diff --git a/compiler-rt/cmake/Modules/CompilerRTUtils.cmake b/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
--- a/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
+++ b/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
@@ -441,7 +441,11 @@
 
 function(get_compiler_rt_install_dir arch install_dir)
   if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
-    get_compiler_rt_target(${arch} target)
+    if(COMPILER_RT_DEFAULT_TARGET_ONLY)
+      set(target ${LLVM_RUNTIME_TRIPLE})
+    else()
+      get_compiler_rt_target(${arch} target)
+    endif()
     set(${install_dir} ${COMPILER_RT_INSTALL_LIBRARY_DIR}/${target} PARENT_SCOPE)
   else()
     set(${install_dir} ${COMPILER_RT_INSTALL_LIBRARY_DIR} PARENT_SCOPE)
@@ -450,7 +454,11 @@
 
 function(get_compiler_rt_output_dir arch output_dir)
   if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
-    get_compiler_rt_target(${arch} target)
+    if(COMPILER_RT_DEFAULT_TARGET_ONLY)
+      set(target ${LLVM_RUNTIME_TRIPLE})
+    else()
+      get_compiler_rt_target(${arch} target)
+    endif()
     set(${output_dir} ${COMPILER_RT_OUTPUT_LIBRARY_DIR}/${target} PARENT_SCOPE)
   else()
     set(${output_dir} ${COMPILER_RT_OUTPUT_LIBRARY_DIR} PARENT_SCOPE)
diff --git a/compiler-rt/cmake/config-ix.cmake b/compiler-rt/cmake/config-ix.cmake
--- a/compiler-rt/cmake/config-ix.cmake
+++ b/compiler-rt/cmake/config-ix.cmake
@@ -693,8 +693,8 @@
   set(CAN_SYMBOLIZE 1)
 endif()
 
-find_program(GNU_LD_EXECUTABLE NAMES ${LLVM_DEFAULT_TARGET_TRIPLE}-ld.bfd ld.bfd DOC "GNU ld")
-find_program(GOLD_EXECUTABLE NAMES ${LLVM_DEFAULT_TARGET_TRIPLE}-ld.gold ld.gold DOC "GNU gold")
+find_program(GNU_LD_EXECUTABLE NAMES ${LLVM_RUNTIME_TRIPLE}-ld.bfd ld.bfd DOC "GNU ld")
+find_program(GOLD_EXECUTABLE NAMES ${LLVM_RUNTIME_TRIPLE}-ld.gold ld.gold DOC "GNU gold")
 
 if(COMPILER_RT_SUPPORTED_ARCH)
   list(REMOVE_DUPLICATES COMPILER_RT_SUPPORTED_ARCH)
diff --git a/libc/lib/CMakeLists.txt b/libc/lib/CMakeLists.txt
--- a/libc/lib/CMakeLists.txt
+++ b/libc/lib/CMakeLists.txt
@@ -10,7 +10,7 @@
 )
 
 if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR)
-  set(LIBC_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE})
+  set(LIBC_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_RUNTIME_TRIPLE})
 else()
   set(LIBC_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX})
 endif()
diff --git a/libcxx/CMakeLists.txt b/libcxx/CMakeLists.txt
--- a/libcxx/CMakeLists.txt
+++ b/libcxx/CMakeLists.txt
@@ -414,12 +414,12 @@
 set(LIBCXX_STATIC_OUTPUT_NAME "c++" CACHE STRING "Output name for the static libc++ runtime library.")
 
 if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
-  set(LIBCXX_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE})
+  set(LIBCXX_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_RUNTIME_TRIPLE})
   set(LIBCXX_GENERATED_INCLUDE_DIR "${LLVM_BINARY_DIR}/include/c++/v1")
-  set(LIBCXX_GENERATED_INCLUDE_TARGET_DIR "${LLVM_BINARY_DIR}/include/${LLVM_DEFAULT_TARGET_TRIPLE}/c++/v1")
-  set(LIBCXX_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE} CACHE PATH
+  set(LIBCXX_GENERATED_INCLUDE_TARGET_DIR "${LLVM_BINARY_DIR}/include/${LLVM_RUNTIME_TRIPLE}/c++/v1")
+  set(LIBCXX_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_RUNTIME_TRIPLE} CACHE PATH
       "Path where built libc++ libraries should be installed.")
-  set(LIBCXX_INSTALL_INCLUDE_TARGET_DIR "${CMAKE_INSTALL_INCLUDEDIR}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++/v1" CACHE PATH
+  set(LIBCXX_INSTALL_INCLUDE_TARGET_DIR "${CMAKE_INSTALL_INCLUDEDIR}/${LLVM_RUNTIME_TRIPLE}/c++/v1" CACHE PATH
       "Path where target-specific libc++ headers should be installed.")
   if(LIBCXX_LIBDIR_SUBDIR)
     string(APPEND LIBCXX_LIBRARY_DIR /${LIBCXX_LIBDIR_SUBDIR})
diff --git a/libcxx/docs/BuildingLibcxx.rst b/libcxx/docs/BuildingLibcxx.rst
--- a/libcxx/docs/BuildingLibcxx.rst
+++ b/libcxx/docs/BuildingLibcxx.rst
@@ -281,7 +281,7 @@
 .. option:: LIBCXX_INSTALL_INCLUDE_TARGET_DIR:PATH
 
   **Default**: ``include/c++/v1`` or
-  ``include/${LLVM_DEFAULT_TARGET_TRIPLE}/c++/v1``
+  ``include/${LLVM_RUNTIME_TRIPLE}/c++/v1``
 
   Path where target-specific libc++ headers should be installed. If a relative
   path, relative to ``CMAKE_INSTALL_PREFIX``.
diff --git a/libcxx/lib/abi/CMakeLists.txt b/libcxx/lib/abi/CMakeLists.txt
--- a/libcxx/lib/abi/CMakeLists.txt
+++ b/libcxx/lib/abi/CMakeLists.txt
@@ -43,7 +43,7 @@
 if (CMAKE_CXX_COMPILER_TARGET)
   set(triple "${CMAKE_CXX_COMPILER_TARGET}")
 else()
-  set(triple "${LLVM_DEFAULT_TARGET_TRIPLE}")
+  set(triple "${LLVM_RUNTIME_TRIPLE}")
 endif()
 cxx_abi_list_identifier(abi_list_identifier
   "${triple}"
diff --git a/libcxx/test/CMakeLists.txt b/libcxx/test/CMakeLists.txt
--- a/libcxx/test/CMakeLists.txt
+++ b/libcxx/test/CMakeLists.txt
@@ -31,7 +31,7 @@
 if (CMAKE_CXX_COMPILER_TARGET)
   serialize_lit_param(target_triple "\"${CMAKE_CXX_COMPILER_TARGET}\"")
 else()
-  serialize_lit_param(target_triple "\"${LLVM_DEFAULT_TARGET_TRIPLE}\"")
+  serialize_lit_param(target_triple "\"${LLVM_RUNTIME_TRIPLE}\"")
 endif()
 
 if (LLVM_USE_SANITIZER)
diff --git a/libcxxabi/CMakeLists.txt b/libcxxabi/CMakeLists.txt
--- a/libcxxabi/CMakeLists.txt
+++ b/libcxxabi/CMakeLists.txt
@@ -189,8 +189,8 @@
 
 if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
   set(LIBCXXABI_HEADER_DIR ${LLVM_BINARY_DIR})
-  set(LIBCXXABI_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE})
-  set(LIBCXXABI_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE} CACHE PATH
+  set(LIBCXXABI_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_RUNTIME_TRIPLE})
+  set(LIBCXXABI_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_RUNTIME_TRIPLE} CACHE PATH
       "Path where built libc++abi libraries should be installed.")
   if(LIBCXX_LIBDIR_SUBDIR)
     string(APPEND LIBCXXABI_LIBRARY_DIR /${LIBCXXABI_LIBDIR_SUBDIR})
diff --git a/libcxxabi/test/CMakeLists.txt b/libcxxabi/test/CMakeLists.txt
--- a/libcxxabi/test/CMakeLists.txt
+++ b/libcxxabi/test/CMakeLists.txt
@@ -50,7 +50,7 @@
 if (CMAKE_CXX_COMPILER_TARGET)
   serialize_lit_param(target_triple "\"${CMAKE_CXX_COMPILER_TARGET}\"")
 else()
-  serialize_lit_param(target_triple "\"${LLVM_DEFAULT_TARGET_TRIPLE}\"")
+  serialize_lit_param(target_triple "\"${LLVM_RUNTIME_TRIPLE}\"")
 endif()
 
 foreach(param IN LISTS LIBCXXABI_TEST_PARAMS)
diff --git a/libunwind/CMakeLists.txt b/libunwind/CMakeLists.txt
--- a/libunwind/CMakeLists.txt
+++ b/libunwind/CMakeLists.txt
@@ -115,8 +115,8 @@
 set(LIBUNWIND_STATIC_OUTPUT_NAME "unwind" CACHE STRING "Output name for the static libunwind runtime library.")
 
 if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
-  set(LIBUNWIND_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE})
-  set(LIBUNWIND_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE} CACHE PATH
+  set(LIBUNWIND_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_RUNTIME_TRIPLE})
+  set(LIBUNWIND_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_RUNTIME_TRIPLE} CACHE PATH
       "Path where built libunwind libraries should be installed.")
   if(LIBCXX_LIBDIR_SUBDIR)
     string(APPEND LIBUNWIND_LIBRARY_DIR /${LIBUNWIND_LIBDIR_SUBDIR})
diff --git a/libunwind/test/CMakeLists.txt b/libunwind/test/CMakeLists.txt
--- a/libunwind/test/CMakeLists.txt
+++ b/libunwind/test/CMakeLists.txt
@@ -29,7 +29,7 @@
 if (CMAKE_CXX_COMPILER_TARGET)
   serialize_lit_param(target_triple "\"${CMAKE_CXX_COMPILER_TARGET}\"")
 else()
-  serialize_lit_param(target_triple "\"${LLVM_DEFAULT_TARGET_TRIPLE}\"")
+  serialize_lit_param(target_triple "\"${LLVM_RUNTIME_TRIPLE}\"")
 endif()
 
 foreach(param IN LISTS LIBUNWIND_TEST_PARAMS)
diff --git a/llvm/CMakeLists.txt b/llvm/CMakeLists.txt
--- a/llvm/CMakeLists.txt
+++ b/llvm/CMakeLists.txt
@@ -860,6 +860,10 @@
 include(SetTargetTriple)
 set_llvm_target_triple()
 
+# TODO: This would ideally only be set in the runtimes build, but not until
+# we deprecate support for building compiler-rt with LLVM_ENABLE_PROJECTS.
+set(LLVM_RUNTIME_TRIPLE "${LLVM_TARGET_TRIPLE}" CACHE STRING "")
+
 if(WIN32 OR CYGWIN)
   if(BUILD_SHARED_LIBS OR LLVM_BUILD_LLVM_DYLIB)
     set(LLVM_ENABLE_PLUGINS_default ON)
diff --git a/llvm/cmake/modules/LLVMExternalProjectUtils.cmake b/llvm/cmake/modules/LLVMExternalProjectUtils.cmake
--- a/llvm/cmake/modules/LLVMExternalProjectUtils.cmake
+++ b/llvm/cmake/modules/LLVMExternalProjectUtils.cmake
@@ -78,7 +78,7 @@
   endif()
 
   if(NOT ARG_TARGET_TRIPLE)
-    set(target_triple ${LLVM_DEFAULT_TARGET_TRIPLE})
+    set(target_triple ${LLVM_RUNTIME_TRIPLE})
   else()
     set(target_triple ${ARG_TARGET_TRIPLE})
   endif()
diff --git a/llvm/runtimes/CMakeLists.txt b/llvm/runtimes/CMakeLists.txt
--- a/llvm/runtimes/CMakeLists.txt
+++ b/llvm/runtimes/CMakeLists.txt
@@ -74,7 +74,7 @@
                            DEPENDS ${ARG_DEPENDS}
                            CMAKE_ARGS -DLLVM_LIBRARY_OUTPUT_INTDIR=${LLVM_LIBRARY_DIR}
                                       -DLLVM_RUNTIME_OUTPUT_INTDIR=${LLVM_TOOLS_BINARY_DIR}
-                                      -DLLVM_DEFAULT_TARGET_TRIPLE=${LLVM_TARGET_TRIPLE}
+                                      -DLLVM_RUNTIME_TRIPLE=${LLVM_RUNTIME_TRIPLE}
                                       -DLLVM_ENABLE_PER_TARGET_RUNTIME_DIR=${LLVM_ENABLE_PER_TARGET_RUNTIME_DIR_default}
                                       -DCMAKE_C_COMPILER_WORKS=ON
                                       -DCMAKE_ASM_COMPILER_WORKS=ON
@@ -108,7 +108,7 @@
                            DEPENDS ${ARG_DEPENDS}
                            CMAKE_ARGS -DLLVM_LIBRARY_OUTPUT_INTDIR=${LLVM_LIBRARY_DIR}
                                       -DLLVM_RUNTIME_OUTPUT_INTDIR=${LLVM_TOOLS_BINARY_DIR}
-                                      -DLLVM_DEFAULT_TARGET_TRIPLE=${target}
+                                      -DLLVM_RUNTIME_TRIPLE=${target}
                                       -DLLVM_ENABLE_PER_TARGET_RUNTIME_DIR=ON
                                       -DCMAKE_C_COMPILER_WORKS=ON
                                       -DCMAKE_ASM_COMPILER_WORKS=ON
@@ -229,7 +229,7 @@
                            # Builtins were built separately above
                            CMAKE_ARGS -DCOMPILER_RT_BUILD_BUILTINS=Off
                                       -DLLVM_INCLUDE_TESTS=${LLVM_INCLUDE_TESTS}
-                                      -DLLVM_DEFAULT_TARGET_TRIPLE=${LLVM_TARGET_TRIPLE}
+                                      -DLLVM_RUNTIME_TRIPLE=${LLVM_RUNTIME_TRIPLE}
                                       -DLLVM_ENABLE_PROJECTS_USED=${LLVM_ENABLE_PROJECTS_USED}
                                       -DLLVM_ENABLE_PER_TARGET_RUNTIME_DIR=${LLVM_ENABLE_PER_TARGET_RUNTIME_DIR_default}
                                       -DLLVM_BUILD_TOOLS=${LLVM_BUILD_TOOLS}
@@ -354,7 +354,7 @@
                            # Builtins were built separately above
                            CMAKE_ARGS -DCOMPILER_RT_BUILD_BUILTINS=Off
                                       -DLLVM_INCLUDE_TESTS=${LLVM_INCLUDE_TESTS}
-                                      -DLLVM_DEFAULT_TARGET_TRIPLE=${target}
+                                      -DLLVM_RUNTIME_TRIPLE=${target}
                                       -DLLVM_ENABLE_PROJECTS_USED=${LLVM_ENABLE_PROJECTS_USED}
                                       -DLLVM_ENABLE_PER_TARGET_RUNTIME_DIR=ON
                                       -DCMAKE_C_COMPILER_WORKS=ON
diff --git a/runtimes/CMakeLists.txt b/runtimes/CMakeLists.txt
--- a/runtimes/CMakeLists.txt
+++ b/runtimes/CMakeLists.txt
@@ -161,8 +161,8 @@
 # Host triple is used by tests to check if they are running natively.
 include(GetHostTriple)
 get_host_triple(LLVM_HOST_TRIPLE)
-set(LLVM_DEFAULT_TARGET_TRIPLE "${LLVM_HOST_TRIPLE}" CACHE STRING
-  "Default target for which the runtimes will be built.")
+set(LLVM_RUNTIME_TRIPLE "${LLVM_HOST_TRIPLE}" CACHE STRING
+  "Triple used as runtime instrallation path.")
 
 option(LLVM_INCLUDE_TESTS "Generate build targets for the runtimes unit tests." ON)
 option(LLVM_INCLUDE_DOCS "Generate build targets for the runtimes documentation." ON)