Project import generated by Copybara.
GitOrigin-RevId: fb3f4b013c3acab0ea3cb14c4d29f4e6d9caa33c
Change-Id: Id51b0538150a61ebfd370348c8ed47881798cf7d
diff --git a/libc/hdr/fenv_macros.h b/libc/hdr/fenv_macros.h
index 1ad28cc..a2e4462 100644
--- a/libc/hdr/fenv_macros.h
+++ b/libc/hdr/fenv_macros.h
@@ -17,6 +17,52 @@
#include <fenv.h>
+// In some environment, FE_ALL_EXCEPT is set to 0 and the remaining exceptions
+// FE_* are missing.
+#if (FE_ALL_EXCEPT == 0)
+#ifndef FE_DIVBYZERO
+#define FE_DIVBYZERO 0
+#endif // FE_DIVBYZERO
+
+#ifndef FE_INEXACT
+#define FE_INEXACT 0
+#endif // FE_INEXACT
+
+#ifndef FE_INVALID
+#define FE_INVALID 0
+#endif // FE_INVALID
+
+#ifndef FE_OVERFLOW
+#define FE_OVERFLOW 0
+#endif // FE_OVERFLOW
+
+#ifndef FE_UNDERFLOW
+#define FE_UNDERFLOW 0
+#endif // FE_UNDERFLOW
+#else
+// If this is not provided by the system, define it for use internally.
+#ifndef __FE_DENORM
+#define __FE_DENORM (1 << 6)
+#endif
+#endif
+
+// Rounding mode macros might be missing.
+#ifndef FE_DOWNWARD
+#define FE_DOWNWARD 0x400
+#endif // FE_DOWNWARD
+
+#ifndef FE_TONEAREST
+#define FE_TONEAREST 0
+#endif // FE_TONEAREST
+
+#ifndef FE_TOWARDZERO
+#define FE_TOWARDZERO 0xC00
+#endif // FE_TOWARDZERO
+
+#ifndef FE_UPWARD
+#define FE_UPWARD 0x800
+#endif // FE_UPWARD
+
#endif // LLVM_LIBC_FULL_BUILD
#endif // LLVM_LIBC_HDR_FENV_MACROS_H
