diff --git a/glm/core/intrinsic_common.inl b/glm/core/intrinsic_common.inl
index 28ad3c6c..cee0f8c4 100644
--- a/glm/core/intrinsic_common.inl
+++ b/glm/core/intrinsic_common.inl
@@ -270,12 +270,12 @@ inline __m128 _mm_inf_ps(__m128 x)
 
 // SSE scalar reciprocal sqrt using rsqrt op, plus one Newton-Rhaphson iteration
 // By Elan Ruskin, 
-inline __m128 _mm_sqrt_wip_ss(__m128 const x)
+inline __m128 _mm_sqrt_wip_ss(__m128 const & x)
 {
-	__m128 recip = _mm_rsqrt_ss( x );  // "estimate" opcode
-	const static __m128 three = { 3, 3, 3, 3 }; // aligned consts for fast load
-	const static __m128 half = { 0.5,0.5,0.5,0.5 };
-	__m128 halfrecip = _mm_mul_ss( half, recip );
-	__m128 threeminus_xrr = _mm_sub_ss( three, _mm_mul_ss( x, _mm_mul_ss ( recip, recip ) ) );
-	return _mm_mul_ss( halfrecip, threeminus_xrr );
+	__m128 recip = _mm_rsqrt_ss(x);  // "estimate" opcode
+	const static __m128 three = {3, 3, 3, 3}; // aligned consts for fast load
+	const static __m128 half = {0.5,0.5,0.5,0.5};
+	__m128 halfrecip = _mm_mul_ss(half, recip);
+	__m128 threeminus_xrr = _mm_sub_ss(three, _mm_mul_ss(x, _mm_mul_ss (recip, recip)));
+	return _mm_mul_ss( halfrecip, threeminus_xrr);
 }
diff --git a/glm/setup.hpp b/glm/setup.hpp
index 80698816..0828a3cf 100644
--- a/glm/setup.hpp
+++ b/glm/setup.hpp
@@ -250,6 +250,37 @@
 #	define GLM_INSTRUCTION_SET GLM_INSTRUCTION_SET_PURE
 #endif
 
+#define GLM_INSTRUCTION_SET_SSSE3	0x00000008 // tmmintrin.h (SSSE3 + SSE3 + SSE2 + SSE1)
+#define GLM_INSTRUCTION_SET_POPCNT	0x00000800 // popcntintrin.h
+#define GLM_INSTRUCTION_SET_SSE4A	0x00000020 // ammintrin.h (SSE4A + POPCNT + SSE3 + SSE2 + SSE)
+#define GLM_INSTRUCTION_SET_SSE4_1	0x00000040 // smmintrin.h (SSE4_1 + SSSE3 + SSE3 + SSE2 + SSE)
+#define GLM_INSTRUCTION_SET_SSE4_2	0x00000080 // nmmintrin.h (SSE4_2 + SSE4_1 + SSSE3 + SSE3 + SSE2 + SSE)
+#define GLM_INSTRUCTION_SET_SSE5	0x00000100 // bmmintrin.h (SSE4A + SSE3 + SSE2 + SSE deprecated)
+#define GLM_INSTRUCTION_SET_AES		0x00000200 // wmmintrin.h (AES + PCLMUL + SSE2 + SSE1)
+#define GLM_INSTRUCTION_SET_PCLMUL	0x00000400 // wmmintrin.h (AES + PCLMUL + SSE2 + SSE1)
+#define GLM_INSTRUCTION_SET_AVX		0x00000800 // immintrin.h (AES + PCLMUL + SSE4_2 + SSE4_1 + SSSE3 + SSE3 + SSE2 + SSE)
+
+#if(GLM_INSTRUCTION_SET != GLM_INSTRUCTION_SET_PURE)
+#	if(GLM_INSTRUCTION_SET & GLM_INSTRUCTION_SET_MMX)
+#		include <mmintrin.h>
+#	endif
+#	if(GLM_INSTRUCTION_SET & GLM_INSTRUCTION_SET_3DNOW)
+#		include <mm3dnow.h>
+#	endif
+#	if(GLM_INSTRUCTION_SET & GLM_INSTRUCTION_SET_SSE)
+#		include <xmmintrin.h>
+#	endif
+#	if(GLM_INSTRUCTION_SET & GLM_INSTRUCTION_SET_SSE2)
+#		include <emmintrin.h>
+#	endif
+#	if(GLM_INSTRUCTION_SET & GLM_INSTRUCTION_SET_SSE3)
+#		include <pmmintrin.h>
+#	endif
+#	if(GLM_INSTRUCTION_SET & GLM_INSTRUCTION_SET_SSSE3)
+#		include <tmmintrin.h>
+#	endif
+#endif
+
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 // Swizzle operators