Merge pull request #193 from Schultzer/add-signum

Add signum
rust-lang · Jul 2, 2019 · b03bda3 · b03bda3
2 parents 885afa3 + 311e4c8
commit b03bda3
Showing 1 changed file with 20 additions and 4 deletions.
diff --git a/src/lib.rs b/src/lib.rs
@@ -73,8 +73,7 @@ pub trait F32Ext: private::Sealed + Sized {
 
  fn abs(self) -> Self;
 
- // NOTE depends on unstable intrinsics::copysignf32
- // fn signum(self) -> Self;
+ fn signum(self) -> Self;
 
  fn mul_add(self, a: Self, b: Self) -> Self;
 
@@ -178,6 +177,15 @@ impl F32Ext for f32 {
  fabsf(self)
  }
 
+ #[inline]
+ fn signum(self) -> Self {
+ if self.is_nan() {
+ f32::NAN
+ } else {
+ copysignf(1., self)
+ }
+ }
+
  #[inline]
  fn mul_add(self, a: Self, b: Self) -> Self {
  fmaf(self, a, b)
@@ -361,8 +369,7 @@ pub trait F64Ext: private::Sealed + Sized {
 
  fn abs(self) -> Self;
 
- // NOTE depends on unstable intrinsics::copysignf64
- // fn signum(self) -> Self;
+ fn signum(self) -> Self;
 
  fn mul_add(self, a: Self, b: Self) -> Self;
 
@@ -466,6 +473,15 @@ impl F64Ext for f64 {
  fabs(self)
  }
 
+ #[inline]
+ fn signum(self) -> Self {
+ if self.is_nan() {
+ f64::NAN
+ } else {
+ copysign(1., self)
+ }
+ }
+
  #[inline]
  fn mul_add(self, a: Self, b: Self) -> Self {
  fma(self, a, b)