diff --git a/library/compiler-builtins/libm/src/math/atan2.rs b/library/compiler-builtins/libm/src/math/atan2.rs
index b9bf0da935bc..c668731cf376 100644
--- a/library/compiler-builtins/libm/src/math/atan2.rs
+++ b/library/compiler-builtins/libm/src/math/atan2.rs
@@ -114,12 +114,18 @@ pub fn atan2(y: f64, x: f64) -> f64 {
     }
 }
 
-#[test]
-fn sanity_check() {
-    assert_eq!(atan2(0.0, 1.0), 0.0);
-    assert_eq!(atan2(0.0, -1.0), PI);
-    assert_eq!(atan2(-0.0, -1.0), -PI);
-    assert_eq!(atan2(3.0, 2.0), atan(3.0 / 2.0));
-    assert_eq!(atan2(2.0, -1.0), atan(2.0 / -1.0) + PI);
-    assert_eq!(atan2(-2.0, -1.0), atan(-2.0 / -1.0) - PI);
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    #[cfg_attr(x86_no_sse, ignore = "FIXME(i586): possible incorrect rounding")]
+    fn sanity_check() {
+        assert_eq!(atan2(0.0, 1.0), 0.0);
+        assert_eq!(atan2(0.0, -1.0), PI);
+        assert_eq!(atan2(-0.0, -1.0), -PI);
+        assert_eq!(atan2(3.0, 2.0), atan(3.0 / 2.0));
+        assert_eq!(atan2(2.0, -1.0), atan(2.0 / -1.0) + PI);
+        assert_eq!(atan2(-2.0, -1.0), atan(-2.0 / -1.0) - PI);
+    }
 }
diff --git a/library/compiler-builtins/libm/src/math/sin.rs b/library/compiler-builtins/libm/src/math/sin.rs
index e04e0d6a09dc..229fa4bef083 100644
--- a/library/compiler-builtins/libm/src/math/sin.rs
+++ b/library/compiler-builtins/libm/src/math/sin.rs
@@ -81,12 +81,15 @@ pub fn sin(x: f64) -> f64 {
     }
 }
 
-#[test]
-fn test_near_pi() {
-    let x = f64::from_bits(0x400921fb000FD5DD); // 3.141592026217707
-    let sx = f64::from_bits(0x3ea50d15ced1a4a2); // 6.273720864039205e-7
-    let result = sin(x);
-    #[cfg(all(target_arch = "x86", not(target_feature = "sse2")))]
-    let result = force_eval!(result);
-    assert_eq!(result, sx);
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    #[cfg_attr(x86_no_sse, ignore = "FIXME(i586): possible incorrect rounding")]
+    fn test_near_pi() {
+        let x = f64::from_bits(0x400921fb000FD5DD); // 3.141592026217707
+        let sx = f64::from_bits(0x3ea50d15ced1a4a2); // 6.273720864039205e-7
+        assert_eq!(sin(x), sx);
+    }
 }