Index: llvm/cmake/modules/HandleLLVMOptions.cmake
===================================================================
--- llvm/cmake/modules/HandleLLVMOptions.cmake
+++ llvm/cmake/modules/HandleLLVMOptions.cmake
@@ -13,7 +13,7 @@
 include(CheckSymbolExists)
 include(CMakeDependentOption)
 
-if(CMAKE_LINKER MATCHES "lld-link" OR (WIN32 AND LLVM_USE_LINKER STREQUAL "lld") OR LLVM_ENABLE_LLD)
+if(CMAKE_LINKER MATCHES "lld-link" OR MSVC AND (LLVM_USE_LINKER STREQUAL "lld" OR LLVM_ENABLE_LLD))
   set(LINKER_IS_LLD_LINK TRUE)
 else()
   set(LINKER_IS_LLD_LINK FALSE)
@@ -941,7 +941,7 @@
   message(FATAL_ERROR "LLVM_BUILD_INSTRUMENTED and LLVM_BUILD_INSTRUMENTED_COVERAGE cannot both be specified")
 endif()
 
-if(LLVM_ENABLE_LTO AND LLVM_ON_WIN32 AND NOT LINKER_IS_LLD_LINK)
+if(LLVM_ENABLE_LTO AND LLVM_ON_WIN32 AND NOT LINKER_IS_LLD_LINK AND NOT MINGW)
   message(FATAL_ERROR "When compiling for Windows, LLVM_ENABLE_LTO requires using lld as the linker (point CMAKE_LINKER at lld-link.exe)")
 endif()
 if(uppercase_LLVM_ENABLE_LTO STREQUAL "THIN")
@@ -956,7 +956,7 @@
   if(APPLE)
     append("-Wl,-cache_path_lto,${PROJECT_BINARY_DIR}/lto.cache"
            CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
-  elseif(UNIX AND LLVM_USE_LINKER STREQUAL "lld")
+  elseif((UNIX OR MINGW) AND LLVM_USE_LINKER STREQUAL "lld")
     append("-Wl,--thinlto-cache-dir=${PROJECT_BINARY_DIR}/lto.cache"
            CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
   elseif(LLVM_USE_LINKER STREQUAL "gold")