Index: scipy/scipy/special/_round.h
===================================================================
--- scipy.orig/scipy/special/_round.h	2025-01-16 15:19:54.008128507 +0100
+++ scipy/scipy/special/_round.h	2025-01-16 15:19:54.008128507 +0100
@@ -84,5 +84,12 @@
 
 #endif
 
+/* SH4 is not C99 compliant, see https://github.com/scipy/scipy/issues/15584 */
+#ifndef FE_UPWARD
+#define FE_UPWARD -1
+#endif
+#ifndef FE_DOWNWARD
+#define FE_DOWNWARD -1
+#endif
 
 #endif /* _round.h */