diff --git a/compiler-rt/cmake/builtin-config-ix.cmake b/compiler-rt/cmake/builtin-config-ix.cmake
--- a/compiler-rt/cmake/builtin-config-ix.cmake
+++ b/compiler-rt/cmake/builtin-config-ix.cmake
@@ -116,6 +116,10 @@
       ${DARWIN_ios_MIN_VER_FLAG}=${DARWIN_ios_BUILTIN_MIN_VER})
     set(DARWIN_ios_BUILTIN_ALL_POSSIBLE_ARCHS ${ARM64} ${ARM32})
     set(DARWIN_iossim_BUILTIN_ALL_POSSIBLE_ARCHS ${X86} ${X86_64})
+    find_darwin_sdk_version(iossim_sdk_version "iphonesimulator")
+    if ("${iossim_sdk_version}" VERSION_GREATER 14.0 OR "${iossim_sdk_version}" VERSION_EQUAL 14.0)
+      list(APPEND DARWIN_iossim_BUILTIN_ALL_POSSIBLE_ARCHS arm64)
+    endif()
   endif()
   if(COMPILER_RT_ENABLE_WATCHOS)
     list(APPEND DARWIN_EMBEDDED_PLATFORMS watchos)
@@ -125,6 +129,10 @@
       ${DARWIN_watchos_MIN_VER_FLAG}=${DARWIN_watchos_BUILTIN_MIN_VER})
     set(DARWIN_watchos_BUILTIN_ALL_POSSIBLE_ARCHS armv7 armv7k arm64_32)
     set(DARWIN_watchossim_BUILTIN_ALL_POSSIBLE_ARCHS ${X86})
+    find_darwin_sdk_version(watchossim_sdk_version "watchsimulator")
+    if ("${watchossim_sdk_version}" VERSION_GREATER 7.0 OR "${watchossim_sdk_version}" VERSION_EQUAL 7.0)
+      list(APPEND DARWIN_watchossim_BUILTIN_ALL_POSSIBLE_ARCHS arm64)
+    endif()
   endif()
   if(COMPILER_RT_ENABLE_TVOS)
     list(APPEND DARWIN_EMBEDDED_PLATFORMS tvos)
@@ -134,6 +142,10 @@
       ${DARWIN_tvos_MIN_VER_FLAG}=${DARWIN_tvos_BUILTIN_MIN_VER})
     set(DARWIN_tvos_BUILTIN_ALL_POSSIBLE_ARCHS armv7 arm64)
     set(DARWIN_tvossim_BUILTIN_ALL_POSSIBLE_ARCHS ${X86} ${X86_64})
+    find_darwin_sdk_version(tvossim_sdk_version "appletvsimulator")
+    if ("${tvossim_sdk_version}" VERSION_GREATER 14.0 OR "${tvossim_sdk_version}" VERSION_EQUAL 14.0)
+      list(APPEND DARWIN_tvossim_BUILTIN_ALL_POSSIBLE_ARCHS arm64)
+    endif()
   endif()
 
   set(BUILTIN_SUPPORTED_OS osx)