Auto merge of #72449 - ecstatic-morse:const-float-bitcast, r=RalfJung

Const floating point bitcasts and classification

Makes the `f32` and `f64` methods described in #72447 and #72505 unstably const.

r? @RalfJung

5 files changed, 238 insertions, 34 deletions

diff --git a/library/core/src/lib.rs b/library/core/src/lib.rs
index 19cd05de2a7..99f8cc66638 100644
--- a/library/core/src/lib.rs
+++ b/library/core/src/lib.rs
@@ -73,6 +73,8 @@
 #![feature(const_discriminant)]
 #![feature(const_checked_int_methods)]
 #![feature(const_euclidean_int_methods)]
+#![feature(const_float_classify)]
+#![feature(const_float_bits_conv)]
 #![feature(const_overflowing_int_methods)]
 #![feature(const_int_unchecked_arith)]
 #![feature(const_int_pow)]
diff --git a/library/core/src/num/f32.rs b/library/core/src/num/f32.rs
index 9fb7296ce31..043f0b14f24 100644
--- a/library/core/src/num/f32.rs
+++ b/library/core/src/num/f32.rs
@@ -381,8 +381,9 @@ impl f32 {
     /// assert!(!f.is_nan());
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")]
     #[inline]
-    pub fn is_nan(self) -> bool {
+    pub const fn is_nan(self) -> bool {
         self != self
     }
 
@@ -390,7 +391,8 @@ impl f32 {
     // concerns about portability, so this implementation is for
     // private use internally.
     #[inline]
-    fn abs_private(self) -> f32 {
+    #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")]
+    const fn abs_private(self) -> f32 {
         f32::from_bits(self.to_bits() & 0x7fff_ffff)
     }
 
@@ -410,8 +412,9 @@ impl f32 {
     /// assert!(neg_inf.is_infinite());
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")]
     #[inline]
-    pub fn is_infinite(self) -> bool {
+    pub const fn is_infinite(self) -> bool {
         self.abs_private() == Self::INFINITY
     }
 
@@ -430,8 +433,9 @@ impl f32 {
     /// assert!(!neg_inf.is_finite());
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")]
     #[inline]
-    pub fn is_finite(self) -> bool {
+    pub const fn is_finite(self) -> bool {
         // There's no need to handle NaN separately: if self is NaN,
         // the comparison is not true, exactly as desired.
         self.abs_private() < Self::INFINITY
@@ -457,9 +461,10 @@ impl f32 {
     /// ```
     /// [subnormal]: https://en.wikipedia.org/wiki/Denormal_number
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")]
     #[inline]
-    pub fn is_normal(self) -> bool {
-        self.classify() == FpCategory::Normal
+    pub const fn is_normal(self) -> bool {
+        matches!(self.classify(), FpCategory::Normal)
     }
 
     /// Returns the floating point category of the number. If only one property
@@ -476,7 +481,8 @@ impl f32 {
     /// assert_eq!(inf.classify(), FpCategory::Infinite);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn classify(self) -> FpCategory {
+    #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")]
+    pub const fn classify(self) -> FpCategory {
         const EXP_MASK: u32 = 0x7f800000;
         const MAN_MASK: u32 = 0x007fffff;
 
@@ -501,8 +507,9 @@ impl f32 {
     /// assert!(!g.is_sign_positive());
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")]
     #[inline]
-    pub fn is_sign_positive(self) -> bool {
+    pub const fn is_sign_positive(self) -> bool {
         !self.is_sign_negative()
     }
 
@@ -517,8 +524,9 @@ impl f32 {
     /// assert!(g.is_sign_negative());
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")]
     #[inline]
-    pub fn is_sign_negative(self) -> bool {
+    pub const fn is_sign_negative(self) -> bool {
         // IEEE754 says: isSignMinus(x) is true if and only if x has negative sign. isSignMinus
         // applies to zeros and NaNs as well.
         self.to_bits() & 0x8000_0000 != 0
@@ -652,8 +660,9 @@ impl f32 {
     ///
     /// ```
     #[stable(feature = "float_bits_conv", since = "1.20.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn to_bits(self) -> u32 {
+    pub const fn to_bits(self) -> u32 {
         // SAFETY: `u32` is a plain old datatype so we can always transmute to it
         unsafe { mem::transmute(self) }
     }
@@ -695,8 +704,9 @@ impl f32 {
     /// assert_eq!(v, 12.5);
     /// ```
     #[stable(feature = "float_bits_conv", since = "1.20.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn from_bits(v: u32) -> Self {
+    pub const fn from_bits(v: u32) -> Self {
         // SAFETY: `u32` is a plain old datatype so we can always transmute from it
         // It turns out the safety issues with sNaN were overblown! Hooray!
         unsafe { mem::transmute(v) }
@@ -712,8 +722,9 @@ impl f32 {
     /// assert_eq!(bytes, [0x41, 0x48, 0x00, 0x00]);
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn to_be_bytes(self) -> [u8; 4] {
+    pub const fn to_be_bytes(self) -> [u8; 4] {
         self.to_bits().to_be_bytes()
     }
 
@@ -727,8 +738,9 @@ impl f32 {
     /// assert_eq!(bytes, [0x00, 0x00, 0x48, 0x41]);
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn to_le_bytes(self) -> [u8; 4] {
+    pub const fn to_le_bytes(self) -> [u8; 4] {
         self.to_bits().to_le_bytes()
     }
 
@@ -755,8 +767,9 @@ impl f32 {
     /// );
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn to_ne_bytes(self) -> [u8; 4] {
+    pub const fn to_ne_bytes(self) -> [u8; 4] {
         self.to_bits().to_ne_bytes()
     }
 
@@ -769,8 +782,9 @@ impl f32 {
     /// assert_eq!(value, 12.5);
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn from_be_bytes(bytes: [u8; 4]) -> Self {
+    pub const fn from_be_bytes(bytes: [u8; 4]) -> Self {
         Self::from_bits(u32::from_be_bytes(bytes))
     }
 
@@ -783,8 +797,9 @@ impl f32 {
     /// assert_eq!(value, 12.5);
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn from_le_bytes(bytes: [u8; 4]) -> Self {
+    pub const fn from_le_bytes(bytes: [u8; 4]) -> Self {
         Self::from_bits(u32::from_le_bytes(bytes))
     }
 
@@ -808,8 +823,9 @@ impl f32 {
     /// assert_eq!(value, 12.5);
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn from_ne_bytes(bytes: [u8; 4]) -> Self {
+    pub const fn from_ne_bytes(bytes: [u8; 4]) -> Self {
         Self::from_bits(u32::from_ne_bytes(bytes))
     }
 
diff --git a/library/core/src/num/f64.rs b/library/core/src/num/f64.rs
index a5b1eb3f1fd..24624b88d59 100644
--- a/library/core/src/num/f64.rs
+++ b/library/core/src/num/f64.rs
@@ -380,8 +380,9 @@ impl f64 {
     /// assert!(!f.is_nan());
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")]
     #[inline]
-    pub fn is_nan(self) -> bool {
+    pub const fn is_nan(self) -> bool {
         self != self
     }
 
@@ -389,7 +390,8 @@ impl f64 {
     // concerns about portability, so this implementation is for
     // private use internally.
     #[inline]
-    fn abs_private(self) -> f64 {
+    #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")]
+    const fn abs_private(self) -> f64 {
         f64::from_bits(self.to_bits() & 0x7fff_ffff_ffff_ffff)
     }
 
@@ -409,8 +411,9 @@ impl f64 {
     /// assert!(neg_inf.is_infinite());
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")]
     #[inline]
-    pub fn is_infinite(self) -> bool {
+    pub const fn is_infinite(self) -> bool {
         self.abs_private() == Self::INFINITY
     }
 
@@ -429,8 +432,9 @@ impl f64 {
     /// assert!(!neg_inf.is_finite());
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")]
     #[inline]
-    pub fn is_finite(self) -> bool {
+    pub const fn is_finite(self) -> bool {
         // There's no need to handle NaN separately: if self is NaN,
         // the comparison is not true, exactly as desired.
         self.abs_private() < Self::INFINITY
@@ -456,9 +460,10 @@ impl f64 {
     /// ```
     /// [subnormal]: https://en.wikipedia.org/wiki/Denormal_number
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")]
     #[inline]
-    pub fn is_normal(self) -> bool {
-        self.classify() == FpCategory::Normal
+    pub const fn is_normal(self) -> bool {
+        matches!(self.classify(), FpCategory::Normal)
     }
 
     /// Returns the floating point category of the number. If only one property
@@ -475,7 +480,8 @@ impl f64 {
     /// assert_eq!(inf.classify(), FpCategory::Infinite);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn classify(self) -> FpCategory {
+    #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")]
+    pub const fn classify(self) -> FpCategory {
         const EXP_MASK: u64 = 0x7ff0000000000000;
         const MAN_MASK: u64 = 0x000fffffffffffff;
 
@@ -500,8 +506,9 @@ impl f64 {
     /// assert!(!g.is_sign_positive());
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")]
     #[inline]
-    pub fn is_sign_positive(self) -> bool {
+    pub const fn is_sign_positive(self) -> bool {
         !self.is_sign_negative()
     }
 
@@ -524,8 +531,9 @@ impl f64 {
     /// assert!(g.is_sign_negative());
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")]
     #[inline]
-    pub fn is_sign_negative(self) -> bool {
+    pub const fn is_sign_negative(self) -> bool {
         self.to_bits() & 0x8000_0000_0000_0000 != 0
     }
 
@@ -666,8 +674,9 @@ impl f64 {
     ///
     /// ```
     #[stable(feature = "float_bits_conv", since = "1.20.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn to_bits(self) -> u64 {
+    pub const fn to_bits(self) -> u64 {
         // SAFETY: `u64` is a plain old datatype so we can always transmute to it
         unsafe { mem::transmute(self) }
     }
@@ -709,8 +718,9 @@ impl f64 {
     /// assert_eq!(v, 12.5);
     /// ```
     #[stable(feature = "float_bits_conv", since = "1.20.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn from_bits(v: u64) -> Self {
+    pub const fn from_bits(v: u64) -> Self {
         // SAFETY: `u64` is a plain old datatype so we can always transmute from it
         // It turns out the safety issues with sNaN were overblown! Hooray!
         unsafe { mem::transmute(v) }
@@ -726,8 +736,9 @@ impl f64 {
     /// assert_eq!(bytes, [0x40, 0x29, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]);
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn to_be_bytes(self) -> [u8; 8] {
+    pub const fn to_be_bytes(self) -> [u8; 8] {
         self.to_bits().to_be_bytes()
     }
 
@@ -741,8 +752,9 @@ impl f64 {
     /// assert_eq!(bytes, [0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x29, 0x40]);
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn to_le_bytes(self) -> [u8; 8] {
+    pub const fn to_le_bytes(self) -> [u8; 8] {
         self.to_bits().to_le_bytes()
     }
 
@@ -769,8 +781,9 @@ impl f64 {
     /// );
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn to_ne_bytes(self) -> [u8; 8] {
+    pub const fn to_ne_bytes(self) -> [u8; 8] {
         self.to_bits().to_ne_bytes()
     }
 
@@ -783,8 +796,9 @@ impl f64 {
     /// assert_eq!(value, 12.5);
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn from_be_bytes(bytes: [u8; 8]) -> Self {
+    pub const fn from_be_bytes(bytes: [u8; 8]) -> Self {
         Self::from_bits(u64::from_be_bytes(bytes))
     }
 
@@ -797,8 +811,9 @@ impl f64 {
     /// assert_eq!(value, 12.5);
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn from_le_bytes(bytes: [u8; 8]) -> Self {
+    pub const fn from_le_bytes(bytes: [u8; 8]) -> Self {
         Self::from_bits(u64::from_le_bytes(bytes))
     }
 
@@ -822,8 +837,9 @@ impl f64 {
     /// assert_eq!(value, 12.5);
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn from_ne_bytes(bytes: [u8; 8]) -> Self {
+    pub const fn from_ne_bytes(bytes: [u8; 8]) -> Self {
         Self::from_bits(u64::from_ne_bytes(bytes))
     }
 
diff --git a/src/test/ui/consts/const-float-bits-conv.rs b/src/test/ui/consts/const-float-bits-conv.rs
new file mode 100644
index 00000000000..2dfc6de8597
--- /dev/null
+++ b/src/test/ui/consts/const-float-bits-conv.rs
@@ -0,0 +1,93 @@
+// compile-flags: -Zmir-opt-level=0
+// run-pass
+
+#![feature(const_panic)]
+#![feature(const_float_bits_conv)]
+#![feature(const_float_classify)]
+
+// Don't promote
+const fn nop<T>(x: T) -> T { x }
+
+macro_rules! const_assert {
+    ($a:expr) => {
+        {
+            const _: () = assert!($a);
+            assert!(nop($a));
+        }
+    };
+    ($a:expr, $b:expr) => {
+        {
+            const _: () = assert!($a == $b);
+            assert_eq!(nop($a), nop($b));
+        }
+    };
+}
+
+fn f32() {
+    const_assert!((1f32).to_bits(), 0x3f800000);
+    const_assert!(u32::from_be_bytes(1f32.to_be_bytes()), 0x3f800000);
+    const_assert!((12.5f32).to_bits(), 0x41480000);
+    const_assert!(u32::from_le_bytes(12.5f32.to_le_bytes()), 0x41480000);
+    const_assert!((1337f32).to_bits(), 0x44a72000);
+    const_assert!(u32::from_ne_bytes(1337f32.to_ne_bytes()), 0x44a72000);
+    const_assert!((-14.25f32).to_bits(), 0xc1640000);
+    const_assert!(f32::from_bits(0x3f800000), 1.0);
+    const_assert!(f32::from_be_bytes(0x3f800000u32.to_be_bytes()), 1.0);
+    const_assert!(f32::from_bits(0x41480000), 12.5);
+    const_assert!(f32::from_le_bytes(0x41480000u32.to_le_bytes()), 12.5);
+    const_assert!(f32::from_bits(0x44a72000), 1337.0);
+    const_assert!(f32::from_ne_bytes(0x44a72000u32.to_ne_bytes()), 1337.0);
+    const_assert!(f32::from_bits(0xc1640000), -14.25);
+
+    // Check that NaNs roundtrip their bits regardless of signalingness
+    // 0xA is 0b1010; 0x5 is 0b0101 -- so these two together clobbers all the mantissa bits
+    const MASKED_NAN1: u32 = f32::NAN.to_bits() ^ 0x002A_AAAA;
+    const MASKED_NAN2: u32 = f32::NAN.to_bits() ^ 0x0055_5555;
+
+    const_assert!(f32::from_bits(MASKED_NAN1).is_nan());
+    const_assert!(f32::from_bits(MASKED_NAN1).is_nan());
+
+    // LLVM does not guarantee that loads and stores of NaNs preserve their exact bit pattern.
+    // In practice, this seems to only cause a problem on x86, since the most widely used calling
+    // convention mandates that floating point values are returned on the x87 FPU stack. See #73328.
+    if !cfg!(target_arch = "x86") {
+        const_assert!(f32::from_bits(MASKED_NAN1).to_bits(), MASKED_NAN1);
+        const_assert!(f32::from_bits(MASKED_NAN2).to_bits(), MASKED_NAN2);
+    }
+}
+
+fn f64() {
+    const_assert!((1f64).to_bits(), 0x3ff0000000000000);
+    const_assert!(u64::from_be_bytes(1f64.to_be_bytes()), 0x3ff0000000000000);
+    const_assert!((12.5f64).to_bits(), 0x4029000000000000);
+    const_assert!(u64::from_le_bytes(12.5f64.to_le_bytes()), 0x4029000000000000);
+    const_assert!((1337f64).to_bits(), 0x4094e40000000000);
+    const_assert!(u64::from_ne_bytes(1337f64.to_ne_bytes()), 0x4094e40000000000);
+    const_assert!((-14.25f64).to_bits(), 0xc02c800000000000);
+    const_assert!(f64::from_bits(0x3ff0000000000000), 1.0);
+    const_assert!(f64::from_be_bytes(0x3ff0000000000000u64.to_be_bytes()), 1.0);
+    const_assert!(f64::from_bits(0x4029000000000000), 12.5);
+    const_assert!(f64::from_le_bytes(0x4029000000000000u64.to_le_bytes()), 12.5);
+    const_assert!(f64::from_bits(0x4094e40000000000), 1337.0);
+    const_assert!(f64::from_ne_bytes(0x4094e40000000000u64.to_ne_bytes()), 1337.0);
+    const_assert!(f64::from_bits(0xc02c800000000000), -14.25);
+
+    // Check that NaNs roundtrip their bits regardless of signalingness
+    // 0xA is 0b1010; 0x5 is 0b0101 -- so these two together clobbers all the mantissa bits
+    const MASKED_NAN1: u64 = f64::NAN.to_bits() ^ 0x000A_AAAA_AAAA_AAAA;
+    const MASKED_NAN2: u64 = f64::NAN.to_bits() ^ 0x0005_5555_5555_5555;
+
+    const_assert!(f64::from_bits(MASKED_NAN1).is_nan());
+    const_assert!(f64::from_bits(MASKED_NAN1).is_nan());
+
+    // See comment above.
+    if !cfg!(target_arch = "x86") {
+        const_assert!(f64::from_bits(MASKED_NAN1).to_bits(), MASKED_NAN1);
+        const_assert!(f64::from_bits(MASKED_NAN2).to_bits(), MASKED_NAN2);
+    }
+}
+
+fn main() {
+    f32();
+    f64();
+}
diff --git a/src/test/ui/consts/const-float-classify.rs b/src/test/ui/consts/const-float-classify.rs
new file mode 100644
index 00000000000..36fec9976be
--- /dev/null
+++ b/src/test/ui/consts/const-float-classify.rs
@@ -0,0 +1,77 @@
+// compile-flags: -Zmir-opt-level=0
+// run-pass
+
+#![feature(const_panic)]
+#![feature(const_float_bits_conv)]
+#![feature(const_float_classify)]
+#![feature(const_trait_impl)]
+#![allow(incomplete_features)]
+
+// Don't promote
+const fn nop<T>(x: T) -> T { x }
+
+macro_rules! const_assert {
+    ($a:expr, $b:expr) => {
+        {
+            const _: () = assert!($a == $b);
+            assert_eq!(nop($a), nop($b));
+        }
+    };
+}
+
+macro_rules! suite {
+    ( $( $tt:tt )* ) => {
+        fn f32() {
+            suite_inner!(f32 $($tt)*);
+        }
+
+        fn f64() {
+            suite_inner!(f64 $($tt)*);
+        }
+    }
+
+}
+
+macro_rules! suite_inner {
+    (
+        $ty:ident [$( $fn:ident ),*]
+        $val:expr => [$($out:ident),*]
+
+        $( $tail:tt )*
+    ) => {
+        $( const_assert!($ty::$fn($val), $out); )*
+        suite_inner!($ty [$($fn),*] $($tail)*)
+    };
+
+    ( $ty:ident [$( $fn:ident ),*]) => {};
+}
+
+#[derive(Debug)]
+struct NonDet;
+
+impl const PartialEq<NonDet> for bool {
+    fn eq(&self, _: &NonDet) -> bool {
+        true
+    }
+}
+
+// The result of the `is_sign` methods are not checked for correctness, since LLVM does not
+// guarantee anything about the signedness of NaNs. See
+// https://github.com/rust-lang/rust/issues/55131.
+
+suite! {
+                   [is_nan, is_infinite, is_finite, is_normal, is_sign_positive, is_sign_negative]
+     -0.0 / 0.0 => [  true,       false,     false,     false,           NonDet,           NonDet]
+      0.0 / 0.0 => [  true,       false,     false,     false,           NonDet,           NonDet]
+            1.0 => [ false,       false,      true,      true,             true,            false]
+           -1.0 => [ false,       false,      true,      true,            false,             true]
+            0.0 => [ false,       false,      true,     false,             true,            false]
+           -0.0 => [ false,       false,      true,     false,            false,             true]
+      1.0 / 0.0 => [ false,        true,     false,     false,             true,            false]
+     -1.0 / 0.0 => [ false,        true,     false,     false,            false,             true]
+}
+
+fn main() {
+    f32();
+    f64();
+}