Index: CMakeLists.txt
===================================================================
--- CMakeLists.txt
+++ CMakeLists.txt
@@ -310,7 +310,7 @@
 set(LLVM_EXAMPLES_BINARY_DIR ${LLVM_BINARY_DIR}/examples)
 set(LLVM_INCLUDE_DIR ${CMAKE_CURRENT_BINARY_DIR}/include)
 
-set(LLVM_ALL_TARGETS
+set(LLVM_STABLE_TARGETS
   AArch64
   AMDGPU
   ARM
@@ -328,11 +328,18 @@
   XCore
   )
 
+set(LLVM_ALL_TARGETS
+  ${LLVM_STABLE_TARGETS}
+  AVR
+  Nios2
+  WebAssembly
+  )
+
 # List of targets with JIT support:
 set(LLVM_TARGETS_WITH_JIT X86 PowerPC AArch64 ARM Mips SystemZ)
 
-set(LLVM_TARGETS_TO_BUILD "all"
-    CACHE STRING "Semicolon-separated list of targets to build, or \"all\".")
+set(LLVM_TARGETS_TO_BUILD "stable"
+    CACHE STRING "Semicolon-separated list of targets to build, or \"stable\", or \"all\".")
 
 set(LLVM_EXPERIMENTAL_TARGETS_TO_BUILD ""
   CACHE STRING "Semicolon-separated list of experimental targets to build.")
@@ -365,7 +372,9 @@
 
 option(LLVM_ENABLE_ZLIB "Use zlib for compression/decompression if available." ON)
 
-if( LLVM_TARGETS_TO_BUILD STREQUAL "all" )
+if( LLVM_TARGETS_TO_BUILD STREQUAL "stable" )
+  set( LLVM_TARGETS_TO_BUILD ${LLVM_STABLE_TARGETS} )
+elseif( LLVM_TARGETS_TO_BUILD STREQUAL "all" )
   set( LLVM_TARGETS_TO_BUILD ${LLVM_ALL_TARGETS} )
 endif()