--- CMakeLists.txt.orig	2019-10-15 02:51:03 UTC
+++ CMakeLists.txt
@@ -42,13 +42,12 @@ find_package(OpenMP REQUIRED)
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${OpenMP_CXX_FLAGS}")
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DXXH_INLINE_ALL -ftemplate-depth=3000")
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wno-unused-function")
-set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fprefetch-loop-arrays -funroll-loops")
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -D__XROOT__='\"${CMAKE_SOURCE_DIR}/src\"'")
 #set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -D__XFILE__='\"$(subst ${CMAKE_SOURCE_DIR}/,,$(abspath $<))\"'")
 
 set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${ZLIB_EXE_LINKER_FLAGS} ${OpenMP_EXE_LINKER_FLAGS}")
 
-set(CMAKE_CXX_FLAGS_RELEASE "-O3 -DNDEBUG")
+set(CMAKE_CXX_FLAGS_RELEASE "-DNDEBUG")
 set(CMAKE_CXX_FLAGS_DEBUG "-g -ggdb -O1 -D_LIBCPP_DEBUG -D_GLIBCXX_DEBUG")
 
 if (COVERAGE)