1 files changed, 24 insertions, 0 deletions
diff --git a/winsup/cygwin/math/fdiml.c b/winsup/cygwin/math/fdiml.c
new file mode 100644
index 000000000..3be0679ac
--- /dev/null
+++ b/winsup/cygwin/math/fdiml.c
@@ -0,0 +1,24 @@
+/**
+ * This file has no copyright assigned and is placed in the Public Domain.
+ * This file is part of the mingw-w64 runtime package.
+ * No warranty is given; refer to the file DISCLAIMER.PD within this package.
+ */
+#include <errno.h>
+#include <math.h>
+
+long double
+fdiml (long double x, long double y)
+{
+  int cx = fpclassify (x), cy = fpclassify (y);
+  long double r;
+
+  if (cx == FP_NAN || cy == FP_NAN
+      || (y < 0 && cx == FP_INFINITE && cy == FP_INFINITE))
+    return x - y;  /* Take care invalid flag is raised.  */
+  if (x <= y)
+    return 0.0;
+  r = x - y;
+  if (fpclassify (r) == FP_INFINITE)
+    errno = ERANGE;
+  return r;
+}