1 files changed, 15 insertions, 3 deletions
diff --git a/winsup/mingw/mingwex/math/sqrtl.c b/winsup/mingw/mingwex/math/sqrtl.c
index 0bd301390..dba68d878 100644
--- a/winsup/mingw/mingwex/math/sqrtl.c
+++ b/winsup/mingw/mingwex/math/sqrtl.c
@@ -1,8 +1,20 @@
 #include <math.h>
+#include <errno.h>
+
+extern long double  __QNANL;
+
 long double
 sqrtl (long double x)
 {
-  long double res;
-  asm ("fsqrt" : "=t" (res) : "0" (x));
-  return res;
+  if (x < 0.0L )
+    {
+      errno = EDOM;
+      return __QNANL;
+    }
+  else
+    {
+      long double res;
+      asm ("fsqrt" : "=t" (res) : "0" (x));
+      return res;
+    }
 }