diff --git a/compiler-rt/cmake/config-ix.cmake b/compiler-rt/cmake/config-ix.cmake
index bfbd7970f8505..166b8ce08532a 100644
--- a/compiler-rt/cmake/config-ix.cmake
+++ b/compiler-rt/cmake/config-ix.cmake
@@ -208,32 +208,6 @@ macro(get_test_cc_for_arch arch cc_out cflags_out)
   endif()
 endmacro()
 
-# Returns CFLAGS that should be used to run tests for the
-# specific apple platform and architecture.
-function(get_test_cflags_for_apple_platform platform arch cflags_out)
-  is_valid_apple_platform("${platform}" is_valid_platform)
-  if (NOT is_valid_platform)
-    message(FATAL_ERROR "\"${platform}\" is not a valid apple platform")
-  endif()
-  set(test_cflags "")
-  get_target_flags_for_arch(${arch} test_cflags)
-  list(APPEND test_cflags ${DARWIN_${platform}_CFLAGS})
-  string(REPLACE ";" " " test_cflags_str "${test_cflags}")
-  string(APPEND test_cflags_str "${COMPILER_RT_TEST_COMPILER_CFLAGS}")
-  set(${cflags_out} "${test_cflags_str}" PARENT_SCOPE)
-endfunction()
-
-function(is_valid_apple_platform platform is_valid_out)
-  set(is_valid FALSE)
-  if ("${platform}" STREQUAL "")
-    message(FATAL_ERROR "platform cannot be empty")
-  endif()
-  if ("${platform}" MATCHES "^(osx|((ios|watchos|tvos)(sim)?))$")
-    set(is_valid TRUE)
-  endif()
-  set(${is_valid_out} ${is_valid} PARENT_SCOPE)
-endfunction()
-
 set(ARM64 aarch64)
 set(ARM32 arm armhf)
 set(HEXAGON hexagon)
diff --git a/compiler-rt/test/asan/CMakeLists.txt b/compiler-rt/test/asan/CMakeLists.txt
index e6f299a4de735..2a44aebd55dd8 100644
--- a/compiler-rt/test/asan/CMakeLists.txt
+++ b/compiler-rt/test/asan/CMakeLists.txt
@@ -81,22 +81,15 @@ endforeach()
 # variable to select which iOS device or simulator to use, e.g.:
 # SANITIZER_IOSSIM_TEST_DEVICE_IDENTIFIER="iPhone 6"
 if(APPLE)
-  # FIXME(dliew): This logic should be refactored to the way UBSan Darwin
-  # testing is done.
   set(EXCLUDE_FROM_ALL ON)
 
   set(ASAN_TEST_TARGET_CC ${COMPILER_RT_TEST_COMPILER})
   set(ASAN_TEST_DYNAMIC True)
 
-  list_intersect(ASAN_TEST_IOSSIM_ARCHS ASAN_SUPPORTED_ARCH DARWIN_iossim_ARCHS)
-  foreach(arch ${ASAN_TEST_IOSSIM_ARCHS})
+  foreach(arch ${DARWIN_iossim_ARCHS})
     set(ASAN_TEST_APPLE_PLATFORM "iossim")
     set(ASAN_TEST_TARGET_ARCH ${arch})
-    get_test_cflags_for_apple_platform(
-      "${ASAN_TEST_APPLE_PLATFORM}"
-      "${ASAN_TEST_TARGET_ARCH}"
-      ASAN_TEST_TARGET_CFLAGS
-      )
+    set(ASAN_TEST_TARGET_CFLAGS "-arch ${arch} -isysroot ${DARWIN_iossim_SYSROOT} ${COMPILER_RT_TEST_COMPILER_CFLAGS}")
     set(ASAN_TEST_CONFIG_SUFFIX "-${arch}-${ASAN_TEST_APPLE_PLATFORM}")
     get_bits_for_arch(${arch} ASAN_TEST_BITS)
     string(TOUPPER ${arch} ARCH_UPPER_CASE)
@@ -110,14 +103,10 @@ if(APPLE)
       DEPENDS ${ASAN_TEST_DEPS})
   endforeach()
 
-  list_intersect(ASAN_TEST_IOS_ARCHS ASAN_SUPPORTED_ARCH DARWIN_ios_ARCHS)
-  foreach (arch ${ASAN_TEST_IOS_ARCHS})
+  foreach (arch ${DARWIN_ios_ARCHS})
     set(ASAN_TEST_APPLE_PLATFORM "ios")
     set(ASAN_TEST_TARGET_ARCH ${arch})
-    get_test_cflags_for_apple_platform(
-      "${ASAN_TEST_APPLE_PLATFORM}"
-      "${arch}"
-      ASAN_TEST_TARGET_CFLAGS)
+    set(ASAN_TEST_TARGET_CFLAGS "-arch ${arch} -isysroot ${DARWIN_ios_SYSROOT} ${COMPILER_RT_TEST_COMPILER_CFLAGS}")
     set(ASAN_TEST_CONFIG_SUFFIX "-${arch}-${ASAN_TEST_APPLE_PLATFORM}")
     get_bits_for_arch(${arch} ASAN_TEST_BITS)
     string(TOUPPER ${arch} ARCH_UPPER_CASE)
diff --git a/compiler-rt/test/fuzzer/CMakeLists.txt b/compiler-rt/test/fuzzer/CMakeLists.txt
index 9acbfdd9c6dab..8e9f12dd12252 100644
--- a/compiler-rt/test/fuzzer/CMakeLists.txt
+++ b/compiler-rt/test/fuzzer/CMakeLists.txt
@@ -89,19 +89,12 @@ if("${CMAKE_SYSTEM_NAME}" STREQUAL "Linux")
 endif()
 
 if (APPLE)
-  # FIXME(dliew): This logic should be refactored to the way UBSan Darwin
-  # testing is done.
   set(EXCLUDE_FROM_ALL ON)
 
-  list_intersect(FUZZER_TEST_IOS_ARCHS FUZZER_SUPPORTED_ARCH DARWIN_ios_ARCHS)
-  foreach(arch ${FUZZER_TEST_IOS_ARCHS})
+  foreach(arch ${DARWIN_ios_ARCHS})
     set(LIBFUZZER_TEST_APPLE_PLATFORM "ios")
     set(LIBFUZZER_TEST_TARGET_ARCH ${arch})
-    get_test_cflags_for_apple_platform(
-      "${LIBFUZZER_TEST_APPLE_PLATFORM}"
-      "${LIBFUZZER_TEST_TARGET_ARCH}"
-      LIBFUZZER_TEST_FLAGS
-      )
+    set(LIBFUZZER_TEST_FLAGS "-arch ${arch} -isysroot ${DARWIN_ios_SYSROOT} ${COMPILER_RT_TEST_COMPILER_CFLAGS}")
     set(LIBFUZZER_TEST_CONFIG_SUFFIX "-${arch}-${LIBFUZZER_TEST_APPLE_PLATFORM}")
     string(TOUPPER ${arch} ARCH_UPPER_CASE)
     set(CONFIG_NAME "IOS${ARCH_UPPER_CASE}Config")
diff --git a/compiler-rt/test/tsan/CMakeLists.txt b/compiler-rt/test/tsan/CMakeLists.txt
index d95993ed425d7..c62eb1d6b3d3b 100644
--- a/compiler-rt/test/tsan/CMakeLists.txt
+++ b/compiler-rt/test/tsan/CMakeLists.txt
@@ -49,53 +49,39 @@ endforeach()
 # variable to select which iOS device or simulator to use, e.g.:
 # SANITIZER_IOSSIM_TEST_DEVICE_IDENTIFIER="iPhone 6"
 if(APPLE)
-  # FIXME(dliew): This logic should be refactored to the way UBSan Darwin
-  # testing is done.
   set(EXCLUDE_FROM_ALL ON)
 
   set(TSAN_TEST_TARGET_CC ${COMPILER_RT_TEST_COMPILER})
 
-  list_intersect(TSAN_TEST_IOSSIM_ARCHS TSAN_SUPPORTED_ARCH DARWIN_iossim_ARCHS)
-  foreach(arch ${TSAN_TEST_IOSSIM_ARCHS})
-    set(TSAN_TEST_APPLE_PLATFORM "iossim")
-    set(TSAN_TEST_TARGET_ARCH ${arch})
-    get_test_cflags_for_apple_platform(
-      "${TSAN_TEST_APPLE_PLATFORM}"
-      "${TSAN_TEST_TARGET_ARCH}"
-      TSAN_TEST_TARGET_CFLAGS
-      )
-    set(TSAN_TEST_CONFIG_SUFFIX "-${arch}-${TSAN_TEST_APPLE_PLATFORM}")
-    string(TOUPPER ${arch} ARCH_UPPER_CASE)
-    set(CONFIG_NAME "IOSSim${ARCH_UPPER_CASE}Config")
-    configure_lit_site_cfg(
-      ${CMAKE_CURRENT_SOURCE_DIR}/lit.site.cfg.in
-      ${CMAKE_CURRENT_BINARY_DIR}/${CONFIG_NAME}/lit.site.cfg
-      )
-    add_lit_testsuite(check-tsan-iossim-${arch} "ThreadSanitizer iOS Simulator ${arch} tests"
-      ${CMAKE_CURRENT_BINARY_DIR}/${CONFIG_NAME}/
-      DEPENDS ${TSAN_TEST_DEPS})
-  endforeach()
+  set(TSAN_TEST_APPLE_PLATFORM "iossim")
+  set(arch "x86_64")
+  set(TSAN_TEST_TARGET_ARCH ${arch})
+  set(TSAN_TEST_TARGET_CFLAGS "-arch ${arch} -isysroot ${DARWIN_iossim_SYSROOT} ${COMPILER_RT_TEST_COMPILER_CFLAGS}")
+  set(TSAN_TEST_CONFIG_SUFFIX "-${arch}-${TSAN_TEST_APPLE_PLATFORM}")
+  string(TOUPPER ${arch} ARCH_UPPER_CASE)
+  set(CONFIG_NAME "IOSSim${ARCH_UPPER_CASE}Config")
+  configure_lit_site_cfg(
+    ${CMAKE_CURRENT_SOURCE_DIR}/lit.site.cfg.in
+    ${CMAKE_CURRENT_BINARY_DIR}/${CONFIG_NAME}/lit.site.cfg
+    )
+  add_lit_testsuite(check-tsan-iossim-${arch} "ThreadSanitizer iOS Simulator ${arch} tests"
+    ${CMAKE_CURRENT_BINARY_DIR}/${CONFIG_NAME}/
+    DEPENDS ${TSAN_TEST_DEPS})
 
-  list_intersect(TSAN_TEST_IOS_ARCHS TSAN_SUPPORTED_ARCH DARWIN_ios_ARCHS)
-  foreach(arch ${TSAN_TEST_IOS_ARCHS})
-    set(TSAN_TEST_APPLE_PLATFORM "ios")
-    set(TSAN_TEST_TARGET_ARCH ${arch})
-    get_test_cflags_for_apple_platform(
-      "${TSAN_TEST_APPLE_PLATFORM}"
-      "${TSAN_TEST_TARGET_ARCH}"
-      TSAN_TEST_TARGET_CFLAGS
-      )
-    set(TSAN_TEST_CONFIG_SUFFIX "-${arch}-${TSAN_TEST_APPLE_PLATFORM}")
-    string(TOUPPER ${arch} ARCH_UPPER_CASE)
-    set(CONFIG_NAME "IOS${ARCH_UPPER_CASE}Config")
-    configure_lit_site_cfg(
-      ${CMAKE_CURRENT_SOURCE_DIR}/lit.site.cfg.in
-      ${CMAKE_CURRENT_BINARY_DIR}/${CONFIG_NAME}/lit.site.cfg
-      )
-    add_lit_testsuite(check-tsan-ios-${arch} "ThreadSanitizer iOS ${arch} tests"
-      ${CMAKE_CURRENT_BINARY_DIR}/${CONFIG_NAME}/
-      DEPENDS ${TSAN_TEST_DEPS})
-  endforeach()
+  set(TSAN_TEST_APPLE_PLATFORM "ios")
+  set(arch "arm64")
+  set(TSAN_TEST_TARGET_ARCH ${arch})
+  set(TSAN_TEST_TARGET_CFLAGS "-arch ${arch} -isysroot ${DARWIN_ios_SYSROOT} ${COMPILER_RT_TEST_COMPILER_CFLAGS}")
+  set(TSAN_TEST_CONFIG_SUFFIX "-${arch}-${TSAN_TEST_APPLE_PLATFORM}")
+  string(TOUPPER ${arch} ARCH_UPPER_CASE)
+  set(CONFIG_NAME "IOS${ARCH_UPPER_CASE}Config")
+  configure_lit_site_cfg(
+    ${CMAKE_CURRENT_SOURCE_DIR}/lit.site.cfg.in
+    ${CMAKE_CURRENT_BINARY_DIR}/${CONFIG_NAME}/lit.site.cfg
+    )
+  add_lit_testsuite(check-tsan-ios-${arch} "ThreadSanitizer iOS Simulator ${arch} tests"
+    ${CMAKE_CURRENT_BINARY_DIR}/${CONFIG_NAME}/
+    DEPENDS ${TSAN_TEST_DEPS})
 
   set(EXCLUDE_FROM_ALL OFF)
 endif()
diff --git a/compiler-rt/test/ubsan/CMakeLists.txt b/compiler-rt/test/ubsan/CMakeLists.txt
index 280f96777406a..60ef84d7530fb 100644
--- a/compiler-rt/test/ubsan/CMakeLists.txt
+++ b/compiler-rt/test/ubsan/CMakeLists.txt
@@ -113,11 +113,7 @@ if(APPLE)
   endif()
   foreach(platform ${UBSAN_APPLE_PLATFORMS})
     foreach(arch ${DARWIN_${platform}_ARCHS})
-      get_test_cflags_for_apple_platform(
-        "${platform}"
-        "${arch}"
-        UBSAN_TEST_TARGET_CFLAGS
-      )
+      set(UBSAN_TEST_TARGET_CFLAGS "-arch ${arch} -isysroot ${DARWIN_${platform}_SYSROOT}")
       if (";${UBSAN_SUPPORTED_ARCH};" MATCHES ";${arch};")
         add_ubsan_device_testsuite("Standalone" ubsan ${platform} ${arch})
       endif()