(f64::NAN.to_bits() ^ NAN_MASK2); assert_f64_biteq!(nan0.next_down(), nan0); assert_f64_biteq!(nan1.next_down(), nan1); assert_f64_biteq!(nan2.next_down(), nan2); @@ -715,9 +743,8 @@ fn test_float_bits_conv() { assert_approx_eq!(f64::from_bits(0xc02c800000000000), -14.25); // Check that NaNs roundtrip their bits regardless of signaling-ness - // 0xA is 0b1010; 0x5 is 0b0101 -- so these two together clobbers all the mantissa bits - let masked_nan1 = f64::NAN.to_bits() ^ 0x000A_AAAA_AAAA_AAAA; - let masked_nan2 = f64::NAN.to_bits() ^ 0x0005_5555_5555_5555; + let masked_nan1 = f64::NAN.to_bits() ^ NAN_MASK1; + let masked_nan2 = f64::NAN.to_bits() ^ NAN_MASK2; assert!(f64::from_bits(masked_nan1).is_nan()); assert!(f64::from_bits(masked_nan2).is_nan()); From 36a20f7b3831915148ff3281e53e755835e07ac4 Mon Sep 17 00:00:00 2001 From: Trevor Gross Date: Fri, 21 Jun 2024 03:30:15 -0400 Subject: [PATCH 02/16] Reword docs for `f32` and `f64` Better explain the reasoning for the `next_up`/`next_down` integer implementation, as requested by Ralf. --- core/src/num/f32.rs | 10 ++++++---- core/src/num/f64.rs | 10 ++++++---- 2 files changed, 12 insertions(+), 8 deletions(-) diff --git a/core/src/num/f32.rs b/core/src/num/f32.rs index 271965c28840a..b9c84a66ed138 100644 --- a/core/src/num/f32.rs +++ b/core/src/num/f32.rs @@ -796,8 +796,9 @@ impl f32 { #[unstable(feature = "float_next_up_down", issue = "91399")] #[rustc_const_unstable(feature = "float_next_up_down", issue = "91399")] pub const fn next_up(self) -> Self { - // We must use strictly integer arithmetic to prevent denormals from - // flushing to zero after an arithmetic operation on some platforms. + // Some targets violate Rust's assumption of IEEE semantics, e.g. by flushing + // denormals to zero. This is in general unsound and unsupported, but here + // we do our best to still produce the correct result on such targets. let bits = self.to_bits(); if self.is_nan() || bits == Self::INFINITY.to_bits() { return self; @@ -843,8 +844,9 @@ impl f32 { #[unstable(feature = "float_next_up_down", issue = "91399")] #[rustc_const_unstable(feature = "float_next_up_down", issue = "91399")] pub const fn next_down(self) -> Self { - // We must use strictly integer arithmetic to prevent denormals from - // flushing to zero after an arithmetic operation on some platforms. + // Some targets violate Rust's assumption of IEEE semantics, e.g. by flushing + // denormals to zero. This is in general unsound and unsupported, but here + // we do our best to still produce the correct result on such targets. let bits = self.to_bits(); if self.is_nan() || bits == Self::NEG_INFINITY.to_bits() { return self; diff --git a/core/src/num/f64.rs b/core/src/num/f64.rs index bccd39f605941..f8e4555fc44f2 100644 --- a/core/src/num/f64.rs +++ b/core/src/num/f64.rs @@ -804,8 +804,9 @@ impl f64 { #[unstable(feature = "float_next_up_down", issue = "91399")] #[rustc_const_unstable(feature = "float_next_up_down", issue = "91399")] pub const fn next_up(self) -> Self { - // We must use strictly integer arithmetic to prevent denormals from - // flushing to zero after an arithmetic operation on some platforms. + // Some targets violate Rust's assumption of IEEE semantics, e.g. by flushing + // denormals to zero. This is in general unsound and unsupported, but here + // we do our best to still produce the correct result on such targets. let bits = self.to_bits(); if self.is_nan() || bits == Self::INFINITY.to_bits() { return self; @@ -851,8 +852,9 @@ impl f64 { #[unstable(feature = "float_next_up_down", issue = "91399")] #[rustc_const_unstable(feature = "float_next_up_down", issue = "91399")] pub const fn next_down(self) -> Self { - // We must use strictly integer arithmetic to prevent denormals from - // flushing to zero after an arithmetic operation on some platforms. + // Some targets violate Rust's assumption of IEEE semantics, e.g. by flushing + // denormals to zero. This is in general unsound and unsupported, but here + // we do our best to still produce the correct result on such targets. let bits = self.to_bits(); if self.is_nan() || bits == Self::NEG_INFINITY.to_bits() { return self; From 1069a68900700a1d005d780d8fa4f702c9d305cb Mon Sep 17 00:00:00 2001 From: Jubilee Young Date: Mon, 24 Jun 2024 20:24:10 -0700 Subject: [PATCH 03/16] core: VaArgSafe is an unsafe trait `T: VaArgSafe` is relied on for soundness. Safe impls promise nothing. Therefore this must be an unsafe trait. Slightly pedantic, as only core can impl this, but we could choose to unseal the trait. That would allow soundly (but unsafely) implementing this for e.g. a `#[repr(C)] struct` that should be passable by varargs. --- core/src/ffi/mod.rs | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/core/src/ffi/mod.rs b/core/src/ffi/mod.rs index 618897b3ababd..6d1f10f521176 100644 --- a/core/src/ffi/mod.rs +++ b/core/src/ffi/mod.rs @@ -484,7 +484,7 @@ mod sealed_trait { all supported platforms", issue = "44930" )] - pub trait VaArgSafe {} + pub unsafe trait VaArgSafe {} } macro_rules! impl_va_arg_safe { @@ -494,7 +494,7 @@ macro_rules! impl_va_arg_safe { reason = "the `c_variadic` feature has not been properly tested on \ all supported platforms", issue = "44930")] - impl sealed_trait::VaArgSafe for $t {} + unsafe impl sealed_trait::VaArgSafe for $t {} )+ } } @@ -509,14 +509,15 @@ impl_va_arg_safe! {f64} all supported platforms", issue = "44930" )] -impl sealed_trait::VaArgSafe for *mut T {} +unsafe impl sealed_trait::VaArgSafe for *mut T {} + #[unstable( feature = "c_variadic", reason = "the `c_variadic` feature has not been properly tested on \ all supported platforms", issue = "44930" )] -impl sealed_trait::VaArgSafe for *const T {} +unsafe impl sealed_trait::VaArgSafe for *const T {} #[unstable( feature = "c_variadic", From b0e050324f9a016a1f0bd940be406c34af6930fc Mon Sep 17 00:00:00 2001 From: Trevor Gross Date: Thu, 20 Jun 2024 22:05:07 -0400 Subject: [PATCH 04/16] Add build.rs config for reliable `f16` and `f128` There are some complexities about what platforms we can test f16 and f128 on. Put this in build.rs so we have an easy way to configure tests with a single attribute, and keep it up to date. --- std/build.rs | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) diff --git a/std/build.rs b/std/build.rs index 7d975df545ecf..55388648a14b9 100644 --- a/std/build.rs +++ b/std/build.rs @@ -7,6 +7,10 @@ fn main() { let target_vendor = env::var("CARGO_CFG_TARGET_VENDOR").expect("CARGO_CFG_TARGET_VENDOR was not set"); let target_env = env::var("CARGO_CFG_TARGET_ENV").expect("CARGO_CFG_TARGET_ENV was not set"); + let target_pointer_width: u32 = env::var("CARGO_CFG_TARGET_POINTER_WIDTH") + .expect("CARGO_CFG_TARGET_POINTER_WIDTH was not set") + .parse() + .unwrap(); println!("cargo:rustc-check-cfg=cfg(netbsd10)"); if target_os == "netbsd" && env::var("RUSTC_STD_NETBSD10").is_ok() { @@ -70,4 +74,62 @@ fn main() { println!("cargo:rustc-cfg=backtrace_in_libstd"); println!("cargo:rustc-env=STD_ENV_ARCH={}", env::var("CARGO_CFG_TARGET_ARCH").unwrap()); + + // Emit these on platforms that have no known ABI bugs, LLVM selection bugs, lowering bugs, + // missing symbols, or other problems, to determine when tests get run. + // If more broken platforms are found, please update the tracking issue at + // + // + // Some of these match arms are redundant; the goal is to separate reasons that the type is + // unreliable, even when multiple reasons might fail the same platform. + println!("cargo:rustc-check-cfg=cfg(reliable_f16)"); + println!("cargo:rustc-check-cfg=cfg(reliable_f128)"); + + let has_reliable_f16 = match (target_arch.as_str(), target_os.as_str()) { + // Selection failure until recent LLVM + // FIXME(llvm19): can probably be removed at the version bump + ("loongarch64", _) => false, + // Selection failure + ("s390x", _) => false, + // Unsupported + ("arm64ec", _) => false, + // MinGW ABI bugs + ("x86", "windows") => false, + // x86 has ABI bugs that show up with optimizations. This should be partially fixed with + // the compiler-builtins update. + ("x86" | "x86_64", _) => false, + // Missing `__gnu_h2f_ieee` and `__gnu_f2h_ieee` + ("powerpc" | "powerpc64" | "powerpc64le", _) => false, + // Missing `__extendhfsf` and `__truncsfhf` + ("riscv32" | "riscv64", _) => false, + // Most OSs are missing `__extendhfsf` and `__truncsfhf` + (_, "linux" | "macos") => true, + // Almost all OSs besides Linux and MacOS are missing symbols until compiler-builtins can + // be updated. will get some of these, the + // next CB update should get the rest. + _ => false, + }; + + let has_reliable_f128 = match (target_arch.as_str(), target_os.as_str()) { + // Unsupported + ("arm64ec", _) => false, + // ABI and precision bugs + // + ("powerpc" | "powerpc64", _) => false, + // Selection bug + ("nvptx64", _) => false, + // ABI unsupported + ("sparc", _) => false, + // 64-bit Linux is about the only platform to have f128 symbols by default + (_, "linux") if target_pointer_width == 64 => true, + // Same as for f16, except MacOS is also missing f128 symbols. + _ => false, + }; + + if has_reliable_f16 { + println!("cargo:rustc-cfg=reliable_f16"); + } + if has_reliable_f128 { + println!("cargo:rustc-cfg=reliable_f128"); + } } From 6cb3d34841e09d9656a1c39c95b6bad486916adb Mon Sep 17 00:00:00 2001 From: Trevor Gross Date: Tue, 18 Jun 2024 18:22:14 -0500 Subject: [PATCH 05/16] Add doctests to existing `f16` and `f128` functions The symbols that these tests rely on are not available on all platforms and some ABIs are buggy, tests that rely on external functions are configured to only run on x86 (`f128`) or aarch64 (`f16`). --- core/src/num/f128.rs | 36 ++++++++++++++++++++++++++++++++++-- core/src/num/f16.rs | 36 ++++++++++++++++++++++++++++++++++-- 2 files changed, 68 insertions(+), 4 deletions(-) diff --git a/core/src/num/f128.rs b/core/src/num/f128.rs index 129f62fb43d1a..490d7bd504dfe 100644 --- a/core/src/num/f128.rs +++ b/core/src/num/f128.rs @@ -221,8 +221,22 @@ impl f128 { pub const MAX_10_EXP: i32 = 4_932; /// Returns `true` if this value is NaN. + /// + /// ``` + /// #![feature(f128)] + /// # // FIXME(f16_f128): remove when `unordtf2` is available + /// # #[cfg(target_arch = "x86_64", target_os = "linux")] { + /// + /// let nan = f128::NAN; + /// let f = 7.0_f128; + /// + /// assert!(nan.is_nan()); + /// assert!(!f.is_nan()); + /// # } + /// ``` #[inline] #[must_use] + #[cfg(not(bootstrap))] #[unstable(feature = "f128", issue = "116909")] #[allow(clippy::eq_op)] // > if you intended to check if the operand is NaN, use `.is_nan()` instead :) pub const fn is_nan(self) -> bool { @@ -234,7 +248,7 @@ impl f128 { /// meaning to the sign bit in case of a NaN, and as Rust doesn't guarantee that /// the bit pattern of NaNs are conserved over arithmetic operations, the result of /// `is_sign_positive` on a NaN might produce an unexpected result in some cases. - /// See [explanation of NaN as a special value](f32) for more info. + /// See [explanation of NaN as a special value](f128) for more info. /// /// ``` /// #![feature(f128)] @@ -257,7 +271,7 @@ impl f128 { /// meaning to the sign bit in case of a NaN, and as Rust doesn't guarantee that /// the bit pattern of NaNs are conserved over arithmetic operations, the result of /// `is_sign_negative` on a NaN might produce an unexpected result in some cases. - /// See [explanation of NaN as a special value](f32) for more info. + /// See [explanation of NaN as a special value](f128) for more info. /// /// ``` /// #![feature(f128)] @@ -287,6 +301,14 @@ impl f128 { /// /// Note that this function is distinct from `as` casting, which attempts to /// preserve the *numeric* value, and not the bitwise value. + /// + /// ``` + /// #![feature(f128)] + /// + /// # // FIXME(f16_f128): enable this once const casting works + /// # // assert_ne!((1f128).to_bits(), 1f128 as u128); // to_bits() is not casting! + /// assert_eq!((12.5f128).to_bits(), 0x40029000000000000000000000000000); + /// ``` #[inline] #[unstable(feature = "f128", issue = "116909")] #[must_use = "this returns the result of the operation, without modifying the original"] @@ -326,6 +348,16 @@ impl f128 { /// /// Note that this function is distinct from `as` casting, which attempts to /// preserve the *numeric* value, and not the bitwise value. + /// + /// ``` + /// #![feature(f128)] + /// # // FIXME(f16_f128): remove when `eqtf2` is available + /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] { + /// + /// let v = f128::from_bits(0x40029000000000000000000000000000); + /// assert_eq!(v, 12.5); + /// # } + /// ``` #[inline] #[must_use] #[unstable(feature = "f128", issue = "116909")] diff --git a/core/src/num/f16.rs b/core/src/num/f16.rs index 7a488cd6bf6fa..4b0c25fcce967 100644 --- a/core/src/num/f16.rs +++ b/core/src/num/f16.rs @@ -216,8 +216,21 @@ impl f16 { pub const MAX_10_EXP: i32 = 4; /// Returns `true` if this value is NaN. + /// + /// ``` + /// #![feature(f16)] + /// # #[cfg(target_arch = "x86_64")] { // FIXME(f16_f128): remove when ABI bugs are fixed + /// + /// let nan = f16::NAN; + /// let f = 7.0_f16; + /// + /// assert!(nan.is_nan()); + /// assert!(!f.is_nan()); + /// # } + /// ``` #[inline] #[must_use] + #[cfg(not(bootstrap))] #[unstable(feature = "f16", issue = "116909")] #[allow(clippy::eq_op)] // > if you intended to check if the operand is NaN, use `.is_nan()` instead :) pub const fn is_nan(self) -> bool { @@ -229,7 +242,7 @@ impl f16 { /// meaning to the sign bit in case of a NaN, and as Rust doesn't guarantee that /// the bit pattern of NaNs are conserved over arithmetic operations, the result of /// `is_sign_positive` on a NaN might produce an unexpected result in some cases. - /// See [explanation of NaN as a special value](f32) for more info. + /// See [explanation of NaN as a special value](f16) for more info. /// /// ``` /// #![feature(f16)] @@ -252,7 +265,7 @@ impl f16 { /// meaning to the sign bit in case of a NaN, and as Rust doesn't guarantee that /// the bit pattern of NaNs are conserved over arithmetic operations, the result of /// `is_sign_negative` on a NaN might produce an unexpected result in some cases. - /// See [explanation of NaN as a special value](f32) for more info. + /// See [explanation of NaN as a special value](f16) for more info. /// /// ``` /// #![feature(f16)] @@ -282,6 +295,16 @@ impl f16 { /// /// Note that this function is distinct from `as` casting, which attempts to /// preserve the *numeric* value, and not the bitwise value. + /// + /// ``` + /// #![feature(f16)] + /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885 + /// + /// # // FIXME(f16_f128): enable this once const casting works + /// # // assert_ne!((1f16).to_bits(), 1f16 as u128); // to_bits() is not casting! + /// assert_eq!((12.5f16).to_bits(), 0x4a40); + /// # } + /// ``` #[inline] #[unstable(feature = "f16", issue = "116909")] #[must_use = "this returns the result of the operation, without modifying the original"] @@ -321,6 +344,15 @@ impl f16 { /// /// Note that this function is distinct from `as` casting, which attempts to /// preserve the *numeric* value, and not the bitwise value. + /// + /// ``` + /// #![feature(f16)] + /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885 + /// + /// let v = f16::from_bits(0x4a40); + /// assert_eq!(v, 12.5); + /// # } + /// ``` #[inline] #[must_use] #[unstable(feature = "f16", issue = "116909")] From 561daffd3f5d2827b1834bd7fb70de2b2bf18774 Mon Sep 17 00:00:00 2001 From: Trevor Gross Date: Tue, 18 Jun 2024 18:25:07 -0500 Subject: [PATCH 06/16] Add more `f16` and `f128` library functions and constants This adds everything that was directly or transitively blocked on const arithmetic for these types, which was recently merged. Since const arithmetic is recent, most of these need to be gated by `bootstrap`. Anything that relies on intrinsics that are still missing is excluded. --- core/src/num/f128.rs | 640 ++++++++++++++++++++++++++++++++++++++++++- core/src/num/f16.rs | 612 ++++++++++++++++++++++++++++++++++++++++- std/src/f128.rs | 30 ++ std/src/f16.rs | 29 ++ 4 files changed, 1309 insertions(+), 2 deletions(-) diff --git a/core/src/num/f128.rs b/core/src/num/f128.rs index 490d7bd504dfe..58ed98c888cc6 100644 --- a/core/src/num/f128.rs +++ b/core/src/num/f128.rs @@ -11,6 +11,7 @@ #![unstable(feature = "f128", issue = "116909")] +use crate::convert::FloatToInt; use crate::mem; /// Basic mathematical constants. @@ -220,12 +221,50 @@ impl f128 { #[unstable(feature = "f128", issue = "116909")] pub const MAX_10_EXP: i32 = 4_932; + /// Not a Number (NaN). + /// + /// Note that IEEE 754 doesn't define just a single NaN value; + /// a plethora of bit patterns are considered to be NaN. + /// Furthermore, the standard makes a difference + /// between a "signaling" and a "quiet" NaN, + /// and allows inspecting its "payload" (the unspecified bits in the bit pattern). + /// This constant isn't guaranteed to equal to any specific NaN bitpattern, + /// and the stability of its representation over Rust versions + /// and target platforms isn't guaranteed. + #[cfg(not(bootstrap))] + #[allow(clippy::eq_op)] + #[rustc_diagnostic_item = "f128_nan"] + #[unstable(feature = "f128", issue = "116909")] + pub const NAN: f128 = 0.0_f128 / 0.0_f128; + + /// Infinity (∞). + #[cfg(not(bootstrap))] + #[unstable(feature = "f128", issue = "116909")] + pub const INFINITY: f128 = 1.0_f128 / 0.0_f128; + + /// Negative infinity (−∞). + #[cfg(not(bootstrap))] + #[unstable(feature = "f128", issue = "116909")] + pub const NEG_INFINITY: f128 = -1.0_f128 / 0.0_f128; + + /// Sign bit + #[cfg(not(bootstrap))] + pub(crate) const SIGN_MASK: u128 = 0x8000_0000_0000_0000_0000_0000_0000_0000; + + /// Minimum representable positive value (min subnormal) + #[cfg(not(bootstrap))] + const TINY_BITS: u128 = 0x1; + + /// Minimum representable negative value (min negative subnormal) + #[cfg(not(bootstrap))] + const NEG_TINY_BITS: u128 = Self::TINY_BITS | Self::SIGN_MASK; + /// Returns `true` if this value is NaN. /// /// ``` /// #![feature(f128)] /// # // FIXME(f16_f128): remove when `unordtf2` is available - /// # #[cfg(target_arch = "x86_64", target_os = "linux")] { + /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] { /// /// let nan = f128::NAN; /// let f = 7.0_f128; @@ -243,6 +282,78 @@ impl f128 { self != self } + // FIXME(#50145): `abs` is publicly unavailable in core due to + // concerns about portability, so this implementation is for + // private use internally. + #[inline] + #[cfg(not(bootstrap))] + #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")] + pub(crate) const fn abs_private(self) -> f128 { + // SAFETY: This transmutation is fine. Probably. For the reasons std is using it. + unsafe { + mem::transmute::(mem::transmute::(self) & !Self::SIGN_MASK) + } + } + + /// Returns `true` if this value is positive infinity or negative infinity, and + /// `false` otherwise. + /// + /// ``` + /// #![feature(f128)] + /// # // FIXME(f16_f128): remove when `eqtf2` is available + /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] { + /// + /// let f = 7.0f128; + /// let inf = f128::INFINITY; + /// let neg_inf = f128::NEG_INFINITY; + /// let nan = f128::NAN; + /// + /// assert!(!f.is_infinite()); + /// assert!(!nan.is_infinite()); + /// + /// assert!(inf.is_infinite()); + /// assert!(neg_inf.is_infinite()); + /// # } + /// ``` + #[inline] + #[must_use] + #[cfg(not(bootstrap))] + #[unstable(feature = "f128", issue = "116909")] + #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")] + pub const fn is_infinite(self) -> bool { + (self == f128::INFINITY) | (self == f128::NEG_INFINITY) + } + + /// Returns `true` if this number is neither infinite nor NaN. + /// + /// ``` + /// #![feature(f128)] + /// # // FIXME(f16_f128): remove when `lttf2` is available + /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] { + /// + /// let f = 7.0f128; + /// let inf: f128 = f128::INFINITY; + /// let neg_inf: f128 = f128::NEG_INFINITY; + /// let nan: f128 = f128::NAN; + /// + /// assert!(f.is_finite()); + /// + /// assert!(!nan.is_finite()); + /// assert!(!inf.is_finite()); + /// assert!(!neg_inf.is_finite()); + /// # } + /// ``` + #[inline] + #[must_use] + #[cfg(not(bootstrap))] + #[unstable(feature = "f128", issue = "116909")] + #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")] + pub const fn is_finite(self) -> bool { + // There's no need to handle NaN separately: if self is NaN, + // the comparison is not true, exactly as desired. + self.abs_private() < Self::INFINITY + } + /// Returns `true` if `self` has a positive sign, including `+0.0`, NaNs with /// positive sign bit and positive infinity. Note that IEEE 754 doesn't assign any /// meaning to the sign bit in case of a NaN, and as Rust doesn't guarantee that @@ -292,6 +403,222 @@ impl f128 { (self.to_bits() & (1 << 127)) != 0 } + /// Returns the least number greater than `self`. + /// + /// Let `TINY` be the smallest representable positive `f128`. Then, + /// - if `self.is_nan()`, this returns `self`; + /// - if `self` is [`NEG_INFINITY`], this returns [`MIN`]; + /// - if `self` is `-TINY`, this returns -0.0; + /// - if `self` is -0.0 or +0.0, this returns `TINY`; + /// - if `self` is [`MAX`] or [`INFINITY`], this returns [`INFINITY`]; + /// - otherwise the unique least value greater than `self` is returned. + /// + /// The identity `x.next_up() == -(-x).next_down()` holds for all non-NaN `x`. When `x` + /// is finite `x == x.next_up().next_down()` also holds. + /// + /// ```rust + /// #![feature(f128)] + /// #![feature(float_next_up_down)] + /// # // FIXME(f16_f128): remove when `eqtf2` is available + /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] { + /// + /// // f128::EPSILON is the difference between 1.0 and the next number up. + /// assert_eq!(1.0f128.next_up(), 1.0 + f128::EPSILON); + /// // But not for most numbers. + /// assert!(0.1f128.next_up() < 0.1 + f128::EPSILON); + /// assert_eq!(4611686018427387904f128.next_up(), 4611686018427387904.000000000000001); + /// # } + /// ``` + /// + /// [`NEG_INFINITY`]: Self::NEG_INFINITY + /// [`INFINITY`]: Self::INFINITY + /// [`MIN`]: Self::MIN + /// [`MAX`]: Self::MAX + #[inline] + #[cfg(not(bootstrap))] + #[unstable(feature = "f128", issue = "116909")] + // #[unstable(feature = "float_next_up_down", issue = "91399")] + pub fn next_up(self) -> Self { + // Some targets violate Rust's assumption of IEEE semantics, e.g. by flushing + // denormals to zero. This is in general unsound and unsupported, but here + // we do our best to still produce the correct result on such targets. + let bits = self.to_bits(); + if self.is_nan() || bits == Self::INFINITY.to_bits() { + return self; + } + + let abs = bits & !Self::SIGN_MASK; + let next_bits = if abs == 0 { + Self::TINY_BITS + } else if bits == abs { + bits + 1 + } else { + bits - 1 + }; + Self::from_bits(next_bits) + } + + /// Returns the greatest number less than `self`. + /// + /// Let `TINY` be the smallest representable positive `f128`. Then, + /// - if `self.is_nan()`, this returns `self`; + /// - if `self` is [`INFINITY`], this returns [`MAX`]; + /// - if `self` is `TINY`, this returns 0.0; + /// - if `self` is -0.0 or +0.0, this returns `-TINY`; + /// - if `self` is [`MIN`] or [`NEG_INFINITY`], this returns [`NEG_INFINITY`]; + /// - otherwise the unique greatest value less than `self` is returned. + /// + /// The identity `x.next_down() == -(-x).next_up()` holds for all non-NaN `x`. When `x` + /// is finite `x == x.next_down().next_up()` also holds. + /// + /// ```rust + /// #![feature(f128)] + /// #![feature(float_next_up_down)] + /// # // FIXME(f16_f128): remove when `eqtf2` is available + /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] { + /// + /// let x = 1.0f128; + /// // Clamp value into range [0, 1). + /// let clamped = x.clamp(0.0, 1.0f128.next_down()); + /// assert!(clamped < 1.0); + /// assert_eq!(clamped.next_up(), 1.0); + /// # } + /// ``` + /// + /// [`NEG_INFINITY`]: Self::NEG_INFINITY + /// [`INFINITY`]: Self::INFINITY + /// [`MIN`]: Self::MIN + /// [`MAX`]: Self::MAX + #[inline] + #[cfg(not(bootstrap))] + #[unstable(feature = "f128", issue = "116909")] + // #[unstable(feature = "float_next_up_down", issue = "91399")] + pub fn next_down(self) -> Self { + // Some targets violate Rust's assumption of IEEE semantics, e.g. by flushing + // denormals to zero. This is in general unsound and unsupported, but here + // we do our best to still produce the correct result on such targets. + let bits = self.to_bits(); + if self.is_nan() || bits == Self::NEG_INFINITY.to_bits() { + return self; + } + + let abs = bits & !Self::SIGN_MASK; + let next_bits = if abs == 0 { + Self::NEG_TINY_BITS + } else if bits == abs { + bits - 1 + } else { + bits + 1 + }; + Self::from_bits(next_bits) + } + + /// Takes the reciprocal (inverse) of a number, `1/x`. + /// + /// ``` + /// #![feature(f128)] + /// # // FIXME(f16_f128): remove when `eqtf2` is available + /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] { + /// + /// let x = 2.0_f128; + /// let abs_difference = (x.recip() - (1.0 / x)).abs(); + /// + /// assert!(abs_difference <= f128::EPSILON); + /// # } + /// ``` + #[inline] + #[cfg(not(bootstrap))] + #[unstable(feature = "f128", issue = "116909")] + #[must_use = "this returns the result of the operation, without modifying the original"] + pub fn recip(self) -> Self { + 1.0 / self + } + + /// Converts radians to degrees. + /// + /// ``` + /// #![feature(f128)] + /// # // FIXME(f16_f128): remove when `eqtf2` is available + /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] { + /// + /// let angle = std::f128::consts::PI; + /// + /// let abs_difference = (angle.to_degrees() - 180.0).abs(); + /// assert!(abs_difference <= f128::EPSILON); + /// # } + /// ``` + #[inline] + #[cfg(not(bootstrap))] + #[unstable(feature = "f128", issue = "116909")] + #[must_use = "this returns the result of the operation, without modifying the original"] + pub fn to_degrees(self) -> Self { + // Use a literal for better precision. + const PIS_IN_180: f128 = 57.2957795130823208767981548141051703324054724665643215491602_f128; + self * PIS_IN_180 + } + + /// Converts degrees to radians. + /// + /// ``` + /// #![feature(f128)] + /// # // FIXME(f16_f128): remove when `eqtf2` is available + /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] { + /// + /// let angle = 180.0f128; + /// + /// let abs_difference = (angle.to_radians() - std::f128::consts::PI).abs(); + /// + /// assert!(abs_difference <= 1e-30); + /// # } + /// ``` + #[inline] + #[cfg(not(bootstrap))] + #[unstable(feature = "f128", issue = "116909")] + #[must_use = "this returns the result of the operation, without modifying the original"] + pub fn to_radians(self) -> f128 { + // Use a literal for better precision. + const RADS_PER_DEG: f128 = + 0.0174532925199432957692369076848861271344287188854172545609719_f128; + self * RADS_PER_DEG + } + + /// Rounds toward zero and converts to any primitive integer type, + /// assuming that the value is finite and fits in that type. + /// + /// ``` + /// #![feature(f128)] + /// # // FIXME(f16_f128): remove when `float*itf` is available + /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] { + /// + /// let value = 4.6_f128; + /// let rounded = unsafe { value.to_int_unchecked::() }; + /// assert_eq!(rounded, 4); + /// + /// let value = -128.9_f128; + /// let rounded = unsafe { value.to_int_unchecked::() }; + /// assert_eq!(rounded, i8::MIN); + /// # } + /// ``` + /// + /// # Safety + /// + /// The value must: + /// + /// * Not be `NaN` + /// * Not be infinite + /// * Be representable in the return type `Int`, after truncating off its fractional part + #[inline] + #[unstable(feature = "f128", issue = "116909")] + #[must_use = "this returns the result of the operation, without modifying the original"] + pub unsafe fn to_int_unchecked(self) -> Int + where + Self: FloatToInt, + { + // SAFETY: the caller must uphold the safety contract for + // `FloatToInt::to_int_unchecked`. + unsafe { FloatToInt::::to_int_unchecked(self) } + } + /// Raw transmutation to `u128`. /// /// This is currently identical to `transmute::(self)` on all platforms. @@ -367,4 +694,315 @@ impl f128 { // Stability concerns. unsafe { mem::transmute(v) } } + + /// Return the memory representation of this floating point number as a byte array in + /// big-endian (network) byte order. + /// + /// See [`from_bits`](Self::from_bits) for some discussion of the + /// portability of this operation (there are almost no issues). + /// + /// # Examples + /// + /// ``` + /// #![feature(f128)] + /// + /// let bytes = 12.5f128.to_be_bytes(); + /// assert_eq!( + /// bytes, + /// [0x40, 0x02, 0x90, 0x00, 0x00, 0x00, 0x00, 0x00, + /// 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00] + /// ); + /// ``` + #[inline] + #[unstable(feature = "f128", issue = "116909")] + #[must_use = "this returns the result of the operation, without modifying the original"] + pub fn to_be_bytes(self) -> [u8; 16] { + self.to_bits().to_be_bytes() + } + + /// Return the memory representation of this floating point number as a byte array in + /// little-endian byte order. + /// + /// See [`from_bits`](Self::from_bits) for some discussion of the + /// portability of this operation (there are almost no issues). + /// + /// # Examples + /// + /// ``` + /// #![feature(f128)] + /// + /// let bytes = 12.5f128.to_le_bytes(); + /// assert_eq!( + /// bytes, + /// [0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + /// 0x00, 0x00, 0x00, 0x00, 0x00, 0x90, 0x02, 0x40] + /// ); + /// ``` + #[inline] + #[unstable(feature = "f128", issue = "116909")] + #[must_use = "this returns the result of the operation, without modifying the original"] + pub fn to_le_bytes(self) -> [u8; 16] { + self.to_bits().to_le_bytes() + } + + /// Return the memory representation of this floating point number as a byte array in + /// native byte order. + /// + /// As the target platform's native endianness is used, portable code + /// should use [`to_be_bytes`] or [`to_le_bytes`], as appropriate, instead. + /// + /// [`to_be_bytes`]: f128::to_be_bytes + /// [`to_le_bytes`]: f128::to_le_bytes + /// + /// See [`from_bits`](Self::from_bits) for some discussion of the + /// portability of this operation (there are almost no issues). + /// + /// # Examples + /// + /// ``` + /// #![feature(f128)] + /// + /// let bytes = 12.5f128.to_ne_bytes(); + /// assert_eq!( + /// bytes, + /// if cfg!(target_endian = "big") { + /// [0x40, 0x02, 0x90, 0x00, 0x00, 0x00, 0x00, 0x00, + /// 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00] + /// } else { + /// [0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + /// 0x00, 0x00, 0x00, 0x00, 0x00, 0x90, 0x02, 0x40] + /// } + /// ); + /// ``` + #[inline] + #[unstable(feature = "f128", issue = "116909")] + #[must_use = "this returns the result of the operation, without modifying the original"] + pub fn to_ne_bytes(self) -> [u8; 16] { + self.to_bits().to_ne_bytes() + } + + /// Create a floating point value from its representation as a byte array in big endian. + /// + /// See [`from_bits`](Self::from_bits) for some discussion of the + /// portability of this operation (there are almost no issues). + /// + /// # Examples + /// + /// ``` + /// #![feature(f128)] + /// # // FIXME(f16_f128): remove when `eqtf2` is available + /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] { + /// + /// let value = f128::from_be_bytes( + /// [0x40, 0x02, 0x90, 0x00, 0x00, 0x00, 0x00, 0x00, + /// 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00] + /// ); + /// assert_eq!(value, 12.5); + /// # } + /// ``` + #[inline] + #[must_use] + #[unstable(feature = "f128", issue = "116909")] + pub fn from_be_bytes(bytes: [u8; 16]) -> Self { + Self::from_bits(u128::from_be_bytes(bytes)) + } + + /// Create a floating point value from its representation as a byte array in little endian. + /// + /// See [`from_bits`](Self::from_bits) for some discussion of the + /// portability of this operation (there are almost no issues). + /// + /// # Examples + /// + /// ``` + /// #![feature(f128)] + /// # // FIXME(f16_f128): remove when `eqtf2` is available + /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] { + /// + /// let value = f128::from_le_bytes( + /// [0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + /// 0x00, 0x00, 0x00, 0x00, 0x00, 0x90, 0x02, 0x40] + /// ); + /// assert_eq!(value, 12.5); + /// # } + /// ``` + #[inline] + #[must_use] + #[unstable(feature = "f128", issue = "116909")] + pub fn from_le_bytes(bytes: [u8; 16]) -> Self { + Self::from_bits(u128::from_le_bytes(bytes)) + } + + /// Create a floating point value from its representation as a byte array in native endian. + /// + /// As the target platform's native endianness is used, portable code + /// likely wants to use [`from_be_bytes`] or [`from_le_bytes`], as + /// appropriate instead. + /// + /// [`from_be_bytes`]: f128::from_be_bytes + /// [`from_le_bytes`]: f128::from_le_bytes + /// + /// See [`from_bits`](Self::from_bits) for some discussion of the + /// portability of this operation (there are almost no issues). + /// + /// # Examples + /// + /// ``` + /// #![feature(f128)] + /// # // FIXME(f16_f128): remove when `eqtf2` is available + /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] { + /// + /// let value = f128::from_ne_bytes(if cfg!(target_endian = "big") { + /// [0x40, 0x02, 0x90, 0x00, 0x00, 0x00, 0x00, 0x00, + /// 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00] + /// } else { + /// [0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + /// 0x00, 0x00, 0x00, 0x00, 0x00, 0x90, 0x02, 0x40] + /// }); + /// assert_eq!(value, 12.5); + /// # } + /// ``` + #[inline] + #[must_use] + #[unstable(feature = "f128", issue = "116909")] + pub fn from_ne_bytes(bytes: [u8; 16]) -> Self { + Self::from_bits(u128::from_ne_bytes(bytes)) + } + + /// Return the ordering between `self` and `other`. + /// + /// Unlike the standard partial comparison between floating point numbers, + /// this comparison always produces an ordering in accordance to + /// the `totalOrder` predicate as defined in the IEEE 754 (2008 revision) + /// floating point standard. The values are ordered in the following sequence: + /// + /// - negative quiet NaN + /// - negative signaling NaN + /// - negative infinity + /// - negative numbers + /// - negative subnormal numbers + /// - negative zero + /// - positive zero + /// - positive subnormal numbers + /// - positive numbers + /// - positive infinity + /// - positive signaling NaN + /// - positive quiet NaN. + /// + /// The ordering established by this function does not always agree with the + /// [`PartialOrd`] and [`PartialEq`] implementations of `f128`. For example, + /// they consider negative and positive zero equal, while `total_cmp` + /// doesn't. + /// + /// The interpretation of the signaling NaN bit follows the definition in + /// the IEEE 754 standard, which may not match the interpretation by some of + /// the older, non-conformant (e.g. MIPS) hardware implementations. + /// + /// # Example + /// + /// ``` + /// #![feature(f128)] + /// + /// struct GoodBoy { + /// name: &'static str, + /// weight: f128, + /// } + /// + /// let mut bois = vec![ + /// GoodBoy { name: "Pucci", weight: 0.1 }, + /// GoodBoy { name: "Woofer", weight: 99.0 }, + /// GoodBoy { name: "Yapper", weight: 10.0 }, + /// GoodBoy { name: "Chonk", weight: f128::INFINITY }, + /// GoodBoy { name: "Abs. Unit", weight: f128::NAN }, + /// GoodBoy { name: "Floaty", weight: -5.0 }, + /// ]; + /// + /// bois.sort_by(|a, b| a.weight.total_cmp(&b.weight)); + /// + /// // `f128::NAN` could be positive or negative, which will affect the sort order. + /// if f128::NAN.is_sign_negative() { + /// bois.into_iter().map(|b| b.weight) + /// .zip([f128::NAN, -5.0, 0.1, 10.0, 99.0, f128::INFINITY].iter()) + /// .for_each(|(a, b)| assert_eq!(a.to_bits(), b.to_bits())) + /// } else { + /// bois.into_iter().map(|b| b.weight) + /// .zip([-5.0, 0.1, 10.0, 99.0, f128::INFINITY, f128::NAN].iter()) + /// .for_each(|(a, b)| assert_eq!(a.to_bits(), b.to_bits())) + /// } + /// ``` + #[inline] + #[must_use] + #[cfg(not(bootstrap))] + #[unstable(feature = "f128", issue = "116909")] + pub fn total_cmp(&self, other: &Self) -> crate::cmp::Ordering { + let mut left = self.to_bits() as i128; + let mut right = other.to_bits() as i128; + + // In case of negatives, flip all the bits except the sign + // to achieve a similar layout as two's complement integers + // + // Why does this work? IEEE 754 floats consist of three fields: + // Sign bit, exponent and mantissa. The set of exponent and mantissa + // fields as a whole have the property that their bitwise order is + // equal to the numeric magnitude where the magnitude is defined. + // The magnitude is not normally defined on NaN values, but + // IEEE 754 totalOrder defines the NaN values also to follow the + // bitwise order. This leads to order explained in the doc comment. + // However, the representation of magnitude is the same for negative + // and positive numbers – only the sign bit is different. + // To easily compare the floats as signed integers, we need to + // flip the exponent and mantissa bits in case of negative numbers. + // We effectively convert the numbers to "two's complement" form. + // + // To do the flipping, we construct a mask and XOR against it. + // We branchlessly calculate an "all-ones except for the sign bit" + // mask from negative-signed values: right shifting sign-extends + // the integer, so we "fill" the mask with sign bits, and then + // convert to unsigned to push one more zero bit. + // On positive values, the mask is all zeros, so it's a no-op. + left ^= (((left >> 127) as u128) >> 1) as i128; + right ^= (((right >> 127) as u128) >> 1) as i128; + + left.cmp(&right) + } + + /// Restrict a value to a certain interval unless it is NaN. + /// + /// Returns `max` if `self` is greater than `max`, and `min` if `self` is + /// less than `min`. Otherwise this returns `self`. + /// + /// Note that this function returns NaN if the initial value was NaN as + /// well. + /// + /// # Panics + /// + /// Panics if `min > max`, `min` is NaN, or `max` is NaN. + /// + /// # Examples + /// + /// ``` + /// #![feature(f128)] + /// # // FIXME(f16_f128): remove when `{eq,gt,unord}tf` are available + /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] { + /// + /// assert!((-3.0f128).clamp(-2.0, 1.0) == -2.0); + /// assert!((0.0f128).clamp(-2.0, 1.0) == 0.0); + /// assert!((2.0f128).clamp(-2.0, 1.0) == 1.0); + /// assert!((f128::NAN).clamp(-2.0, 1.0).is_nan()); + /// # } + /// ``` + #[inline] + #[cfg(not(bootstrap))] + #[unstable(feature = "f128", issue = "116909")] + #[must_use = "method returns a new number and does not mutate the original value"] + pub fn clamp(mut self, min: f128, max: f128) -> f128 { + assert!(min <= max, "min > max, or either was NaN. min = {min:?}, max = {max:?}"); + if self < min { + self = min; + } + if self > max { + self = max; + } + self + } } diff --git a/core/src/num/f16.rs b/core/src/num/f16.rs index 4b0c25fcce967..3c58b0af9c27e 100644 --- a/core/src/num/f16.rs +++ b/core/src/num/f16.rs @@ -11,6 +11,7 @@ #![unstable(feature = "f16", issue = "116909")] +use crate::convert::FloatToInt; use crate::mem; /// Basic mathematical constants. @@ -215,11 +216,49 @@ impl f16 { #[unstable(feature = "f16", issue = "116909")] pub const MAX_10_EXP: i32 = 4; + /// Not a Number (NaN). + /// + /// Note that IEEE 754 doesn't define just a single NaN value; + /// a plethora of bit patterns are considered to be NaN. + /// Furthermore, the standard makes a difference + /// between a "signaling" and a "quiet" NaN, + /// and allows inspecting its "payload" (the unspecified bits in the bit pattern). + /// This constant isn't guaranteed to equal to any specific NaN bitpattern, + /// and the stability of its representation over Rust versions + /// and target platforms isn't guaranteed. + #[cfg(not(bootstrap))] + #[allow(clippy::eq_op)] + #[rustc_diagnostic_item = "f16_nan"] + #[unstable(feature = "f16", issue = "116909")] + pub const NAN: f16 = 0.0_f16 / 0.0_f16; + + /// Infinity (∞). + #[cfg(not(bootstrap))] + #[unstable(feature = "f16", issue = "116909")] + pub const INFINITY: f16 = 1.0_f16 / 0.0_f16; + + /// Negative infinity (−∞). + #[cfg(not(bootstrap))] + #[unstable(feature = "f16", issue = "116909")] + pub const NEG_INFINITY: f16 = -1.0_f16 / 0.0_f16; + + /// Sign bit + #[cfg(not(bootstrap))] + const SIGN_MASK: u16 = 0x8000; + + /// Minimum representable positive value (min subnormal) + #[cfg(not(bootstrap))] + const TINY_BITS: u16 = 0x1; + + /// Minimum representable negative value (min negative subnormal) + #[cfg(not(bootstrap))] + const NEG_TINY_BITS: u16 = Self::TINY_BITS | Self::SIGN_MASK; + /// Returns `true` if this value is NaN. /// /// ``` /// #![feature(f16)] - /// # #[cfg(target_arch = "x86_64")] { // FIXME(f16_f128): remove when ABI bugs are fixed + /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885 /// /// let nan = f16::NAN; /// let f = 7.0_f16; @@ -237,6 +276,74 @@ impl f16 { self != self } + // FIXMxE(#50145): `abs` is publicly unavailable in core due to + // concerns about portability, so this implementation is for + // private use internally. + #[inline] + #[cfg(not(bootstrap))] + #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")] + pub(crate) const fn abs_private(self) -> f16 { + // SAFETY: This transmutation is fine. Probably. For the reasons std is using it. + unsafe { mem::transmute::(mem::transmute::(self) & !Self::SIGN_MASK) } + } + + /// Returns `true` if this value is positive infinity or negative infinity, and + /// `false` otherwise. + /// + /// ``` + /// #![feature(f16)] + /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885 + /// + /// let f = 7.0f16; + /// let inf = f16::INFINITY; + /// let neg_inf = f16::NEG_INFINITY; + /// let nan = f16::NAN; + /// + /// assert!(!f.is_infinite()); + /// assert!(!nan.is_infinite()); + /// + /// assert!(inf.is_infinite()); + /// assert!(neg_inf.is_infinite()); + /// # } + /// ``` + #[inline] + #[must_use] + #[cfg(not(bootstrap))] + #[unstable(feature = "f16", issue = "116909")] + #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")] + pub const fn is_infinite(self) -> bool { + (self == f16::INFINITY) | (self == f16::NEG_INFINITY) + } + + /// Returns `true` if this number is neither infinite nor NaN. + /// + /// ``` + /// #![feature(f16)] + /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885 + /// + /// let f = 7.0f16; + /// let inf: f16 = f16::INFINITY; + /// let neg_inf: f16 = f16::NEG_INFINITY; + /// let nan: f16 = f16::NAN; + /// + /// assert!(f.is_finite()); + /// + /// assert!(!nan.is_finite()); + /// assert!(!inf.is_finite()); + /// assert!(!neg_inf.is_finite()); + /// # } + /// ``` + #[inline] + #[must_use] + #[cfg(not(bootstrap))] + #[unstable(feature = "f16", issue = "116909")] + #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")] + pub const fn is_finite(self) -> bool { + // There's no need to handle NaN separately: if self is NaN, + // the comparison is not true, exactly as desired. + self.abs_private() < Self::INFINITY + } + /// Returns `true` if `self` has a positive sign, including `+0.0`, NaNs with /// positive sign bit and positive infinity. Note that IEEE 754 doesn't assign any /// meaning to the sign bit in case of a NaN, and as Rust doesn't guarantee that @@ -286,6 +393,220 @@ impl f16 { (self.to_bits() & (1 << 15)) != 0 } + /// Returns the least number greater than `self`. + /// + /// Let `TINY` be the smallest representable positive `f16`. Then, + /// - if `self.is_nan()`, this returns `self`; + /// - if `self` is [`NEG_INFINITY`], this returns [`MIN`]; + /// - if `self` is `-TINY`, this returns -0.0; + /// - if `self` is -0.0 or +0.0, this returns `TINY`; + /// - if `self` is [`MAX`] or [`INFINITY`], this returns [`INFINITY`]; + /// - otherwise the unique least value greater than `self` is returned. + /// + /// The identity `x.next_up() == -(-x).next_down()` holds for all non-NaN `x`. When `x` + /// is finite `x == x.next_up().next_down()` also holds. + /// + /// ```rust + /// #![feature(f16)] + /// #![feature(float_next_up_down)] + /// # // FIXME(f16_f128): ABI issues on MSVC + /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] { + /// + /// // f16::EPSILON is the difference between 1.0 and the next number up. + /// assert_eq!(1.0f16.next_up(), 1.0 + f16::EPSILON); + /// // But not for most numbers. + /// assert!(0.1f16.next_up() < 0.1 + f16::EPSILON); + /// assert_eq!(4356f16.next_up(), 4360.0); + /// # } + /// ``` + /// + /// [`NEG_INFINITY`]: Self::NEG_INFINITY + /// [`INFINITY`]: Self::INFINITY + /// [`MIN`]: Self::MIN + /// [`MAX`]: Self::MAX + #[inline] + #[cfg(not(bootstrap))] + #[unstable(feature = "f16", issue = "116909")] + // #[unstable(feature = "float_next_up_down", issue = "91399")] + pub fn next_up(self) -> Self { + // Some targets violate Rust's assumption of IEEE semantics, e.g. by flushing + // denormals to zero. This is in general unsound and unsupported, but here + // we do our best to still produce the correct result on such targets. + let bits = self.to_bits(); + if self.is_nan() || bits == Self::INFINITY.to_bits() { + return self; + } + + let abs = bits & !Self::SIGN_MASK; + let next_bits = if abs == 0 { + Self::TINY_BITS + } else if bits == abs { + bits + 1 + } else { + bits - 1 + }; + Self::from_bits(next_bits) + } + + /// Returns the greatest number less than `self`. + /// + /// Let `TINY` be the smallest representable positive `f16`. Then, + /// - if `self.is_nan()`, this returns `self`; + /// - if `self` is [`INFINITY`], this returns [`MAX`]; + /// - if `self` is `TINY`, this returns 0.0; + /// - if `self` is -0.0 or +0.0, this returns `-TINY`; + /// - if `self` is [`MIN`] or [`NEG_INFINITY`], this returns [`NEG_INFINITY`]; + /// - otherwise the unique greatest value less than `self` is returned. + /// + /// The identity `x.next_down() == -(-x).next_up()` holds for all non-NaN `x`. When `x` + /// is finite `x == x.next_down().next_up()` also holds. + /// + /// ```rust + /// #![feature(f16)] + /// #![feature(float_next_up_down)] + /// # // FIXME(f16_f128): ABI issues on MSVC + /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] { + /// + /// let x = 1.0f16; + /// // Clamp value into range [0, 1). + /// let clamped = x.clamp(0.0, 1.0f16.next_down()); + /// assert!(clamped < 1.0); + /// assert_eq!(clamped.next_up(), 1.0); + /// # } + /// ``` + /// + /// [`NEG_INFINITY`]: Self::NEG_INFINITY + /// [`INFINITY`]: Self::INFINITY + /// [`MIN`]: Self::MIN + /// [`MAX`]: Self::MAX + #[inline] + #[cfg(not(bootstrap))] + #[unstable(feature = "f16", issue = "116909")] + // #[unstable(feature = "float_next_up_down", issue = "91399")] + pub fn next_down(self) -> Self { + // Some targets violate Rust's assumption of IEEE semantics, e.g. by flushing + // denormals to zero. This is in general unsound and unsupported, but here + // we do our best to still produce the correct result on such targets. + let bits = self.to_bits(); + if self.is_nan() || bits == Self::NEG_INFINITY.to_bits() { + return self; + } + + let abs = bits & !Self::SIGN_MASK; + let next_bits = if abs == 0 { + Self::NEG_TINY_BITS + } else if bits == abs { + bits - 1 + } else { + bits + 1 + }; + Self::from_bits(next_bits) + } + + /// Takes the reciprocal (inverse) of a number, `1/x`. + /// + /// ``` + /// #![feature(f16)] + /// # // FIXME(f16_f128): remove when `extendhfsf2` and `truncsfhf2` are available + /// # #[cfg(target_os = "linux")] { + /// + /// let x = 2.0_f16; + /// let abs_difference = (x.recip() - (1.0 / x)).abs(); + /// + /// assert!(abs_difference <= f16::EPSILON); + /// # } + /// ``` + #[inline] + #[cfg(not(bootstrap))] + #[unstable(feature = "f16", issue = "116909")] + #[must_use = "this returns the result of the operation, without modifying the original"] + pub fn recip(self) -> Self { + 1.0 / self + } + + /// Converts radians to degrees. + /// + /// ``` + /// #![feature(f16)] + /// # // FIXME(f16_f128): remove when `extendhfsf2` and `truncsfhf2` are available + /// # #[cfg(target_os = "linux")] { + /// + /// let angle = std::f16::consts::PI; + /// + /// let abs_difference = (angle.to_degrees() - 180.0).abs(); + /// assert!(abs_difference <= 0.5); + /// # } + /// ``` + #[inline] + #[cfg(not(bootstrap))] + #[unstable(feature = "f16", issue = "116909")] + #[must_use = "this returns the result of the operation, without modifying the original"] + pub fn to_degrees(self) -> Self { + // Use a literal for better precision. + const PIS_IN_180: f16 = 57.2957795130823208767981548141051703_f16; + self * PIS_IN_180 + } + + /// Converts degrees to radians. + /// + /// ``` + /// #![feature(f16)] + /// # // FIXME(f16_f128): remove when `extendhfsf2` and `truncsfhf2` are available + /// # #[cfg(target_os = "linux")] { + /// + /// let angle = 180.0f16; + /// + /// let abs_difference = (angle.to_radians() - std::f16::consts::PI).abs(); + /// + /// assert!(abs_difference <= 0.01); + /// # } + /// ``` + #[inline] + #[cfg(not(bootstrap))] + #[unstable(feature = "f16", issue = "116909")] + #[must_use = "this returns the result of the operation, without modifying the original"] + pub fn to_radians(self) -> f16 { + // Use a literal for better precision. + const RADS_PER_DEG: f16 = 0.017453292519943295769236907684886_f16; + self * RADS_PER_DEG + } + + /// Rounds toward zero and converts to any primitive integer type, + /// assuming that the value is finite and fits in that type. + /// + /// ``` + /// #![feature(f16)] + /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885 + /// + /// let value = 4.6_f16; + /// let rounded = unsafe { value.to_int_unchecked::() }; + /// assert_eq!(rounded, 4); + /// + /// let value = -128.9_f16; + /// let rounded = unsafe { value.to_int_unchecked::() }; + /// assert_eq!(rounded, i8::MIN); + /// # } + /// ``` + /// + /// # Safety + /// + /// The value must: + /// + /// * Not be `NaN` + /// * Not be infinite + /// * Be representable in the return type `Int`, after truncating off its fractional part + #[inline] + #[unstable(feature = "f16", issue = "116909")] + #[must_use = "this returns the result of the operation, without modifying the original"] + pub unsafe fn to_int_unchecked(self) -> Int + where + Self: FloatToInt, + { + // SAFETY: the caller must uphold the safety contract for + // `FloatToInt::to_int_unchecked`. + unsafe { FloatToInt::::to_int_unchecked(self) } + } + /// Raw transmutation to `u16`. /// /// This is currently identical to `transmute::(self)` on all platforms. @@ -362,4 +683,293 @@ impl f16 { // Stability concerns. unsafe { mem::transmute(v) } } + + /// Return the memory representation of this floating point number as a byte array in + /// big-endian (network) byte order. + /// + /// See [`from_bits`](Self::from_bits) for some discussion of the + /// portability of this operation (there are almost no issues). + /// + /// # Examples + /// + /// ``` + /// #![feature(f16)] + /// + /// let bytes = 12.5f16.to_be_bytes(); + /// assert_eq!(bytes, [0x4a, 0x40]); + /// ``` + #[inline] + #[unstable(feature = "f16", issue = "116909")] + #[must_use = "this returns the result of the operation, without modifying the original"] + pub fn to_be_bytes(self) -> [u8; 2] { + self.to_bits().to_be_bytes() + } + + /// Return the memory representation of this floating point number as a byte array in + /// little-endian byte order. + /// + /// See [`from_bits`](Self::from_bits) for some discussion of the + /// portability of this operation (there are almost no issues). + /// + /// # Examples + /// + /// ``` + /// #![feature(f16)] + /// + /// let bytes = 12.5f16.to_le_bytes(); + /// assert_eq!(bytes, [0x40, 0x4a]); + /// ``` + #[inline] + #[unstable(feature = "f16", issue = "116909")] + #[must_use = "this returns the result of the operation, without modifying the original"] + pub fn to_le_bytes(self) -> [u8; 2] { + self.to_bits().to_le_bytes() + } + + /// Return the memory representation of this floating point number as a byte array in + /// native byte order. + /// + /// As the target platform's native endianness is used, portable code + /// should use [`to_be_bytes`] or [`to_le_bytes`], as appropriate, instead. + /// + /// [`to_be_bytes`]: f16::to_be_bytes + /// [`to_le_bytes`]: f16::to_le_bytes + /// + /// See [`from_bits`](Self::from_bits) for some discussion of the + /// portability of this operation (there are almost no issues). + /// + /// # Examples + /// + /// ``` + /// #![feature(f16)] + /// + /// let bytes = 12.5f16.to_ne_bytes(); + /// assert_eq!( + /// bytes, + /// if cfg!(target_endian = "big") { + /// [0x4a, 0x40] + /// } else { + /// [0x40, 0x4a] + /// } + /// ); + /// ``` + #[inline] + #[unstable(feature = "f16", issue = "116909")] + #[must_use = "this returns the result of the operation, without modifying the original"] + pub fn to_ne_bytes(self) -> [u8; 2] { + self.to_bits().to_ne_bytes() + } + + /// Create a floating point value from its representation as a byte array in big endian. + /// + /// See [`from_bits`](Self::from_bits) for some discussion of the + /// portability of this operation (there are almost no issues). + /// + /// # Examples + /// + /// ``` + /// #![feature(f16)] + /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885 + /// + /// let value = f16::from_be_bytes([0x4a, 0x40]); + /// assert_eq!(value, 12.5); + /// # } + /// ``` + #[inline] + #[must_use] + #[unstable(feature = "f16", issue = "116909")] + pub fn from_be_bytes(bytes: [u8; 2]) -> Self { + Self::from_bits(u16::from_be_bytes(bytes)) + } + + /// Create a floating point value from its representation as a byte array in little endian. + /// + /// See [`from_bits`](Self::from_bits) for some discussion of the + /// portability of this operation (there are almost no issues). + /// + /// # Examples + /// + /// ``` + /// #![feature(f16)] + /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885 + /// + /// let value = f16::from_le_bytes([0x40, 0x4a]); + /// assert_eq!(value, 12.5); + /// # } + /// ``` + #[inline] + #[must_use] + #[unstable(feature = "f16", issue = "116909")] + pub fn from_le_bytes(bytes: [u8; 2]) -> Self { + Self::from_bits(u16::from_le_bytes(bytes)) + } + + /// Create a floating point value from its representation as a byte array in native endian. + /// + /// As the target platform's native endianness is used, portable code + /// likely wants to use [`from_be_bytes`] or [`from_le_bytes`], as + /// appropriate instead. + /// + /// [`from_be_bytes`]: f16::from_be_bytes + /// [`from_le_bytes`]: f16::from_le_bytes + /// + /// See [`from_bits`](Self::from_bits) for some discussion of the + /// portability of this operation (there are almost no issues). + /// + /// # Examples + /// + /// ``` + /// #![feature(f16)] + /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885 + /// + /// let value = f16::from_ne_bytes(if cfg!(target_endian = "big") { + /// [0x4a, 0x40] + /// } else { + /// [0x40, 0x4a] + /// }); + /// assert_eq!(value, 12.5); + /// # } + /// ``` + #[inline] + #[must_use] + #[unstable(feature = "f16", issue = "116909")] + pub fn from_ne_bytes(bytes: [u8; 2]) -> Self { + Self::from_bits(u16::from_ne_bytes(bytes)) + } + + /// Return the ordering between `self` and `other`. + /// + /// Unlike the standard partial comparison between floating point numbers, + /// this comparison always produces an ordering in accordance to + /// the `totalOrder` predicate as defined in the IEEE 754 (2008 revision) + /// floating point standard. The values are ordered in the following sequence: + /// + /// - negative quiet NaN + /// - negative signaling NaN + /// - negative infinity + /// - negative numbers + /// - negative subnormal numbers + /// - negative zero + /// - positive zero + /// - positive subnormal numbers + /// - positive numbers + /// - positive infinity + /// - positive signaling NaN + /// - positive quiet NaN. + /// + /// The ordering established by this function does not always agree with the + /// [`PartialOrd`] and [`PartialEq`] implementations of `f16`. For example, + /// they consider negative and positive zero equal, while `total_cmp` + /// doesn't. + /// + /// The interpretation of the signaling NaN bit follows the definition in + /// the IEEE 754 standard, which may not match the interpretation by some of + /// the older, non-conformant (e.g. MIPS) hardware implementations. + /// + /// # Example + /// + /// ``` + /// #![feature(f16)] + /// + /// struct GoodBoy { + /// name: &'static str, + /// weight: f16, + /// } + /// + /// let mut bois = vec![ + /// GoodBoy { name: "Pucci", weight: 0.1 }, + /// GoodBoy { name: "Woofer", weight: 99.0 }, + /// GoodBoy { name: "Yapper", weight: 10.0 }, + /// GoodBoy { name: "Chonk", weight: f16::INFINITY }, + /// GoodBoy { name: "Abs. Unit", weight: f16::NAN }, + /// GoodBoy { name: "Floaty", weight: -5.0 }, + /// ]; + /// + /// bois.sort_by(|a, b| a.weight.total_cmp(&b.weight)); + /// + /// // `f16::NAN` could be positive or negative, which will affect the sort order. + /// if f16::NAN.is_sign_negative() { + /// bois.into_iter().map(|b| b.weight) + /// .zip([f16::NAN, -5.0, 0.1, 10.0, 99.0, f16::INFINITY].iter()) + /// .for_each(|(a, b)| assert_eq!(a.to_bits(), b.to_bits())) + /// } else { + /// bois.into_iter().map(|b| b.weight) + /// .zip([-5.0, 0.1, 10.0, 99.0, f16::INFINITY, f16::NAN].iter()) + /// .for_each(|(a, b)| assert_eq!(a.to_bits(), b.to_bits())) + /// } + /// ``` + #[inline] + #[must_use] + #[cfg(not(bootstrap))] + #[unstable(feature = "f16", issue = "116909")] + pub fn total_cmp(&self, other: &Self) -> crate::cmp::Ordering { + let mut left = self.to_bits() as i16; + let mut right = other.to_bits() as i16; + + // In case of negatives, flip all the bits except the sign + // to achieve a similar layout as two's complement integers + // + // Why does this work? IEEE 754 floats consist of three fields: + // Sign bit, exponent and mantissa. The set of exponent and mantissa + // fields as a whole have the property that their bitwise order is + // equal to the numeric magnitude where the magnitude is defined. + // The magnitude is not normally defined on NaN values, but + // IEEE 754 totalOrder defines the NaN values also to follow the + // bitwise order. This leads to order explained in the doc comment. + // However, the representation of magnitude is the same for negative + // and positive numbers – only the sign bit is different. + // To easily compare the floats as signed integers, we need to + // flip the exponent and mantissa bits in case of negative numbers. + // We effectively convert the numbers to "two's complement" form. + // + // To do the flipping, we construct a mask and XOR against it. + // We branchlessly calculate an "all-ones except for the sign bit" + // mask from negative-signed values: right shifting sign-extends + // the integer, so we "fill" the mask with sign bits, and then + // convert to unsigned to push one more zero bit. + // On positive values, the mask is all zeros, so it's a no-op. + left ^= (((left >> 15) as u16) >> 1) as i16; + right ^= (((right >> 15) as u16) >> 1) as i16; + + left.cmp(&right) + } + + /// Restrict a value to a certain interval unless it is NaN. + /// + /// Returns `max` if `self` is greater than `max`, and `min` if `self` is + /// less than `min`. Otherwise this returns `self`. + /// + /// Note that this function returns NaN if the initial value was NaN as + /// well. + /// + /// # Panics + /// + /// Panics if `min > max`, `min` is NaN, or `max` is NaN. + /// + /// # Examples + /// + /// ``` + /// #![feature(f16)] + /// # #[cfg(target_arch = "aarch64")] { // FIXME(f16_F128): rust-lang/rust#123885 + /// + /// assert!((-3.0f16).clamp(-2.0, 1.0) == -2.0); + /// assert!((0.0f16).clamp(-2.0, 1.0) == 0.0); + /// assert!((2.0f16).clamp(-2.0, 1.0) == 1.0); + /// assert!((f16::NAN).clamp(-2.0, 1.0).is_nan()); + /// # } + /// ``` + #[inline] + #[cfg(not(bootstrap))] + #[unstable(feature = "f16", issue = "116909")] + #[must_use = "method returns a new number and does not mutate the original value"] + pub fn clamp(mut self, min: f16, max: f16) -> f16 { + assert!(min <= max, "min > max, or either was NaN. min = {min:?}, max = {max:?}"); + if self < min { + self = min; + } + if self > max { + self = max; + } + self + } } diff --git a/std/src/f128.rs b/std/src/f128.rs index 491235a872eaf..0591c6f517b44 100644 --- a/std/src/f128.rs +++ b/std/src/f128.rs @@ -32,4 +32,34 @@ impl f128 { pub fn powi(self, n: i32) -> f128 { unsafe { intrinsics::powif128(self, n) } } + + /// Computes the absolute value of `self`. + /// + /// This function always returns the precise result. + /// + /// # Examples + /// + /// ``` + /// #![feature(f128)] + /// # #[cfg(reliable_f128)] { // FIXME(f16_f128): reliable_f128 + /// + /// let x = 3.5_f128; + /// let y = -3.5_f128; + /// + /// assert_eq!(x.abs(), x); + /// assert_eq!(y.abs(), -y); + /// + /// assert!(f128::NAN.abs().is_nan()); + /// # } + /// ``` + #[inline] + #[cfg(not(bootstrap))] + #[rustc_allow_incoherent_impl] + #[unstable(feature = "f128", issue = "116909")] + #[must_use = "method returns a new number and does not mutate the original value"] + pub fn abs(self) -> Self { + // FIXME(f16_f128): replace with `intrinsics::fabsf128` when available + // We don't do this now because LLVM has lowering bugs for f128 math. + Self::from_bits(self.to_bits() & !(1 << 127)) + } } diff --git a/std/src/f16.rs b/std/src/f16.rs index 1cb655ffabd84..d48518622999a 100644 --- a/std/src/f16.rs +++ b/std/src/f16.rs @@ -32,4 +32,33 @@ impl f16 { pub fn powi(self, n: i32) -> f16 { unsafe { intrinsics::powif16(self, n) } } + + /// Computes the absolute value of `self`. + /// + /// This function always returns the precise result. + /// + /// # Examples + /// + /// ``` + /// #![feature(f16)] + /// # #[cfg(reliable_f16)] { + /// + /// let x = 3.5_f16; + /// let y = -3.5_f16; + /// + /// assert_eq!(x.abs(), x); + /// assert_eq!(y.abs(), -y); + /// + /// assert!(f16::NAN.abs().is_nan()); + /// # } + /// ``` + #[inline] + #[cfg(not(bootstrap))] + #[rustc_allow_incoherent_impl] + #[unstable(feature = "f16", issue = "116909")] + #[must_use = "method returns a new number and does not mutate the original value"] + pub fn abs(self) -> Self { + // FIXME(f16_f128): replace with `intrinsics::fabsf16` when available + Self::from_bits(self.to_bits() & !(1 << 15)) + } } From 19cfdb2c317c317d9445402803f9d4c5136b42cb Mon Sep 17 00:00:00 2001 From: Trevor Gross Date: Tue, 18 Jun 2024 18:27:28 -0500 Subject: [PATCH 07/16] Add tests for `f16` and `f128` This suite tests all library functions that are now available for the types. Tests are only run on certain platforms where `f16` and `f128` are known to work (have symbols available and don't crash LLVM). --- std/src/f128/tests.rs | 527 ++++++++++++++++++++++++++++++++++++++++-- std/src/f16/tests.rs | 526 +++++++++++++++++++++++++++++++++++++++-- std/src/macros.rs | 11 +- 3 files changed, 1029 insertions(+), 35 deletions(-) diff --git a/std/src/f128/tests.rs b/std/src/f128/tests.rs index b64c7f856a15f..bd7a921c502a7 100644 --- a/std/src/f128/tests.rs +++ b/std/src/f128/tests.rs @@ -1,29 +1,31 @@ -#![allow(dead_code)] // FIXME(f16_f128): remove once constants are used +#![cfg(not(bootstrap))] +// FIXME(f16_f128): only tested on platforms that have symbols and aren't buggy +#![cfg(reliable_f128)] + +use crate::f128::consts; +use crate::num::*; /// Smallest number const TINY_BITS: u128 = 0x1; + /// Next smallest number const TINY_UP_BITS: u128 = 0x2; + /// Exponent = 0b11...10, Sifnificand 0b1111..10. Min val > 0 -const MAX_DOWN_BITS: u128 = 0x7ffeffffffffffffffffffffffffffff; +const MAX_DOWN_BITS: u128 = 0x7ffefffffffffffffffffffffffffffe; + /// Zeroed exponent, full significant const LARGEST_SUBNORMAL_BITS: u128 = 0x0000ffffffffffffffffffffffffffff; + /// Exponent = 0b1, zeroed significand const SMALLEST_NORMAL_BITS: u128 = 0x00010000000000000000000000000000; + /// First pattern over the mantissa const NAN_MASK1: u128 = 0x0000aaaaaaaaaaaaaaaaaaaaaaaaaaaa; + /// Second pattern over the mantissa const NAN_MASK2: u128 = 0x00005555555555555555555555555555; -/// Compare by value -#[allow(unused_macros)] -macro_rules! assert_f128_eq { - ($a:expr, $b:expr) => { - let (l, r): (&f128, &f128) = (&$a, &$b); - assert_eq!(*l, *r, "\na: {:#0130x}\nb: {:#0130x}", l.to_bits(), r.to_bits()) - }; -} - /// Compare by representation #[allow(unused_macros)] macro_rules! assert_f128_biteq { @@ -31,10 +33,503 @@ macro_rules! assert_f128_biteq { let (l, r): (&f128, &f128) = (&$a, &$b); let lb = l.to_bits(); let rb = r.to_bits(); - assert_eq!( - lb, rb, - "float {:?} is not bitequal to {:?}.\na: {:#0130x}\nb: {:#0130x}", - *l, *r, lb, rb - ); + assert_eq!(lb, rb, "float {l:?} is not bitequal to {r:?}.\na: {lb:#034x}\nb: {rb:#034x}"); }; } + +#[test] +fn test_num_f128() { + test_num(10f128, 2f128); +} + +// FIXME(f16_f128): add min and max tests when available + +#[test] +fn test_nan() { + let nan: f128 = f128::NAN; + assert!(nan.is_nan()); + assert!(!nan.is_infinite()); + assert!(!nan.is_finite()); + assert!(nan.is_sign_positive()); + assert!(!nan.is_sign_negative()); + // FIXME(f16_f128): classify + // assert!(!nan.is_normal()); + // assert_eq!(Fp::Nan, nan.classify()); +} + +#[test] +fn test_infinity() { + let inf: f128 = f128::INFINITY; + assert!(inf.is_infinite()); + assert!(!inf.is_finite()); + assert!(inf.is_sign_positive()); + assert!(!inf.is_sign_negative()); + assert!(!inf.is_nan()); + // FIXME(f16_f128): classify + // assert!(!inf.is_normal()); + // assert_eq!(Fp::Infinite, inf.classify()); +} + +#[test] +fn test_neg_infinity() { + let neg_inf: f128 = f128::NEG_INFINITY; + assert!(neg_inf.is_infinite()); + assert!(!neg_inf.is_finite()); + assert!(!neg_inf.is_sign_positive()); + assert!(neg_inf.is_sign_negative()); + assert!(!neg_inf.is_nan()); + // FIXME(f16_f128): classify + // assert!(!neg_inf.is_normal()); + // assert_eq!(Fp::Infinite, neg_inf.classify()); +} + +#[test] +fn test_zero() { + let zero: f128 = 0.0f128; + assert_eq!(0.0, zero); + assert!(!zero.is_infinite()); + assert!(zero.is_finite()); + assert!(zero.is_sign_positive()); + assert!(!zero.is_sign_negative()); + assert!(!zero.is_nan()); + // FIXME(f16_f128): classify + // assert!(!zero.is_normal()); + // assert_eq!(Fp::Zero, zero.classify()); +} + +#[test] +fn test_neg_zero() { + let neg_zero: f128 = -0.0; + assert_eq!(0.0, neg_zero); + assert!(!neg_zero.is_infinite()); + assert!(neg_zero.is_finite()); + assert!(!neg_zero.is_sign_positive()); + assert!(neg_zero.is_sign_negative()); + assert!(!neg_zero.is_nan()); + // FIXME(f16_f128): classify + // assert!(!neg_zero.is_normal()); + // assert_eq!(Fp::Zero, neg_zero.classify()); +} + +#[test] +fn test_one() { + let one: f128 = 1.0f128; + assert_eq!(1.0, one); + assert!(!one.is_infinite()); + assert!(one.is_finite()); + assert!(one.is_sign_positive()); + assert!(!one.is_sign_negative()); + assert!(!one.is_nan()); + // FIXME(f16_f128): classify + // assert!(one.is_normal()); + // assert_eq!(Fp::Normal, one.classify()); +} + +#[test] +fn test_is_nan() { + let nan: f128 = f128::NAN; + let inf: f128 = f128::INFINITY; + let neg_inf: f128 = f128::NEG_INFINITY; + assert!(nan.is_nan()); + assert!(!0.0f128.is_nan()); + assert!(!5.3f128.is_nan()); + assert!(!(-10.732f128).is_nan()); + assert!(!inf.is_nan()); + assert!(!neg_inf.is_nan()); +} + +#[test] +fn test_is_infinite() { + let nan: f128 = f128::NAN; + let inf: f128 = f128::INFINITY; + let neg_inf: f128 = f128::NEG_INFINITY; + assert!(!nan.is_infinite()); + assert!(inf.is_infinite()); + assert!(neg_inf.is_infinite()); + assert!(!0.0f128.is_infinite()); + assert!(!42.8f128.is_infinite()); + assert!(!(-109.2f128).is_infinite()); +} + +#[test] +fn test_is_finite() { + let nan: f128 = f128::NAN; + let inf: f128 = f128::INFINITY; + let neg_inf: f128 = f128::NEG_INFINITY; + assert!(!nan.is_finite()); + assert!(!inf.is_finite()); + assert!(!neg_inf.is_finite()); + assert!(0.0f128.is_finite()); + assert!(42.8f128.is_finite()); + assert!((-109.2f128).is_finite()); +} + +// FIXME(f16_f128): add `test_is_normal` and `test_classify` when classify is working +// FIXME(f16_f128): add missing math functions when available + +#[test] +fn test_abs() { + assert_eq!(f128::INFINITY.abs(), f128::INFINITY); + assert_eq!(1f128.abs(), 1f128); + assert_eq!(0f128.abs(), 0f128); + assert_eq!((-0f128).abs(), 0f128); + assert_eq!((-1f128).abs(), 1f128); + assert_eq!(f128::NEG_INFINITY.abs(), f128::INFINITY); + assert_eq!((1f128 / f128::NEG_INFINITY).abs(), 0f128); + assert!(f128::NAN.abs().is_nan()); +} + +#[test] +fn test_is_sign_positive() { + assert!(f128::INFINITY.is_sign_positive()); + assert!(1f128.is_sign_positive()); + assert!(0f128.is_sign_positive()); + assert!(!(-0f128).is_sign_positive()); + assert!(!(-1f128).is_sign_positive()); + assert!(!f128::NEG_INFINITY.is_sign_positive()); + assert!(!(1f128 / f128::NEG_INFINITY).is_sign_positive()); + assert!(f128::NAN.is_sign_positive()); + assert!(!(-f128::NAN).is_sign_positive()); +} + +#[test] +fn test_is_sign_negative() { + assert!(!f128::INFINITY.is_sign_negative()); + assert!(!1f128.is_sign_negative()); + assert!(!0f128.is_sign_negative()); + assert!((-0f128).is_sign_negative()); + assert!((-1f128).is_sign_negative()); + assert!(f128::NEG_INFINITY.is_sign_negative()); + assert!((1f128 / f128::NEG_INFINITY).is_sign_negative()); + assert!(!f128::NAN.is_sign_negative()); + assert!((-f128::NAN).is_sign_negative()); +} + +#[test] +fn test_next_up() { + let tiny = f128::from_bits(TINY_BITS); + let tiny_up = f128::from_bits(TINY_UP_BITS); + let max_down = f128::from_bits(MAX_DOWN_BITS); + let largest_subnormal = f128::from_bits(LARGEST_SUBNORMAL_BITS); + let smallest_normal = f128::from_bits(SMALLEST_NORMAL_BITS); + assert_f128_biteq!(f128::NEG_INFINITY.next_up(), f128::MIN); + assert_f128_biteq!(f128::MIN.next_up(), -max_down); + assert_f128_biteq!((-1.0 - f128::EPSILON).next_up(), -1.0); + assert_f128_biteq!((-smallest_normal).next_up(), -largest_subnormal); + assert_f128_biteq!((-tiny_up).next_up(), -tiny); + assert_f128_biteq!((-tiny).next_up(), -0.0f128); + assert_f128_biteq!((-0.0f128).next_up(), tiny); + assert_f128_biteq!(0.0f128.next_up(), tiny); + assert_f128_biteq!(tiny.next_up(), tiny_up); + assert_f128_biteq!(largest_subnormal.next_up(), smallest_normal); + assert_f128_biteq!(1.0f128.next_up(), 1.0 + f128::EPSILON); + assert_f128_biteq!(f128::MAX.next_up(), f128::INFINITY); + assert_f128_biteq!(f128::INFINITY.next_up(), f128::INFINITY); + + // Check that NaNs roundtrip. + let nan0 = f128::NAN; + let nan1 = f128::from_bits(f128::NAN.to_bits() ^ 0x002a_aaaa); + let nan2 = f128::from_bits(f128::NAN.to_bits() ^ 0x0055_5555); + assert_f128_biteq!(nan0.next_up(), nan0); + assert_f128_biteq!(nan1.next_up(), nan1); + assert_f128_biteq!(nan2.next_up(), nan2); +} + +#[test] +fn test_next_down() { + let tiny = f128::from_bits(TINY_BITS); + let tiny_up = f128::from_bits(TINY_UP_BITS); + let max_down = f128::from_bits(MAX_DOWN_BITS); + let largest_subnormal = f128::from_bits(LARGEST_SUBNORMAL_BITS); + let smallest_normal = f128::from_bits(SMALLEST_NORMAL_BITS); + assert_f128_biteq!(f128::NEG_INFINITY.next_down(), f128::NEG_INFINITY); + assert_f128_biteq!(f128::MIN.next_down(), f128::NEG_INFINITY); + assert_f128_biteq!((-max_down).next_down(), f128::MIN); + assert_f128_biteq!((-1.0f128).next_down(), -1.0 - f128::EPSILON); + assert_f128_biteq!((-largest_subnormal).next_down(), -smallest_normal); + assert_f128_biteq!((-tiny).next_down(), -tiny_up); + assert_f128_biteq!((-0.0f128).next_down(), -tiny); + assert_f128_biteq!((0.0f128).next_down(), -tiny); + assert_f128_biteq!(tiny.next_down(), 0.0f128); + assert_f128_biteq!(tiny_up.next_down(), tiny); + assert_f128_biteq!(smallest_normal.next_down(), largest_subnormal); + assert_f128_biteq!((1.0 + f128::EPSILON).next_down(), 1.0f128); + assert_f128_biteq!(f128::MAX.next_down(), max_down); + assert_f128_biteq!(f128::INFINITY.next_down(), f128::MAX); + + // Check that NaNs roundtrip. + let nan0 = f128::NAN; + let nan1 = f128::from_bits(f128::NAN.to_bits() ^ 0x002a_aaaa); + let nan2 = f128::from_bits(f128::NAN.to_bits() ^ 0x0055_5555); + assert_f128_biteq!(nan0.next_down(), nan0); + assert_f128_biteq!(nan1.next_down(), nan1); + assert_f128_biteq!(nan2.next_down(), nan2); +} + +#[test] +fn test_recip() { + let nan: f128 = f128::NAN; + let inf: f128 = f128::INFINITY; + let neg_inf: f128 = f128::NEG_INFINITY; + assert_eq!(1.0f128.recip(), 1.0); + assert_eq!(2.0f128.recip(), 0.5); + assert_eq!((-0.4f128).recip(), -2.5); + assert_eq!(0.0f128.recip(), inf); + assert!(nan.recip().is_nan()); + assert_eq!(inf.recip(), 0.0); + assert_eq!(neg_inf.recip(), 0.0); +} + +#[test] +fn test_to_degrees() { + let pi: f128 = consts::PI; + let nan: f128 = f128::NAN; + let inf: f128 = f128::INFINITY; + let neg_inf: f128 = f128::NEG_INFINITY; + assert_eq!(0.0f128.to_degrees(), 0.0); + assert_approx_eq!((-5.8f128).to_degrees(), -332.315521); + assert_eq!(pi.to_degrees(), 180.0); + assert!(nan.to_degrees().is_nan()); + assert_eq!(inf.to_degrees(), inf); + assert_eq!(neg_inf.to_degrees(), neg_inf); + assert_eq!(1_f128.to_degrees(), 57.2957795130823208767981548141051703); +} + +#[test] +fn test_to_radians() { + let pi: f128 = consts::PI; + let nan: f128 = f128::NAN; + let inf: f128 = f128::INFINITY; + let neg_inf: f128 = f128::NEG_INFINITY; + assert_eq!(0.0f128.to_radians(), 0.0); + assert_approx_eq!(154.6f128.to_radians(), 2.698279); + assert_approx_eq!((-332.31f128).to_radians(), -5.799903); + // check approx rather than exact because round trip for pi doesn't fall on an exactly + // representable value (unlike `f32` and `f64`). + assert_approx_eq!(180.0f128.to_radians(), pi); + assert!(nan.to_radians().is_nan()); + assert_eq!(inf.to_radians(), inf); + assert_eq!(neg_inf.to_radians(), neg_inf); +} + +#[test] +fn test_real_consts() { + // FIXME(f16_f128): add math tests when available + use super::consts; + + let pi: f128 = consts::PI; + let frac_pi_2: f128 = consts::FRAC_PI_2; + let frac_pi_3: f128 = consts::FRAC_PI_3; + let frac_pi_4: f128 = consts::FRAC_PI_4; + let frac_pi_6: f128 = consts::FRAC_PI_6; + let frac_pi_8: f128 = consts::FRAC_PI_8; + let frac_1_pi: f128 = consts::FRAC_1_PI; + let frac_2_pi: f128 = consts::FRAC_2_PI; + // let frac_2_sqrtpi: f128 = consts::FRAC_2_SQRT_PI; + // let sqrt2: f128 = consts::SQRT_2; + // let frac_1_sqrt2: f128 = consts::FRAC_1_SQRT_2; + // let e: f128 = consts::E; + // let log2_e: f128 = consts::LOG2_E; + // let log10_e: f128 = consts::LOG10_E; + // let ln_2: f128 = consts::LN_2; + // let ln_10: f128 = consts::LN_10; + + assert_approx_eq!(frac_pi_2, pi / 2f128); + assert_approx_eq!(frac_pi_3, pi / 3f128); + assert_approx_eq!(frac_pi_4, pi / 4f128); + assert_approx_eq!(frac_pi_6, pi / 6f128); + assert_approx_eq!(frac_pi_8, pi / 8f128); + assert_approx_eq!(frac_1_pi, 1f128 / pi); + assert_approx_eq!(frac_2_pi, 2f128 / pi); + // assert_approx_eq!(frac_2_sqrtpi, 2f128 / pi.sqrt()); + // assert_approx_eq!(sqrt2, 2f128.sqrt()); + // assert_approx_eq!(frac_1_sqrt2, 1f128 / 2f128.sqrt()); + // assert_approx_eq!(log2_e, e.log2()); + // assert_approx_eq!(log10_e, e.log10()); + // assert_approx_eq!(ln_2, 2f128.ln()); + // assert_approx_eq!(ln_10, 10f128.ln()); +} + +#[test] +fn test_float_bits_conv() { + assert_eq!((1f128).to_bits(), 0x3fff0000000000000000000000000000); + assert_eq!((12.5f128).to_bits(), 0x40029000000000000000000000000000); + assert_eq!((1337f128).to_bits(), 0x40094e40000000000000000000000000); + assert_eq!((-14.25f128).to_bits(), 0xc002c800000000000000000000000000); + assert_approx_eq!(f128::from_bits(0x3fff0000000000000000000000000000), 1.0); + assert_approx_eq!(f128::from_bits(0x40029000000000000000000000000000), 12.5); + assert_approx_eq!(f128::from_bits(0x40094e40000000000000000000000000), 1337.0); + assert_approx_eq!(f128::from_bits(0xc002c800000000000000000000000000), -14.25); + + // Check that NaNs roundtrip their bits regardless of signaling-ness + // 0xA is 0b1010; 0x5 is 0b0101 -- so these two together clobbers all the mantissa bits + let masked_nan1 = f128::NAN.to_bits() ^ NAN_MASK1; + let masked_nan2 = f128::NAN.to_bits() ^ NAN_MASK2; + assert!(f128::from_bits(masked_nan1).is_nan()); + assert!(f128::from_bits(masked_nan2).is_nan()); + + assert_eq!(f128::from_bits(masked_nan1).to_bits(), masked_nan1); + assert_eq!(f128::from_bits(masked_nan2).to_bits(), masked_nan2); +} + +#[test] +#[should_panic] +fn test_clamp_min_greater_than_max() { + let _ = 1.0f128.clamp(3.0, 1.0); +} + +#[test] +#[should_panic] +fn test_clamp_min_is_nan() { + let _ = 1.0f128.clamp(f128::NAN, 1.0); +} + +#[test] +#[should_panic] +fn test_clamp_max_is_nan() { + let _ = 1.0f128.clamp(3.0, f128::NAN); +} + +#[test] +fn test_total_cmp() { + use core::cmp::Ordering; + + fn quiet_bit_mask() -> u128 { + 1 << (f128::MANTISSA_DIGITS - 2) + } + + // FIXME(f16_f128): test subnormals when powf is available + // fn min_subnorm() -> f128 { + // f128::MIN_POSITIVE / f128::powf(2.0, f128::MANTISSA_DIGITS as f128 - 1.0) + // } + + // fn max_subnorm() -> f128 { + // f128::MIN_POSITIVE - min_subnorm() + // } + + fn q_nan() -> f128 { + f128::from_bits(f128::NAN.to_bits() | quiet_bit_mask()) + } + + fn s_nan() -> f128 { + f128::from_bits((f128::NAN.to_bits() & !quiet_bit_mask()) + 42) + } + + assert_eq!(Ordering::Equal, (-q_nan()).total_cmp(&-q_nan())); + assert_eq!(Ordering::Equal, (-s_nan()).total_cmp(&-s_nan())); + assert_eq!(Ordering::Equal, (-f128::INFINITY).total_cmp(&-f128::INFINITY)); + assert_eq!(Ordering::Equal, (-f128::MAX).total_cmp(&-f128::MAX)); + assert_eq!(Ordering::Equal, (-2.5_f128).total_cmp(&-2.5)); + assert_eq!(Ordering::Equal, (-1.0_f128).total_cmp(&-1.0)); + assert_eq!(Ordering::Equal, (-1.5_f128).total_cmp(&-1.5)); + assert_eq!(Ordering::Equal, (-0.5_f128).total_cmp(&-0.5)); + assert_eq!(Ordering::Equal, (-f128::MIN_POSITIVE).total_cmp(&-f128::MIN_POSITIVE)); + // assert_eq!(Ordering::Equal, (-max_subnorm()).total_cmp(&-max_subnorm())); + // assert_eq!(Ordering::Equal, (-min_subnorm()).total_cmp(&-min_subnorm())); + assert_eq!(Ordering::Equal, (-0.0_f128).total_cmp(&-0.0)); + assert_eq!(Ordering::Equal, 0.0_f128.total_cmp(&0.0)); + // assert_eq!(Ordering::Equal, min_subnorm().total_cmp(&min_subnorm())); + // assert_eq!(Ordering::Equal, max_subnorm().total_cmp(&max_subnorm())); + assert_eq!(Ordering::Equal, f128::MIN_POSITIVE.total_cmp(&f128::MIN_POSITIVE)); + assert_eq!(Ordering::Equal, 0.5_f128.total_cmp(&0.5)); + assert_eq!(Ordering::Equal, 1.0_f128.total_cmp(&1.0)); + assert_eq!(Ordering::Equal, 1.5_f128.total_cmp(&1.5)); + assert_eq!(Ordering::Equal, 2.5_f128.total_cmp(&2.5)); + assert_eq!(Ordering::Equal, f128::MAX.total_cmp(&f128::MAX)); + assert_eq!(Ordering::Equal, f128::INFINITY.total_cmp(&f128::INFINITY)); + assert_eq!(Ordering::Equal, s_nan().total_cmp(&s_nan())); + assert_eq!(Ordering::Equal, q_nan().total_cmp(&q_nan())); + + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&-s_nan())); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&-f128::INFINITY)); + assert_eq!(Ordering::Less, (-f128::INFINITY).total_cmp(&-f128::MAX)); + assert_eq!(Ordering::Less, (-f128::MAX).total_cmp(&-2.5)); + assert_eq!(Ordering::Less, (-2.5_f128).total_cmp(&-1.5)); + assert_eq!(Ordering::Less, (-1.5_f128).total_cmp(&-1.0)); + assert_eq!(Ordering::Less, (-1.0_f128).total_cmp(&-0.5)); + assert_eq!(Ordering::Less, (-0.5_f128).total_cmp(&-f128::MIN_POSITIVE)); + // assert_eq!(Ordering::Less, (-f128::MIN_POSITIVE).total_cmp(&-max_subnorm())); + // assert_eq!(Ordering::Less, (-max_subnorm()).total_cmp(&-min_subnorm())); + // assert_eq!(Ordering::Less, (-min_subnorm()).total_cmp(&-0.0)); + assert_eq!(Ordering::Less, (-0.0_f128).total_cmp(&0.0)); + // assert_eq!(Ordering::Less, 0.0_f128.total_cmp(&min_subnorm())); + // assert_eq!(Ordering::Less, min_subnorm().total_cmp(&max_subnorm())); + // assert_eq!(Ordering::Less, max_subnorm().total_cmp(&f128::MIN_POSITIVE)); + assert_eq!(Ordering::Less, f128::MIN_POSITIVE.total_cmp(&0.5)); + assert_eq!(Ordering::Less, 0.5_f128.total_cmp(&1.0)); + assert_eq!(Ordering::Less, 1.0_f128.total_cmp(&1.5)); + assert_eq!(Ordering::Less, 1.5_f128.total_cmp(&2.5)); + assert_eq!(Ordering::Less, 2.5_f128.total_cmp(&f128::MAX)); + assert_eq!(Ordering::Less, f128::MAX.total_cmp(&f128::INFINITY)); + assert_eq!(Ordering::Less, f128::INFINITY.total_cmp(&s_nan())); + assert_eq!(Ordering::Less, s_nan().total_cmp(&q_nan())); + + assert_eq!(Ordering::Greater, (-s_nan()).total_cmp(&-q_nan())); + assert_eq!(Ordering::Greater, (-f128::INFINITY).total_cmp(&-s_nan())); + assert_eq!(Ordering::Greater, (-f128::MAX).total_cmp(&-f128::INFINITY)); + assert_eq!(Ordering::Greater, (-2.5_f128).total_cmp(&-f128::MAX)); + assert_eq!(Ordering::Greater, (-1.5_f128).total_cmp(&-2.5)); + assert_eq!(Ordering::Greater, (-1.0_f128).total_cmp(&-1.5)); + assert_eq!(Ordering::Greater, (-0.5_f128).total_cmp(&-1.0)); + assert_eq!(Ordering::Greater, (-f128::MIN_POSITIVE).total_cmp(&-0.5)); + // assert_eq!(Ordering::Greater, (-max_subnorm()).total_cmp(&-f128::MIN_POSITIVE)); + // assert_eq!(Ordering::Greater, (-min_subnorm()).total_cmp(&-max_subnorm())); + // assert_eq!(Ordering::Greater, (-0.0_f128).total_cmp(&-min_subnorm())); + assert_eq!(Ordering::Greater, 0.0_f128.total_cmp(&-0.0)); + // assert_eq!(Ordering::Greater, min_subnorm().total_cmp(&0.0)); + // assert_eq!(Ordering::Greater, max_subnorm().total_cmp(&min_subnorm())); + // assert_eq!(Ordering::Greater, f128::MIN_POSITIVE.total_cmp(&max_subnorm())); + assert_eq!(Ordering::Greater, 0.5_f128.total_cmp(&f128::MIN_POSITIVE)); + assert_eq!(Ordering::Greater, 1.0_f128.total_cmp(&0.5)); + assert_eq!(Ordering::Greater, 1.5_f128.total_cmp(&1.0)); + assert_eq!(Ordering::Greater, 2.5_f128.total_cmp(&1.5)); + assert_eq!(Ordering::Greater, f128::MAX.total_cmp(&2.5)); + assert_eq!(Ordering::Greater, f128::INFINITY.total_cmp(&f128::MAX)); + assert_eq!(Ordering::Greater, s_nan().total_cmp(&f128::INFINITY)); + assert_eq!(Ordering::Greater, q_nan().total_cmp(&s_nan())); + + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&-s_nan())); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&-f128::INFINITY)); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&-f128::MAX)); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&-2.5)); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&-1.5)); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&-1.0)); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&-0.5)); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&-f128::MIN_POSITIVE)); + // assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&-max_subnorm())); + // assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&-min_subnorm())); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&-0.0)); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&0.0)); + // assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&min_subnorm())); + // assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&max_subnorm())); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&f128::MIN_POSITIVE)); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&0.5)); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&1.0)); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&1.5)); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&2.5)); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&f128::MAX)); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&f128::INFINITY)); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&s_nan())); + + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&-f128::INFINITY)); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&-f128::MAX)); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&-2.5)); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&-1.5)); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&-1.0)); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&-0.5)); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&-f128::MIN_POSITIVE)); + // assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&-max_subnorm())); + // assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&-min_subnorm())); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&-0.0)); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&0.0)); + // assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&min_subnorm())); + // assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&max_subnorm())); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&f128::MIN_POSITIVE)); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&0.5)); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&1.0)); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&1.5)); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&2.5)); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&f128::MAX)); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&f128::INFINITY)); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&s_nan())); +} diff --git a/std/src/f16/tests.rs b/std/src/f16/tests.rs index d65c43eca4bb8..bb6a811529e17 100644 --- a/std/src/f16/tests.rs +++ b/std/src/f16/tests.rs @@ -1,35 +1,37 @@ -#![allow(dead_code)] // FIXME(f16_f128): remove once constants are used +#![cfg(not(bootstrap))] +// FIXME(f16_f128): only tested on platforms that have symbols and aren't buggy +#![cfg(reliable_f16)] + +use crate::f16::consts; +use crate::num::*; // We run out of precision pretty quickly with f16 -const F16_APPROX_L1: f16 = 0.001; +// const F16_APPROX_L1: f16 = 0.001; const F16_APPROX_L2: f16 = 0.01; -const F16_APPROX_L3: f16 = 0.1; +// const F16_APPROX_L3: f16 = 0.1; const F16_APPROX_L4: f16 = 0.5; /// Smallest number const TINY_BITS: u16 = 0x1; + /// Next smallest number const TINY_UP_BITS: u16 = 0x2; + /// Exponent = 0b11...10, Sifnificand 0b1111..10. Min val > 0 const MAX_DOWN_BITS: u16 = 0x7bfe; + /// Zeroed exponent, full significant const LARGEST_SUBNORMAL_BITS: u16 = 0x03ff; + /// Exponent = 0b1, zeroed significand const SMALLEST_NORMAL_BITS: u16 = 0x0400; + /// First pattern over the mantissa const NAN_MASK1: u16 = 0x02aa; + /// Second pattern over the mantissa const NAN_MASK2: u16 = 0x0155; -/// Compare by value -#[allow(unused_macros)] -macro_rules! assert_f16_eq { - ($a:expr, $b:expr) => { - let (l, r): (&f16, &f16) = (&$a, &$b); - assert_eq!(*l, *r, "\na: {:#018x}\nb: {:#018x}", l.to_bits(), r.to_bits()) - }; -} - /// Compare by representation #[allow(unused_macros)] macro_rules! assert_f16_biteq { @@ -37,10 +39,500 @@ macro_rules! assert_f16_biteq { let (l, r): (&f16, &f16) = (&$a, &$b); let lb = l.to_bits(); let rb = r.to_bits(); - assert_eq!( - lb, rb, - "float {:?} is not bitequal to {:?}.\na: {:#018x}\nb: {:#018x}", - *l, *r, lb, rb - ); + assert_eq!(lb, rb, "float {l:?} ({lb:#04x}) is not bitequal to {r:?} ({rb:#04x})"); }; } + +#[test] +fn test_num_f16() { + test_num(10f16, 2f16); +} + +// FIXME(f16_f128): add min and max tests when available + +#[test] +fn test_nan() { + let nan: f16 = f16::NAN; + assert!(nan.is_nan()); + assert!(!nan.is_infinite()); + assert!(!nan.is_finite()); + assert!(nan.is_sign_positive()); + assert!(!nan.is_sign_negative()); + // FIXME(f16_f128): classify + // assert!(!nan.is_normal()); + // assert_eq!(Fp::Nan, nan.classify()); +} + +#[test] +fn test_infinity() { + let inf: f16 = f16::INFINITY; + assert!(inf.is_infinite()); + assert!(!inf.is_finite()); + assert!(inf.is_sign_positive()); + assert!(!inf.is_sign_negative()); + assert!(!inf.is_nan()); + // FIXME(f16_f128): classify + // assert!(!inf.is_normal()); + // assert_eq!(Fp::Infinite, inf.classify()); +} + +#[test] +fn test_neg_infinity() { + let neg_inf: f16 = f16::NEG_INFINITY; + assert!(neg_inf.is_infinite()); + assert!(!neg_inf.is_finite()); + assert!(!neg_inf.is_sign_positive()); + assert!(neg_inf.is_sign_negative()); + assert!(!neg_inf.is_nan()); + // FIXME(f16_f128): classify + // assert!(!neg_inf.is_normal()); + // assert_eq!(Fp::Infinite, neg_inf.classify()); +} + +#[test] +fn test_zero() { + let zero: f16 = 0.0f16; + assert_eq!(0.0, zero); + assert!(!zero.is_infinite()); + assert!(zero.is_finite()); + assert!(zero.is_sign_positive()); + assert!(!zero.is_sign_negative()); + assert!(!zero.is_nan()); + // FIXME(f16_f128): classify + // assert!(!zero.is_normal()); + // assert_eq!(Fp::Zero, zero.classify()); +} + +#[test] +fn test_neg_zero() { + let neg_zero: f16 = -0.0; + assert_eq!(0.0, neg_zero); + assert!(!neg_zero.is_infinite()); + assert!(neg_zero.is_finite()); + assert!(!neg_zero.is_sign_positive()); + assert!(neg_zero.is_sign_negative()); + assert!(!neg_zero.is_nan()); + // FIXME(f16_f128): classify + // assert!(!neg_zero.is_normal()); + // assert_eq!(Fp::Zero, neg_zero.classify()); +} + +#[test] +fn test_one() { + let one: f16 = 1.0f16; + assert_eq!(1.0, one); + assert!(!one.is_infinite()); + assert!(one.is_finite()); + assert!(one.is_sign_positive()); + assert!(!one.is_sign_negative()); + assert!(!one.is_nan()); + // FIXME(f16_f128): classify + // assert!(one.is_normal()); + // assert_eq!(Fp::Normal, one.classify()); +} + +#[test] +fn test_is_nan() { + let nan: f16 = f16::NAN; + let inf: f16 = f16::INFINITY; + let neg_inf: f16 = f16::NEG_INFINITY; + assert!(nan.is_nan()); + assert!(!0.0f16.is_nan()); + assert!(!5.3f16.is_nan()); + assert!(!(-10.732f16).is_nan()); + assert!(!inf.is_nan()); + assert!(!neg_inf.is_nan()); +} + +#[test] +fn test_is_infinite() { + let nan: f16 = f16::NAN; + let inf: f16 = f16::INFINITY; + let neg_inf: f16 = f16::NEG_INFINITY; + assert!(!nan.is_infinite()); + assert!(inf.is_infinite()); + assert!(neg_inf.is_infinite()); + assert!(!0.0f16.is_infinite()); + assert!(!42.8f16.is_infinite()); + assert!(!(-109.2f16).is_infinite()); +} + +#[test] +fn test_is_finite() { + let nan: f16 = f16::NAN; + let inf: f16 = f16::INFINITY; + let neg_inf: f16 = f16::NEG_INFINITY; + assert!(!nan.is_finite()); + assert!(!inf.is_finite()); + assert!(!neg_inf.is_finite()); + assert!(0.0f16.is_finite()); + assert!(42.8f16.is_finite()); + assert!((-109.2f16).is_finite()); +} + +// FIXME(f16_f128): add `test_is_normal` and `test_classify` when classify is working +// FIXME(f16_f128): add missing math functions when available + +#[test] +fn test_abs() { + assert_eq!(f16::INFINITY.abs(), f16::INFINITY); + assert_eq!(1f16.abs(), 1f16); + assert_eq!(0f16.abs(), 0f16); + assert_eq!((-0f16).abs(), 0f16); + assert_eq!((-1f16).abs(), 1f16); + assert_eq!(f16::NEG_INFINITY.abs(), f16::INFINITY); + assert_eq!((1f16 / f16::NEG_INFINITY).abs(), 0f16); + assert!(f16::NAN.abs().is_nan()); +} + +#[test] +fn test_is_sign_positive() { + assert!(f16::INFINITY.is_sign_positive()); + assert!(1f16.is_sign_positive()); + assert!(0f16.is_sign_positive()); + assert!(!(-0f16).is_sign_positive()); + assert!(!(-1f16).is_sign_positive()); + assert!(!f16::NEG_INFINITY.is_sign_positive()); + assert!(!(1f16 / f16::NEG_INFINITY).is_sign_positive()); + assert!(f16::NAN.is_sign_positive()); + assert!(!(-f16::NAN).is_sign_positive()); +} + +#[test] +fn test_is_sign_negative() { + assert!(!f16::INFINITY.is_sign_negative()); + assert!(!1f16.is_sign_negative()); + assert!(!0f16.is_sign_negative()); + assert!((-0f16).is_sign_negative()); + assert!((-1f16).is_sign_negative()); + assert!(f16::NEG_INFINITY.is_sign_negative()); + assert!((1f16 / f16::NEG_INFINITY).is_sign_negative()); + assert!(!f16::NAN.is_sign_negative()); + assert!((-f16::NAN).is_sign_negative()); +} + +#[test] +fn test_next_up() { + let tiny = f16::from_bits(TINY_BITS); + let tiny_up = f16::from_bits(TINY_UP_BITS); + let max_down = f16::from_bits(MAX_DOWN_BITS); + let largest_subnormal = f16::from_bits(LARGEST_SUBNORMAL_BITS); + let smallest_normal = f16::from_bits(SMALLEST_NORMAL_BITS); + assert_f16_biteq!(f16::NEG_INFINITY.next_up(), f16::MIN); + assert_f16_biteq!(f16::MIN.next_up(), -max_down); + assert_f16_biteq!((-1.0 - f16::EPSILON).next_up(), -1.0); + assert_f16_biteq!((-smallest_normal).next_up(), -largest_subnormal); + assert_f16_biteq!((-tiny_up).next_up(), -tiny); + assert_f16_biteq!((-tiny).next_up(), -0.0f16); + assert_f16_biteq!((-0.0f16).next_up(), tiny); + assert_f16_biteq!(0.0f16.next_up(), tiny); + assert_f16_biteq!(tiny.next_up(), tiny_up); + assert_f16_biteq!(largest_subnormal.next_up(), smallest_normal); + assert_f16_biteq!(1.0f16.next_up(), 1.0 + f16::EPSILON); + assert_f16_biteq!(f16::MAX.next_up(), f16::INFINITY); + assert_f16_biteq!(f16::INFINITY.next_up(), f16::INFINITY); + + // Check that NaNs roundtrip. + let nan0 = f16::NAN; + let nan1 = f16::from_bits(f16::NAN.to_bits() ^ NAN_MASK1); + let nan2 = f16::from_bits(f16::NAN.to_bits() ^ NAN_MASK2); + assert_f16_biteq!(nan0.next_up(), nan0); + assert_f16_biteq!(nan1.next_up(), nan1); + assert_f16_biteq!(nan2.next_up(), nan2); +} + +#[test] +fn test_next_down() { + let tiny = f16::from_bits(TINY_BITS); + let tiny_up = f16::from_bits(TINY_UP_BITS); + let max_down = f16::from_bits(MAX_DOWN_BITS); + let largest_subnormal = f16::from_bits(LARGEST_SUBNORMAL_BITS); + let smallest_normal = f16::from_bits(SMALLEST_NORMAL_BITS); + assert_f16_biteq!(f16::NEG_INFINITY.next_down(), f16::NEG_INFINITY); + assert_f16_biteq!(f16::MIN.next_down(), f16::NEG_INFINITY); + assert_f16_biteq!((-max_down).next_down(), f16::MIN); + assert_f16_biteq!((-1.0f16).next_down(), -1.0 - f16::EPSILON); + assert_f16_biteq!((-largest_subnormal).next_down(), -smallest_normal); + assert_f16_biteq!((-tiny).next_down(), -tiny_up); + assert_f16_biteq!((-0.0f16).next_down(), -tiny); + assert_f16_biteq!((0.0f16).next_down(), -tiny); + assert_f16_biteq!(tiny.next_down(), 0.0f16); + assert_f16_biteq!(tiny_up.next_down(), tiny); + assert_f16_biteq!(smallest_normal.next_down(), largest_subnormal); + assert_f16_biteq!((1.0 + f16::EPSILON).next_down(), 1.0f16); + assert_f16_biteq!(f16::MAX.next_down(), max_down); + assert_f16_biteq!(f16::INFINITY.next_down(), f16::MAX); + + // Check that NaNs roundtrip. + let nan0 = f16::NAN; + let nan1 = f16::from_bits(f16::NAN.to_bits() ^ NAN_MASK1); + let nan2 = f16::from_bits(f16::NAN.to_bits() ^ NAN_MASK2); + assert_f16_biteq!(nan0.next_down(), nan0); + assert_f16_biteq!(nan1.next_down(), nan1); + assert_f16_biteq!(nan2.next_down(), nan2); +} + +#[test] +fn test_recip() { + let nan: f16 = f16::NAN; + let inf: f16 = f16::INFINITY; + let neg_inf: f16 = f16::NEG_INFINITY; + assert_eq!(1.0f16.recip(), 1.0); + assert_eq!(2.0f16.recip(), 0.5); + assert_eq!((-0.4f16).recip(), -2.5); + assert_eq!(0.0f16.recip(), inf); + assert!(nan.recip().is_nan()); + assert_eq!(inf.recip(), 0.0); + assert_eq!(neg_inf.recip(), 0.0); +} + +#[test] +fn test_to_degrees() { + let pi: f16 = consts::PI; + let nan: f16 = f16::NAN; + let inf: f16 = f16::INFINITY; + let neg_inf: f16 = f16::NEG_INFINITY; + assert_eq!(0.0f16.to_degrees(), 0.0); + assert_approx_eq!((-5.8f16).to_degrees(), -332.315521); + assert_approx_eq!(pi.to_degrees(), 180.0, F16_APPROX_L4); + assert!(nan.to_degrees().is_nan()); + assert_eq!(inf.to_degrees(), inf); + assert_eq!(neg_inf.to_degrees(), neg_inf); + assert_eq!(1_f16.to_degrees(), 57.2957795130823208767981548141051703); +} + +#[test] +fn test_to_radians() { + let pi: f16 = consts::PI; + let nan: f16 = f16::NAN; + let inf: f16 = f16::INFINITY; + let neg_inf: f16 = f16::NEG_INFINITY; + assert_eq!(0.0f16.to_radians(), 0.0); + assert_approx_eq!(154.6f16.to_radians(), 2.698279); + assert_approx_eq!((-332.31f16).to_radians(), -5.799903); + assert_approx_eq!(180.0f16.to_radians(), pi, F16_APPROX_L2); + assert!(nan.to_radians().is_nan()); + assert_eq!(inf.to_radians(), inf); + assert_eq!(neg_inf.to_radians(), neg_inf); +} + +#[test] +fn test_real_consts() { + // FIXME(f16_f128): add math tests when available + use super::consts; + + let pi: f16 = consts::PI; + let frac_pi_2: f16 = consts::FRAC_PI_2; + let frac_pi_3: f16 = consts::FRAC_PI_3; + let frac_pi_4: f16 = consts::FRAC_PI_4; + let frac_pi_6: f16 = consts::FRAC_PI_6; + let frac_pi_8: f16 = consts::FRAC_PI_8; + let frac_1_pi: f16 = consts::FRAC_1_PI; + let frac_2_pi: f16 = consts::FRAC_2_PI; + // let frac_2_sqrtpi: f16 = consts::FRAC_2_SQRT_PI; + // let sqrt2: f16 = consts::SQRT_2; + // let frac_1_sqrt2: f16 = consts::FRAC_1_SQRT_2; + // let e: f16 = consts::E; + // let log2_e: f16 = consts::LOG2_E; + // let log10_e: f16 = consts::LOG10_E; + // let ln_2: f16 = consts::LN_2; + // let ln_10: f16 = consts::LN_10; + + assert_approx_eq!(frac_pi_2, pi / 2f16); + assert_approx_eq!(frac_pi_3, pi / 3f16); + assert_approx_eq!(frac_pi_4, pi / 4f16); + assert_approx_eq!(frac_pi_6, pi / 6f16); + assert_approx_eq!(frac_pi_8, pi / 8f16); + assert_approx_eq!(frac_1_pi, 1f16 / pi); + assert_approx_eq!(frac_2_pi, 2f16 / pi); + // assert_approx_eq!(frac_2_sqrtpi, 2f16 / pi.sqrt()); + // assert_approx_eq!(sqrt2, 2f16.sqrt()); + // assert_approx_eq!(frac_1_sqrt2, 1f16 / 2f16.sqrt()); + // assert_approx_eq!(log2_e, e.log2()); + // assert_approx_eq!(log10_e, e.log10()); + // assert_approx_eq!(ln_2, 2f16.ln()); + // assert_approx_eq!(ln_10, 10f16.ln()); +} + +#[test] +fn test_float_bits_conv() { + assert_eq!((1f16).to_bits(), 0x3c00); + assert_eq!((12.5f16).to_bits(), 0x4a40); + assert_eq!((1337f16).to_bits(), 0x6539); + assert_eq!((-14.25f16).to_bits(), 0xcb20); + assert_approx_eq!(f16::from_bits(0x3c00), 1.0); + assert_approx_eq!(f16::from_bits(0x4a40), 12.5); + assert_approx_eq!(f16::from_bits(0x6539), 1337.0); + assert_approx_eq!(f16::from_bits(0xcb20), -14.25); + + // Check that NaNs roundtrip their bits regardless of signaling-ness + let masked_nan1 = f16::NAN.to_bits() ^ NAN_MASK1; + let masked_nan2 = f16::NAN.to_bits() ^ NAN_MASK2; + assert!(f16::from_bits(masked_nan1).is_nan()); + assert!(f16::from_bits(masked_nan2).is_nan()); + + assert_eq!(f16::from_bits(masked_nan1).to_bits(), masked_nan1); + assert_eq!(f16::from_bits(masked_nan2).to_bits(), masked_nan2); +} + +#[test] +#[should_panic] +fn test_clamp_min_greater_than_max() { + let _ = 1.0f16.clamp(3.0, 1.0); +} + +#[test] +#[should_panic] +fn test_clamp_min_is_nan() { + let _ = 1.0f16.clamp(f16::NAN, 1.0); +} + +#[test] +#[should_panic] +fn test_clamp_max_is_nan() { + let _ = 1.0f16.clamp(3.0, f16::NAN); +} + +#[test] +fn test_total_cmp() { + use core::cmp::Ordering; + + fn quiet_bit_mask() -> u16 { + 1 << (f16::MANTISSA_DIGITS - 2) + } + + // FIXME(f16_f128): test subnormals when powf is available + // fn min_subnorm() -> f16 { + // f16::MIN_POSITIVE / f16::powf(2.0, f16::MANTISSA_DIGITS as f16 - 1.0) + // } + + // fn max_subnorm() -> f16 { + // f16::MIN_POSITIVE - min_subnorm() + // } + + fn q_nan() -> f16 { + f16::from_bits(f16::NAN.to_bits() | quiet_bit_mask()) + } + + fn s_nan() -> f16 { + f16::from_bits((f16::NAN.to_bits() & !quiet_bit_mask()) + 42) + } + + assert_eq!(Ordering::Equal, (-q_nan()).total_cmp(&-q_nan())); + assert_eq!(Ordering::Equal, (-s_nan()).total_cmp(&-s_nan())); + assert_eq!(Ordering::Equal, (-f16::INFINITY).total_cmp(&-f16::INFINITY)); + assert_eq!(Ordering::Equal, (-f16::MAX).total_cmp(&-f16::MAX)); + assert_eq!(Ordering::Equal, (-2.5_f16).total_cmp(&-2.5)); + assert_eq!(Ordering::Equal, (-1.0_f16).total_cmp(&-1.0)); + assert_eq!(Ordering::Equal, (-1.5_f16).total_cmp(&-1.5)); + assert_eq!(Ordering::Equal, (-0.5_f16).total_cmp(&-0.5)); + assert_eq!(Ordering::Equal, (-f16::MIN_POSITIVE).total_cmp(&-f16::MIN_POSITIVE)); + // assert_eq!(Ordering::Equal, (-max_subnorm()).total_cmp(&-max_subnorm())); + // assert_eq!(Ordering::Equal, (-min_subnorm()).total_cmp(&-min_subnorm())); + assert_eq!(Ordering::Equal, (-0.0_f16).total_cmp(&-0.0)); + assert_eq!(Ordering::Equal, 0.0_f16.total_cmp(&0.0)); + // assert_eq!(Ordering::Equal, min_subnorm().total_cmp(&min_subnorm())); + // assert_eq!(Ordering::Equal, max_subnorm().total_cmp(&max_subnorm())); + assert_eq!(Ordering::Equal, f16::MIN_POSITIVE.total_cmp(&f16::MIN_POSITIVE)); + assert_eq!(Ordering::Equal, 0.5_f16.total_cmp(&0.5)); + assert_eq!(Ordering::Equal, 1.0_f16.total_cmp(&1.0)); + assert_eq!(Ordering::Equal, 1.5_f16.total_cmp(&1.5)); + assert_eq!(Ordering::Equal, 2.5_f16.total_cmp(&2.5)); + assert_eq!(Ordering::Equal, f16::MAX.total_cmp(&f16::MAX)); + assert_eq!(Ordering::Equal, f16::INFINITY.total_cmp(&f16::INFINITY)); + assert_eq!(Ordering::Equal, s_nan().total_cmp(&s_nan())); + assert_eq!(Ordering::Equal, q_nan().total_cmp(&q_nan())); + + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&-s_nan())); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&-f16::INFINITY)); + assert_eq!(Ordering::Less, (-f16::INFINITY).total_cmp(&-f16::MAX)); + assert_eq!(Ordering::Less, (-f16::MAX).total_cmp(&-2.5)); + assert_eq!(Ordering::Less, (-2.5_f16).total_cmp(&-1.5)); + assert_eq!(Ordering::Less, (-1.5_f16).total_cmp(&-1.0)); + assert_eq!(Ordering::Less, (-1.0_f16).total_cmp(&-0.5)); + assert_eq!(Ordering::Less, (-0.5_f16).total_cmp(&-f16::MIN_POSITIVE)); + // assert_eq!(Ordering::Less, (-f16::MIN_POSITIVE).total_cmp(&-max_subnorm())); + // assert_eq!(Ordering::Less, (-max_subnorm()).total_cmp(&-min_subnorm())); + // assert_eq!(Ordering::Less, (-min_subnorm()).total_cmp(&-0.0)); + assert_eq!(Ordering::Less, (-0.0_f16).total_cmp(&0.0)); + // assert_eq!(Ordering::Less, 0.0_f16.total_cmp(&min_subnorm())); + // assert_eq!(Ordering::Less, min_subnorm().total_cmp(&max_subnorm())); + // assert_eq!(Ordering::Less, max_subnorm().total_cmp(&f16::MIN_POSITIVE)); + assert_eq!(Ordering::Less, f16::MIN_POSITIVE.total_cmp(&0.5)); + assert_eq!(Ordering::Less, 0.5_f16.total_cmp(&1.0)); + assert_eq!(Ordering::Less, 1.0_f16.total_cmp(&1.5)); + assert_eq!(Ordering::Less, 1.5_f16.total_cmp(&2.5)); + assert_eq!(Ordering::Less, 2.5_f16.total_cmp(&f16::MAX)); + assert_eq!(Ordering::Less, f16::MAX.total_cmp(&f16::INFINITY)); + assert_eq!(Ordering::Less, f16::INFINITY.total_cmp(&s_nan())); + assert_eq!(Ordering::Less, s_nan().total_cmp(&q_nan())); + + assert_eq!(Ordering::Greater, (-s_nan()).total_cmp(&-q_nan())); + assert_eq!(Ordering::Greater, (-f16::INFINITY).total_cmp(&-s_nan())); + assert_eq!(Ordering::Greater, (-f16::MAX).total_cmp(&-f16::INFINITY)); + assert_eq!(Ordering::Greater, (-2.5_f16).total_cmp(&-f16::MAX)); + assert_eq!(Ordering::Greater, (-1.5_f16).total_cmp(&-2.5)); + assert_eq!(Ordering::Greater, (-1.0_f16).total_cmp(&-1.5)); + assert_eq!(Ordering::Greater, (-0.5_f16).total_cmp(&-1.0)); + assert_eq!(Ordering::Greater, (-f16::MIN_POSITIVE).total_cmp(&-0.5)); + // assert_eq!(Ordering::Greater, (-max_subnorm()).total_cmp(&-f16::MIN_POSITIVE)); + // assert_eq!(Ordering::Greater, (-min_subnorm()).total_cmp(&-max_subnorm())); + // assert_eq!(Ordering::Greater, (-0.0_f16).total_cmp(&-min_subnorm())); + assert_eq!(Ordering::Greater, 0.0_f16.total_cmp(&-0.0)); + // assert_eq!(Ordering::Greater, min_subnorm().total_cmp(&0.0)); + // assert_eq!(Ordering::Greater, max_subnorm().total_cmp(&min_subnorm())); + // assert_eq!(Ordering::Greater, f16::MIN_POSITIVE.total_cmp(&max_subnorm())); + assert_eq!(Ordering::Greater, 0.5_f16.total_cmp(&f16::MIN_POSITIVE)); + assert_eq!(Ordering::Greater, 1.0_f16.total_cmp(&0.5)); + assert_eq!(Ordering::Greater, 1.5_f16.total_cmp(&1.0)); + assert_eq!(Ordering::Greater, 2.5_f16.total_cmp(&1.5)); + assert_eq!(Ordering::Greater, f16::MAX.total_cmp(&2.5)); + assert_eq!(Ordering::Greater, f16::INFINITY.total_cmp(&f16::MAX)); + assert_eq!(Ordering::Greater, s_nan().total_cmp(&f16::INFINITY)); + assert_eq!(Ordering::Greater, q_nan().total_cmp(&s_nan())); + + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&-s_nan())); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&-f16::INFINITY)); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&-f16::MAX)); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&-2.5)); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&-1.5)); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&-1.0)); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&-0.5)); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&-f16::MIN_POSITIVE)); + // assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&-max_subnorm())); + // assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&-min_subnorm())); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&-0.0)); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&0.0)); + // assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&min_subnorm())); + // assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&max_subnorm())); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&f16::MIN_POSITIVE)); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&0.5)); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&1.0)); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&1.5)); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&2.5)); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&f16::MAX)); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&f16::INFINITY)); + assert_eq!(Ordering::Less, (-q_nan()).total_cmp(&s_nan())); + + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&-f16::INFINITY)); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&-f16::MAX)); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&-2.5)); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&-1.5)); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&-1.0)); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&-0.5)); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&-f16::MIN_POSITIVE)); + // assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&-max_subnorm())); + // assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&-min_subnorm())); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&-0.0)); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&0.0)); + // assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&min_subnorm())); + // assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&max_subnorm())); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&f16::MIN_POSITIVE)); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&0.5)); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&1.0)); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&1.5)); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&2.5)); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&f16::MAX)); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&f16::INFINITY)); + assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&s_nan())); +} diff --git a/std/src/macros.rs b/std/src/macros.rs index 58df83bd79d23..972b6015932db 100644 --- a/std/src/macros.rs +++ b/std/src/macros.rs @@ -373,10 +373,17 @@ macro_rules! dbg { }; } +/// Verify that floats are within a tolerance of each other, 1.0e-6 by default. #[cfg(test)] macro_rules! assert_approx_eq { - ($a:expr, $b:expr) => {{ + ($a:expr, $b:expr) => {{ assert_approx_eq!($a, $b, 1.0e-6) }}; + ($a:expr, $b:expr, $lim:expr) => {{ let (a, b) = (&$a, &$b); - assert!((*a - *b).abs() < 1.0e-6, "{} is not approximately equal to {}", *a, *b); + let diff = (*a - *b).abs(); + assert!( + diff < $lim, + "{a:?} is not approximately equal to {b:?} (threshold {lim:?}, actual {diff:?})", + lim = $lim + ); }}; } From 2ddf794235264173835e82a5e02ae67464e06563 Mon Sep 17 00:00:00 2001 From: cyrgani <85427285+cyrgani@users.noreply.github.com> Date: Tue, 25 Jun 2024 13:37:22 +0200 Subject: [PATCH 08/16] Add missing slash in const_eval_select doc comment --- core/src/intrinsics.rs | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/core/src/intrinsics.rs b/core/src/intrinsics.rs index 6b5054a9f0612..9ba1c6a415470 100644 --- a/core/src/intrinsics.rs +++ b/core/src/intrinsics.rs @@ -2579,7 +2579,7 @@ extern "rust-intrinsic" { /// fn runtime() -> i32 { 1 } /// const fn compiletime() -> i32 { 2 } /// -// // ⚠ This code violates the required equivalence of `compiletime` +/// // ⚠ This code violates the required equivalence of `compiletime` /// // and `runtime`. /// const_eval_select((), compiletime, runtime) /// } From cfb802176cbf7e8f64521b161a0d01ebee104a56 Mon Sep 17 00:00:00 2001 From: ash <97464181+Borgerr@users.noreply.github.com> Date: Sat, 22 Jun 2024 18:53:31 -0600 Subject: [PATCH 09/16] #126333 remove `PathBuf::as_mut_vec` reference at top of `PathBuf::_push` --- std/src/path.rs | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/std/src/path.rs b/std/src/path.rs index 72073d1328023..13947122dcadc 100644 --- a/std/src/path.rs +++ b/std/src/path.rs @@ -1290,7 +1290,8 @@ impl PathBuf { fn _push(&mut self, path: &Path) { // in general, a separator is needed if the rightmost byte is not a separator - let mut need_sep = self.as_mut_vec().last().map(|c| !is_sep_byte(*c)).unwrap_or(false); + let buf = self.inner.as_encoded_bytes(); + let mut need_sep = buf.last().map(|c| !is_sep_byte(*c)).unwrap_or(false); // in the special case of `C:` on Windows, do *not* add a separator let comps = self.components(); From 37f78f46760bc66d6691145ee110c90acbfe9f94 Mon Sep 17 00:00:00 2001 From: ash <97464181+Borgerr@users.noreply.github.com> Date: Sun, 23 Jun 2024 08:36:23 -0600 Subject: [PATCH 10/16] inner truncate methods for UEFI platforms --- std/src/ffi/os_str.rs | 5 +++++ std/src/path.rs | 6 +++--- std/src/sys/os_str/bytes.rs | 5 +++++ 3 files changed, 13 insertions(+), 3 deletions(-) diff --git a/std/src/ffi/os_str.rs b/std/src/ffi/os_str.rs index f6b9de26c1c4d..318fe205e0faf 100644 --- a/std/src/ffi/os_str.rs +++ b/std/src/ffi/os_str.rs @@ -557,6 +557,11 @@ impl OsString { pub(crate) fn as_mut_vec_for_path_buf(&mut self) -> &mut Vec { self.inner.as_mut_vec_for_path_buf() } + + #[inline] + pub(crate) fn truncate(&mut self, len: usize) { + self.inner.truncate(len); + } } #[stable(feature = "rust1", since = "1.0.0")] diff --git a/std/src/path.rs b/std/src/path.rs index 13947122dcadc..fb7476a3b267a 100644 --- a/std/src/path.rs +++ b/std/src/path.rs @@ -1305,7 +1305,7 @@ impl PathBuf { // absolute `path` replaces `self` if path.is_absolute() || path.prefix().is_some() { - self.as_mut_vec().truncate(0); + self.inner.truncate(0); // verbatim paths need . and .. removed } else if comps.prefix_verbatim() && !path.inner.is_empty() { @@ -1350,7 +1350,7 @@ impl PathBuf { // `path` has a root but no prefix, e.g., `\windows` (Windows only) } else if path.has_root() { let prefix_len = self.components().prefix_remaining(); - self.as_mut_vec().truncate(prefix_len); + self.inner.truncate(prefix_len); // `path` is a pure relative path } else if need_sep { @@ -1383,7 +1383,7 @@ impl PathBuf { pub fn pop(&mut self) -> bool { match self.parent().map(|p| p.as_u8_slice().len()) { Some(len) => { - self.as_mut_vec().truncate(len); + self.inner.truncate(len); true } None => false, diff --git a/std/src/sys/os_str/bytes.rs b/std/src/sys/os_str/bytes.rs index f7c6b0877aa62..e494f7d1dea10 100644 --- a/std/src/sys/os_str/bytes.rs +++ b/std/src/sys/os_str/bytes.rs @@ -207,6 +207,11 @@ impl Buf { pub(crate) fn as_mut_vec_for_path_buf(&mut self) -> &mut Vec { &mut self.inner } + + #[inline] + pub(crate) fn truncate(&mut self, len: usize) { + self.inner.truncate(len); + } } impl Slice { From 7cec6ef8d5e23f4d361f258dddb10d4837fbf5cf Mon Sep 17 00:00:00 2001 From: ash <97464181+Borgerr@users.noreply.github.com> Date: Sun, 23 Jun 2024 17:24:59 -0600 Subject: [PATCH 11/16] remove references to `PathBuf::as_mut_vec` in `PathBuf::_set_extension` --- std/src/path.rs | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/std/src/path.rs b/std/src/path.rs index fb7476a3b267a..fb488ae94a1e6 100644 --- a/std/src/path.rs +++ b/std/src/path.rs @@ -1511,15 +1511,14 @@ impl PathBuf { // truncate until right after the file stem let end_file_stem = file_stem[file_stem.len()..].as_ptr().addr(); let start = self.inner.as_encoded_bytes().as_ptr().addr(); - let v = self.as_mut_vec(); - v.truncate(end_file_stem.wrapping_sub(start)); + self.inner.truncate(end_file_stem.wrapping_sub(start)); // add the new extension, if any - let new = extension.as_encoded_bytes(); + let new = extension; if !new.is_empty() { - v.reserve_exact(new.len() + 1); - v.push(b'.'); - v.extend_from_slice(new); + self.inner.reserve_exact(new.len() + 1); + self.inner.push(OsStr::new(".")); + self.inner.push(new); } true From e6c45e4a7112b5f6110ad7e4ef823b91d36927ec Mon Sep 17 00:00:00 2001 From: ash <97464181+Borgerr@users.noreply.github.com> Date: Tue, 25 Jun 2024 07:34:35 -0600 Subject: [PATCH 12/16] `PathBuf::as_mut_vec` removed and verified for UEFI and Windows platforms #126333 --- std/src/ffi/os_str.rs | 15 ++++++++++----- std/src/path.rs | 11 +++-------- std/src/sys/os_str/bytes.rs | 15 ++++++++++----- std/src/sys/os_str/wtf8.rs | 16 +++++++++++++--- std/src/sys_common/wtf8.rs | 12 ++++++------ 5 files changed, 42 insertions(+), 27 deletions(-) diff --git a/std/src/ffi/os_str.rs b/std/src/ffi/os_str.rs index 318fe205e0faf..4a417c84a30a5 100644 --- a/std/src/ffi/os_str.rs +++ b/std/src/ffi/os_str.rs @@ -552,15 +552,20 @@ impl OsString { OsStr::from_inner_mut(self.inner.leak()) } - /// Part of a hack to make PathBuf::push/pop more efficient. + /// Provides plumbing to core `Vec::truncate`. + /// More well behaving alternative to allowing outer types + /// full mutable access to the core `Vec`. #[inline] - pub(crate) fn as_mut_vec_for_path_buf(&mut self) -> &mut Vec { - self.inner.as_mut_vec_for_path_buf() + pub(crate) fn truncate(&mut self, len: usize) { + self.inner.truncate(len); } + /// Provides plumbing to core `Vec::extend_from_slice`. + /// More well behaving alternative to allowing outer types + /// full mutable access to the core `Vec`. #[inline] - pub(crate) fn truncate(&mut self, len: usize) { - self.inner.truncate(len); + pub(crate) fn extend_from_slice(&mut self, other: &[u8]) { + self.inner.extend_from_slice(other); } } diff --git a/std/src/path.rs b/std/src/path.rs index fb488ae94a1e6..caae8f924d2b1 100644 --- a/std/src/path.rs +++ b/std/src/path.rs @@ -1163,11 +1163,6 @@ pub struct PathBuf { } impl PathBuf { - #[inline] - fn as_mut_vec(&mut self) -> &mut Vec { - self.inner.as_mut_vec_for_path_buf() - } - /// Allocates an empty `PathBuf`. /// /// # Examples @@ -2645,18 +2640,18 @@ impl Path { None => { // Enough capacity for the extension and the dot let capacity = self_len + extension.len() + 1; - let whole_path = self_bytes.iter(); + let whole_path = self_bytes; (capacity, whole_path) } Some(previous_extension) => { let capacity = self_len + extension.len() - previous_extension.len(); - let path_till_dot = self_bytes[..self_len - previous_extension.len()].iter(); + let path_till_dot = &self_bytes[..self_len - previous_extension.len()]; (capacity, path_till_dot) } }; let mut new_path = PathBuf::with_capacity(new_capacity); - new_path.as_mut_vec().extend(slice_to_copy); + new_path.inner.extend_from_slice(slice_to_copy); new_path.set_extension(extension); new_path } diff --git a/std/src/sys/os_str/bytes.rs b/std/src/sys/os_str/bytes.rs index e494f7d1dea10..2a7477e3afc20 100644 --- a/std/src/sys/os_str/bytes.rs +++ b/std/src/sys/os_str/bytes.rs @@ -202,15 +202,20 @@ impl Buf { self.as_slice().into_rc() } - /// Part of a hack to make PathBuf::push/pop more efficient. + /// Provides plumbing to core `Vec::truncate`. + /// More well behaving alternative to allowing outer types + /// full mutable access to the core `Vec`. #[inline] - pub(crate) fn as_mut_vec_for_path_buf(&mut self) -> &mut Vec { - &mut self.inner + pub(crate) fn truncate(&mut self, len: usize) { + self.inner.truncate(len); } + /// Provides plumbing to core `Vec::extend_from_slice`. + /// More well behaving alternative to allowing outer types + /// full mutable access to the core `Vec`. #[inline] - pub(crate) fn truncate(&mut self, len: usize) { - self.inner.truncate(len); + pub(crate) fn extend_from_slice(&mut self, other: &[u8]) { + self.inner.extend_from_slice(other); } } diff --git a/std/src/sys/os_str/wtf8.rs b/std/src/sys/os_str/wtf8.rs index 96690f8c44e9c..edb923a47501c 100644 --- a/std/src/sys/os_str/wtf8.rs +++ b/std/src/sys/os_str/wtf8.rs @@ -165,10 +165,20 @@ impl Buf { self.as_slice().into_rc() } - /// Part of a hack to make PathBuf::push/pop more efficient. + /// Provides plumbing to core `Vec::truncate`. + /// More well behaving alternative to allowing outer types + /// full mutable access to the core `Vec`. #[inline] - pub(crate) fn as_mut_vec_for_path_buf(&mut self) -> &mut Vec { - self.inner.as_mut_vec_for_path_buf() + pub(crate) fn truncate(&mut self, len: usize) { + self.inner.truncate(len); + } + + /// Provides plumbing to core `Vec::extend_from_slice`. + /// More well behaving alternative to allowing outer types + /// full mutable access to the core `Vec`. + #[inline] + pub(crate) fn extend_from_slice(&mut self, other: &[u8]) { + self.inner.extend_from_slice(other); } } diff --git a/std/src/sys_common/wtf8.rs b/std/src/sys_common/wtf8.rs index 84128a4b595f7..708f62f476e73 100644 --- a/std/src/sys_common/wtf8.rs +++ b/std/src/sys_common/wtf8.rs @@ -474,13 +474,13 @@ impl Wtf8Buf { Wtf8Buf { bytes: bytes.into_vec(), is_known_utf8: false } } - /// Part of a hack to make PathBuf::push/pop more efficient. + /// Provides plumbing to core `Vec::extend_from_slice`. + /// More well behaving alternative to allowing outer types + /// full mutable access to the core `Vec`. #[inline] - pub(crate) fn as_mut_vec_for_path_buf(&mut self) -> &mut Vec { - // FIXME: this function should not even exist, as it implies violating Wtf8Buf invariants - // For now, simply assume that is about to happen. - self.is_known_utf8 = false; - &mut self.bytes + pub(crate) fn extend_from_slice(&mut self, other: &[u8]) { + self.bytes.extend_from_slice(other); + self.is_known_utf8 = self.is_known_utf8 || self.next_surrogate(0).is_none(); } } From 5d08a54141c180e2a6907f5e10c939864e0328a0 Mon Sep 17 00:00:00 2001 From: mu001999 Date: Tue, 25 Jun 2024 23:29:44 +0800 Subject: [PATCH 13/16] Detect unused structs which derived Default --- alloc/src/sync/tests.rs | 2 +- core/src/default.rs | 1 + 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/alloc/src/sync/tests.rs b/alloc/src/sync/tests.rs index 49eae718c1690..1b123aa58f205 100644 --- a/alloc/src/sync/tests.rs +++ b/alloc/src/sync/tests.rs @@ -396,7 +396,7 @@ fn show_arc() { // Make sure deriving works with Arc #[derive(Eq, Ord, PartialEq, PartialOrd, Clone, Debug, Default)] -struct Foo { +struct _Foo { inner: Arc, } diff --git a/core/src/default.rs b/core/src/default.rs index 4524b352ec817..5cacedcb241a5 100644 --- a/core/src/default.rs +++ b/core/src/default.rs @@ -103,6 +103,7 @@ use crate::ascii::Char as AsciiChar; /// ``` #[cfg_attr(not(test), rustc_diagnostic_item = "Default")] #[stable(feature = "rust1", since = "1.0.0")] +#[cfg_attr(not(bootstrap), rustc_trivial_field_reads)] pub trait Default: Sized { /// Returns the "default value" for a type. /// From 4039a7f34e7d55ec109d241e135a4c9275ba7ac3 Mon Sep 17 00:00:00 2001 From: The 8472 Date: Sun, 23 Jun 2024 22:16:22 +0200 Subject: [PATCH 14/16] fix Drop items getting leaked in Filter::next_chunk The optimization only makes sense for non-drop elements anyway. Use the default implementation for items that are Drop instead. It also simplifies the implementation. --- core/src/iter/adapters/filter.rs | 88 ++++++++++++++++---------------- 1 file changed, 43 insertions(+), 45 deletions(-) diff --git a/core/src/iter/adapters/filter.rs b/core/src/iter/adapters/filter.rs index ca23d1b13a88b..1c99f3938e270 100644 --- a/core/src/iter/adapters/filter.rs +++ b/core/src/iter/adapters/filter.rs @@ -3,7 +3,7 @@ use crate::iter::{adapters::SourceIter, FusedIterator, InPlaceIterable, TrustedF use crate::num::NonZero; use crate::ops::Try; use core::array; -use core::mem::{ManuallyDrop, MaybeUninit}; +use core::mem::MaybeUninit; use core::ops::ControlFlow; /// An iterator that filters the elements of `iter` with `predicate`. @@ -27,6 +27,41 @@ impl Filter { } } +impl Filter +where + I: Iterator, + P: FnMut(&I::Item) -> bool, +{ + #[inline] + fn next_chunk_dropless( + &mut self, + ) -> Result<[I::Item; N], array::IntoIter> { + let mut array: [MaybeUninit; N] = [const { MaybeUninit::uninit() }; N]; + let mut initialized = 0; + + let result = self.iter.try_for_each(|element| { + let idx = initialized; + initialized = idx + (self.predicate)(&element) as usize; + + // SAFETY: Loop conditions ensure the index is in bounds. + unsafe { array.get_unchecked_mut(idx) }.write(element); + + if initialized < N { ControlFlow::Continue(()) } else { ControlFlow::Break(()) } + }); + + match result { + ControlFlow::Break(()) => { + // SAFETY: The loop above is only explicitly broken when the array has been fully initialized + Ok(unsafe { MaybeUninit::array_assume_init(array) }) + } + ControlFlow::Continue(()) => { + // SAFETY: The range is in bounds since the loop breaks when reaching N elements. + Err(unsafe { array::IntoIter::new_unchecked(array, 0..initialized) }) + } + } + } +} + #[stable(feature = "core_impl_debug", since = "1.9.0")] impl fmt::Debug for Filter { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { @@ -64,52 +99,15 @@ where fn next_chunk( &mut self, ) -> Result<[Self::Item; N], array::IntoIter> { - let mut array: [MaybeUninit; N] = [const { MaybeUninit::uninit() }; N]; - - struct Guard<'a, T> { - array: &'a mut [MaybeUninit], - initialized: usize, - } - - impl Drop for Guard<'_, T> { - #[inline] - fn drop(&mut self) { - if const { crate::mem::needs_drop::() } { - // SAFETY: self.initialized is always <= N, which also is the length of the array. - unsafe { - core::ptr::drop_in_place(MaybeUninit::slice_assume_init_mut( - self.array.get_unchecked_mut(..self.initialized), - )); - } - } + let fun = const { + if crate::mem::needs_drop::() { + array::iter_next_chunk:: + } else { + Self::next_chunk_dropless:: } - } - - let mut guard = Guard { array: &mut array, initialized: 0 }; - - let result = self.iter.try_for_each(|element| { - let idx = guard.initialized; - guard.initialized = idx + (self.predicate)(&element) as usize; - - // SAFETY: Loop conditions ensure the index is in bounds. - unsafe { guard.array.get_unchecked_mut(idx) }.write(element); - - if guard.initialized < N { ControlFlow::Continue(()) } else { ControlFlow::Break(()) } - }); + }; - let guard = ManuallyDrop::new(guard); - - match result { - ControlFlow::Break(()) => { - // SAFETY: The loop above is only explicitly broken when the array has been fully initialized - Ok(unsafe { MaybeUninit::array_assume_init(array) }) - } - ControlFlow::Continue(()) => { - let initialized = guard.initialized; - // SAFETY: The range is in bounds since the loop breaks when reaching N elements. - Err(unsafe { array::IntoIter::new_unchecked(array, 0..initialized) }) - } - } + fun(self) } #[inline] From f90972a41040ee4ceb9662ae9b37cb93573bd742 Mon Sep 17 00:00:00 2001 From: The 8472 Date: Mon, 24 Jun 2024 19:56:22 +0200 Subject: [PATCH 15/16] add comments explaining optimizations for Filter::next_chunk --- core/src/iter/adapters/filter.rs | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/core/src/iter/adapters/filter.rs b/core/src/iter/adapters/filter.rs index 1c99f3938e270..ba49070329c22 100644 --- a/core/src/iter/adapters/filter.rs +++ b/core/src/iter/adapters/filter.rs @@ -41,8 +41,9 @@ where let result = self.iter.try_for_each(|element| { let idx = initialized; + // branchless index update combined with unconditionally copying the value even when + // it is filtered reduces branching and dependencies in the loop. initialized = idx + (self.predicate)(&element) as usize; - // SAFETY: Loop conditions ensure the index is in bounds. unsafe { array.get_unchecked_mut(idx) }.write(element); @@ -99,6 +100,7 @@ where fn next_chunk( &mut self, ) -> Result<[Self::Item; N], array::IntoIter> { + // avoid codegen for the dead branch let fun = const { if crate::mem::needs_drop::() { array::iter_next_chunk:: From ff33a6672e79e9c0ed4341c8a39a773911b8b5e4 Mon Sep 17 00:00:00 2001 From: The 8472 Date: Tue, 25 Jun 2024 23:22:27 +0200 Subject: [PATCH 16/16] regression test for leaks in the the Filter::next_chunk implementation previously next_chunk would forget items rejected by the filter --- core/tests/iter/adapters/filter.rs | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/core/tests/iter/adapters/filter.rs b/core/tests/iter/adapters/filter.rs index a2050d89d8564..167851e33336e 100644 --- a/core/tests/iter/adapters/filter.rs +++ b/core/tests/iter/adapters/filter.rs @@ -1,4 +1,5 @@ use core::iter::*; +use std::rc::Rc; #[test] fn test_iterator_filter_count() { @@ -50,3 +51,15 @@ fn test_double_ended_filter() { assert_eq!(it.next().unwrap(), &2); assert_eq!(it.next_back(), None); } + +#[test] +fn test_next_chunk_does_not_leak() { + let drop_witness: [_; 5] = std::array::from_fn(|_| Rc::new(())); + + let v = (0..5).map(|i| drop_witness[i].clone()).collect::>(); + let _ = v.into_iter().filter(|_| false).next_chunk::<1>(); + + for ref w in drop_witness { + assert_eq!(Rc::strong_count(w), 1); + } +}