Implement 'Display', 'LowerExp', and 'UpperExp' for 'f128';

Author: bjoernager

library/core/src/fmt/float.rs

@@ -236,6 +236,9 @@ floating! { f32 f64 }
 #[cfg(target_has_reliable_f16)]
 floating! { f16 }
 
+#[cfg(target_has_reliable_f128)]
+floating! { f128 }
+
 // FIXME(f16_f128): A fallback is used when the backend+target does not support f16 well, in order
 // to avoid ICEs.
 
@@ -275,10 +278,38 @@ impl UpperExp for f16 {
     }
 }
 
+#[cfg(not(target_has_reliable_f128))]
 #[stable(feature = "rust1", since = "1.0.0")]
 impl Debug for f128 {
     #[inline]
     fn fmt(&self, f: &mut Formatter<'_>) -> Result {
         write!(f, "{:#034x}", self.to_bits())
     }
 }
+
+#[cfg(not(target_has_reliable_f128))]
+#[stable(feature = "rust1", since = "1.0.0")]
+impl Display for f128 {
+    #[inline]
+    fn fmt(&self, fmt: &mut Formatter<'_>) -> Result {
+        Debug::fmt(self, fmt)
+    }
+}
+
+#[cfg(not(target_has_reliable_f128))]
+#[stable(feature = "rust1", since = "1.0.0")]
+impl LowerExp for f128 {
+    #[inline]
+    fn fmt(&self, fmt: &mut Formatter<'_>) -> Result {
+        Debug::fmt(self, fmt)
+    }
+}
+
+#[cfg(not(target_has_reliable_f128))]
+#[stable(feature = "rust1", since = "1.0.0")]
+impl UpperExp for f128 {
+    #[inline]
+    fn fmt(&self, fmt: &mut Formatter<'_>) -> Result {
+        Debug::fmt(self, fmt)
+    }
+}