Disable fast math (#514)

Author: lbittarello

CHANGELOG.rst

@@ -7,6 +7,13 @@
 Changelog
 =========
 
+4.2.2 - unreleased
+------------------
+
+**Other changes:**
+
+- We disabled fast math to avoid invalid results (e.g., when dividing by zero).
+
 
 4.2.1 - 2026-02-04
 ------------------

setup.py

@@ -79,7 +79,6 @@
         "-Xpreprocessor",
         "-fopenmp",
         "-O3",
-        "-ffast-math",
         "--std=c++17",
         f"-DJEMALLOC_INSTALL_SUFFIX={je_install_suffix}",
     ]
@@ -101,7 +100,6 @@
     extra_compile_args = [
         "-fopenmp",
         "-O3",
-        "-ffast-math",
         "--std=c++17",
         f"-DJEMALLOC_INSTALL_SUFFIX={je_install_suffix}",
     ]
@@ -168,6 +166,7 @@
             "initializedcheck": False,
             "nonecheck": False,
             "cdivision": True,
+            "cpow": True,
             "legacy_implicit_noexcept": True,
         },
     ),