use approximate equality with 1 ULP of tolerance

2018-07-12 12:20:55 -05:00
parent 262c392cf2
commit 5b950eaea2
2 changed files with 9 additions and 3 deletions
--- a/library/compiler-builtins/libm/src/lib.rs
+++ b/library/compiler-builtins/libm/src/lib.rs
@@ -10,3 +10,9 @@ pub use fabsf::fabsf;
 pub use powf::powf;
 pub use scalbnf::scalbnf;
 pub use sqrtf::sqrtf;
+
+/// Approximate equality with 1 ULP of tolerance
+#[doc(hidden)]
+pub fn _eqf(a: u32, b: u32) -> bool {
+    (a as i32).wrapping_sub(b as i32).abs() <= 1
+}