110 

   111 // rewrite of BBox::intersect for ray packets

   112 __m128 BBox::intersect_packet(const RayPacket &rays, __m128 &a, __m128 &b)

   113 {

   114 	register __m128 tnear = mZero;

   115 	register __m128 tfar = mInf;

   116 	register __m128 t1, t2;

   117 	register __m128 mask = mAllSet;

   118 

   119 	for (int i = 0; i < 3; i++)

   120 	{

   121 		const __m128 mL = _mm_set_ps1(L[i]);

   122 		const __m128 mH = _mm_set_ps1(H[i]);

   123 		mask = _mm_and_ps(mask,

   124 		_mm_or_ps(

   125 		_mm_or_ps(_mm_cmplt_ps(rays.dir.ma[i], mMEps), _mm_cmpgt_ps(rays.dir.ma[i], mEps)),

   126 		_mm_and_ps(_mm_cmpge_ps(rays.o.ma[i], mL), _mm_cmple_ps(rays.o.ma[i], mH))

   127 		));

   128 		if (!_mm_movemask_ps(mask))

   129 			return mask;

   130 

   131 		/* compute the intersection distance of the planes */

   132 		t1 = _mm_div_ps(_mm_sub_ps(mL, rays.o.ma[i]), rays.dir.ma[i]);

   133 		t2 = _mm_div_ps(_mm_sub_ps(mH, rays.o.ma[i]), rays.dir.ma[i]);

   134 

   135 		__m128 t = _mm_min_ps(t1, t2);

   136 		t2 = _mm_max_ps(t1, t2);

   137 		t1 = t;

   138 

   139 		tnear = _mm_max_ps(tnear, t1);	/* want largest Tnear */

   140 		tfar = _mm_min_ps(tfar, t2);	/* want smallest Tfar */

   141 

   142 		mask = _mm_and_ps(mask,

   143 			_mm_and_ps(_mm_cmple_ps(tnear, tfar), _mm_cmpge_ps(tfar, mZero)));

   144 		if (!_mm_movemask_ps(mask))

   145 			return mask;

   146 	}

   147 

   148 	a = tnear;

   149 	b = tfar;

   150 	return mask;

   151 }