diff --git a/llvm/Makefile.config.in b/llvm/Makefile.config.in
index 7b9af41403ee3630fb5c8ac1785f111f89b91042..b565bb44f7cbb5b87f6dbe6b2c671e44caaa02a5 100644
--- a/llvm/Makefile.config.in
+++ b/llvm/Makefile.config.in
@@ -337,8 +337,6 @@ BINUTILS_INCDIR := @BINUTILS_INCDIR@
 NO_MISSING_FIELD_INITIALIZERS = @NO_MISSING_FIELD_INITIALIZERS@
 # -Wno-variadic-macros
 NO_VARIADIC_MACROS = @NO_VARIADIC_MACROS@
-# -Wcovered-switch-default
-COVERED_SWITCH_DEFAULT = @COVERED_SWITCH_DEFAULT@
 
 # Was polly found in tools/polly?
 LLVM_HAS_POLLY = @LLVM_HAS_POLLY@
diff --git a/llvm/Makefile.rules b/llvm/Makefile.rules
index a56f26edb3578b41288db85d6560919e3df05822..a1edb6b7dd835c1c4ab0d77721e5e3fe31606821 100644
--- a/llvm/Makefile.rules
+++ b/llvm/Makefile.rules
@@ -650,7 +650,7 @@ ifndef NO_PEDANTIC
 CompileCommonOpts += -pedantic -Wno-long-long
 endif
 CompileCommonOpts += -Wall -W -Wno-unused-parameter -Wwrite-strings \
-                     $(EXTRA_OPTIONS) $(COVERED_SWITCH_DEFAULT)
+                     $(EXTRA_OPTIONS)
 # Enable cast-qual for C++; the workaround is to use const_cast.
 CXX.Flags += -Wcast-qual
 
diff --git a/llvm/autoconf/configure.ac b/llvm/autoconf/configure.ac
index b28508e67c4b3fe3a4f1dd0c97197b54de18fea4..3a86531a9d9aeb80f49a0d828b6dc40e1f841201 100644
--- a/llvm/autoconf/configure.ac
+++ b/llvm/autoconf/configure.ac
@@ -1115,8 +1115,7 @@ dnl Check optional compiler flags.
 AC_MSG_CHECKING([optional compiler flags])
 CXX_FLAG_CHECK(NO_VARIADIC_MACROS, [-Wno-variadic-macros])
 CXX_FLAG_CHECK(NO_MISSING_FIELD_INITIALIZERS, [-Wno-missing-field-initializers])
-CXX_FLAG_CHECK(COVERED_SWITCH_DEFAULT, [-Wcovered-switch-default])
-AC_MSG_RESULT([$NO_VARIADIC_MACROS $NO_MISSING_FIELD_INITIALIZERS $COVERED_SWITCH_DEFAULT])
+AC_MSG_RESULT([$NO_VARIADIC_MACROS $NO_MISSING_FIELD_INITIALIZERS])
 
 dnl===-----------------------------------------------------------------------===
 dnl===
diff --git a/llvm/cmake/modules/HandleLLVMOptions.cmake b/llvm/cmake/modules/HandleLLVMOptions.cmake
index afe43472fb71108baa2a20c93c4be44559ce46ba..496e8b3f5466467565295684ea5af9b54b92b6b6 100644
--- a/llvm/cmake/modules/HandleLLVMOptions.cmake
+++ b/llvm/cmake/modules/HandleLLVMOptions.cmake
@@ -182,10 +182,6 @@ elseif( LLVM_COMPILER_IS_GCC_COMPATIBLE )
     if (LLVM_ENABLE_PEDANTIC)
       add_llvm_definitions( -pedantic -Wno-long-long )
     endif (LLVM_ENABLE_PEDANTIC)
-    check_cxx_compiler_flag("-Wcovered-switch-default" SUPPORTS_COVERED_SWITCH_DEFAULT_FLAG)
-    if( SUPPORTS_COVERED_SWITCH_DEFAULT_FLAG )
-      add_llvm_definitions( -Wcovered-switch-default )
-    endif()
   endif (LLVM_ENABLE_WARNINGS)
   if (LLVM_ENABLE_WERROR)
     add_llvm_definitions( -Werror )
diff --git a/llvm/configure b/llvm/configure
index 848972866e63dc3d23dac2144408379d5deac99e..85347601cdb5578f8f436260a4be7a83cec30492 100755
--- a/llvm/configure
+++ b/llvm/configure
@@ -765,7 +765,6 @@ CONVENIENCE_LTDL_FALSE
 LIBADD_DL
 NO_VARIADIC_MACROS
 NO_MISSING_FIELD_INITIALIZERS
-COVERED_SWITCH_DEFAULT
 USE_UDIS86
 USE_OPROFILE
 HAVE_PTHREAD
@@ -10464,7 +10463,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<EOF
-#line 10467 "configure"
+#line 10466 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -12223,10 +12222,8 @@ NO_VARIADIC_MACROS=`$CXX -Wno-variadic-macros -fsyntax-only -xc /dev/null 2>/dev
 
 NO_MISSING_FIELD_INITIALIZERS=`$CXX -Wno-missing-field-initializers -fsyntax-only -xc /dev/null 2>/dev/null && echo -Wno-missing-field-initializers`
 
-COVERED_SWITCH_DEFAULT=`$CXX -Wcovered-switch-default -fsyntax-only -xc /dev/null 2>/dev/null && echo -Wcovered-switch-default`
-
-{ echo "$as_me:$LINENO: result: $NO_VARIADIC_MACROS $NO_MISSING_FIELD_INITIALIZERS $COVERED_SWITCH_DEFAULT" >&5
-echo "${ECHO_T}$NO_VARIADIC_MACROS $NO_MISSING_FIELD_INITIALIZERS $COVERED_SWITCH_DEFAULT" >&6; }
+{ echo "$as_me:$LINENO: result: $NO_VARIADIC_MACROS $NO_MISSING_FIELD_INITIALIZERS" >&5
+echo "${ECHO_T}$NO_VARIADIC_MACROS $NO_MISSING_FIELD_INITIALIZERS" >&6; }
 
 
 
@@ -21977,7 +21974,6 @@ CONVENIENCE_LTDL_FALSE!$CONVENIENCE_LTDL_FALSE$ac_delim
 LIBADD_DL!$LIBADD_DL$ac_delim
 NO_VARIADIC_MACROS!$NO_VARIADIC_MACROS$ac_delim
 NO_MISSING_FIELD_INITIALIZERS!$NO_MISSING_FIELD_INITIALIZERS$ac_delim
-COVERED_SWITCH_DEFAULT!$COVERED_SWITCH_DEFAULT$ac_delim
 USE_UDIS86!$USE_UDIS86$ac_delim
 USE_OPROFILE!$USE_OPROFILE$ac_delim
 HAVE_PTHREAD!$HAVE_PTHREAD$ac_delim
@@ -22005,7 +22001,7 @@ LIBOBJS!$LIBOBJS$ac_delim
 LTLIBOBJS!$LTLIBOBJS$ac_delim
 _ACEOF
 
-  if test `sed -n "s/.*$ac_delim\$/X/p" conf$$subs.sed | grep -c X` = 92; then
+  if test `sed -n "s/.*$ac_delim\$/X/p" conf$$subs.sed | grep -c X` = 91; then
     break
   elif $ac_last_try; then
     { { echo "$as_me:$LINENO: error: could not make $CONFIG_STATUS" >&5
diff --git a/llvm/projects/sample/Makefile.llvm.config.in b/llvm/projects/sample/Makefile.llvm.config.in
index 9e0c34ca684652e6e36ad1d6e5a11bcf4d86125e..a53e7b165bb64e156d669caf9325b5742bcb6f03 100644
--- a/llvm/projects/sample/Makefile.llvm.config.in
+++ b/llvm/projects/sample/Makefile.llvm.config.in
@@ -301,8 +301,6 @@ BINUTILS_INCDIR := @BINUTILS_INCDIR@
 NO_MISSING_FIELD_INITIALIZERS = @NO_MISSING_FIELD_INITIALIZERS@
 # -Wno-variadic-macros
 NO_VARIADIC_MACROS = @NO_VARIADIC_MACROS@
-# -Wcovered-switch-default
-COVERED_SWITCH_DEFAULT = @COVERED_SWITCH_DEFAULT@
 
 # Was polly found in tools/polly?
 LLVM_HAS_POLLY = @LLVM_HAS_POLLY@
diff --git a/llvm/projects/sample/Makefile.llvm.rules b/llvm/projects/sample/Makefile.llvm.rules
index 7467d84fcd21b766fe80e6abaa2866aa55efe464..f496bd4bc6f2fa647ed9a291ee3151b367094ae8 100644
--- a/llvm/projects/sample/Makefile.llvm.rules
+++ b/llvm/projects/sample/Makefile.llvm.rules
@@ -571,7 +571,7 @@ ifndef NO_PEDANTIC
 CompileCommonOpts += -pedantic -Wno-long-long
 endif
 CompileCommonOpts += -Wall -W -Wno-unused-parameter -Wwrite-strings \
-                     $(EXTRA_OPTIONS) $(COVERED_SWITCH_DEFAULT)
+                     $(EXTRA_OPTIONS)
 # Enable cast-qual for C++; the workaround is to use const_cast.
 CXX.Flags += -Wcast-qual
 
diff --git a/llvm/projects/sample/autoconf/configure.ac b/llvm/projects/sample/autoconf/configure.ac
index a1110ec6a2cf11989a8e77b5158cfc556322e39b..1caff5111295779168e8078eab9dbf1cc263e308 100644
--- a/llvm/projects/sample/autoconf/configure.ac
+++ b/llvm/projects/sample/autoconf/configure.ac
@@ -1019,8 +1019,7 @@ dnl Check optional compiler flags.
 AC_MSG_CHECKING([optional compiler flags])
 CXX_FLAG_CHECK(NO_VARIADIC_MACROS, [-Wno-variadic-macros])
 CXX_FLAG_CHECK(NO_MISSING_FIELD_INITIALIZERS, [-Wno-missing-field-initializers])
-CXX_FLAG_CHECK(COVERED_SWITCH_DEFAULT, [-Wcovered-switch-default])
-AC_MSG_RESULT([$NO_VARIADIC_MACROS $NO_MISSING_FIELD_INITIALIZERS $COVERED_SWITCH_DEFAULT])
+AC_MSG_RESULT([$NO_VARIADIC_MACROS $NO_MISSING_FIELD_INITIALIZERS])
 
 dnl===-----------------------------------------------------------------------===
 dnl===
diff --git a/llvm/projects/sample/configure b/llvm/projects/sample/configure
index 052a7f2909187043c062dd77f02698fc2dca62a9..dab1dc5d5a670dfe2fd87c354334cd63c1857fb0 100755
--- a/llvm/projects/sample/configure
+++ b/llvm/projects/sample/configure
@@ -762,7 +762,6 @@ CONVENIENCE_LTDL_FALSE
 LIBADD_DL
 NO_VARIADIC_MACROS
 NO_MISSING_FIELD_INITIALIZERS
-COVERED_SWITCH_DEFAULT
 USE_UDIS86
 USE_OPROFILE
 HAVE_PTHREAD
@@ -10366,7 +10365,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<EOF
-#line 10369 "configure"
+#line 10368 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -12125,10 +12124,8 @@ NO_VARIADIC_MACROS=`$CXX -Wno-variadic-macros -fsyntax-only -xc /dev/null 2>/dev
 
 NO_MISSING_FIELD_INITIALIZERS=`$CXX -Wno-missing-field-initializers -fsyntax-only -xc /dev/null 2>/dev/null && echo -Wno-missing-field-initializers`
 
-COVERED_SWITCH_DEFAULT=`$CXX -Wcovered-switch-default -fsyntax-only -xc /dev/null 2>/dev/null && echo -Wcovered-switch-default`
-
-{ echo "$as_me:$LINENO: result: $NO_VARIADIC_MACROS $NO_MISSING_FIELD_INITIALIZERS $COVERED_SWITCH_DEFAULT" >&5
-echo "${ECHO_T}$NO_VARIADIC_MACROS $NO_MISSING_FIELD_INITIALIZERS $COVERED_SWITCH_DEFAULT" >&6; }
+{ echo "$as_me:$LINENO: result: $NO_VARIADIC_MACROS $NO_MISSING_FIELD_INITIALIZERS" >&5
+echo "${ECHO_T}$NO_VARIADIC_MACROS $NO_MISSING_FIELD_INITIALIZERS" >&6; }
 
 
 
@@ -21819,7 +21816,6 @@ CONVENIENCE_LTDL_FALSE!$CONVENIENCE_LTDL_FALSE$ac_delim
 LIBADD_DL!$LIBADD_DL$ac_delim
 NO_VARIADIC_MACROS!$NO_VARIADIC_MACROS$ac_delim
 NO_MISSING_FIELD_INITIALIZERS!$NO_MISSING_FIELD_INITIALIZERS$ac_delim
-COVERED_SWITCH_DEFAULT!$COVERED_SWITCH_DEFAULT$ac_delim
 USE_UDIS86!$USE_UDIS86$ac_delim
 USE_OPROFILE!$USE_OPROFILE$ac_delim
 HAVE_PTHREAD!$HAVE_PTHREAD$ac_delim
@@ -21847,7 +21843,7 @@ LIBOBJS!$LIBOBJS$ac_delim
 LTLIBOBJS!$LTLIBOBJS$ac_delim
 _ACEOF
 
-  if test `sed -n "s/.*$ac_delim\$/X/p" conf$$subs.sed | grep -c X` = 91; then
+  if test `sed -n "s/.*$ac_delim\$/X/p" conf$$subs.sed | grep -c X` = 90; then
     break
   elif $ac_last_try; then
     { { echo "$as_me:$LINENO: error: could not make $CONFIG_STATUS" >&5