diff --git a/llvm/autoconf/m4/huge_val.m4 b/llvm/autoconf/m4/huge_val.m4
index 87f8d0450577..fd94c11c86e0 100644
--- a/llvm/autoconf/m4/huge_val.m4
+++ b/llvm/autoconf/m4/huge_val.m4
@@ -4,15 +4,15 @@
 #
 AC_DEFUN([AC_HUGE_VAL_CHECK],[
   AC_CACHE_CHECK([for HUGE_VAL sanity], [ac_cv_huge_val_sanity],[
-    AC_LANG_PUSH(C)
-    CPPFLAGS=-pedantic
+    AC_LANG_PUSH([C++])
+    CXXFLAGS=-pedantic
     AC_RUN_IFELSE(
       AC_LANG_PROGRAM(
         [#include <math.h>],
         [double x = HUGE_VAL; return x != x; ]),
       [ac_cv_huge_val_sanity=yes],[ac_cv_huge_val_sanity=no],
       [ac_cv_huge_val_sanity=yes])
-    AC_LANG_POP(C)
+    AC_LANG_POP([C++])
     ])
   AC_SUBST(HUGE_VAL_SANITY,$ac_cv_huge_val_sanity)
 ])
diff --git a/llvm/configure b/llvm/configure
index 6699d673438a..72406575deb6 100755
--- a/llvm/configure
+++ b/llvm/configure
@@ -29183,13 +29183,13 @@ if test "${ac_cv_huge_val_sanity+set}" = set; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
 
-    ac_ext=c
-ac_cpp='$CPP $CPPFLAGS'
-ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
-ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
-ac_compiler_gnu=$ac_cv_c_compiler_gnu
+    ac_ext=cpp
+ac_cpp='$CXXCPP $CPPFLAGS'
+ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
 
-    CPPFLAGS=-pedantic
+    CXXFLAGS=-pedantic
     if test "$cross_compiling" = yes; then
   ac_cv_huge_val_sanity=yes
 else