core/num/
f32.rs

1//! Constants for the `f32` single-precision floating point type.
2//!
3//! *[See also the `f32` primitive type][f32].*
4//!
5//! Mathematically significant numbers are provided in the `consts` sub-module.
6//!
7//! For the constants defined directly in this module
8//! (as distinct from those defined in the `consts` sub-module),
9//! new code should instead use the associated constants
10//! defined directly on the `f32` type.
11
12#![stable(feature = "rust1", since = "1.0.0")]
13
14#[cfg(not(feature = "ferrocene_certified"))]
15use crate::convert::FloatToInt;
16#[cfg(not(feature = "ferrocene_certified"))]
17use crate::num::FpCategory;
18#[cfg(not(feature = "ferrocene_certified"))]
19use crate::panic::const_assert;
20#[cfg(not(feature = "ferrocene_certified"))]
21use crate::{cfg_select, intrinsics, mem};
22
23// Ferrocene addition: imports for certified subset
24#[cfg(feature = "ferrocene_certified")]
25#[rustfmt::skip]
26use crate::mem;
27
28/// The radix or base of the internal representation of `f32`.
29/// Use [`f32::RADIX`] instead.
30///
31/// # Examples
32///
33/// ```rust
34/// // deprecated way
35/// # #[allow(deprecated, deprecated_in_future)]
36/// let r = std::f32::RADIX;
37///
38/// // intended way
39/// let r = f32::RADIX;
40/// ```
41#[stable(feature = "rust1", since = "1.0.0")]
42#[deprecated(since = "TBD", note = "replaced by the `RADIX` associated constant on `f32`")]
43#[rustc_diagnostic_item = "f32_legacy_const_radix"]
44pub const RADIX: u32 = f32::RADIX;
45
46/// Number of significant digits in base 2.
47/// Use [`f32::MANTISSA_DIGITS`] instead.
48///
49/// # Examples
50///
51/// ```rust
52/// // deprecated way
53/// # #[allow(deprecated, deprecated_in_future)]
54/// let d = std::f32::MANTISSA_DIGITS;
55///
56/// // intended way
57/// let d = f32::MANTISSA_DIGITS;
58/// ```
59#[stable(feature = "rust1", since = "1.0.0")]
60#[deprecated(
61    since = "TBD",
62    note = "replaced by the `MANTISSA_DIGITS` associated constant on `f32`"
63)]
64#[rustc_diagnostic_item = "f32_legacy_const_mantissa_dig"]
65pub const MANTISSA_DIGITS: u32 = f32::MANTISSA_DIGITS;
66
67/// Approximate number of significant digits in base 10.
68/// Use [`f32::DIGITS`] instead.
69///
70/// # Examples
71///
72/// ```rust
73/// // deprecated way
74/// # #[allow(deprecated, deprecated_in_future)]
75/// let d = std::f32::DIGITS;
76///
77/// // intended way
78/// let d = f32::DIGITS;
79/// ```
80#[stable(feature = "rust1", since = "1.0.0")]
81#[deprecated(since = "TBD", note = "replaced by the `DIGITS` associated constant on `f32`")]
82#[rustc_diagnostic_item = "f32_legacy_const_digits"]
83pub const DIGITS: u32 = f32::DIGITS;
84
85/// [Machine epsilon] value for `f32`.
86/// Use [`f32::EPSILON`] instead.
87///
88/// This is the difference between `1.0` and the next larger representable number.
89///
90/// [Machine epsilon]: https://en.wikipedia.org/wiki/Machine_epsilon
91///
92/// # Examples
93///
94/// ```rust
95/// // deprecated way
96/// # #[allow(deprecated, deprecated_in_future)]
97/// let e = std::f32::EPSILON;
98///
99/// // intended way
100/// let e = f32::EPSILON;
101/// ```
102#[stable(feature = "rust1", since = "1.0.0")]
103#[deprecated(since = "TBD", note = "replaced by the `EPSILON` associated constant on `f32`")]
104#[rustc_diagnostic_item = "f32_legacy_const_epsilon"]
105pub const EPSILON: f32 = f32::EPSILON;
106
107/// Smallest finite `f32` value.
108/// Use [`f32::MIN`] instead.
109///
110/// # Examples
111///
112/// ```rust
113/// // deprecated way
114/// # #[allow(deprecated, deprecated_in_future)]
115/// let min = std::f32::MIN;
116///
117/// // intended way
118/// let min = f32::MIN;
119/// ```
120#[stable(feature = "rust1", since = "1.0.0")]
121#[deprecated(since = "TBD", note = "replaced by the `MIN` associated constant on `f32`")]
122#[rustc_diagnostic_item = "f32_legacy_const_min"]
123pub const MIN: f32 = f32::MIN;
124
125/// Smallest positive normal `f32` value.
126/// Use [`f32::MIN_POSITIVE`] instead.
127///
128/// # Examples
129///
130/// ```rust
131/// // deprecated way
132/// # #[allow(deprecated, deprecated_in_future)]
133/// let min = std::f32::MIN_POSITIVE;
134///
135/// // intended way
136/// let min = f32::MIN_POSITIVE;
137/// ```
138#[stable(feature = "rust1", since = "1.0.0")]
139#[deprecated(since = "TBD", note = "replaced by the `MIN_POSITIVE` associated constant on `f32`")]
140#[rustc_diagnostic_item = "f32_legacy_const_min_positive"]
141pub const MIN_POSITIVE: f32 = f32::MIN_POSITIVE;
142
143/// Largest finite `f32` value.
144/// Use [`f32::MAX`] instead.
145///
146/// # Examples
147///
148/// ```rust
149/// // deprecated way
150/// # #[allow(deprecated, deprecated_in_future)]
151/// let max = std::f32::MAX;
152///
153/// // intended way
154/// let max = f32::MAX;
155/// ```
156#[stable(feature = "rust1", since = "1.0.0")]
157#[deprecated(since = "TBD", note = "replaced by the `MAX` associated constant on `f32`")]
158#[rustc_diagnostic_item = "f32_legacy_const_max"]
159pub const MAX: f32 = f32::MAX;
160
161/// One greater than the minimum possible normal power of 2 exponent.
162/// Use [`f32::MIN_EXP`] instead.
163///
164/// # Examples
165///
166/// ```rust
167/// // deprecated way
168/// # #[allow(deprecated, deprecated_in_future)]
169/// let min = std::f32::MIN_EXP;
170///
171/// // intended way
172/// let min = f32::MIN_EXP;
173/// ```
174#[stable(feature = "rust1", since = "1.0.0")]
175#[deprecated(since = "TBD", note = "replaced by the `MIN_EXP` associated constant on `f32`")]
176#[rustc_diagnostic_item = "f32_legacy_const_min_exp"]
177pub const MIN_EXP: i32 = f32::MIN_EXP;
178
179/// Maximum possible power of 2 exponent.
180/// Use [`f32::MAX_EXP`] instead.
181///
182/// # Examples
183///
184/// ```rust
185/// // deprecated way
186/// # #[allow(deprecated, deprecated_in_future)]
187/// let max = std::f32::MAX_EXP;
188///
189/// // intended way
190/// let max = f32::MAX_EXP;
191/// ```
192#[stable(feature = "rust1", since = "1.0.0")]
193#[deprecated(since = "TBD", note = "replaced by the `MAX_EXP` associated constant on `f32`")]
194#[rustc_diagnostic_item = "f32_legacy_const_max_exp"]
195pub const MAX_EXP: i32 = f32::MAX_EXP;
196
197/// Minimum possible normal power of 10 exponent.
198/// Use [`f32::MIN_10_EXP`] instead.
199///
200/// # Examples
201///
202/// ```rust
203/// // deprecated way
204/// # #[allow(deprecated, deprecated_in_future)]
205/// let min = std::f32::MIN_10_EXP;
206///
207/// // intended way
208/// let min = f32::MIN_10_EXP;
209/// ```
210#[stable(feature = "rust1", since = "1.0.0")]
211#[deprecated(since = "TBD", note = "replaced by the `MIN_10_EXP` associated constant on `f32`")]
212#[rustc_diagnostic_item = "f32_legacy_const_min_10_exp"]
213pub const MIN_10_EXP: i32 = f32::MIN_10_EXP;
214
215/// Maximum possible power of 10 exponent.
216/// Use [`f32::MAX_10_EXP`] instead.
217///
218/// # Examples
219///
220/// ```rust
221/// // deprecated way
222/// # #[allow(deprecated, deprecated_in_future)]
223/// let max = std::f32::MAX_10_EXP;
224///
225/// // intended way
226/// let max = f32::MAX_10_EXP;
227/// ```
228#[stable(feature = "rust1", since = "1.0.0")]
229#[deprecated(since = "TBD", note = "replaced by the `MAX_10_EXP` associated constant on `f32`")]
230#[rustc_diagnostic_item = "f32_legacy_const_max_10_exp"]
231pub const MAX_10_EXP: i32 = f32::MAX_10_EXP;
232
233/// Not a Number (NaN).
234/// Use [`f32::NAN`] instead.
235///
236/// # Examples
237///
238/// ```rust
239/// // deprecated way
240/// # #[allow(deprecated, deprecated_in_future)]
241/// let nan = std::f32::NAN;
242///
243/// // intended way
244/// let nan = f32::NAN;
245/// ```
246#[stable(feature = "rust1", since = "1.0.0")]
247#[deprecated(since = "TBD", note = "replaced by the `NAN` associated constant on `f32`")]
248#[rustc_diagnostic_item = "f32_legacy_const_nan"]
249pub const NAN: f32 = f32::NAN;
250
251/// Infinity (∞).
252/// Use [`f32::INFINITY`] instead.
253///
254/// # Examples
255///
256/// ```rust
257/// // deprecated way
258/// # #[allow(deprecated, deprecated_in_future)]
259/// let inf = std::f32::INFINITY;
260///
261/// // intended way
262/// let inf = f32::INFINITY;
263/// ```
264#[stable(feature = "rust1", since = "1.0.0")]
265#[deprecated(since = "TBD", note = "replaced by the `INFINITY` associated constant on `f32`")]
266#[rustc_diagnostic_item = "f32_legacy_const_infinity"]
267pub const INFINITY: f32 = f32::INFINITY;
268
269/// Negative infinity (−∞).
270/// Use [`f32::NEG_INFINITY`] instead.
271///
272/// # Examples
273///
274/// ```rust
275/// // deprecated way
276/// # #[allow(deprecated, deprecated_in_future)]
277/// let ninf = std::f32::NEG_INFINITY;
278///
279/// // intended way
280/// let ninf = f32::NEG_INFINITY;
281/// ```
282#[stable(feature = "rust1", since = "1.0.0")]
283#[deprecated(since = "TBD", note = "replaced by the `NEG_INFINITY` associated constant on `f32`")]
284#[rustc_diagnostic_item = "f32_legacy_const_neg_infinity"]
285pub const NEG_INFINITY: f32 = f32::NEG_INFINITY;
286
287/// Basic mathematical constants.
288#[stable(feature = "rust1", since = "1.0.0")]
289#[rustc_diagnostic_item = "f32_consts_mod"]
290pub mod consts {
291    // FIXME: replace with mathematical constants from cmath.
292
293    /// Archimedes' constant (π)
294    #[stable(feature = "rust1", since = "1.0.0")]
295    pub const PI: f32 = 3.14159265358979323846264338327950288_f32;
296
297    /// The full circle constant (τ)
298    ///
299    /// Equal to 2π.
300    #[stable(feature = "tau_constant", since = "1.47.0")]
301    pub const TAU: f32 = 6.28318530717958647692528676655900577_f32;
302
303    /// The golden ratio (φ)
304    #[unstable(feature = "more_float_constants", issue = "146939")]
305    pub const PHI: f32 = 1.618033988749894848204586834365638118_f32;
306
307    /// The Euler-Mascheroni constant (γ)
308    #[unstable(feature = "more_float_constants", issue = "146939")]
309    pub const EGAMMA: f32 = 0.577215664901532860606512090082402431_f32;
310
311    /// π/2
312    #[stable(feature = "rust1", since = "1.0.0")]
313    pub const FRAC_PI_2: f32 = 1.57079632679489661923132169163975144_f32;
314
315    /// π/3
316    #[stable(feature = "rust1", since = "1.0.0")]
317    pub const FRAC_PI_3: f32 = 1.04719755119659774615421446109316763_f32;
318
319    /// π/4
320    #[stable(feature = "rust1", since = "1.0.0")]
321    pub const FRAC_PI_4: f32 = 0.785398163397448309615660845819875721_f32;
322
323    /// π/6
324    #[stable(feature = "rust1", since = "1.0.0")]
325    pub const FRAC_PI_6: f32 = 0.52359877559829887307710723054658381_f32;
326
327    /// π/8
328    #[stable(feature = "rust1", since = "1.0.0")]
329    pub const FRAC_PI_8: f32 = 0.39269908169872415480783042290993786_f32;
330
331    /// 1/π
332    #[stable(feature = "rust1", since = "1.0.0")]
333    pub const FRAC_1_PI: f32 = 0.318309886183790671537767526745028724_f32;
334
335    /// 1/sqrt(π)
336    #[unstable(feature = "more_float_constants", issue = "146939")]
337    pub const FRAC_1_SQRT_PI: f32 = 0.564189583547756286948079451560772586_f32;
338
339    /// 1/sqrt(2π)
340    #[doc(alias = "FRAC_1_SQRT_TAU")]
341    #[unstable(feature = "more_float_constants", issue = "146939")]
342    pub const FRAC_1_SQRT_2PI: f32 = 0.398942280401432677939946059934381868_f32;
343
344    /// 2/π
345    #[stable(feature = "rust1", since = "1.0.0")]
346    pub const FRAC_2_PI: f32 = 0.636619772367581343075535053490057448_f32;
347
348    /// 2/sqrt(π)
349    #[stable(feature = "rust1", since = "1.0.0")]
350    pub const FRAC_2_SQRT_PI: f32 = 1.12837916709551257389615890312154517_f32;
351
352    /// sqrt(2)
353    #[stable(feature = "rust1", since = "1.0.0")]
354    pub const SQRT_2: f32 = 1.41421356237309504880168872420969808_f32;
355
356    /// 1/sqrt(2)
357    #[stable(feature = "rust1", since = "1.0.0")]
358    pub const FRAC_1_SQRT_2: f32 = 0.707106781186547524400844362104849039_f32;
359
360    /// sqrt(3)
361    #[unstable(feature = "more_float_constants", issue = "146939")]
362    pub const SQRT_3: f32 = 1.732050807568877293527446341505872367_f32;
363
364    /// 1/sqrt(3)
365    #[unstable(feature = "more_float_constants", issue = "146939")]
366    pub const FRAC_1_SQRT_3: f32 = 0.577350269189625764509148780501957456_f32;
367
368    /// Euler's number (e)
369    #[stable(feature = "rust1", since = "1.0.0")]
370    pub const E: f32 = 2.71828182845904523536028747135266250_f32;
371
372    /// log<sub>2</sub>(e)
373    #[stable(feature = "rust1", since = "1.0.0")]
374    pub const LOG2_E: f32 = 1.44269504088896340735992468100189214_f32;
375
376    /// log<sub>2</sub>(10)
377    #[stable(feature = "extra_log_consts", since = "1.43.0")]
378    pub const LOG2_10: f32 = 3.32192809488736234787031942948939018_f32;
379
380    /// log<sub>10</sub>(e)
381    #[stable(feature = "rust1", since = "1.0.0")]
382    pub const LOG10_E: f32 = 0.434294481903251827651128918916605082_f32;
383
384    /// log<sub>10</sub>(2)
385    #[stable(feature = "extra_log_consts", since = "1.43.0")]
386    pub const LOG10_2: f32 = 0.301029995663981195213738894724493027_f32;
387
388    /// ln(2)
389    #[stable(feature = "rust1", since = "1.0.0")]
390    pub const LN_2: f32 = 0.693147180559945309417232121458176568_f32;
391
392    /// ln(10)
393    #[stable(feature = "rust1", since = "1.0.0")]
394    pub const LN_10: f32 = 2.30258509299404568401799145468436421_f32;
395}
396
397impl f32 {
398    /// The radix or base of the internal representation of `f32`.
399    #[stable(feature = "assoc_int_consts", since = "1.43.0")]
400    pub const RADIX: u32 = 2;
401
402    /// Number of significant digits in base 2.
403    ///
404    /// Note that the size of the mantissa in the bitwise representation is one
405    /// smaller than this since the leading 1 is not stored explicitly.
406    #[stable(feature = "assoc_int_consts", since = "1.43.0")]
407    pub const MANTISSA_DIGITS: u32 = 24;
408
409    /// Approximate number of significant digits in base 10.
410    ///
411    /// This is the maximum <i>x</i> such that any decimal number with <i>x</i>
412    /// significant digits can be converted to `f32` and back without loss.
413    ///
414    /// Equal to floor(log<sub>10</sub>&nbsp;2<sup>[`MANTISSA_DIGITS`]&nbsp;&minus;&nbsp;1</sup>).
415    ///
416    /// [`MANTISSA_DIGITS`]: f32::MANTISSA_DIGITS
417    #[stable(feature = "assoc_int_consts", since = "1.43.0")]
418    pub const DIGITS: u32 = 6;
419
420    /// [Machine epsilon] value for `f32`.
421    ///
422    /// This is the difference between `1.0` and the next larger representable number.
423    ///
424    /// Equal to 2<sup>1&nbsp;&minus;&nbsp;[`MANTISSA_DIGITS`]</sup>.
425    ///
426    /// [Machine epsilon]: https://en.wikipedia.org/wiki/Machine_epsilon
427    /// [`MANTISSA_DIGITS`]: f32::MANTISSA_DIGITS
428    #[stable(feature = "assoc_int_consts", since = "1.43.0")]
429    #[rustc_diagnostic_item = "f32_epsilon"]
430    pub const EPSILON: f32 = 1.19209290e-07_f32;
431
432    /// Smallest finite `f32` value.
433    ///
434    /// Equal to &minus;[`MAX`].
435    ///
436    /// [`MAX`]: f32::MAX
437    #[stable(feature = "assoc_int_consts", since = "1.43.0")]
438    pub const MIN: f32 = -3.40282347e+38_f32;
439    /// Smallest positive normal `f32` value.
440    ///
441    /// Equal to 2<sup>[`MIN_EXP`]&nbsp;&minus;&nbsp;1</sup>.
442    ///
443    /// [`MIN_EXP`]: f32::MIN_EXP
444    #[stable(feature = "assoc_int_consts", since = "1.43.0")]
445    pub const MIN_POSITIVE: f32 = 1.17549435e-38_f32;
446    /// Largest finite `f32` value.
447    ///
448    /// Equal to
449    /// (1&nbsp;&minus;&nbsp;2<sup>&minus;[`MANTISSA_DIGITS`]</sup>)&nbsp;2<sup>[`MAX_EXP`]</sup>.
450    ///
451    /// [`MANTISSA_DIGITS`]: f32::MANTISSA_DIGITS
452    /// [`MAX_EXP`]: f32::MAX_EXP
453    #[stable(feature = "assoc_int_consts", since = "1.43.0")]
454    pub const MAX: f32 = 3.40282347e+38_f32;
455
456    /// One greater than the minimum possible *normal* power of 2 exponent
457    /// for a significand bounded by 1 ≤ x < 2 (i.e. the IEEE definition).
458    ///
459    /// This corresponds to the exact minimum possible *normal* power of 2 exponent
460    /// for a significand bounded by 0.5 ≤ x < 1 (i.e. the C definition).
461    /// In other words, all normal numbers representable by this type are
462    /// greater than or equal to 0.5&nbsp;×&nbsp;2<sup><i>MIN_EXP</i></sup>.
463    #[stable(feature = "assoc_int_consts", since = "1.43.0")]
464    pub const MIN_EXP: i32 = -125;
465    /// One greater than the maximum possible power of 2 exponent
466    /// for a significand bounded by 1 ≤ x < 2 (i.e. the IEEE definition).
467    ///
468    /// This corresponds to the exact maximum possible power of 2 exponent
469    /// for a significand bounded by 0.5 ≤ x < 1 (i.e. the C definition).
470    /// In other words, all numbers representable by this type are
471    /// strictly less than 2<sup><i>MAX_EXP</i></sup>.
472    #[stable(feature = "assoc_int_consts", since = "1.43.0")]
473    pub const MAX_EXP: i32 = 128;
474
475    /// Minimum <i>x</i> for which 10<sup><i>x</i></sup> is normal.
476    ///
477    /// Equal to ceil(log<sub>10</sub>&nbsp;[`MIN_POSITIVE`]).
478    ///
479    /// [`MIN_POSITIVE`]: f32::MIN_POSITIVE
480    #[stable(feature = "assoc_int_consts", since = "1.43.0")]
481    pub const MIN_10_EXP: i32 = -37;
482    /// Maximum <i>x</i> for which 10<sup><i>x</i></sup> is normal.
483    ///
484    /// Equal to floor(log<sub>10</sub>&nbsp;[`MAX`]).
485    ///
486    /// [`MAX`]: f32::MAX
487    #[stable(feature = "assoc_int_consts", since = "1.43.0")]
488    pub const MAX_10_EXP: i32 = 38;
489
490    /// Not a Number (NaN).
491    ///
492    /// Note that IEEE 754 doesn't define just a single NaN value; a plethora of bit patterns are
493    /// considered to be NaN. Furthermore, the standard makes a difference between a "signaling" and
494    /// a "quiet" NaN, and allows inspecting its "payload" (the unspecified bits in the bit pattern)
495    /// and its sign. See the [specification of NaN bit patterns](f32#nan-bit-patterns) for more
496    /// info.
497    ///
498    /// This constant is guaranteed to be a quiet NaN (on targets that follow the Rust assumptions
499    /// that the quiet/signaling bit being set to 1 indicates a quiet NaN). Beyond that, nothing is
500    /// guaranteed about the specific bit pattern chosen here: both payload and sign are arbitrary.
501    /// The concrete bit pattern may change across Rust versions and target platforms.
502    #[stable(feature = "assoc_int_consts", since = "1.43.0")]
503    #[rustc_diagnostic_item = "f32_nan"]
504    #[allow(clippy::eq_op)]
505    pub const NAN: f32 = 0.0_f32 / 0.0_f32;
506    /// Infinity (∞).
507    #[stable(feature = "assoc_int_consts", since = "1.43.0")]
508    pub const INFINITY: f32 = 1.0_f32 / 0.0_f32;
509    /// Negative infinity (−∞).
510    #[stable(feature = "assoc_int_consts", since = "1.43.0")]
511    pub const NEG_INFINITY: f32 = -1.0_f32 / 0.0_f32;
512
513    /// Sign bit
514    #[cfg(not(feature = "ferrocene_certified"))]
515    pub(crate) const SIGN_MASK: u32 = 0x8000_0000;
516
517    /// Exponent mask
518    #[cfg(not(feature = "ferrocene_certified"))]
519    pub(crate) const EXP_MASK: u32 = 0x7f80_0000;
520
521    /// Mantissa mask
522    #[cfg(not(feature = "ferrocene_certified"))]
523    pub(crate) const MAN_MASK: u32 = 0x007f_ffff;
524
525    /// Minimum representable positive value (min subnormal)
526    #[cfg(not(feature = "ferrocene_certified"))]
527    const TINY_BITS: u32 = 0x1;
528
529    /// Minimum representable negative value (min negative subnormal)
530    #[cfg(not(feature = "ferrocene_certified"))]
531    const NEG_TINY_BITS: u32 = Self::TINY_BITS | Self::SIGN_MASK;
532
533    /// Returns `true` if this value is NaN.
534    ///
535    /// ```
536    /// let nan = f32::NAN;
537    /// let f = 7.0_f32;
538    ///
539    /// assert!(nan.is_nan());
540    /// assert!(!f.is_nan());
541    /// ```
542    #[must_use]
543    #[stable(feature = "rust1", since = "1.0.0")]
544    #[rustc_const_stable(feature = "const_float_classify", since = "1.83.0")]
545    #[inline]
546    #[allow(clippy::eq_op)] // > if you intended to check if the operand is NaN, use `.is_nan()` instead :)
547    #[cfg(not(feature = "ferrocene_certified"))]
548    pub const fn is_nan(self) -> bool {
549        self != self
550    }
551
552    /// Returns `true` if this value is positive infinity or negative infinity, and
553    /// `false` otherwise.
554    ///
555    /// ```
556    /// let f = 7.0f32;
557    /// let inf = f32::INFINITY;
558    /// let neg_inf = f32::NEG_INFINITY;
559    /// let nan = f32::NAN;
560    ///
561    /// assert!(!f.is_infinite());
562    /// assert!(!nan.is_infinite());
563    ///
564    /// assert!(inf.is_infinite());
565    /// assert!(neg_inf.is_infinite());
566    /// ```
567    #[must_use]
568    #[stable(feature = "rust1", since = "1.0.0")]
569    #[rustc_const_stable(feature = "const_float_classify", since = "1.83.0")]
570    #[inline]
571    #[cfg(not(feature = "ferrocene_certified"))]
572    pub const fn is_infinite(self) -> bool {
573        // Getting clever with transmutation can result in incorrect answers on some FPUs
574        // FIXME: alter the Rust <-> Rust calling convention to prevent this problem.
575        // See https://github.com/rust-lang/rust/issues/72327
576        (self == f32::INFINITY) | (self == f32::NEG_INFINITY)
577    }
578
579    /// Returns `true` if this number is neither infinite nor NaN.
580    ///
581    /// ```
582    /// let f = 7.0f32;
583    /// let inf = f32::INFINITY;
584    /// let neg_inf = f32::NEG_INFINITY;
585    /// let nan = f32::NAN;
586    ///
587    /// assert!(f.is_finite());
588    ///
589    /// assert!(!nan.is_finite());
590    /// assert!(!inf.is_finite());
591    /// assert!(!neg_inf.is_finite());
592    /// ```
593    #[must_use]
594    #[stable(feature = "rust1", since = "1.0.0")]
595    #[rustc_const_stable(feature = "const_float_classify", since = "1.83.0")]
596    #[inline]
597    #[cfg(not(feature = "ferrocene_certified"))]
598    pub const fn is_finite(self) -> bool {
599        // There's no need to handle NaN separately: if self is NaN,
600        // the comparison is not true, exactly as desired.
601        self.abs() < Self::INFINITY
602    }
603
604    /// Returns `true` if the number is [subnormal].
605    ///
606    /// ```
607    /// let min = f32::MIN_POSITIVE; // 1.17549435e-38f32
608    /// let max = f32::MAX;
609    /// let lower_than_min = 1.0e-40_f32;
610    /// let zero = 0.0_f32;
611    ///
612    /// assert!(!min.is_subnormal());
613    /// assert!(!max.is_subnormal());
614    ///
615    /// assert!(!zero.is_subnormal());
616    /// assert!(!f32::NAN.is_subnormal());
617    /// assert!(!f32::INFINITY.is_subnormal());
618    /// // Values between `0` and `min` are Subnormal.
619    /// assert!(lower_than_min.is_subnormal());
620    /// ```
621    /// [subnormal]: https://en.wikipedia.org/wiki/Denormal_number
622    #[must_use]
623    #[stable(feature = "is_subnormal", since = "1.53.0")]
624    #[rustc_const_stable(feature = "const_float_classify", since = "1.83.0")]
625    #[inline]
626    #[cfg(not(feature = "ferrocene_certified"))]
627    pub const fn is_subnormal(self) -> bool {
628        matches!(self.classify(), FpCategory::Subnormal)
629    }
630
631    /// Returns `true` if the number is neither zero, infinite,
632    /// [subnormal], or NaN.
633    ///
634    /// ```
635    /// let min = f32::MIN_POSITIVE; // 1.17549435e-38f32
636    /// let max = f32::MAX;
637    /// let lower_than_min = 1.0e-40_f32;
638    /// let zero = 0.0_f32;
639    ///
640    /// assert!(min.is_normal());
641    /// assert!(max.is_normal());
642    ///
643    /// assert!(!zero.is_normal());
644    /// assert!(!f32::NAN.is_normal());
645    /// assert!(!f32::INFINITY.is_normal());
646    /// // Values between `0` and `min` are Subnormal.
647    /// assert!(!lower_than_min.is_normal());
648    /// ```
649    /// [subnormal]: https://en.wikipedia.org/wiki/Denormal_number
650    #[must_use]
651    #[stable(feature = "rust1", since = "1.0.0")]
652    #[rustc_const_stable(feature = "const_float_classify", since = "1.83.0")]
653    #[inline]
654    #[cfg(not(feature = "ferrocene_certified"))]
655    pub const fn is_normal(self) -> bool {
656        matches!(self.classify(), FpCategory::Normal)
657    }
658
659    /// Returns the floating point category of the number. If only one property
660    /// is going to be tested, it is generally faster to use the specific
661    /// predicate instead.
662    ///
663    /// ```
664    /// use std::num::FpCategory;
665    ///
666    /// let num = 12.4_f32;
667    /// let inf = f32::INFINITY;
668    ///
669    /// assert_eq!(num.classify(), FpCategory::Normal);
670    /// assert_eq!(inf.classify(), FpCategory::Infinite);
671    /// ```
672    #[stable(feature = "rust1", since = "1.0.0")]
673    #[rustc_const_stable(feature = "const_float_classify", since = "1.83.0")]
674    #[cfg(not(feature = "ferrocene_certified"))]
675    pub const fn classify(self) -> FpCategory {
676        // We used to have complicated logic here that avoids the simple bit-based tests to work
677        // around buggy codegen for x87 targets (see
678        // https://github.com/rust-lang/rust/issues/114479). However, some LLVM versions later, none
679        // of our tests is able to find any difference between the complicated and the naive
680        // version, so now we are back to the naive version.
681        let b = self.to_bits();
682        match (b & Self::MAN_MASK, b & Self::EXP_MASK) {
683            (0, Self::EXP_MASK) => FpCategory::Infinite,
684            (_, Self::EXP_MASK) => FpCategory::Nan,
685            (0, 0) => FpCategory::Zero,
686            (_, 0) => FpCategory::Subnormal,
687            _ => FpCategory::Normal,
688        }
689    }
690
691    /// Returns `true` if `self` has a positive sign, including `+0.0`, NaNs with
692    /// positive sign bit and positive infinity.
693    ///
694    /// Note that IEEE 754 doesn't assign any meaning to the sign bit in case of
695    /// a NaN, and as Rust doesn't guarantee that the bit pattern of NaNs are
696    /// conserved over arithmetic operations, the result of `is_sign_positive` on
697    /// a NaN might produce an unexpected or non-portable result. See the [specification
698    /// of NaN bit patterns](f32#nan-bit-patterns) for more info. Use `self.signum() == 1.0`
699    /// if you need fully portable behavior (will return `false` for all NaNs).
700    ///
701    /// ```
702    /// let f = 7.0_f32;
703    /// let g = -7.0_f32;
704    ///
705    /// assert!(f.is_sign_positive());
706    /// assert!(!g.is_sign_positive());
707    /// ```
708    #[must_use]
709    #[stable(feature = "rust1", since = "1.0.0")]
710    #[rustc_const_stable(feature = "const_float_classify", since = "1.83.0")]
711    #[inline]
712    #[cfg(not(feature = "ferrocene_certified"))]
713    pub const fn is_sign_positive(self) -> bool {
714        !self.is_sign_negative()
715    }
716
717    /// Returns `true` if `self` has a negative sign, including `-0.0`, NaNs with
718    /// negative sign bit and negative infinity.
719    ///
720    /// Note that IEEE 754 doesn't assign any meaning to the sign bit in case of
721    /// a NaN, and as Rust doesn't guarantee that the bit pattern of NaNs are
722    /// conserved over arithmetic operations, the result of `is_sign_negative` on
723    /// a NaN might produce an unexpected or non-portable result. See the [specification
724    /// of NaN bit patterns](f32#nan-bit-patterns) for more info. Use `self.signum() == -1.0`
725    /// if you need fully portable behavior (will return `false` for all NaNs).
726    ///
727    /// ```
728    /// let f = 7.0f32;
729    /// let g = -7.0f32;
730    ///
731    /// assert!(!f.is_sign_negative());
732    /// assert!(g.is_sign_negative());
733    /// ```
734    #[must_use]
735    #[stable(feature = "rust1", since = "1.0.0")]
736    #[rustc_const_stable(feature = "const_float_classify", since = "1.83.0")]
737    #[inline]
738    #[cfg(not(feature = "ferrocene_certified"))]
739    pub const fn is_sign_negative(self) -> bool {
740        // IEEE754 says: isSignMinus(x) is true if and only if x has negative sign. isSignMinus
741        // applies to zeros and NaNs as well.
742        self.to_bits() & 0x8000_0000 != 0
743    }
744
745    /// Returns the least number greater than `self`.
746    ///
747    /// Let `TINY` be the smallest representable positive `f32`. Then,
748    ///  - if `self.is_nan()`, this returns `self`;
749    ///  - if `self` is [`NEG_INFINITY`], this returns [`MIN`];
750    ///  - if `self` is `-TINY`, this returns -0.0;
751    ///  - if `self` is -0.0 or +0.0, this returns `TINY`;
752    ///  - if `self` is [`MAX`] or [`INFINITY`], this returns [`INFINITY`];
753    ///  - otherwise the unique least value greater than `self` is returned.
754    ///
755    /// The identity `x.next_up() == -(-x).next_down()` holds for all non-NaN `x`. When `x`
756    /// is finite `x == x.next_up().next_down()` also holds.
757    ///
758    /// ```rust
759    /// // f32::EPSILON is the difference between 1.0 and the next number up.
760    /// assert_eq!(1.0f32.next_up(), 1.0 + f32::EPSILON);
761    /// // But not for most numbers.
762    /// assert!(0.1f32.next_up() < 0.1 + f32::EPSILON);
763    /// assert_eq!(16777216f32.next_up(), 16777218.0);
764    /// ```
765    ///
766    /// This operation corresponds to IEEE-754 `nextUp`.
767    ///
768    /// [`NEG_INFINITY`]: Self::NEG_INFINITY
769    /// [`INFINITY`]: Self::INFINITY
770    /// [`MIN`]: Self::MIN
771    /// [`MAX`]: Self::MAX
772    #[inline]
773    #[doc(alias = "nextUp")]
774    #[stable(feature = "float_next_up_down", since = "1.86.0")]
775    #[rustc_const_stable(feature = "float_next_up_down", since = "1.86.0")]
776    #[cfg(not(feature = "ferrocene_certified"))]
777    pub const fn next_up(self) -> Self {
778        // Some targets violate Rust's assumption of IEEE semantics, e.g. by flushing
779        // denormals to zero. This is in general unsound and unsupported, but here
780        // we do our best to still produce the correct result on such targets.
781        let bits = self.to_bits();
782        if self.is_nan() || bits == Self::INFINITY.to_bits() {
783            return self;
784        }
785
786        let abs = bits & !Self::SIGN_MASK;
787        let next_bits = if abs == 0 {
788            Self::TINY_BITS
789        } else if bits == abs {
790            bits + 1
791        } else {
792            bits - 1
793        };
794        Self::from_bits(next_bits)
795    }
796
797    /// Returns the greatest number less than `self`.
798    ///
799    /// Let `TINY` be the smallest representable positive `f32`. Then,
800    ///  - if `self.is_nan()`, this returns `self`;
801    ///  - if `self` is [`INFINITY`], this returns [`MAX`];
802    ///  - if `self` is `TINY`, this returns 0.0;
803    ///  - if `self` is -0.0 or +0.0, this returns `-TINY`;
804    ///  - if `self` is [`MIN`] or [`NEG_INFINITY`], this returns [`NEG_INFINITY`];
805    ///  - otherwise the unique greatest value less than `self` is returned.
806    ///
807    /// The identity `x.next_down() == -(-x).next_up()` holds for all non-NaN `x`. When `x`
808    /// is finite `x == x.next_down().next_up()` also holds.
809    ///
810    /// ```rust
811    /// let x = 1.0f32;
812    /// // Clamp value into range [0, 1).
813    /// let clamped = x.clamp(0.0, 1.0f32.next_down());
814    /// assert!(clamped < 1.0);
815    /// assert_eq!(clamped.next_up(), 1.0);
816    /// ```
817    ///
818    /// This operation corresponds to IEEE-754 `nextDown`.
819    ///
820    /// [`NEG_INFINITY`]: Self::NEG_INFINITY
821    /// [`INFINITY`]: Self::INFINITY
822    /// [`MIN`]: Self::MIN
823    /// [`MAX`]: Self::MAX
824    #[inline]
825    #[doc(alias = "nextDown")]
826    #[stable(feature = "float_next_up_down", since = "1.86.0")]
827    #[rustc_const_stable(feature = "float_next_up_down", since = "1.86.0")]
828    #[cfg(not(feature = "ferrocene_certified"))]
829    pub const fn next_down(self) -> Self {
830        // Some targets violate Rust's assumption of IEEE semantics, e.g. by flushing
831        // denormals to zero. This is in general unsound and unsupported, but here
832        // we do our best to still produce the correct result on such targets.
833        let bits = self.to_bits();
834        if self.is_nan() || bits == Self::NEG_INFINITY.to_bits() {
835            return self;
836        }
837
838        let abs = bits & !Self::SIGN_MASK;
839        let next_bits = if abs == 0 {
840            Self::NEG_TINY_BITS
841        } else if bits == abs {
842            bits - 1
843        } else {
844            bits + 1
845        };
846        Self::from_bits(next_bits)
847    }
848
849    /// Takes the reciprocal (inverse) of a number, `1/x`.
850    ///
851    /// ```
852    /// let x = 2.0_f32;
853    /// let abs_difference = (x.recip() - (1.0 / x)).abs();
854    ///
855    /// assert!(abs_difference <= f32::EPSILON);
856    /// ```
857    #[must_use = "this returns the result of the operation, without modifying the original"]
858    #[stable(feature = "rust1", since = "1.0.0")]
859    #[rustc_const_stable(feature = "const_float_methods", since = "1.85.0")]
860    #[inline]
861    #[cfg(not(feature = "ferrocene_certified"))]
862    pub const fn recip(self) -> f32 {
863        1.0 / self
864    }
865
866    /// Converts radians to degrees.
867    ///
868    /// # Unspecified precision
869    ///
870    /// The precision of this function is non-deterministic. This means it varies by platform,
871    /// Rust version, and can even differ within the same execution from one invocation to the next.
872    ///
873    /// # Examples
874    ///
875    /// ```
876    /// let angle = std::f32::consts::PI;
877    ///
878    /// let abs_difference = (angle.to_degrees() - 180.0).abs();
879    /// # #[cfg(any(not(target_arch = "x86"), target_feature = "sse2"))]
880    /// assert!(abs_difference <= f32::EPSILON);
881    /// ```
882    #[must_use = "this returns the result of the operation, \
883                  without modifying the original"]
884    #[stable(feature = "f32_deg_rad_conversions", since = "1.7.0")]
885    #[rustc_const_stable(feature = "const_float_methods", since = "1.85.0")]
886    #[inline]
887    #[cfg(not(feature = "ferrocene_certified"))]
888    pub const fn to_degrees(self) -> f32 {
889        // Use a literal to avoid double rounding, consts::PI is already rounded,
890        // and dividing would round again.
891        const PIS_IN_180: f32 = 57.2957795130823208767981548141051703_f32;
892        self * PIS_IN_180
893    }
894
895    /// Converts degrees to radians.
896    ///
897    /// # Unspecified precision
898    ///
899    /// The precision of this function is non-deterministic. This means it varies by platform,
900    /// Rust version, and can even differ within the same execution from one invocation to the next.
901    ///
902    /// # Examples
903    ///
904    /// ```
905    /// let angle = 180.0f32;
906    ///
907    /// let abs_difference = (angle.to_radians() - std::f32::consts::PI).abs();
908    ///
909    /// assert!(abs_difference <= f32::EPSILON);
910    /// ```
911    #[must_use = "this returns the result of the operation, \
912                  without modifying the original"]
913    #[stable(feature = "f32_deg_rad_conversions", since = "1.7.0")]
914    #[rustc_const_stable(feature = "const_float_methods", since = "1.85.0")]
915    #[inline]
916    #[cfg(not(feature = "ferrocene_certified"))]
917    pub const fn to_radians(self) -> f32 {
918        // The division here is correctly rounded with respect to the true value of π/180.
919        // Although π is irrational and already rounded, the double rounding happens
920        // to produce correct result for f32.
921        const RADS_PER_DEG: f32 = consts::PI / 180.0;
922        self * RADS_PER_DEG
923    }
924
925    /// Returns the maximum of the two numbers, ignoring NaN.
926    ///
927    /// If one of the arguments is NaN, then the other argument is returned.
928    /// This follows the IEEE 754-2008 semantics for maxNum, except for handling of signaling NaNs;
929    /// this function handles all NaNs the same way and avoids maxNum's problems with associativity.
930    /// This also matches the behavior of libm’s fmax. In particular, if the inputs compare equal
931    /// (such as for the case of `+0.0` and `-0.0`), either input may be returned non-deterministically.
932    ///
933    /// ```
934    /// let x = 1.0f32;
935    /// let y = 2.0f32;
936    ///
937    /// assert_eq!(x.max(y), y);
938    /// ```
939    #[must_use = "this returns the result of the comparison, without modifying either input"]
940    #[stable(feature = "rust1", since = "1.0.0")]
941    #[rustc_const_stable(feature = "const_float_methods", since = "1.85.0")]
942    #[inline]
943    #[cfg(not(feature = "ferrocene_certified"))]
944    pub const fn max(self, other: f32) -> f32 {
945        intrinsics::maxnumf32(self, other)
946    }
947
948    /// Returns the minimum of the two numbers, ignoring NaN.
949    ///
950    /// If one of the arguments is NaN, then the other argument is returned.
951    /// This follows the IEEE 754-2008 semantics for minNum, except for handling of signaling NaNs;
952    /// this function handles all NaNs the same way and avoids minNum's problems with associativity.
953    /// This also matches the behavior of libm’s fmin. In particular, if the inputs compare equal
954    /// (such as for the case of `+0.0` and `-0.0`), either input may be returned non-deterministically.
955    ///
956    /// ```
957    /// let x = 1.0f32;
958    /// let y = 2.0f32;
959    ///
960    /// assert_eq!(x.min(y), x);
961    /// ```
962    #[must_use = "this returns the result of the comparison, without modifying either input"]
963    #[stable(feature = "rust1", since = "1.0.0")]
964    #[rustc_const_stable(feature = "const_float_methods", since = "1.85.0")]
965    #[inline]
966    #[cfg(not(feature = "ferrocene_certified"))]
967    pub const fn min(self, other: f32) -> f32 {
968        intrinsics::minnumf32(self, other)
969    }
970
971    /// Returns the maximum of the two numbers, propagating NaN.
972    ///
973    /// This returns NaN when *either* argument is NaN, as opposed to
974    /// [`f32::max`] which only returns NaN when *both* arguments are NaN.
975    ///
976    /// ```
977    /// #![feature(float_minimum_maximum)]
978    /// let x = 1.0f32;
979    /// let y = 2.0f32;
980    ///
981    /// assert_eq!(x.maximum(y), y);
982    /// assert!(x.maximum(f32::NAN).is_nan());
983    /// ```
984    ///
985    /// If one of the arguments is NaN, then NaN is returned. Otherwise this returns the greater
986    /// of the two numbers. For this operation, -0.0 is considered to be less than +0.0.
987    /// Note that this follows the semantics specified in IEEE 754-2019.
988    ///
989    /// Also note that "propagation" of NaNs here doesn't necessarily mean that the bitpattern of a NaN
990    /// operand is conserved; see the [specification of NaN bit patterns](f32#nan-bit-patterns) for more info.
991    #[must_use = "this returns the result of the comparison, without modifying either input"]
992    #[unstable(feature = "float_minimum_maximum", issue = "91079")]
993    #[inline]
994    #[cfg(not(feature = "ferrocene_certified"))]
995    pub const fn maximum(self, other: f32) -> f32 {
996        intrinsics::maximumf32(self, other)
997    }
998
999    /// Returns the minimum of the two numbers, propagating NaN.
1000    ///
1001    /// This returns NaN when *either* argument is NaN, as opposed to
1002    /// [`f32::min`] which only returns NaN when *both* arguments are NaN.
1003    ///
1004    /// ```
1005    /// #![feature(float_minimum_maximum)]
1006    /// let x = 1.0f32;
1007    /// let y = 2.0f32;
1008    ///
1009    /// assert_eq!(x.minimum(y), x);
1010    /// assert!(x.minimum(f32::NAN).is_nan());
1011    /// ```
1012    ///
1013    /// If one of the arguments is NaN, then NaN is returned. Otherwise this returns the lesser
1014    /// of the two numbers. For this operation, -0.0 is considered to be less than +0.0.
1015    /// Note that this follows the semantics specified in IEEE 754-2019.
1016    ///
1017    /// Also note that "propagation" of NaNs here doesn't necessarily mean that the bitpattern of a NaN
1018    /// operand is conserved; see the [specification of NaN bit patterns](f32#nan-bit-patterns) for more info.
1019    #[must_use = "this returns the result of the comparison, without modifying either input"]
1020    #[unstable(feature = "float_minimum_maximum", issue = "91079")]
1021    #[inline]
1022    #[cfg(not(feature = "ferrocene_certified"))]
1023    pub const fn minimum(self, other: f32) -> f32 {
1024        intrinsics::minimumf32(self, other)
1025    }
1026
1027    /// Calculates the midpoint (average) between `self` and `rhs`.
1028    ///
1029    /// This returns NaN when *either* argument is NaN or if a combination of
1030    /// +inf and -inf is provided as arguments.
1031    ///
1032    /// # Examples
1033    ///
1034    /// ```
1035    /// assert_eq!(1f32.midpoint(4.0), 2.5);
1036    /// assert_eq!((-5.5f32).midpoint(8.0), 1.25);
1037    /// ```
1038    #[inline]
1039    #[doc(alias = "average")]
1040    #[stable(feature = "num_midpoint", since = "1.85.0")]
1041    #[rustc_const_stable(feature = "num_midpoint", since = "1.85.0")]
1042    #[cfg(not(feature = "ferrocene_certified"))]
1043    pub const fn midpoint(self, other: f32) -> f32 {
1044        cfg_select! {
1045            // Allow faster implementation that have known good 64-bit float
1046            // implementations. Falling back to the branchy code on targets that don't
1047            // have 64-bit hardware floats or buggy implementations.
1048            // https://github.com/rust-lang/rust/pull/121062#issuecomment-2123408114
1049            any(
1050                target_arch = "x86_64",
1051                target_arch = "aarch64",
1052                all(any(target_arch = "riscv32", target_arch = "riscv64"), target_feature = "d"),
1053                all(target_arch = "loongarch64", target_feature = "d"),
1054                all(target_arch = "arm", target_feature = "vfp2"),
1055                target_arch = "wasm32",
1056                target_arch = "wasm64",
1057            ) => {
1058                ((self as f64 + other as f64) / 2.0) as f32
1059            }
1060            _ => {
1061                const HI: f32 = f32::MAX / 2.;
1062
1063                let (a, b) = (self, other);
1064                let abs_a = a.abs();
1065                let abs_b = b.abs();
1066
1067                if abs_a <= HI && abs_b <= HI {
1068                    // Overflow is impossible
1069                    (a + b) / 2.
1070                } else {
1071                    (a / 2.) + (b / 2.)
1072                }
1073            }
1074        }
1075    }
1076
1077    /// Rounds toward zero and converts to any primitive integer type,
1078    /// assuming that the value is finite and fits in that type.
1079    ///
1080    /// ```
1081    /// let value = 4.6_f32;
1082    /// let rounded = unsafe { value.to_int_unchecked::<u16>() };
1083    /// assert_eq!(rounded, 4);
1084    ///
1085    /// let value = -128.9_f32;
1086    /// let rounded = unsafe { value.to_int_unchecked::<i8>() };
1087    /// assert_eq!(rounded, i8::MIN);
1088    /// ```
1089    ///
1090    /// # Safety
1091    ///
1092    /// The value must:
1093    ///
1094    /// * Not be `NaN`
1095    /// * Not be infinite
1096    /// * Be representable in the return type `Int`, after truncating off its fractional part
1097    #[must_use = "this returns the result of the operation, \
1098                  without modifying the original"]
1099    #[stable(feature = "float_approx_unchecked_to", since = "1.44.0")]
1100    #[inline]
1101    #[cfg(not(feature = "ferrocene_certified"))]
1102    pub unsafe fn to_int_unchecked<Int>(self) -> Int
1103    where
1104        Self: FloatToInt<Int>,
1105    {
1106        // SAFETY: the caller must uphold the safety contract for
1107        // `FloatToInt::to_int_unchecked`.
1108        unsafe { FloatToInt::<Int>::to_int_unchecked(self) }
1109    }
1110
1111    /// Raw transmutation to `u32`.
1112    ///
1113    /// This is currently identical to `transmute::<f32, u32>(self)` on all platforms.
1114    ///
1115    /// See [`from_bits`](Self::from_bits) for some discussion of the
1116    /// portability of this operation (there are almost no issues).
1117    ///
1118    /// Note that this function is distinct from `as` casting, which attempts to
1119    /// preserve the *numeric* value, and not the bitwise value.
1120    ///
1121    /// # Examples
1122    ///
1123    /// ```
1124    /// assert_ne!((1f32).to_bits(), 1f32 as u32); // to_bits() is not casting!
1125    /// assert_eq!((12.5f32).to_bits(), 0x41480000);
1126    ///
1127    /// ```
1128    #[must_use = "this returns the result of the operation, \
1129                  without modifying the original"]
1130    #[stable(feature = "float_bits_conv", since = "1.20.0")]
1131    #[rustc_const_stable(feature = "const_float_bits_conv", since = "1.83.0")]
1132    #[inline]
1133    #[allow(unnecessary_transmutes)]
1134    pub const fn to_bits(self) -> u32 {
1135        // SAFETY: `u32` is a plain old datatype so we can always transmute to it.
1136        unsafe { mem::transmute(self) }
1137    }
1138
1139    /// Raw transmutation from `u32`.
1140    ///
1141    /// This is currently identical to `transmute::<u32, f32>(v)` on all platforms.
1142    /// It turns out this is incredibly portable, for two reasons:
1143    ///
1144    /// * Floats and Ints have the same endianness on all supported platforms.
1145    /// * IEEE 754 very precisely specifies the bit layout of floats.
1146    ///
1147    /// However there is one caveat: prior to the 2008 version of IEEE 754, how
1148    /// to interpret the NaN signaling bit wasn't actually specified. Most platforms
1149    /// (notably x86 and ARM) picked the interpretation that was ultimately
1150    /// standardized in 2008, but some didn't (notably MIPS). As a result, all
1151    /// signaling NaNs on MIPS are quiet NaNs on x86, and vice-versa.
1152    ///
1153    /// Rather than trying to preserve signaling-ness cross-platform, this
1154    /// implementation favors preserving the exact bits. This means that
1155    /// any payloads encoded in NaNs will be preserved even if the result of
1156    /// this method is sent over the network from an x86 machine to a MIPS one.
1157    ///
1158    /// If the results of this method are only manipulated by the same
1159    /// architecture that produced them, then there is no portability concern.
1160    ///
1161    /// If the input isn't NaN, then there is no portability concern.
1162    ///
1163    /// If you don't care about signalingness (very likely), then there is no
1164    /// portability concern.
1165    ///
1166    /// Note that this function is distinct from `as` casting, which attempts to
1167    /// preserve the *numeric* value, and not the bitwise value.
1168    ///
1169    /// # Examples
1170    ///
1171    /// ```
1172    /// let v = f32::from_bits(0x41480000);
1173    /// assert_eq!(v, 12.5);
1174    /// ```
1175    #[stable(feature = "float_bits_conv", since = "1.20.0")]
1176    #[rustc_const_stable(feature = "const_float_bits_conv", since = "1.83.0")]
1177    #[must_use]
1178    #[inline]
1179    #[allow(unnecessary_transmutes)]
1180    pub const fn from_bits(v: u32) -> Self {
1181        // It turns out the safety issues with sNaN were overblown! Hooray!
1182        // SAFETY: `u32` is a plain old datatype so we can always transmute from it.
1183        unsafe { mem::transmute(v) }
1184    }
1185
1186    /// Returns the memory representation of this floating point number as a byte array in
1187    /// big-endian (network) byte order.
1188    ///
1189    /// See [`from_bits`](Self::from_bits) for some discussion of the
1190    /// portability of this operation (there are almost no issues).
1191    ///
1192    /// # Examples
1193    ///
1194    /// ```
1195    /// let bytes = 12.5f32.to_be_bytes();
1196    /// assert_eq!(bytes, [0x41, 0x48, 0x00, 0x00]);
1197    /// ```
1198    #[must_use = "this returns the result of the operation, \
1199                  without modifying the original"]
1200    #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
1201    #[rustc_const_stable(feature = "const_float_bits_conv", since = "1.83.0")]
1202    #[inline]
1203    #[cfg(not(feature = "ferrocene_certified"))]
1204    pub const fn to_be_bytes(self) -> [u8; 4] {
1205        self.to_bits().to_be_bytes()
1206    }
1207
1208    /// Returns the memory representation of this floating point number as a byte array in
1209    /// little-endian byte order.
1210    ///
1211    /// See [`from_bits`](Self::from_bits) for some discussion of the
1212    /// portability of this operation (there are almost no issues).
1213    ///
1214    /// # Examples
1215    ///
1216    /// ```
1217    /// let bytes = 12.5f32.to_le_bytes();
1218    /// assert_eq!(bytes, [0x00, 0x00, 0x48, 0x41]);
1219    /// ```
1220    #[must_use = "this returns the result of the operation, \
1221                  without modifying the original"]
1222    #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
1223    #[rustc_const_stable(feature = "const_float_bits_conv", since = "1.83.0")]
1224    #[inline]
1225    pub const fn to_le_bytes(self) -> [u8; 4] {
1226        self.to_bits().to_le_bytes()
1227    }
1228
1229    /// Returns the memory representation of this floating point number as a byte array in
1230    /// native byte order.
1231    ///
1232    /// As the target platform's native endianness is used, portable code
1233    /// should use [`to_be_bytes`] or [`to_le_bytes`], as appropriate, instead.
1234    ///
1235    /// [`to_be_bytes`]: f32::to_be_bytes
1236    /// [`to_le_bytes`]: f32::to_le_bytes
1237    ///
1238    /// See [`from_bits`](Self::from_bits) for some discussion of the
1239    /// portability of this operation (there are almost no issues).
1240    ///
1241    /// # Examples
1242    ///
1243    /// ```
1244    /// let bytes = 12.5f32.to_ne_bytes();
1245    /// assert_eq!(
1246    ///     bytes,
1247    ///     if cfg!(target_endian = "big") {
1248    ///         [0x41, 0x48, 0x00, 0x00]
1249    ///     } else {
1250    ///         [0x00, 0x00, 0x48, 0x41]
1251    ///     }
1252    /// );
1253    /// ```
1254    #[must_use = "this returns the result of the operation, \
1255                  without modifying the original"]
1256    #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
1257    #[rustc_const_stable(feature = "const_float_bits_conv", since = "1.83.0")]
1258    #[inline]
1259    #[cfg(not(feature = "ferrocene_certified"))]
1260    pub const fn to_ne_bytes(self) -> [u8; 4] {
1261        self.to_bits().to_ne_bytes()
1262    }
1263
1264    /// Creates a floating point value from its representation as a byte array in big endian.
1265    ///
1266    /// See [`from_bits`](Self::from_bits) for some discussion of the
1267    /// portability of this operation (there are almost no issues).
1268    ///
1269    /// # Examples
1270    ///
1271    /// ```
1272    /// let value = f32::from_be_bytes([0x41, 0x48, 0x00, 0x00]);
1273    /// assert_eq!(value, 12.5);
1274    /// ```
1275    #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
1276    #[rustc_const_stable(feature = "const_float_bits_conv", since = "1.83.0")]
1277    #[must_use]
1278    #[inline]
1279    #[cfg(not(feature = "ferrocene_certified"))]
1280    pub const fn from_be_bytes(bytes: [u8; 4]) -> Self {
1281        Self::from_bits(u32::from_be_bytes(bytes))
1282    }
1283
1284    /// Creates a floating point value from its representation as a byte array in little endian.
1285    ///
1286    /// See [`from_bits`](Self::from_bits) for some discussion of the
1287    /// portability of this operation (there are almost no issues).
1288    ///
1289    /// # Examples
1290    ///
1291    /// ```
1292    /// let value = f32::from_le_bytes([0x00, 0x00, 0x48, 0x41]);
1293    /// assert_eq!(value, 12.5);
1294    /// ```
1295    #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
1296    #[rustc_const_stable(feature = "const_float_bits_conv", since = "1.83.0")]
1297    #[must_use]
1298    #[inline]
1299    pub const fn from_le_bytes(bytes: [u8; 4]) -> Self {
1300        Self::from_bits(u32::from_le_bytes(bytes))
1301    }
1302
1303    /// Creates a floating point value from its representation as a byte array in native endian.
1304    ///
1305    /// As the target platform's native endianness is used, portable code
1306    /// likely wants to use [`from_be_bytes`] or [`from_le_bytes`], as
1307    /// appropriate instead.
1308    ///
1309    /// [`from_be_bytes`]: f32::from_be_bytes
1310    /// [`from_le_bytes`]: f32::from_le_bytes
1311    ///
1312    /// See [`from_bits`](Self::from_bits) for some discussion of the
1313    /// portability of this operation (there are almost no issues).
1314    ///
1315    /// # Examples
1316    ///
1317    /// ```
1318    /// let value = f32::from_ne_bytes(if cfg!(target_endian = "big") {
1319    ///     [0x41, 0x48, 0x00, 0x00]
1320    /// } else {
1321    ///     [0x00, 0x00, 0x48, 0x41]
1322    /// });
1323    /// assert_eq!(value, 12.5);
1324    /// ```
1325    #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
1326    #[rustc_const_stable(feature = "const_float_bits_conv", since = "1.83.0")]
1327    #[must_use]
1328    #[inline]
1329    #[cfg(not(feature = "ferrocene_certified"))]
1330    pub const fn from_ne_bytes(bytes: [u8; 4]) -> Self {
1331        Self::from_bits(u32::from_ne_bytes(bytes))
1332    }
1333
1334    /// Returns the ordering between `self` and `other`.
1335    ///
1336    /// Unlike the standard partial comparison between floating point numbers,
1337    /// this comparison always produces an ordering in accordance to
1338    /// the `totalOrder` predicate as defined in the IEEE 754 (2008 revision)
1339    /// floating point standard. The values are ordered in the following sequence:
1340    ///
1341    /// - negative quiet NaN
1342    /// - negative signaling NaN
1343    /// - negative infinity
1344    /// - negative numbers
1345    /// - negative subnormal numbers
1346    /// - negative zero
1347    /// - positive zero
1348    /// - positive subnormal numbers
1349    /// - positive numbers
1350    /// - positive infinity
1351    /// - positive signaling NaN
1352    /// - positive quiet NaN.
1353    ///
1354    /// The ordering established by this function does not always agree with the
1355    /// [`PartialOrd`] and [`PartialEq`] implementations of `f32`. For example,
1356    /// they consider negative and positive zero equal, while `total_cmp`
1357    /// doesn't.
1358    ///
1359    /// The interpretation of the signaling NaN bit follows the definition in
1360    /// the IEEE 754 standard, which may not match the interpretation by some of
1361    /// the older, non-conformant (e.g. MIPS) hardware implementations.
1362    ///
1363    /// # Example
1364    ///
1365    /// ```
1366    /// struct GoodBoy {
1367    ///     name: String,
1368    ///     weight: f32,
1369    /// }
1370    ///
1371    /// let mut bois = vec![
1372    ///     GoodBoy { name: "Pucci".to_owned(), weight: 0.1 },
1373    ///     GoodBoy { name: "Woofer".to_owned(), weight: 99.0 },
1374    ///     GoodBoy { name: "Yapper".to_owned(), weight: 10.0 },
1375    ///     GoodBoy { name: "Chonk".to_owned(), weight: f32::INFINITY },
1376    ///     GoodBoy { name: "Abs. Unit".to_owned(), weight: f32::NAN },
1377    ///     GoodBoy { name: "Floaty".to_owned(), weight: -5.0 },
1378    /// ];
1379    ///
1380    /// bois.sort_by(|a, b| a.weight.total_cmp(&b.weight));
1381    ///
1382    /// // `f32::NAN` could be positive or negative, which will affect the sort order.
1383    /// if f32::NAN.is_sign_negative() {
1384    ///     assert!(bois.into_iter().map(|b| b.weight)
1385    ///         .zip([f32::NAN, -5.0, 0.1, 10.0, 99.0, f32::INFINITY].iter())
1386    ///         .all(|(a, b)| a.to_bits() == b.to_bits()))
1387    /// } else {
1388    ///     assert!(bois.into_iter().map(|b| b.weight)
1389    ///         .zip([-5.0, 0.1, 10.0, 99.0, f32::INFINITY, f32::NAN].iter())
1390    ///         .all(|(a, b)| a.to_bits() == b.to_bits()))
1391    /// }
1392    /// ```
1393    #[stable(feature = "total_cmp", since = "1.62.0")]
1394    #[rustc_const_unstable(feature = "const_cmp", issue = "143800")]
1395    #[must_use]
1396    #[inline]
1397    #[cfg(not(feature = "ferrocene_certified"))]
1398    pub const fn total_cmp(&self, other: &Self) -> crate::cmp::Ordering {
1399        let mut left = self.to_bits() as i32;
1400        let mut right = other.to_bits() as i32;
1401
1402        // In case of negatives, flip all the bits except the sign
1403        // to achieve a similar layout as two's complement integers
1404        //
1405        // Why does this work? IEEE 754 floats consist of three fields:
1406        // Sign bit, exponent and mantissa. The set of exponent and mantissa
1407        // fields as a whole have the property that their bitwise order is
1408        // equal to the numeric magnitude where the magnitude is defined.
1409        // The magnitude is not normally defined on NaN values, but
1410        // IEEE 754 totalOrder defines the NaN values also to follow the
1411        // bitwise order. This leads to order explained in the doc comment.
1412        // However, the representation of magnitude is the same for negative
1413        // and positive numbers – only the sign bit is different.
1414        // To easily compare the floats as signed integers, we need to
1415        // flip the exponent and mantissa bits in case of negative numbers.
1416        // We effectively convert the numbers to "two's complement" form.
1417        //
1418        // To do the flipping, we construct a mask and XOR against it.
1419        // We branchlessly calculate an "all-ones except for the sign bit"
1420        // mask from negative-signed values: right shifting sign-extends
1421        // the integer, so we "fill" the mask with sign bits, and then
1422        // convert to unsigned to push one more zero bit.
1423        // On positive values, the mask is all zeros, so it's a no-op.
1424        left ^= (((left >> 31) as u32) >> 1) as i32;
1425        right ^= (((right >> 31) as u32) >> 1) as i32;
1426
1427        left.cmp(&right)
1428    }
1429
1430    /// Restrict a value to a certain interval unless it is NaN.
1431    ///
1432    /// Returns `max` if `self` is greater than `max`, and `min` if `self` is
1433    /// less than `min`. Otherwise this returns `self`.
1434    ///
1435    /// Note that this function returns NaN if the initial value was NaN as
1436    /// well.
1437    ///
1438    /// # Panics
1439    ///
1440    /// Panics if `min > max`, `min` is NaN, or `max` is NaN.
1441    ///
1442    /// # Examples
1443    ///
1444    /// ```
1445    /// assert!((-3.0f32).clamp(-2.0, 1.0) == -2.0);
1446    /// assert!((0.0f32).clamp(-2.0, 1.0) == 0.0);
1447    /// assert!((2.0f32).clamp(-2.0, 1.0) == 1.0);
1448    /// assert!((f32::NAN).clamp(-2.0, 1.0).is_nan());
1449    /// ```
1450    #[must_use = "method returns a new number and does not mutate the original value"]
1451    #[stable(feature = "clamp", since = "1.50.0")]
1452    #[rustc_const_stable(feature = "const_float_methods", since = "1.85.0")]
1453    #[inline]
1454    #[cfg(not(feature = "ferrocene_certified"))]
1455    pub const fn clamp(mut self, min: f32, max: f32) -> f32 {
1456        const_assert!(
1457            min <= max,
1458            "min > max, or either was NaN",
1459            "min > max, or either was NaN. min = {min:?}, max = {max:?}",
1460            min: f32,
1461            max: f32,
1462        );
1463
1464        if self < min {
1465            self = min;
1466        }
1467        if self > max {
1468            self = max;
1469        }
1470        self
1471    }
1472
1473    /// Computes the absolute value of `self`.
1474    ///
1475    /// This function always returns the precise result.
1476    ///
1477    /// # Examples
1478    ///
1479    /// ```
1480    /// let x = 3.5_f32;
1481    /// let y = -3.5_f32;
1482    ///
1483    /// assert_eq!(x.abs(), x);
1484    /// assert_eq!(y.abs(), -y);
1485    ///
1486    /// assert!(f32::NAN.abs().is_nan());
1487    /// ```
1488    #[must_use = "method returns a new number and does not mutate the original value"]
1489    #[stable(feature = "rust1", since = "1.0.0")]
1490    #[rustc_const_stable(feature = "const_float_methods", since = "1.85.0")]
1491    #[inline]
1492    #[cfg(not(feature = "ferrocene_certified"))]
1493    pub const fn abs(self) -> f32 {
1494        intrinsics::fabsf32(self)
1495    }
1496
1497    /// Returns a number that represents the sign of `self`.
1498    ///
1499    /// - `1.0` if the number is positive, `+0.0` or `INFINITY`
1500    /// - `-1.0` if the number is negative, `-0.0` or `NEG_INFINITY`
1501    /// - NaN if the number is NaN
1502    ///
1503    /// # Examples
1504    ///
1505    /// ```
1506    /// let f = 3.5_f32;
1507    ///
1508    /// assert_eq!(f.signum(), 1.0);
1509    /// assert_eq!(f32::NEG_INFINITY.signum(), -1.0);
1510    ///
1511    /// assert!(f32::NAN.signum().is_nan());
1512    /// ```
1513    #[must_use = "method returns a new number and does not mutate the original value"]
1514    #[stable(feature = "rust1", since = "1.0.0")]
1515    #[rustc_const_stable(feature = "const_float_methods", since = "1.85.0")]
1516    #[inline]
1517    #[cfg(not(feature = "ferrocene_certified"))]
1518    pub const fn signum(self) -> f32 {
1519        if self.is_nan() { Self::NAN } else { 1.0_f32.copysign(self) }
1520    }
1521
1522    /// Returns a number composed of the magnitude of `self` and the sign of
1523    /// `sign`.
1524    ///
1525    /// Equal to `self` if the sign of `self` and `sign` are the same, otherwise equal to `-self`.
1526    /// If `self` is a NaN, then a NaN with the same payload as `self` and the sign bit of `sign` is
1527    /// returned.
1528    ///
1529    /// If `sign` is a NaN, then this operation will still carry over its sign into the result. Note
1530    /// that IEEE 754 doesn't assign any meaning to the sign bit in case of a NaN, and as Rust
1531    /// doesn't guarantee that the bit pattern of NaNs are conserved over arithmetic operations, the
1532    /// result of `copysign` with `sign` being a NaN might produce an unexpected or non-portable
1533    /// result. See the [specification of NaN bit patterns](primitive@f32#nan-bit-patterns) for more
1534    /// info.
1535    ///
1536    /// # Examples
1537    ///
1538    /// ```
1539    /// let f = 3.5_f32;
1540    ///
1541    /// assert_eq!(f.copysign(0.42), 3.5_f32);
1542    /// assert_eq!(f.copysign(-0.42), -3.5_f32);
1543    /// assert_eq!((-f).copysign(0.42), 3.5_f32);
1544    /// assert_eq!((-f).copysign(-0.42), -3.5_f32);
1545    ///
1546    /// assert!(f32::NAN.copysign(1.0).is_nan());
1547    /// ```
1548    #[must_use = "method returns a new number and does not mutate the original value"]
1549    #[inline]
1550    #[stable(feature = "copysign", since = "1.35.0")]
1551    #[rustc_const_stable(feature = "const_float_methods", since = "1.85.0")]
1552    #[cfg(not(feature = "ferrocene_certified"))]
1553    pub const fn copysign(self, sign: f32) -> f32 {
1554        intrinsics::copysignf32(self, sign)
1555    }
1556
1557    /// Float addition that allows optimizations based on algebraic rules.
1558    ///
1559    /// See [algebraic operators](primitive@f32#algebraic-operators) for more info.
1560    #[must_use = "method returns a new number and does not mutate the original value"]
1561    #[unstable(feature = "float_algebraic", issue = "136469")]
1562    #[rustc_const_unstable(feature = "float_algebraic", issue = "136469")]
1563    #[inline]
1564    #[cfg(not(feature = "ferrocene_certified"))]
1565    pub const fn algebraic_add(self, rhs: f32) -> f32 {
1566        intrinsics::fadd_algebraic(self, rhs)
1567    }
1568
1569    /// Float subtraction that allows optimizations based on algebraic rules.
1570    ///
1571    /// See [algebraic operators](primitive@f32#algebraic-operators) for more info.
1572    #[must_use = "method returns a new number and does not mutate the original value"]
1573    #[unstable(feature = "float_algebraic", issue = "136469")]
1574    #[rustc_const_unstable(feature = "float_algebraic", issue = "136469")]
1575    #[inline]
1576    #[cfg(not(feature = "ferrocene_certified"))]
1577    pub const fn algebraic_sub(self, rhs: f32) -> f32 {
1578        intrinsics::fsub_algebraic(self, rhs)
1579    }
1580
1581    /// Float multiplication that allows optimizations based on algebraic rules.
1582    ///
1583    /// See [algebraic operators](primitive@f32#algebraic-operators) for more info.
1584    #[must_use = "method returns a new number and does not mutate the original value"]
1585    #[unstable(feature = "float_algebraic", issue = "136469")]
1586    #[rustc_const_unstable(feature = "float_algebraic", issue = "136469")]
1587    #[inline]
1588    #[cfg(not(feature = "ferrocene_certified"))]
1589    pub const fn algebraic_mul(self, rhs: f32) -> f32 {
1590        intrinsics::fmul_algebraic(self, rhs)
1591    }
1592
1593    /// Float division that allows optimizations based on algebraic rules.
1594    ///
1595    /// See [algebraic operators](primitive@f32#algebraic-operators) for more info.
1596    #[must_use = "method returns a new number and does not mutate the original value"]
1597    #[unstable(feature = "float_algebraic", issue = "136469")]
1598    #[rustc_const_unstable(feature = "float_algebraic", issue = "136469")]
1599    #[inline]
1600    #[cfg(not(feature = "ferrocene_certified"))]
1601    pub const fn algebraic_div(self, rhs: f32) -> f32 {
1602        intrinsics::fdiv_algebraic(self, rhs)
1603    }
1604
1605    /// Float remainder that allows optimizations based on algebraic rules.
1606    ///
1607    /// See [algebraic operators](primitive@f32#algebraic-operators) for more info.
1608    #[must_use = "method returns a new number and does not mutate the original value"]
1609    #[unstable(feature = "float_algebraic", issue = "136469")]
1610    #[rustc_const_unstable(feature = "float_algebraic", issue = "136469")]
1611    #[inline]
1612    #[cfg(not(feature = "ferrocene_certified"))]
1613    pub const fn algebraic_rem(self, rhs: f32) -> f32 {
1614        intrinsics::frem_algebraic(self, rhs)
1615    }
1616}
1617
1618/// Experimental implementations of floating point functions in `core`.
1619///
1620/// _The standalone functions in this module are for testing only.
1621/// They will be stabilized as inherent methods._
1622#[unstable(feature = "core_float_math", issue = "137578")]
1623#[cfg(not(feature = "ferrocene_certified"))]
1624pub mod math {
1625    use crate::intrinsics;
1626    use crate::num::libm;
1627
1628    /// Experimental version of `floor` in `core`. See [`f32::floor`] for details.
1629    ///
1630    /// # Examples
1631    ///
1632    /// ```
1633    /// #![feature(core_float_math)]
1634    ///
1635    /// use core::f32;
1636    ///
1637    /// let f = 3.7_f32;
1638    /// let g = 3.0_f32;
1639    /// let h = -3.7_f32;
1640    ///
1641    /// assert_eq!(f32::math::floor(f), 3.0);
1642    /// assert_eq!(f32::math::floor(g), 3.0);
1643    /// assert_eq!(f32::math::floor(h), -4.0);
1644    /// ```
1645    ///
1646    /// _This standalone function is for testing only.
1647    /// It will be stabilized as an inherent method._
1648    ///
1649    /// [`f32::floor`]: ../../../std/primitive.f32.html#method.floor
1650    #[inline]
1651    #[unstable(feature = "core_float_math", issue = "137578")]
1652    #[must_use = "method returns a new number and does not mutate the original value"]
1653    pub const fn floor(x: f32) -> f32 {
1654        intrinsics::floorf32(x)
1655    }
1656
1657    /// Experimental version of `ceil` in `core`. See [`f32::ceil`] for details.
1658    ///
1659    /// # Examples
1660    ///
1661    /// ```
1662    /// #![feature(core_float_math)]
1663    ///
1664    /// use core::f32;
1665    ///
1666    /// let f = 3.01_f32;
1667    /// let g = 4.0_f32;
1668    ///
1669    /// assert_eq!(f32::math::ceil(f), 4.0);
1670    /// assert_eq!(f32::math::ceil(g), 4.0);
1671    /// ```
1672    ///
1673    /// _This standalone function is for testing only.
1674    /// It will be stabilized as an inherent method._
1675    ///
1676    /// [`f32::ceil`]: ../../../std/primitive.f32.html#method.ceil
1677    #[inline]
1678    #[doc(alias = "ceiling")]
1679    #[must_use = "method returns a new number and does not mutate the original value"]
1680    #[unstable(feature = "core_float_math", issue = "137578")]
1681    pub const fn ceil(x: f32) -> f32 {
1682        intrinsics::ceilf32(x)
1683    }
1684
1685    /// Experimental version of `round` in `core`. See [`f32::round`] for details.
1686    ///
1687    /// # Examples
1688    ///
1689    /// ```
1690    /// #![feature(core_float_math)]
1691    ///
1692    /// use core::f32;
1693    ///
1694    /// let f = 3.3_f32;
1695    /// let g = -3.3_f32;
1696    /// let h = -3.7_f32;
1697    /// let i = 3.5_f32;
1698    /// let j = 4.5_f32;
1699    ///
1700    /// assert_eq!(f32::math::round(f), 3.0);
1701    /// assert_eq!(f32::math::round(g), -3.0);
1702    /// assert_eq!(f32::math::round(h), -4.0);
1703    /// assert_eq!(f32::math::round(i), 4.0);
1704    /// assert_eq!(f32::math::round(j), 5.0);
1705    /// ```
1706    ///
1707    /// _This standalone function is for testing only.
1708    /// It will be stabilized as an inherent method._
1709    ///
1710    /// [`f32::round`]: ../../../std/primitive.f32.html#method.round
1711    #[inline]
1712    #[unstable(feature = "core_float_math", issue = "137578")]
1713    #[must_use = "method returns a new number and does not mutate the original value"]
1714    pub const fn round(x: f32) -> f32 {
1715        intrinsics::roundf32(x)
1716    }
1717
1718    /// Experimental version of `round_ties_even` in `core`. See [`f32::round_ties_even`] for
1719    /// details.
1720    ///
1721    /// # Examples
1722    ///
1723    /// ```
1724    /// #![feature(core_float_math)]
1725    ///
1726    /// use core::f32;
1727    ///
1728    /// let f = 3.3_f32;
1729    /// let g = -3.3_f32;
1730    /// let h = 3.5_f32;
1731    /// let i = 4.5_f32;
1732    ///
1733    /// assert_eq!(f32::math::round_ties_even(f), 3.0);
1734    /// assert_eq!(f32::math::round_ties_even(g), -3.0);
1735    /// assert_eq!(f32::math::round_ties_even(h), 4.0);
1736    /// assert_eq!(f32::math::round_ties_even(i), 4.0);
1737    /// ```
1738    ///
1739    /// _This standalone function is for testing only.
1740    /// It will be stabilized as an inherent method._
1741    ///
1742    /// [`f32::round_ties_even`]: ../../../std/primitive.f32.html#method.round_ties_even
1743    #[inline]
1744    #[unstable(feature = "core_float_math", issue = "137578")]
1745    #[must_use = "method returns a new number and does not mutate the original value"]
1746    pub const fn round_ties_even(x: f32) -> f32 {
1747        intrinsics::round_ties_even_f32(x)
1748    }
1749
1750    /// Experimental version of `trunc` in `core`. See [`f32::trunc`] for details.
1751    ///
1752    /// # Examples
1753    ///
1754    /// ```
1755    /// #![feature(core_float_math)]
1756    ///
1757    /// use core::f32;
1758    ///
1759    /// let f = 3.7_f32;
1760    /// let g = 3.0_f32;
1761    /// let h = -3.7_f32;
1762    ///
1763    /// assert_eq!(f32::math::trunc(f), 3.0);
1764    /// assert_eq!(f32::math::trunc(g), 3.0);
1765    /// assert_eq!(f32::math::trunc(h), -3.0);
1766    /// ```
1767    ///
1768    /// _This standalone function is for testing only.
1769    /// It will be stabilized as an inherent method._
1770    ///
1771    /// [`f32::trunc`]: ../../../std/primitive.f32.html#method.trunc
1772    #[inline]
1773    #[doc(alias = "truncate")]
1774    #[must_use = "method returns a new number and does not mutate the original value"]
1775    #[unstable(feature = "core_float_math", issue = "137578")]
1776    pub const fn trunc(x: f32) -> f32 {
1777        intrinsics::truncf32(x)
1778    }
1779
1780    /// Experimental version of `fract` in `core`. See [`f32::fract`] for details.
1781    ///
1782    /// # Examples
1783    ///
1784    /// ```
1785    /// #![feature(core_float_math)]
1786    ///
1787    /// use core::f32;
1788    ///
1789    /// let x = 3.6_f32;
1790    /// let y = -3.6_f32;
1791    /// let abs_difference_x = (f32::math::fract(x) - 0.6).abs();
1792    /// let abs_difference_y = (f32::math::fract(y) - (-0.6)).abs();
1793    ///
1794    /// assert!(abs_difference_x <= f32::EPSILON);
1795    /// assert!(abs_difference_y <= f32::EPSILON);
1796    /// ```
1797    ///
1798    /// _This standalone function is for testing only.
1799    /// It will be stabilized as an inherent method._
1800    ///
1801    /// [`f32::fract`]: ../../../std/primitive.f32.html#method.fract
1802    #[inline]
1803    #[unstable(feature = "core_float_math", issue = "137578")]
1804    #[must_use = "method returns a new number and does not mutate the original value"]
1805    pub const fn fract(x: f32) -> f32 {
1806        x - trunc(x)
1807    }
1808
1809    /// Experimental version of `mul_add` in `core`. See [`f32::mul_add`] for details.
1810    ///
1811    /// # Examples
1812    ///
1813    /// ```
1814    /// #![feature(core_float_math)]
1815    ///
1816    /// # // FIXME(#140515): mingw has an incorrect fma
1817    /// # // https://sourceforge.net/p/mingw-w64/bugs/848/
1818    /// # #[cfg(all(target_os = "windows", target_env = "gnu", not(target_abi = "llvm")))] {
1819    /// use core::f32;
1820    ///
1821    /// let m = 10.0_f32;
1822    /// let x = 4.0_f32;
1823    /// let b = 60.0_f32;
1824    ///
1825    /// assert_eq!(f32::math::mul_add(m, x, b), 100.0);
1826    /// assert_eq!(m * x + b, 100.0);
1827    ///
1828    /// let one_plus_eps = 1.0_f32 + f32::EPSILON;
1829    /// let one_minus_eps = 1.0_f32 - f32::EPSILON;
1830    /// let minus_one = -1.0_f32;
1831    ///
1832    /// // The exact result (1 + eps) * (1 - eps) = 1 - eps * eps.
1833    /// assert_eq!(
1834    ///     f32::math::mul_add(one_plus_eps, one_minus_eps, minus_one),
1835    ///     -f32::EPSILON * f32::EPSILON
1836    /// );
1837    /// // Different rounding with the non-fused multiply and add.
1838    /// assert_eq!(one_plus_eps * one_minus_eps + minus_one, 0.0);
1839    /// # }
1840    /// ```
1841    ///
1842    /// _This standalone function is for testing only.
1843    /// It will be stabilized as an inherent method._
1844    ///
1845    /// [`f32::mul_add`]: ../../../std/primitive.f32.html#method.mul_add
1846    #[inline]
1847    #[doc(alias = "fmaf", alias = "fusedMultiplyAdd")]
1848    #[must_use = "method returns a new number and does not mutate the original value"]
1849    #[unstable(feature = "core_float_math", issue = "137578")]
1850    #[rustc_const_unstable(feature = "const_mul_add", issue = "146724")]
1851    pub const fn mul_add(x: f32, y: f32, z: f32) -> f32 {
1852        intrinsics::fmaf32(x, y, z)
1853    }
1854
1855    /// Experimental version of `div_euclid` in `core`. See [`f32::div_euclid`] for details.
1856    ///
1857    /// # Examples
1858    ///
1859    /// ```
1860    /// #![feature(core_float_math)]
1861    ///
1862    /// use core::f32;
1863    ///
1864    /// let a: f32 = 7.0;
1865    /// let b = 4.0;
1866    /// assert_eq!(f32::math::div_euclid(a, b), 1.0); // 7.0 > 4.0 * 1.0
1867    /// assert_eq!(f32::math::div_euclid(-a, b), -2.0); // -7.0 >= 4.0 * -2.0
1868    /// assert_eq!(f32::math::div_euclid(a, -b), -1.0); // 7.0 >= -4.0 * -1.0
1869    /// assert_eq!(f32::math::div_euclid(-a, -b), 2.0); // -7.0 >= -4.0 * 2.0
1870    /// ```
1871    ///
1872    /// _This standalone function is for testing only.
1873    /// It will be stabilized as an inherent method._
1874    ///
1875    /// [`f32::div_euclid`]: ../../../std/primitive.f32.html#method.div_euclid
1876    #[inline]
1877    #[unstable(feature = "core_float_math", issue = "137578")]
1878    #[must_use = "method returns a new number and does not mutate the original value"]
1879    pub fn div_euclid(x: f32, rhs: f32) -> f32 {
1880        let q = trunc(x / rhs);
1881        if x % rhs < 0.0 {
1882            return if rhs > 0.0 { q - 1.0 } else { q + 1.0 };
1883        }
1884        q
1885    }
1886
1887    /// Experimental version of `rem_euclid` in `core`. See [`f32::rem_euclid`] for details.
1888    ///
1889    /// # Examples
1890    ///
1891    /// ```
1892    /// #![feature(core_float_math)]
1893    ///
1894    /// use core::f32;
1895    ///
1896    /// let a: f32 = 7.0;
1897    /// let b = 4.0;
1898    /// assert_eq!(f32::math::rem_euclid(a, b), 3.0);
1899    /// assert_eq!(f32::math::rem_euclid(-a, b), 1.0);
1900    /// assert_eq!(f32::math::rem_euclid(a, -b), 3.0);
1901    /// assert_eq!(f32::math::rem_euclid(-a, -b), 1.0);
1902    /// // limitation due to round-off error
1903    /// assert!(f32::math::rem_euclid(-f32::EPSILON, 3.0) != 0.0);
1904    /// ```
1905    ///
1906    /// _This standalone function is for testing only.
1907    /// It will be stabilized as an inherent method._
1908    ///
1909    /// [`f32::rem_euclid`]: ../../../std/primitive.f32.html#method.rem_euclid
1910    #[inline]
1911    #[doc(alias = "modulo", alias = "mod")]
1912    #[unstable(feature = "core_float_math", issue = "137578")]
1913    #[must_use = "method returns a new number and does not mutate the original value"]
1914    pub fn rem_euclid(x: f32, rhs: f32) -> f32 {
1915        let r = x % rhs;
1916        if r < 0.0 { r + rhs.abs() } else { r }
1917    }
1918
1919    /// Experimental version of `powi` in `core`. See [`f32::powi`] for details.
1920    ///
1921    /// # Examples
1922    ///
1923    /// ```
1924    /// #![feature(core_float_math)]
1925    ///
1926    /// use core::f32;
1927    ///
1928    /// let x = 2.0_f32;
1929    /// let abs_difference = (f32::math::powi(x, 2) - (x * x)).abs();
1930    /// assert!(abs_difference <= 1e-5);
1931    ///
1932    /// assert_eq!(f32::math::powi(f32::NAN, 0), 1.0);
1933    /// ```
1934    ///
1935    /// _This standalone function is for testing only.
1936    /// It will be stabilized as an inherent method._
1937    ///
1938    /// [`f32::powi`]: ../../../std/primitive.f32.html#method.powi
1939    #[inline]
1940    #[must_use = "method returns a new number and does not mutate the original value"]
1941    #[unstable(feature = "core_float_math", issue = "137578")]
1942    pub fn powi(x: f32, n: i32) -> f32 {
1943        intrinsics::powif32(x, n)
1944    }
1945
1946    /// Experimental version of `sqrt` in `core`. See [`f32::sqrt`] for details.
1947    ///
1948    /// # Examples
1949    ///
1950    /// ```
1951    /// #![feature(core_float_math)]
1952    ///
1953    /// use core::f32;
1954    ///
1955    /// let positive = 4.0_f32;
1956    /// let negative = -4.0_f32;
1957    /// let negative_zero = -0.0_f32;
1958    ///
1959    /// assert_eq!(f32::math::sqrt(positive), 2.0);
1960    /// assert!(f32::math::sqrt(negative).is_nan());
1961    /// assert_eq!(f32::math::sqrt(negative_zero), negative_zero);
1962    /// ```
1963    ///
1964    /// _This standalone function is for testing only.
1965    /// It will be stabilized as an inherent method._
1966    ///
1967    /// [`f32::sqrt`]: ../../../std/primitive.f32.html#method.sqrt
1968    #[inline]
1969    #[doc(alias = "squareRoot")]
1970    #[unstable(feature = "core_float_math", issue = "137578")]
1971    #[must_use = "method returns a new number and does not mutate the original value"]
1972    pub fn sqrt(x: f32) -> f32 {
1973        intrinsics::sqrtf32(x)
1974    }
1975
1976    /// Experimental version of `abs_sub` in `core`. See [`f32::abs_sub`] for details.
1977    ///
1978    /// # Examples
1979    ///
1980    /// ```
1981    /// #![feature(core_float_math)]
1982    ///
1983    /// use core::f32;
1984    ///
1985    /// let x = 3.0f32;
1986    /// let y = -3.0f32;
1987    ///
1988    /// let abs_difference_x = (f32::math::abs_sub(x, 1.0) - 2.0).abs();
1989    /// let abs_difference_y = (f32::math::abs_sub(y, 1.0) - 0.0).abs();
1990    ///
1991    /// assert!(abs_difference_x <= 1e-6);
1992    /// assert!(abs_difference_y <= 1e-6);
1993    /// ```
1994    ///
1995    /// _This standalone function is for testing only.
1996    /// It will be stabilized as an inherent method._
1997    ///
1998    /// [`f32::abs_sub`]: ../../../std/primitive.f32.html#method.abs_sub
1999    #[inline]
2000    #[stable(feature = "rust1", since = "1.0.0")]
2001    #[deprecated(
2002        since = "1.10.0",
2003        note = "you probably meant `(self - other).abs()`: \
2004            this operation is `(self - other).max(0.0)` \
2005            except that `abs_sub` also propagates NaNs (also \
2006            known as `fdimf` in C). If you truly need the positive \
2007            difference, consider using that expression or the C function \
2008            `fdimf`, depending on how you wish to handle NaN (please consider \
2009            filing an issue describing your use-case too)."
2010    )]
2011    #[must_use = "method returns a new number and does not mutate the original value"]
2012    pub fn abs_sub(x: f32, other: f32) -> f32 {
2013        libm::fdimf(x, other)
2014    }
2015
2016    /// Experimental version of `cbrt` in `core`. See [`f32::cbrt`] for details.
2017    ///
2018    /// # Unspecified precision
2019    ///
2020    /// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
2021    /// can even differ within the same execution from one invocation to the next.
2022    /// This function currently corresponds to the `cbrtf` from libc on Unix
2023    /// and Windows. Note that this might change in the future.
2024    ///
2025    /// # Examples
2026    ///
2027    /// ```
2028    /// #![feature(core_float_math)]
2029    ///
2030    /// use core::f32;
2031    ///
2032    /// let x = 8.0f32;
2033    ///
2034    /// // x^(1/3) - 2 == 0
2035    /// let abs_difference = (f32::math::cbrt(x) - 2.0).abs();
2036    ///
2037    /// assert!(abs_difference <= 1e-6);
2038    /// ```
2039    ///
2040    /// _This standalone function is for testing only.
2041    /// It will be stabilized as an inherent method._
2042    ///
2043    /// [`f32::cbrt`]: ../../../std/primitive.f32.html#method.cbrt
2044    #[inline]
2045    #[must_use = "method returns a new number and does not mutate the original value"]
2046    #[unstable(feature = "core_float_math", issue = "137578")]
2047    pub fn cbrt(x: f32) -> f32 {
2048        libm::cbrtf(x)
2049    }
2050}