diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3184acf..74efb71 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -51,7 +51,7 @@ if (${CMAKE_CXX_COMPILER_ID} STREQUAL GNU)
     if (CMAKE_CXX_COMPILER_VERSION VERSION_LESS 11.0)
         message(FATAL_ERROR "G++ ${MINIMAL_GNU} or higher is required.")
     endif()
-    set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -fira-loop-pressure -ftree-loop-distribution -floop-interchange -fipa-pta -fivopts -s")
+    set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -fmerge-all-constants -fira-loop-pressure -ftree-loop-distribution -floop-interchange -fipa-pta -fivopts -s")
     set(CMAKE_CXX_FLAGS "-fno-use-linker-plugin -fwhole-program ${CMAKE_CXX_FLAGS}")
 elseif(${CMAKE_CXX_COMPILER_ID} STREQUAL Clang)
     if (CMAKE_CXX_COMPILER_VERSION VERSION_LESS 13.0)