Index: compiler-rt/cmake/Modules/AddCompilerRT.cmake
===================================================================
--- compiler-rt/cmake/Modules/AddCompilerRT.cmake
+++ compiler-rt/cmake/Modules/AddCompilerRT.cmake
@@ -389,7 +389,7 @@
       if(COMMAND llvm_setup_rpath)
         llvm_setup_rpath(${libname})
       endif()
-      if(WIN32 AND NOT CYGWIN AND NOT MINGW)
+      if(MSVC)
         set_target_properties(${libname} PROPERTIES IMPORT_PREFIX "")
         set_target_properties(${libname} PROPERTIES IMPORT_SUFFIX ".lib")
       endif()
Index: compiler-rt/cmake/base-config-ix.cmake
===================================================================
--- compiler-rt/cmake/base-config-ix.cmake
+++ compiler-rt/cmake/base-config-ix.cmake
@@ -153,7 +153,7 @@
   option(COMPILER_RT_DEFAULT_TARGET_ONLY "Build builtins only for the default target" Off)
 endif()
 
-if(WIN32 AND NOT MINGW AND NOT CYGWIN)
+if(MSVC)
   set(CMAKE_SHARED_LIBRARY_PREFIX_C "")
   set(CMAKE_SHARED_LIBRARY_PREFIX_CXX "")
   set(CMAKE_STATIC_LIBRARY_PREFIX_C "")