diff --git a/CMakeLists.txt b/CMakeLists.txt
index deb4c5e..b181ed2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -25,7 +25,7 @@ if(NOT PLATFORM_DREAMCAST)
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -m32")
 endif()
 
-set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} -O3 --fast-math")
+set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} -Ofast --fast-math")
 
 set(
     SOURCES
diff --git a/GL/draw.c b/GL/draw.c
index 41b5469..ee94b10 100644
--- a/GL/draw.c
+++ b/GL/draw.c
@@ -285,11 +285,7 @@ static void _fillWithNegZVE(const GLubyte* input, GLubyte* out) {
 
 static void  _fillWhiteARGB(const GLubyte* input, GLubyte* output) {
     _GL_UNUSED(input);
-
-    output[R8IDX] = 255;
-    output[G8IDX] = 255;
-    output[B8IDX] = 255;
-    output[A8IDX] = 255;
+    *((uint32_t*) output) = ~0;
 }
 
 static void _fillZero2f(const GLubyte* input, GLubyte* out) {