From e3c3304557ba9f3888215f995d1bbf58ee1037e9 Mon Sep 17 00:00:00 2001
From: Peter Michael Green <plugwash@debian.org>
Date: Wed, 22 Dec 2021 00:21:25 +0000
Subject: [PATCH] round to storage format in some tests before comparison to
 prevent spurious errors on x87.

---
 library/compiler-builtins/libm/src/math/fma.rs | 5 ++++-
 library/compiler-builtins/libm/src/math/pow.rs | 2 ++
 library/compiler-builtins/libm/src/math/sin.rs | 4 +++-
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/library/compiler-builtins/libm/src/math/fma.rs b/library/compiler-builtins/libm/src/math/fma.rs
index 85d842119cb3..c20de94a57e0 100644
--- a/library/compiler-builtins/libm/src/math/fma.rs
+++ b/library/compiler-builtins/libm/src/math/fma.rs
@@ -218,7 +218,10 @@ mod tests {
             -0.00000000000000022204460492503126,
         );
 
-        assert_eq!(fma(-0.992, -0.992, -0.992), -0.007936000000000007,);
+        let result = fma(-0.992, -0.992, -0.992);
+        //force rounding to storage format on x87 to prevent superious errors.
+        #[cfg(all(target_arch = "x86", not(target_feature = "sse2")))]force_eval!(result);
+        assert_eq!(result, -0.007936000000000007,);
     }
 
     #[test]
diff --git a/library/compiler-builtins/libm/src/math/pow.rs b/library/compiler-builtins/libm/src/math/pow.rs
index f79680a05d01..3249e7eea033 100644
--- a/library/compiler-builtins/libm/src/math/pow.rs
+++ b/library/compiler-builtins/libm/src/math/pow.rs
@@ -484,6 +484,8 @@ mod tests {
                 let exp = expected(*val);
                 let res = computed(*val);
 
+                #[cfg(all(target_arch = "x86", not(target_feature = "sse2")))]force_eval!(exp);
+                #[cfg(all(target_arch = "x86", not(target_feature = "sse2")))]force_eval!(res);
                 assert!(
                     if exp.is_nan() {
                         res.is_nan()
diff --git a/library/compiler-builtins/libm/src/math/sin.rs b/library/compiler-builtins/libm/src/math/sin.rs
index 1329b41a9d60..a562aa6e4a07 100644
--- a/library/compiler-builtins/libm/src/math/sin.rs
+++ b/library/compiler-builtins/libm/src/math/sin.rs
@@ -81,5 +81,7 @@ pub fn sin(x: f64) -> f64 {
 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);
+    let result = sin(x);
+    #[cfg(all(target_arch = "x86", not(target_feature = "sse2")))]force_eval!(result);
+    assert_eq!(result, sx);
 }