diff --git a/CMakeLists.txt b/CMakeLists.txt
index 07f06c90..71126a69 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -8,9 +8,13 @@ set(CMAKE_C_STANDARD_REQUIRED ON)
 # use IPO
 include(CheckIPOSupported)
 check_ipo_supported(RESULT result)
+
 if(result)
     set(CMAKE_INTERPROCEDURAL_OPTIMIZATION TRUE)
-    message(">> IPO is enabled")
+else()
+    message(WARNING ">> IPO disabled. You will get very poor performance!!")
+    message(WARNING ">> IPO disabled. You will get very poor performance!!")
+    message(WARNING ">> IPO disabled. You will get very poor performance!!")
 endif()
 
 
diff --git a/build_ios.sh b/build_ios.sh
index c7a43350..b0c43cb7 100644
--- a/build_ios.sh
+++ b/build_ios.sh
@@ -4,7 +4,7 @@ rm -rf build
 mkdir build
 cd build
 
-FLAGS="-DCMAKE_TOOLCHAIN_FILE=3rd/ios.toolchain.cmake -DPK_BUILD_STATIC_LIB=ON -DDEPLOYMENT_TARGET=13.0"
+FLAGS="-DCMAKE_TOOLCHAIN_FILE=3rd/ios.toolchain.cmake -DPK_BUILD_STATIC_LIB=ON -DDEPLOYMENT_TARGET=13.0 -DENABLE_BITCODE=1"
 
 cmake -B os64 -G Xcode $FLAGS -DPLATFORM=OS64 ..
 cmake --build os64 --config Release