From 6eb240cbc1cb0f506acf9a756a37150160128ccb Mon Sep 17 00:00:00 2001
From: Trevor Gross <tmgross@umich.edu>
Date: Fri, 2 May 2025 00:46:21 +0000
Subject: [PATCH] fmaf: Add a test case from a MinGW failure

This is a known problem in the MinGW fmaf implementation, identified at
[1].  Make sure our implementation passes this edge case.

[1]: https://github.com/rust-lang/rust/issues/140515
---
 libm-test/src/generate/case_list.rs | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/libm-test/src/generate/case_list.rs b/libm-test/src/generate/case_list.rs
index f1e6fcec3..43b28722f 100644
--- a/libm-test/src/generate/case_list.rs
+++ b/libm-test/src/generate/case_list.rs
@@ -269,7 +269,18 @@ fn fma_cases() -> Vec<TestCase<op::fma::Routine>> {
 }
 
 fn fmaf_cases() -> Vec<TestCase<op::fmaf::Routine>> {
-    vec![]
+    let mut v = vec![];
+    TestCase::append_pairs(
+        &mut v,
+        &[
+            // Known rounding error for some implementations (notably MinGW)
+            (
+                (-1.9369631e13f32, 2.1513551e-7, -1.7354427e-24),
+                Some(-4167095.8),
+            ),
+        ],
+    );
+    v
 }
 
 #[cfg(f128_enabled)]