Index: cmake/config-ix.cmake
===================================================================
--- cmake/config-ix.cmake
+++ cmake/config-ix.cmake
@@ -258,6 +258,7 @@
   set(X86_64 x86_64 x86_64h)
 endif()
 
+set(ALL_BUILTIN_SUPPORTED_ARCH i386 ${X86_64} ${ARM32} ${ARM64})
 set(ALL_SANITIZER_COMMON_SUPPORTED_ARCH ${X86_64} i386 i686 powerpc64
   powerpc64le ${ARM32} ${ARM64} mips mips64 mipsel mips64el)
 set(ALL_ASAN_SUPPORTED_ARCH ${X86_64} i386 i686 powerpc64 powerpc64le ${ARM32}
@@ -380,6 +381,8 @@
   # for list_union
   include(CompilerRTUtils)
 
+  list_union(BUILTIN_SUPPORTED_ARCH ALL_BUILTIN_SUPPORTED_ARCH toolchain_arches)
+
   list_union(SANITIZER_COMMON_SUPPORTED_ARCH
     ALL_SANITIZER_COMMON_SUPPORTED_ARCH
     COMPILER_RT_SUPPORTED_ARCH
@@ -414,6 +417,8 @@
 else()
   # Architectures supported by compiler-rt libraries.
   filter_available_targets(SANITIZER_COMMON_SUPPORTED_ARCH
+    ${ALL_BUILTIN_SUPPORTED_ARCH})
+  filter_available_targets(SANITIZER_COMMON_SUPPORTED_ARCH
     ${ALL_SANITIZER_COMMON_SUPPORTED_ARCH})
   # LSan and UBSan common files should be available on all architectures
   # supported by other sanitizers (even if they build into dummy object files).
Index: lib/builtins/CMakeLists.txt
===================================================================
--- lib/builtins/CMakeLists.txt
+++ lib/builtins/CMakeLists.txt
@@ -159,6 +159,7 @@
   x86_64/floatundisf.S
   x86_64/floatundixf.S
   ${GENERIC_SOURCES})
+set(x86_64h_SOURCES ${x86_64_SOURCES})
 
 if(WIN32)
   set(x86_64_SOURCES
@@ -301,14 +302,51 @@
   trunctfsf2.c
   ${GENERIC_SOURCES})
 
+set(armv7_SOURCES ${arm_SOURCES})
+set(armv7s_SOURCES ${arm_SOURCES})
+set(arm64_SOURCES ${aarch64_SOURCES})
+
 add_custom_target(builtins)
 
-if(APPLE)
-  set(OS_OPTION OS osx)
-endif()
+if (APPLE)
+  foreach (os osx)
+    list_union(DARWIN_BUILTIN_ARCHS DARWIN_${os}_ARCHS BUILTIN_SUPPORTED_ARCH)
+    set(${os}_builtin_libs)
+    set(${os}_builtin_lipo_flags)
+    foreach (arch ${DARWIN_BUILTIN_ARCHS})
+      # Filter out generic versions of routines that are re-implemented in
+      # architecture specific manner.  This prevents multiple definitions of the
+      # same symbols, making the symbol selection non-deterministic.
+      foreach (_file ${${arch}_SOURCES})
+        if (${_file} MATCHES ${arch}/*)
+          get_filename_component(_name ${_file} NAME)
+          string(REPLACE ".S" ".c" _cname "${_name}")
+          list(REMOVE_ITEM ${arch}_SOURCES ${_cname})
+        endif ()
+      endforeach ()
+
+      add_compiler_rt_runtime(clang_rt.builtins_${arch} STATIC
+                              OS ${os}
+                              ARCHS ${arch}
+                              SOURCES ${${arch}_SOURCES}
+                              CFLAGS "-std=c99" ${DARWIN_${os}_CFLAGS} -arch ${arch}
+                              PARENT_TARGET builtins)
+      list(APPEND ${os}_builtin_libs clang_rt.builtins_${arch}_${os})
+      set(${os}_builtin_lipo_flags ${${os}_builtin_lipo_flags} -arch ${arch} ${COMPILER_RT_LIBRARY_OUTPUT_DIR}/libclang_rt.builtins_${arch}_${os}.a)
+    endforeach()
 
-if (NOT WIN32 OR MINGW)
-  foreach (arch x86_64 i386 i686 arm aarch64)
+    if(${os}_builtin_libs)
+      add_custom_command(OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/clang_rt.builtins_${os}.a
+        COMMAND lipo -output ${COMPILER_RT_LIBRARY_OUTPUT_DIR}/clang_rt.builtins_${os}.a -create ${${os}_builtin_lipo_flags}
+        DEPENDS ${${os}_builtin_libs}
+        )
+      add_custom_target(clang_rt.builtins_${os}
+        DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/clang_rt.builtins_${os}.a)
+      add_dependencies(builtins clang_rt.builtins_${os})
+    endif()
+  endforeach()
+elseif (NOT WIN32 OR MINGW)
+  foreach (arch ${BUILTIN_SUPPORTED_ARCH})
     if (CAN_TARGET_${arch})
       # Filter out generic versions of routines that are re-implemented in
       # architecture specific manner.  This prevents multiple definitions of the
@@ -323,8 +361,7 @@
 
       add_compiler_rt_runtime(clang_rt.builtins
                               STATIC
-                              ARCH ${arch}
-                              ${OS_OPTION}
+                              ARCHS ${arch}
                               SOURCES ${${arch}_SOURCES}
                               CFLAGS "-std=c99"
                               PARENT_TARGET builtins)