diff --git a/math.d b/math.d
index 098a328..78cc76c 100644
--- a/math.d
+++ b/math.d
@@ -521,7 +521,7 @@ align(16) struct Matrix(T, int D)
 			Matrix result;
 			MatZero(&result);
 
-			glm_mat4_mul(glm_mat.ptr, x.glm_mat.ptr, result.glm_mat.ptr);
+			Mat4MulASM(&this, &x, &result);
 
 			return result;
 		}
@@ -583,21 +583,14 @@ struct Quat
 	}
 }
 
-Mat4
-Mat4MulASM(Mat4 l, Mat4 r)
+void
+Mat4MulASM(Mat4* l, Mat4* r, Mat4* result)
 {
-	Mat4 result;
-
-	auto lp = &l;
-	auto rp = &r;
-	auto res = &result;
-
-	// TODO: fix this
 	asm @trusted 
 	{
-		mov R8, lp;
-		mov R9, rp;
-		mov R10, res;
+		mov    R8,   l;
+		mov    R9,   r;
+		mov    R10,  result;
 
 		movups XMM0, [R8];
 		movups XMM1, [R9+00];
@@ -607,93 +600,91 @@ Mat4MulASM(Mat4 l, Mat4 r)
 
 		movups XMM6, XMM1;
 		shufps XMM6, XMM6, 0; // XMM5 = vec.xxxx;
-		mulps XMM6, XMM0; // XMM6 = col1;
+		mulps  XMM6, XMM0; // XMM6 = col1;
 
 		movups XMM7, XMM2;
 		shufps XMM7, XMM7, 0;
-		mulps XMM7, XMM0; // XMM7 = col2;
+		mulps  XMM7, XMM0; // XMM7 = col2;
 
 		movups XMM8, XMM3;
 		shufps XMM8, XMM8, 0;
-		mulps XMM8, XMM0; // XMM8 = col3;
+		mulps  XMM8, XMM0; // XMM8 = col3;
 
-		movups XMM9, XMM3;
+		movups XMM9, XMM4;
 		shufps XMM9, XMM9, 0;
-		mulps XMM9, XMM0; // XMM9 = col4;
+		mulps  XMM9, XMM0; // XMM9 = col4;
 
 		movups XMM0, [R8+16];
 
 		movups XMM5, XMM1;
 		shufps XMM5, XMM5, 85; // XMM5 = vec.yyyy;
-		mulps XMM5, XMM0;
-		addps XMM6, XMM5;
+		mulps  XMM5, XMM0;
+		addps  XMM6, XMM5;
 
 		movups XMM5, XMM2;
 		shufps XMM5, XMM5, 85;
-		mulps XMM5, XMM0;
-		addps XMM7, XMM5;
+		mulps  XMM5, XMM0;
+		addps  XMM7, XMM5;
 
 		movups XMM5, XMM3;
 		shufps XMM5, XMM5, 85;
-		mulps XMM5, XMM0;
-		addps XMM8, XMM5;
+		mulps  XMM5, XMM0;
+		addps  XMM8, XMM5;
 
 		movups XMM5, XMM4;
 		shufps XMM5, XMM5, 85;
-		mulps XMM5, XMM0;
-		addps XMM9, XMM5;
+		mulps  XMM5, XMM0;
+		addps  XMM9, XMM5;
 
 		movups XMM0, [R8+32];
 
 		movups XMM5, XMM1;
 		shufps XMM5, XMM5, 170; // XMM5 = vec.zzzz;
-		mulps XMM5, XMM0;
-		addps XMM6, XMM5;
+		mulps  XMM5, XMM0;
+		addps  XMM6, XMM5;
 
 		movups XMM5, XMM2;
 		shufps XMM5, XMM5, 170;
-		mulps XMM5, XMM0;
-		addps XMM7, XMM5;
+		mulps  XMM5, XMM0;
+		addps  XMM7, XMM5;
 
 		movups XMM5, XMM3;
 		shufps XMM5, XMM5, 170;
-		mulps XMM5, XMM0;
-		addps XMM8, XMM5;
-
+		mulps  XMM5, XMM0;
+		addps  XMM8, XMM5;
+ 
 		movups XMM5, XMM4;
 		shufps XMM5, XMM5, 170;
-		mulps XMM5, XMM0;
-		addps XMM9, XMM5;
+		mulps  XMM5, XMM0;
+		addps  XMM9, XMM5;
 
 		movups XMM0, [R8+48];
 
 		movups XMM5, XMM1;
 		shufps XMM5, XMM5, 255; // XMM5 = vec.wwww;
-		mulps XMM5, XMM0;
-		addps XMM6, XMM5;
+		mulps  XMM5, XMM0;
+		addps  XMM6, XMM5;
 
 		movups XMM5, XMM2;
 		shufps XMM5, XMM5, 255;
-		mulps XMM5, XMM0;
-		addps XMM7, XMM5;
+		mulps  XMM5, XMM0;
+		addps  XMM7, XMM5;
 
 		movups XMM5, XMM3;
 		shufps XMM5, XMM5, 255;
-		mulps XMM5, XMM0;
-		addps XMM8, XMM5;
+		mulps  XMM5, XMM0;
+		addps  XMM8, XMM5;
 
 		movups XMM5, XMM4;
 		shufps XMM5, XMM5, 255;
-		mulps XMM5, XMM0;
-		addps XMM9, XMM5;
+		mulps  XMM5, XMM0;
+		addps  XMM9, XMM5;
 
 		movups [R10+00], XMM6;
 		movups [R10+16], XMM7;
 		movups [R10+32], XMM8;
 		movups [R10+48], XMM9;
 	}
-
-	return result;
 }
 
 pragma(inline) Mat4