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f*::min/max: fix comparing with libm and IEEE operations #149563

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24 changes: 8 additions & 16 deletions library/core/src/intrinsics/mod.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -2949,8 +2949,7 @@ pub const unsafe fn write_bytes<T>(dst: *mut T, val: u8, count: usize);

/// Returns the minimum of two `f16` values, ignoring NaN.
///
/// This behaves like IEEE 754-2008 minNum. In particular:
/// If one of the arguments is NaN, then the other argument is returned. If the inputs compare equal
/// If one of the arguments is NaN (quiet or signaling), then the other argument is returned. If the inputs compare equal
/// (such as for the case of `+0.0` and `-0.0`), either input may be returned non-deterministically.
Comment on lines 2950 to 2953
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@tgross35 tgross35 Dec 5, 2025

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Is it worth also mentioning the (NaN,NaN) case? Similar to #149477

///
/// Note that, unlike most intrinsics, this is safe to call;
Expand All @@ -2965,8 +2964,7 @@ pub const fn minnumf16(x: f16, y: f16) -> f16;

/// Returns the minimum of two `f32` values, ignoring NaN.
///
/// This behaves like IEEE 754-2008 minNum. In particular:
/// If one of the arguments is NaN, then the other argument is returned. If the inputs compare equal
/// If one of the arguments is NaN (quiet or signaling), then the other argument is returned. If the inputs compare equal
/// (such as for the case of `+0.0` and `-0.0`), either input may be returned non-deterministically.
///
/// Note that, unlike most intrinsics, this is safe to call;
Expand All @@ -2982,8 +2980,7 @@ pub const fn minnumf32(x: f32, y: f32) -> f32;

/// Returns the minimum of two `f64` values, ignoring NaN.
///
/// This behaves like IEEE 754-2008 minNum. In particular:
/// If one of the arguments is NaN, then the other argument is returned. If the inputs compare equal
/// If one of the arguments is NaN (quiet or signaling), then the other argument is returned. If the inputs compare equal
/// (such as for the case of `+0.0` and `-0.0`), either input may be returned non-deterministically.
///
/// Note that, unlike most intrinsics, this is safe to call;
Expand All @@ -2999,8 +2996,7 @@ pub const fn minnumf64(x: f64, y: f64) -> f64;

/// Returns the minimum of two `f128` values, ignoring NaN.
///
/// This behaves like IEEE 754-2008 minNum. In particular:
/// If one of the arguments is NaN, then the other argument is returned. If the inputs compare equal
/// If one of the arguments is NaN (quiet or signaling), then the other argument is returned. If the inputs compare equal
/// (such as for the case of `+0.0` and `-0.0`), either input may be returned non-deterministically.
///
/// Note that, unlike most intrinsics, this is safe to call;
Expand Down Expand Up @@ -3115,8 +3111,7 @@ pub const fn minimumf128(x: f128, y: f128) -> f128 {

/// Returns the maximum of two `f16` values, ignoring NaN.
///
/// This behaves like IEEE 754-2008 maxNum. In particular:
/// If one of the arguments is NaN, then the other argument is returned. If the inputs compare equal
/// If one of the arguments is NaN (quiet or signaling), then the other argument is returned. If the inputs compare equal
/// (such as for the case of `+0.0` and `-0.0`), either input may be returned non-deterministically.
///
/// Note that, unlike most intrinsics, this is safe to call;
Expand All @@ -3131,8 +3126,7 @@ pub const fn maxnumf16(x: f16, y: f16) -> f16;

/// Returns the maximum of two `f32` values, ignoring NaN.
///
/// This behaves like IEEE 754-2008 maxNum. In particular:
/// If one of the arguments is NaN, then the other argument is returned. If the inputs compare equal
/// If one of the arguments is NaN (quiet or signaling), then the other argument is returned. If the inputs compare equal
/// (such as for the case of `+0.0` and `-0.0`), either input may be returned non-deterministically.
///
/// Note that, unlike most intrinsics, this is safe to call;
Expand All @@ -3148,8 +3142,7 @@ pub const fn maxnumf32(x: f32, y: f32) -> f32;

/// Returns the maximum of two `f64` values, ignoring NaN.
///
/// This behaves like IEEE 754-2008 maxNum. In particular:
/// If one of the arguments is NaN, then the other argument is returned. If the inputs compare equal
/// If one of the arguments is NaN (quiet or signaling), then the other argument is returned. If the inputs compare equal
/// (such as for the case of `+0.0` and `-0.0`), either input may be returned non-deterministically.
///
/// Note that, unlike most intrinsics, this is safe to call;
Expand All @@ -3165,8 +3158,7 @@ pub const fn maxnumf64(x: f64, y: f64) -> f64;

/// Returns the maximum of two `f128` values, ignoring NaN.
///
/// This behaves like IEEE 754-2008 maxNum. In particular:
/// If one of the arguments is NaN, then the other argument is returned. If the inputs compare equal
/// If one of the arguments is NaN (quiet or signaling), then the other argument is returned. If the inputs compare equal
/// (such as for the case of `+0.0` and `-0.0`), either input may be returned non-deterministically.
///
/// Note that, unlike most intrinsics, this is safe to call;
Expand Down
30 changes: 16 additions & 14 deletions library/core/src/num/f128.rs
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Expand Up @@ -694,14 +694,15 @@ impl f128 {

/// Returns the maximum of the two numbers, ignoring NaN.
///
/// If exactly one of the arguments is NaN, then the other argument is returned. If both
/// arguments are NaN, the return value is NaN, with the bit pattern picked using the usual
/// [rules for arithmetic operations](f32#nan-bit-patterns). If the inputs compare equal (such
/// as for the case of `+0.0` and `-0.0`), either input may be returned non-deterministically.
/// If exactly one of the arguments is NaN (quiet or signaling), then the other argument is
/// returned. If both arguments are NaN, the return value is NaN, with the bit pattern picked
/// using the usual [rules for arithmetic operations](f32#nan-bit-patterns). If the inputs
/// compare equal (such as for the case of `+0.0` and `-0.0`), either input may be returned
/// non-deterministically.
///
/// This follows the IEEE 754-2008 semantics for `maxNum`, except for handling of signaling NaNs;
/// this function handles all NaNs the same way and avoids `maxNum`'s problems with associativity.
/// This also matches the behavior of libm’s `fmax`.
/// The handling of NaNs follows the IEEE 754-2019 semantics for `maximumNumber`, treating all
/// NaNs the same way to ensure the operation is associative. The handling of signed zeros
/// follows the IEEE 754-2008 semantics for `maxNum`.
///
/// ```
/// #![feature(f128)]
Expand All @@ -725,14 +726,15 @@ impl f128 {

/// Returns the minimum of the two numbers, ignoring NaN.
///
/// If exactly one of the arguments is NaN, then the other argument is returned. If both
/// arguments are NaN, the return value is NaN, with the bit pattern picked using the usual
/// [rules for arithmetic operations](f32#nan-bit-patterns). If the inputs compare equal (such
/// as for the case of `+0.0` and `-0.0`), either input may be returned non-deterministically.
/// If exactly one of the arguments is NaN (quiet or signaling), then the other argument is
/// returned. If both arguments are NaN, the return value is NaN, with the bit pattern picked
/// using the usual [rules for arithmetic operations](f32#nan-bit-patterns). If the inputs
/// compare equal (such as for the case of `+0.0` and `-0.0`), either input may be returned
/// non-deterministically.
///
/// This follows the IEEE 754-2008 semantics for `minNum`, except for handling of signaling NaNs;
/// this function handles all NaNs the same way and avoids `minNum`'s problems with associativity.
/// This also matches the behavior of libm’s `fmin`.
/// The handling of NaNs follows the IEEE 754-2019 semantics for `minimumNumber`, treating all
/// NaNs the same way to ensure the operation is associative. The handling of signed zeros
/// follows the IEEE 754-2008 semantics for `minNum`.
///
/// ```
/// #![feature(f128)]
Expand Down
30 changes: 16 additions & 14 deletions library/core/src/num/f16.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -687,14 +687,15 @@ impl f16 {

/// Returns the maximum of the two numbers, ignoring NaN.
///
/// If exactly one of the arguments is NaN, then the other argument is returned. If both
/// arguments are NaN, the return value is NaN, with the bit pattern picked using the usual
/// [rules for arithmetic operations](f32#nan-bit-patterns). If the inputs compare equal (such
/// as for the case of `+0.0` and `-0.0`), either input may be returned non-deterministically.
/// If exactly one of the arguments is NaN (quiet or signaling), then the other argument is
/// returned. If both arguments are NaN, the return value is NaN, with the bit pattern picked
/// using the usual [rules for arithmetic operations](f32#nan-bit-patterns). If the inputs
/// compare equal (such as for the case of `+0.0` and `-0.0`), either input may be returned
/// non-deterministically.
///
/// This follows the IEEE 754-2008 semantics for `maxNum`, except for handling of signaling NaNs;
/// this function handles all NaNs the same way and avoids `maxNum`'s problems with associativity.
/// This also matches the behavior of libm’s `fmax`.
/// The handling of NaNs follows the IEEE 754-2019 semantics for `maximumNumber`, treating all
/// NaNs the same way to ensure the operation is associative. The handling of signed zeros
/// follows the IEEE 754-2008 semantics for `maxNum`.
///
/// ```
/// #![feature(f16)]
Expand All @@ -717,14 +718,15 @@ impl f16 {

/// Returns the minimum of the two numbers, ignoring NaN.
///
/// If exactly one of the arguments is NaN, then the other argument is returned. If both
/// arguments are NaN, the return value is NaN, with the bit pattern picked using the usual
/// [rules for arithmetic operations](f32#nan-bit-patterns). If the inputs compare equal (such
/// as for the case of `+0.0` and `-0.0`), either input may be returned non-deterministically.
/// If exactly one of the arguments is NaN (quiet or signaling), then the other argument is
/// returned. If both arguments are NaN, the return value is NaN, with the bit pattern picked
/// using the usual [rules for arithmetic operations](f32#nan-bit-patterns). If the inputs
/// compare equal (such as for the case of `+0.0` and `-0.0`), either input may be returned
/// non-deterministically.
///
/// This follows the IEEE 754-2008 semantics for `minNum`, except for handling of signaling NaNs;
/// this function handles all NaNs the same way and avoids `minNum`'s problems with associativity.
/// This also matches the behavior of libm’s `fmin`.
/// The handling of NaNs follows the IEEE 754-2019 semantics for `minimumNumber`, treating all
/// NaNs the same way to ensure the operation is associative. The handling of signed zeros
/// follows the IEEE 754-2008 semantics for `minNum`.
///
/// ```
/// #![feature(f16)]
Expand Down
30 changes: 16 additions & 14 deletions library/core/src/num/f32.rs
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Expand Up @@ -897,14 +897,15 @@ impl f32 {

/// Returns the maximum of the two numbers, ignoring NaN.
///
/// If exactly one of the arguments is NaN, then the other argument is returned. If both
/// arguments are NaN, the return value is NaN, with the bit pattern picked using the usual
/// [rules for arithmetic operations](f32#nan-bit-patterns). If the inputs compare equal (such
/// as for the case of `+0.0` and `-0.0`), either input may be returned non-deterministically.
/// If exactly one of the arguments is NaN (quiet or signaling), then the other argument is
/// returned. If both arguments are NaN, the return value is NaN, with the bit pattern picked
/// using the usual [rules for arithmetic operations](f32#nan-bit-patterns). If the inputs
/// compare equal (such as for the case of `+0.0` and `-0.0`), either input may be returned
/// non-deterministically.
///
/// This follows the IEEE 754-2008 semantics for `maxNum`, except for handling of signaling NaNs;
/// this function handles all NaNs the same way and avoids `maxNum`'s problems with associativity.
/// This also matches the behavior of libm’s `fmax`.
/// The handling of NaNs follows the IEEE 754-2019 semantics for `maximumNumber`, treating all
/// NaNs the same way to ensure the operation is associative. The handling of signed zeros
/// follows the IEEE 754-2008 semantics for `maxNum`.
///
/// ```
/// let x = 1.0f32;
Expand All @@ -923,14 +924,15 @@ impl f32 {

/// Returns the minimum of the two numbers, ignoring NaN.
///
/// If exactly one of the arguments is NaN, then the other argument is returned. If both
/// arguments are NaN, the return value is NaN, with the bit pattern picked using the usual
/// [rules for arithmetic operations](f32#nan-bit-patterns). If the inputs compare equal (such
/// as for the case of `+0.0` and `-0.0`), either input may be returned non-deterministically.
/// If exactly one of the arguments is NaN (quiet or signaling), then the other argument is
/// returned. If both arguments are NaN, the return value is NaN, with the bit pattern picked
/// using the usual [rules for arithmetic operations](f32#nan-bit-patterns). If the inputs
/// compare equal (such as for the case of `+0.0` and `-0.0`), either input may be returned
/// non-deterministically.
///
/// This follows the IEEE 754-2008 semantics for `minNum`, except for handling of signaling NaNs;
/// this function handles all NaNs the same way and avoids `minNum`'s problems with associativity.
/// This also matches the behavior of libm’s `fmin`.
/// The handling of NaNs follows the IEEE 754-2019 semantics for `minimumNumber`, treating all
/// NaNs the same way to ensure the operation is associative. The handling of signed zeros
/// follows the IEEE 754-2008 semantics for `minNum`.
///
/// ```
/// let x = 1.0f32;
Expand Down
30 changes: 16 additions & 14 deletions library/core/src/num/f64.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -915,14 +915,15 @@ impl f64 {

/// Returns the maximum of the two numbers, ignoring NaN.
///
/// If exactly one of the arguments is NaN, then the other argument is returned. If both
/// arguments are NaN, the return value is NaN, with the bit pattern picked using the usual
/// [rules for arithmetic operations](f32#nan-bit-patterns). If the inputs compare equal (such
/// as for the case of `+0.0` and `-0.0`), either input may be returned non-deterministically.
/// If exactly one of the arguments is NaN (quiet or signaling), then the other argument is
/// returned. If both arguments are NaN, the return value is NaN, with the bit pattern picked
/// using the usual [rules for arithmetic operations](f32#nan-bit-patterns). If the inputs
/// compare equal (such as for the case of `+0.0` and `-0.0`), either input may be returned
/// non-deterministically.
///
/// This follows the IEEE 754-2008 semantics for `maxNum`, except for handling of signaling NaNs;
/// this function handles all NaNs the same way and avoids `maxNum`'s problems with associativity.
/// This also matches the behavior of libm’s `fmax`.
/// The handling of NaNs follows the IEEE 754-2019 semantics for `maximumNumber`, treating all
/// NaNs the same way to ensure the operation is associative. The handling of signed zeros
/// follows the IEEE 754-2008 semantics for `maxNum`.
///
/// ```
/// let x = 1.0_f64;
Expand All @@ -941,14 +942,15 @@ impl f64 {

/// Returns the minimum of the two numbers, ignoring NaN.
///
/// If exactly one of the arguments is NaN, then the other argument is returned. If both
/// arguments are NaN, the return value is NaN, with the bit pattern picked using the usual
/// [rules for arithmetic operations](f32#nan-bit-patterns). If the inputs compare equal (such
/// as for the case of `+0.0` and `-0.0`), either input may be returned non-deterministically.
/// If exactly one of the arguments is NaN (quiet or signaling), then the other argument is
/// returned. If both arguments are NaN, the return value is NaN, with the bit pattern picked
/// using the usual [rules for arithmetic operations](f32#nan-bit-patterns). If the inputs
/// compare equal (such as for the case of `+0.0` and `-0.0`), either input may be returned
/// non-deterministically.
///
/// This follows the IEEE 754-2008 semantics for `minNum`, except for handling of signaling NaNs;
/// this function handles all NaNs the same way and avoids `minNum`'s problems with associativity.
/// This also matches the behavior of libm’s `fmin`.
/// The handling of NaNs follows the IEEE 754-2019 semantics for `minimumNumber`, treating all
/// NaNs the same way to ensure the operation is associative. The handling of signed zeros
/// follows the IEEE 754-2008 semantics for `minNum`.
///
/// ```
/// let x = 1.0_f64;
Expand Down
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