1 files changed, 48 insertions, 0 deletions
diff --git a/vendor/libm/src/math/rintf.rs b/vendor/libm/src/math/rintf.rs
new file mode 100644
index 000000000..d427793f7
--- /dev/null
+++ b/vendor/libm/src/math/rintf.rs
@@ -0,0 +1,48 @@
+#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
+pub fn rintf(x: f32) -> f32 {
+    let one_over_e = 1.0 / f32::EPSILON;
+    let as_u32: u32 = x.to_bits();
+    let exponent: u32 = as_u32 >> 23 & 0xff;
+    let is_positive = (as_u32 >> 31) == 0;
+    if exponent >= 0x7f + 23 {
+        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::rintf;
+
+    #[test]
+    fn negative_zero() {
+        assert_eq!(rintf(-0.0_f32).to_bits(), (-0.0_f32).to_bits());
+    }
+
+    #[test]
+    fn sanity_check() {
+        assert_eq!(rintf(-1.0), -1.0);
+        assert_eq!(rintf(2.8), 3.0);
+        assert_eq!(rintf(-0.5), -0.0);
+        assert_eq!(rintf(0.5), 0.0);
+        assert_eq!(rintf(-1.5), -2.0);
+        assert_eq!(rintf(1.5), 2.0);
+    }
+}