BUG: Work-around clang failure to set warning flags in fmod

seberg · seberg · commit 5d3e85d521f9 · 2021-07-07T14:07:21.000-05:00
diff --git a/numpy/core/src/npymath/npy_math_internal.h.src b/numpy/core/src/npymath/npy_math_internal.h.src
@@ -636,14 +636,15 @@ npy_remainder@c@(@type@ a, @type@ b)
         npy_divmod@c@(a, b, &mod);
         return mod;
     }
-    else {
-        /*
-         * in2 == 0 (and not NaN), normal division will give the correct
-         * result (which could be Inf or NaN) and set the correct CPU
-         * floating point error flag.
-         */
-        return npy_fmod@c@(a, b);
-    }
+    /*
+     * in2 == 0 (and not NaN). The result is always NaN here, and we need to
+     * set the invalid flag if a is not NaN.  We should be able to use the
+     * normal fmod, but clang seems to optimize the warning flags away.
+     */
+    if (!npy_isnan(a)) {
+        npy_set_floatstatus_invalid();
+    }
+    return (@type@)NPY_NAN;
 }
 
 NPY_INPLACE @type@
