Turn on LTCG and COMDAT folding.

Author: BillyONeal

CMakeLists.txt

@@ -98,11 +98,11 @@ if(MSVC)
     # either MSVC, or clang-cl
     string(APPEND CMAKE_C_FLAGS " -FC -permissive- -utf-8 /guard:cf")
     string(APPEND CMAKE_CXX_FLAGS " /EHsc -FC -permissive- -utf-8 /guard:cf")
-    string(APPEND CMAKE_C_FLAGS_RELEASE " /Zi")
-    string(APPEND CMAKE_CXX_FLAGS_RELEASE " /Zi")
+    string(APPEND CMAKE_C_FLAGS_RELEASE " /Zi /GL")
+    string(APPEND CMAKE_CXX_FLAGS_RELEASE " /Zi /GL")
 
-    string(APPEND CMAKE_EXE_LINKER_FLAGS_RELWITHDEBINFO " /DEBUG /INCREMENTAL:NO /debugtype:cv,fixup /guard:cf")
-    string(APPEND CMAKE_EXE_LINKER_FLAGS_RELEASE " /DEBUG /INCREMENTAL:NO /debugtype:cv,fixup /guard:cf")
+    string(APPEND CMAKE_EXE_LINKER_FLAGS_RELWITHDEBINFO " /DEBUG /INCREMENTAL:NO /debugtype:cv,fixup /guard:cf /OPT:REF /OPT:ICF /LTCG")
+    string(APPEND CMAKE_EXE_LINKER_FLAGS_RELEASE " /DEBUG /INCREMENTAL:NO /debugtype:cv,fixup /guard:cf /OPT:REF /OPT:ICF /LTCG")
     if (MSVC_CXX_ARCHITECTURE_ID STREQUAL "x64")
         string(APPEND CMAKE_EXE_LINKER_FLAGS_RELWITHDEBINFO " /CETCOMPAT")
         string(APPEND CMAKE_EXE_LINKER_FLAGS_RELEASE " /CETCOMPAT")