diff --git a/include/llvm/Config/config.h.cmake b/include/llvm/Config/config.h.cmake
index adbcc1132fb..e7594babaa6 100644
--- a/include/llvm/Config/config.h.cmake
+++ b/include/llvm/Config/config.h.cmake
@@ -312,6 +312,9 @@
 /* Define to 1 if you have the `roundf' function. */
 #undef HAVE_ROUNDF
 
+/* Define to 1 if you have the `round' function. */
+#cmakedefine HAVE_ROUND ${HAVE_ROUND}
+
 /* Define to 1 if you have the `sbrk' function. */
 #cmakedefine HAVE_SBRK ${HAVE_SBRK}
 
diff --git a/lib/Support/APInt.cpp b/lib/Support/APInt.cpp
index 50025d214bc..1341d214370 100644
--- a/lib/Support/APInt.cpp
+++ b/lib/Support/APInt.cpp
@@ -1382,13 +1382,12 @@ APInt APInt::sqrt() const {
   // libc sqrt function which will probably use a hardware sqrt computation.
   // This should be faster than the algorithm below.
   if (magnitude < 52) {
-#if defined( _MSC_VER ) || defined(_MINIX)
-    // Amazingly, VC++ and Minix don't have round().
-    return APInt(BitWidth,
-                 uint64_t(::sqrt(double(isSingleWord()?VAL:pVal[0]))) + 0.5);
-#else
+#if HAVE_ROUND
     return APInt(BitWidth,
                  uint64_t(::round(::sqrt(double(isSingleWord()?VAL:pVal[0])))));
+#else
+    return APInt(BitWidth,
+                 uint64_t(::sqrt(double(isSingleWord()?VAL:pVal[0]))) + 0.5);
 #endif
   }