Auto merge of #42430 - nagisa:core-float, r=alexcrichton

[rust.git] / src / libcore / num / f64.rs

diff --git a/src/libcore/num/f64.rs b/src/libcore/num/f64.rs
index 991a856834948687cf00c59d5879149733af6bc6..ac6b1e67cd2785b17154e76062210bb6f6f76f8c 100644 (file)
--- a/src/libcore/num/f64.rs
+++ b/src/libcore/num/f64.rs
@@ -143,36 +143,6 @@ pub mod consts {
            reason = "stable interface is via `impl f{32,64}` in later crates",
            issue = "32110")]
 impl Float for f64 {
-    #[inline]
-    fn nan() -> f64 {
-        NAN
-    }
-
-    #[inline]
-    fn infinity() -> f64 {
-        INFINITY
-    }
-
-    #[inline]
-    fn neg_infinity() -> f64 {
-        NEG_INFINITY
-    }
-
-    #[inline]
-    fn zero() -> f64 {
-        0.0
-    }
-
-    #[inline]
-    fn neg_zero() -> f64 {
-        -0.0
-    }
-
-    #[inline]
-    fn one() -> f64 {
-        1.0
-    }
-
     /// Returns `true` if the number is NaN.
     #[inline]
     fn is_nan(self) -> bool {
@@ -214,21 +184,6 @@ fn classify(self) -> Fp {
         }
     }
 
-    /// Returns the mantissa, exponent and sign as integers.
-    fn integer_decode(self) -> (u64, i16, i8) {
-        let bits: u64 = unsafe { mem::transmute(self) };
-        let sign: i8 = if bits >> 63 == 0 { 1 } else { -1 };
-        let mut exponent: i16 = ((bits >> 52) & 0x7ff) as i16;
-        let mantissa = if exponent == 0 {
-            (bits & 0xfffffffffffff) << 1
-        } else {
-            (bits & 0xfffffffffffff) | 0x10000000000000
-        };
-        // Exponent bias + mantissa shift
-        exponent -= 1023 + 52;
-        (mantissa, exponent, sign)
-    }
-
     /// Computes the absolute value of `self`. Returns `Float::nan()` if the
     /// number is `Float::nan()`.
     #[inline]
@@ -287,4 +242,32 @@ fn to_radians(self) -> f64 {
         let value: f64 = consts::PI;
         self * (value / 180.0)
     }
+
+    /// Returns the maximum of the two numbers.
+    #[inline]
+    fn max(self, other: f64) -> f64 {
+        // IEEE754 says: maxNum(x, y) is the canonicalized number y if x < y, x if y < x, the
+        // canonicalized number if one operand is a number and the other a quiet NaN. Otherwise it
+        // is either x or y, canonicalized (this means results might differ among implementations).
+        // When either x or y is a signalingNaN, then the result is according to 6.2.
+        //
+        // Since we do not support sNaN in Rust yet, we do not need to handle them.
+        // FIXME(nagisa): due to https://bugs.llvm.org/show_bug.cgi?id=33303 we canonicalize by
+        // multiplying by 1.0. Should switch to the `canonicalize` when it works.
+        (if self < other || self.is_nan() { other } else { self }) * 1.0
+    }
+
+    /// Returns the minimum of the two numbers.
+    #[inline]
+    fn min(self, other: f64) -> f64 {
+        // IEEE754 says: minNum(x, y) is the canonicalized number x if x < y, y if y < x, the
+        // canonicalized number if one operand is a number and the other a quiet NaN. Otherwise it
+        // is either x or y, canonicalized (this means results might differ among implementations).
+        // When either x or y is a signalingNaN, then the result is according to 6.2.
+        //
+        // Since we do not support sNaN in Rust yet, we do not need to handle them.
+        // FIXME(nagisa): due to https://bugs.llvm.org/show_bug.cgi?id=33303 we canonicalize by
+        // multiplying by 1.0. Should switch to the `canonicalize` when it works.
+        (if self < other || other.is_nan() { self } else { other }) * 1.0
+    }
 }