DOC: Add release note for -ftrapping-math on clang

numpy · Jul 15, 2021 · f1d082c · f1d082c
1 parent 3b564f7
commit f1d082c
Showing 1 changed file with 7 additions and 0 deletions.
diff --git a/doc/release/upcoming_changes/19479.compatibility.rst b/doc/release/upcoming_changes/19479.compatibility.rst
@@ -0,0 +1,7 @@
+Distutils forces strict floating point model on clang
+-----------------------------------------------------
+NumPy now sets the ``-ftrapping-math`` option on clang to enforce correct
+floating point error handling for universal functions.
+Clang defaults to non-IEEE and C99 conform behaviour otherwise.
+This change (using the equivalent but newer ``-ffp-exception-behavior=strict``)
+was attempted in NumPy 1.21, but was effectively never used.