diff --git a/Sources/Core/Debug.h b/Sources/Core/Debug.h
index 33461606d..16af52473 100644
--- a/Sources/Core/Debug.h
+++ b/Sources/Core/Debug.h
@@ -132,15 +132,18 @@ namespace spades {
 
 #ifdef __GNUC__
 #define DEPRECATED(func) func __attribute__((deprecated))
+#define PURE __attribute__((pure))
 #define LIKELY(cond)   __builtin_expect(!!(cond), true)
 #define UNLIKELY(cond) __builtin_expect(!!(cond), false)
 #elif defined(_MSC_VER)
 #define DEPRECATED(func) __declspec(deprecated) func
 #define LIKELY(cond)   (cond)
 #define UNLIKELY(cond) (cond)
+#define PURE
 #else
 #pragma message("WARNING: You need to implement DEPRECATED for this compiler")
 #define DEPRECATED(func) func
+#define PURE
 #pragma message("WARNING: You need to implement LIKELY/UNLIKELY for this compiler")
 #define LIKELY(cond)   (cond)
 #define UNLIKELY(cond) (cond)
diff --git a/Sources/Draw/SWFeatureLevel.h b/Sources/Draw/SWFeatureLevel.h
index 7899ceec8..54b92bddb 100644
--- a/Sources/Draw/SWFeatureLevel.h
+++ b/Sources/Draw/SWFeatureLevel.h
@@ -115,9 +115,9 @@ namespace spades {
 			return tmp;
 		}
 #else
-		static inline float fastDiv(float a, float b) { return a / b; }
-		static inline float fastRcp(float b) { return 1.f / b; }
-		static inline float fastRSqrt(float b) { return 1.f / sqrtf(b); }
+		static inline PURE float fastDiv(float a, float b) { return a / b; }
+		static inline PURE float fastRcp(float b) { return 1.f / b; }
+		static inline PURE float fastRSqrt(float b) { return 1.f / sqrtf(b); }
 #endif
 		static inline float fastSqrt(float s) {
 			if (s == 0.f)
diff --git a/Sources/Draw/SWUtils.h b/Sources/Draw/SWUtils.h
index b047f7455..966ec839a 100644
--- a/Sources/Draw/SWUtils.h
+++ b/Sources/Draw/SWUtils.h
@@ -65,12 +65,12 @@ namespace spades {
 			}
 		}
 
-		static inline int ToFixed8(float v) {
+		static inline PURE int ToFixed8(float v) {
 			int i = static_cast<int>(v * 255.f + .5f);
 			return std::max(std::min(i, 255), 0);
 		}
 
-		static inline int ToFixedFactor8(float v) {
+		static inline PURE int ToFixedFactor8(float v) {
 			int i = static_cast<int>(v * 256.f + .5f);
 			return std::max(std::min(i, 256), 0);
 		}