Index: src/CMakeLists.txt
--- src/CMakeLists.txt.orig
+++ src/CMakeLists.txt
@@ -714,7 +714,7 @@ if(NOT CUSTOM_CFLAGS)
   #-g MUST be set for ALL builds, or there will be no support for them when bugs happen
   set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${MARCH} -g")
   set(CMAKE_C_FLAGS_RELWITHDEBINFO "${CMAKE_C_FLAGS_RELWITHDEBINFO} -O2 -ftree-vectorize")
-  set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} -O3 -ffast-math -fno-finite-math-only")
+  set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} -ffast-math -fno-finite-math-only")
   if(CMAKE_C_COMPILER_ID STREQUAL "GNU")
     set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -O0 -g3 -ggdb3")
     set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} -fexpensive-optimizations")
@@ -724,7 +724,7 @@ if(NOT CUSTOM_CFLAGS)
 
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${MARCH} -g")
   set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELWITHDEBINFO} -O2 -ftree-vectorize")
-  set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -O3 -ffast-math -fno-finite-math-only")
+  set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -ffast-math -fno-finite-math-only")
   if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
     set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -O0 -g3 -ggdb3")
     set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -fexpensive-optimizations")
