1 files changed, 48 insertions, 0 deletions
diff --git a/vendor/compiler_builtins/libm/src/math/rint.rs b/vendor/compiler_builtins/libm/src/math/rint.rs
new file mode 100644
index 000000000..0c6025c1f
--- /dev/null
+++ b/vendor/compiler_builtins/libm/src/math/rint.rs
@@ -0,0 +1,48 @@
+#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
+pub fn rint(x: f64) -> f64 {
+    let one_over_e = 1.0 / f64::EPSILON;
+    let as_u64: u64 = x.to_bits();
+    let exponent: u64 = as_u64 >> 52 & 0x7ff;
+    let is_positive = (as_u64 >> 63) == 0;
+    if exponent >= 0x3ff + 52 {
+        x
+    } else {
+        let ans = if is_positive {
+            x + one_over_e - one_over_e
+        } else {
+            x - one_over_e + one_over_e
+        };
+
+        if ans == 0.0 {
+            if is_positive {
+                0.0
+            } else {
+                -0.0
+            }
+        } else {
+            ans
+        }
+    }
+}
+
+// PowerPC tests are failing on LLVM 13: https://github.com/rust-lang/rust/issues/88520
+#[cfg(not(target_arch = "powerpc64"))]
+#[cfg(test)]
+mod tests {
+    use super::rint;
+
+    #[test]
+    fn negative_zero() {
+        assert_eq!(rint(-0.0_f64).to_bits(), (-0.0_f64).to_bits());
+    }
+
+    #[test]
+    fn sanity_check() {
+        assert_eq!(rint(-1.0), -1.0);
+        assert_eq!(rint(2.8), 3.0);
+        assert_eq!(rint(-0.5), -0.0);
+        assert_eq!(rint(0.5), 0.0);
+        assert_eq!(rint(-1.5), -2.0);
+        assert_eq!(rint(1.5), 2.0);
+    }
+}