Index: compiler-rt/builtins/CMakeLists.txt
===================================================================
--- /dev/null
+++ compiler-rt/builtins/CMakeLists.txt
@@ -0,0 +1,45 @@
+# CMake build for CompilerRT builtins.
+#
+# This includes just builtins and crtbegin/crtend.
+
+if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
+cmake_minimum_required(VERSION 3.4.3)
+project(CompilerRTBuiltins C ASM)
+endif()
+
+list(INSERT CMAKE_MODULE_PATH 0
+  "${CMAKE_CURRENT_LIST_DIR}/../cmake"
+  "${CMAKE_CURRENT_LIST_DIR}/../cmake/Modules")
+
+set(COMPILER_RT_STANDALONE_BUILD TRUE)
+set(COMPILER_RT_BUILTINS_STANDALONE_BUILD TRUE)
+include(base-config-ix)
+include(CompilerRTUtils)
+
+load_llvm_config()
+construct_compiler_rt_default_triple()
+
+if(APPLE)
+  include(CompilerRTDarwinUtils)
+endif()
+if(CMAKE_HOST_APPLE AND APPLE)
+  include(UseLibtool)
+endif()
+
+include(AddCompilerRT)
+
+option(COMPILER_RT_BUILD_BUILTINS "Build builtins" ON)
+mark_as_advanced(COMPILER_RT_BUILD_BUILTINS)
+option(COMPILER_RT_BUILD_CRT "Build crtbegin.o/crtend.o" ON)
+mark_as_advanced(COMPILER_RT_BUILD_CRT)
+option(COMPILER_RT_CRT_USE_EH_FRAME_REGISTRY "Use eh_frame in crtbegin.o/crtend.o" ON)
+mark_as_advanced(COMPILER_RT_CRT_USE_EH_FRAME_REGISTRY)
+
+include(builtin-config-ix)
+
+if(COMPILER_RT_BUILD_BUILTINS)
+  add_subdirectory(${CMAKE_CURRENT_LIST_DIR}/../lib/builtins lib/builtins)
+endif()
+if(COMPILER_RT_BUILD_CRT AND COMPILER_RT_HAS_CRT)
+  add_subdirectory(${CMAKE_CURRENT_LIST_DIR}/../lib/crt lib/crt)
+endif()
Index: compiler-rt/cmake/builtin-config-ix.cmake
===================================================================
--- compiler-rt/cmake/builtin-config-ix.cmake
+++ compiler-rt/cmake/builtin-config-ix.cmake
@@ -13,6 +13,7 @@
 builtin_check_c_compiler_flag(-fomit-frame-pointer  COMPILER_RT_HAS_OMIT_FRAME_POINTER_FLAG)
 builtin_check_c_compiler_flag(-ffreestanding        COMPILER_RT_HAS_FREESTANDING_FLAG)
 builtin_check_c_compiler_flag(-fxray-instrument     COMPILER_RT_HAS_XRAY_COMPILER_FLAG)
+builtin_check_c_compiler_flag(-Wno-pedantic         COMPILER_RT_HAS_WNO_PEDANTIC)
 
 builtin_check_c_compiler_source(COMPILER_RT_HAS_ATOMIC_KEYWORD
 "
@@ -46,6 +47,13 @@
 
 set(ALL_BUILTIN_SUPPORTED_ARCH ${X86} ${X86_64} ${ARM32} ${ARM64}
     ${HEXAGON} ${MIPS32} ${MIPS64} ${PPC64} ${RISCV32} ${RISCV64} ${SPARC} ${SPARCV9} ${WASM32} ${WASM64})
+set(ALL_CRT_SUPPORTED_ARCH ${X86} ${X86_64} ${ARM32} ${ARM64} ${RISCV32} ${RISCV64})
+
+if(ANDROID)
+  set(OS_NAME "Android")
+else()
+  set(OS_NAME "${CMAKE_SYSTEM_NAME}")
+endif()
 
 include(CompilerRTUtils)
 include(CompilerRTDarwinUtils)
@@ -164,6 +172,14 @@
   # Architectures supported by compiler-rt libraries.
   filter_available_targets(BUILTIN_SUPPORTED_ARCH
     ${ALL_BUILTIN_SUPPORTED_ARCH})
+  filter_available_targets(CRT_SUPPORTED_ARCH
+    ${ALL_CRT_SUPPORTED_ARCH})
+
+  if (CRT_SUPPORTED_ARCH AND OS_NAME MATCHES "Linux")
+    set(COMPILER_RT_HAS_CRT TRUE)
+  else()
+    set(COMPILER_RT_HAS_CRT FALSE)
+  endif()
 endif()
 
 message(STATUS "Builtin supported architectures: ${BUILTIN_SUPPORTED_ARCH}")
Index: compiler-rt/cmake/config-ix.cmake
===================================================================
--- compiler-rt/cmake/config-ix.cmake
+++ compiler-rt/cmake/config-ix.cmake
@@ -261,7 +261,6 @@
     ${ARM32} ${ARM64} ${MIPS32} ${MIPS64} ${S390X} ${SPARC} ${SPARCV9})
 set(ALL_ASAN_SUPPORTED_ARCH ${X86} ${X86_64} ${ARM32} ${ARM64}
     ${MIPS32} ${MIPS64} ${PPC64} ${S390X} ${SPARC} ${SPARCV9})
-set(ALL_CRT_SUPPORTED_ARCH ${X86} ${X86_64} ${ARM32} ${ARM64} ${RISCV32} ${RISCV64})
 set(ALL_DFSAN_SUPPORTED_ARCH ${X86_64} ${MIPS64} ${ARM64})
 
 if(ANDROID)
@@ -527,7 +526,6 @@
     SANITIZER_COMMON_SUPPORTED_ARCH)
 
 else()
-  filter_available_targets(CRT_SUPPORTED_ARCH ${ALL_CRT_SUPPORTED_ARCH})
   # Architectures supported by compiler-rt libraries.
   filter_available_targets(SANITIZER_COMMON_SUPPORTED_ARCH
     ${ALL_SANITIZER_COMMON_SUPPORTED_ARCH})
@@ -611,12 +609,6 @@
 
 # TODO: Add builtins support.
 
-if (CRT_SUPPORTED_ARCH AND OS_NAME MATCHES "Linux")
-  set(COMPILER_RT_HAS_CRT TRUE)
-else()
-  set(COMPILER_RT_HAS_CRT FALSE)
-endif()
-
 if (COMPILER_RT_HAS_SANITIZER_COMMON AND DFSAN_SUPPORTED_ARCH AND
     OS_NAME MATCHES "Linux")
   set(COMPILER_RT_HAS_DFSAN TRUE)
Index: compiler-rt/lib/builtins/CMakeLists.txt
===================================================================
--- compiler-rt/lib/builtins/CMakeLists.txt
+++ compiler-rt/lib/builtins/CMakeLists.txt
@@ -2,32 +2,18 @@
 # generic implementations of the core runtime library along with optimized
 # architecture-specific code in various subdirectories.
 
-if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
+if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
   cmake_minimum_required(VERSION 3.4.3)
-
   project(CompilerRTBuiltins C ASM)
-  set(COMPILER_RT_STANDALONE_BUILD TRUE)
-  set(COMPILER_RT_BUILTINS_STANDALONE_BUILD TRUE)
-  list(INSERT CMAKE_MODULE_PATH 0
-    "${CMAKE_SOURCE_DIR}/../../cmake"
-    "${CMAKE_SOURCE_DIR}/../../cmake/Modules")
-  include(base-config-ix)
-  include(CompilerRTUtils)
-
-  load_llvm_config()
-  construct_compiler_rt_default_triple()
-
-  if(APPLE)
-    include(CompilerRTDarwinUtils)
-  endif()
-  if(CMAKE_HOST_APPLE AND APPLE)
-    include(UseLibtool)
+
+  message(WARNING "Using this directory as top-level for build is deprecated, please use compiler-rt/builtins directory instead")
+  if(NOT __BUILTINS_PROCESSED__)
+    set(__BUILTINS_PROCESSED__ TRUE)
+    include(../../builtins/CMakeLists.txt)
+    return()
   endif()
-  include(AddCompilerRT)
 endif()
 
-include(builtin-config-ix)
-
 # TODO: Need to add a mechanism for logging errors when builtin source files are
 # added to a sub-directory and not this CMakeLists file.
 set(GENERIC_SOURCES
Index: llvm/runtimes/CMakeLists.txt
===================================================================
--- llvm/runtimes/CMakeLists.txt
+++ llvm/runtimes/CMakeLists.txt
@@ -235,7 +235,7 @@
     cmake_parse_arguments(ARG "" "" "DEPENDS" ${ARGN})
 
     llvm_ExternalProject_Add(builtins
-                             ${compiler_rt_path}/lib/builtins
+                             ${compiler_rt_path}/builtins
                              DEPENDS ${ARG_DEPENDS}
                              CMAKE_ARGS -DLLVM_LIBRARY_OUTPUT_INTDIR=${LLVM_LIBRARY_DIR}
                                         -DLLVM_RUNTIME_OUTPUT_INTDIR=${LLVM_TOOLS_BINARY_DIR}
@@ -271,7 +271,7 @@
     endforeach()
 
     llvm_ExternalProject_Add(builtins-${target}
-                             ${compiler_rt_path}/lib/builtins
+                             ${compiler_rt_path}/builtins
                              DEPENDS ${ARG_DEPENDS}
                              CMAKE_ARGS -DLLVM_LIBRARY_OUTPUT_INTDIR=${LLVM_LIBRARY_DIR}
                                         -DLLVM_RUNTIME_OUTPUT_INTDIR=${LLVM_TOOLS_BINARY_DIR}