[Bf-blender-cvs] [b886c26] master: Cycles: mix hair minimum width code with SSE intersection code

[Sv. Lockal]

Commit: b886c26d1f70d512b4f68975142372e3bee81c89
Author: Sv. Lockal
Date:   Sat Jan 11 20:47:30 2014 +0400
https://developer.blender.org/rBb886c26d1f70d512b4f68975142372e3bee81c89

Cycles: mix hair minimum width code with SSE intersection code

Gives 6.5% speedup for hair.blend from testsuite.

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D197

===================================================================

M	intern/cycles/kernel/kernel_bvh_traversal.h

===================================================================

diff --git a/intern/cycles/kernel/kernel_bvh_traversal.h b/intern/cycles/kernel/kernel_bvh_traversal.h
index 8f69083..a78e72e 100644
--- a/intern/cycles/kernel/kernel_bvh_traversal.h
+++ b/intern/cycles/kernel/kernel_bvh_traversal.h
@@ -69,7 +69,7 @@ ccl_device bool BVH_FUNCTION_NAME
 	isect->u = 0.0f;
 	isect->v = 0.0f;
 
-#if defined(__KERNEL_SSE2__) && !FEATURE(BVH_HAIR_MINIMUM_WIDTH)
+#if defined(__KERNEL_SSE2__)
 	const shuffle_swap_t shuf_identity = shuffle_swap_identity();
 	const shuffle_swap_t shuf_swap = shuffle_swap_swap();
 	
@@ -101,7 +101,7 @@ ccl_device bool BVH_FUNCTION_NAME
 				bool traverseChild0, traverseChild1;
 				int nodeAddrChild1;
 
-#if !defined(__KERNEL_SSE2__) || FEATURE(BVH_HAIR_MINIMUM_WIDTH)
+#if !defined(__KERNEL_SSE2__)
 				/* Intersect two child bounding boxes, non-SSE version */
 				float t = isect->t;
 
@@ -159,15 +159,36 @@ ccl_device bool BVH_FUNCTION_NAME
 				/* Intersect two child bounding boxes, SSE3 version adapted from Embree */
 
 				/* fetch node data */
-				__m128 *bvh_nodes = (__m128*)kg->__bvh_nodes.data + nodeAddr*BVH_NODE_SIZE;
-				float4 cnodes = ((float4*)bvh_nodes)[3];
+				const __m128 *bvh_nodes = (__m128*)kg->__bvh_nodes.data + nodeAddr*BVH_NODE_SIZE;
+				const float4 cnodes = ((float4*)bvh_nodes)[3];
 
 				/* intersect ray against child nodes */
 				const __m128 tminmaxx = _mm_mul_ps(_mm_sub_ps(shuffle_swap(bvh_nodes[0], shufflex), Psplat[0]), idirsplat[0]);
 				const __m128 tminmaxy = _mm_mul_ps(_mm_sub_ps(shuffle_swap(bvh_nodes[1], shuffley), Psplat[1]), idirsplat[1]);
 				const __m128 tminmaxz = _mm_mul_ps(_mm_sub_ps(shuffle_swap(bvh_nodes[2], shufflez), Psplat[2]), idirsplat[2]);
 
-				const __m128 tminmax = _mm_xor_ps(_mm_max_ps(_mm_max_ps(tminmaxx, tminmaxy), _mm_max_ps(tminmaxz, tsplat)), _mm_castsi128_ps(pn));
+				/* calculate { c0min, c1min, -c0max, -c1max} */
+				__m128 minmax = _mm_max_ps(_mm_max_ps(tminmaxx, tminmaxy), _mm_max_ps(tminmaxz, tsplat));
+				const __m128 tminmax = _mm_xor_ps(minmax, _mm_castsi128_ps(pn));
+
+#if FEATURE(BVH_HAIR_MINIMUM_WIDTH)
+				if(difl != 0.0f) {
+					float4 *tminmaxview = (float4*)&tminmax;
+					float &c0min = tminmaxview->x, &c1min = tminmaxview->y;
+					float &c0max = tminmaxview->z, &c1max = tminmaxview->w;
+
+					float hdiff = 1.0f + difl;
+					float ldiff = 1.0f - difl;
+					if(__float_as_int(cnodes.z) & PATH_RAY_CURVE) {
+						c0min = max(ldiff * c0min, c0min - extmax);
+						c0max = min(hdiff * c0max, c0max + extmax);
+					}
+					if(__float_as_int(cnodes.w) & PATH_RAY_CURVE) {
+						c1min = max(ldiff * c1min, c1min - extmax);
+						c1max = min(hdiff * c1max, c1max + extmax);
+					}
+				}
+#endif
 				const __m128 lrhit = _mm_cmple_ps(tminmax, shuffle_swap(tminmax, shuf_swap));
 
 				/* decide which nodes to traverse next */
@@ -186,7 +207,7 @@ ccl_device bool BVH_FUNCTION_NAME
 
 				if(traverseChild0 && traverseChild1) {
 					/* both children were intersected, push the farther one */
-#if !defined(__KERNEL_SSE2__) || FEATURE(BVH_HAIR_MINIMUM_WIDTH)
+#if !defined(__KERNEL_SSE2__)
 					bool closestChild1 = (c1min < c0min);
 #else
 					union { __m128 m128; float v[4]; } uminmax;
@@ -255,7 +276,7 @@ ccl_device bool BVH_FUNCTION_NAME
 							hit = bvh_triangle_intersect(kg, isect, P, idir, visibility, object, primAddr);
 
 						/* shadow ray early termination */
-#if defined(__KERNEL_SSE2__) && !FEATURE(BVH_HAIR_MINIMUM_WIDTH)
+#if defined(__KERNEL_SSE2__)
 						if(hit) {
 							if(visibility == PATH_RAY_SHADOW_OPAQUE)
 								return true;
@@ -281,7 +302,7 @@ ccl_device bool BVH_FUNCTION_NAME
 					bvh_instance_push(kg, object, ray, &P, &idir, &isect->t, tmax);
 #endif
 
-#if defined(__KERNEL_SSE2__) && !FEATURE(BVH_HAIR_MINIMUM_WIDTH)
+#if defined(__KERNEL_SSE2__)
 					Psplat[0] = _mm_set_ps1(P.x);
 					Psplat[1] = _mm_set_ps1(P.y);
 					Psplat[2] = _mm_set_ps1(P.z);
@@ -317,7 +338,7 @@ ccl_device bool BVH_FUNCTION_NAME
 			bvh_instance_pop(kg, object, ray, &P, &idir, &isect->t, tmax);
 #endif
 
-#if defined(__KERNEL_SSE2__) && !FEATURE(BVH_HAIR_MINIMUM_WIDTH)
+#if defined(__KERNEL_SSE2__)
 			Psplat[0] = _mm_set_ps1(P.x);
 			Psplat[1] = _mm_set_ps1(P.y);
 			Psplat[2] = _mm_set_ps1(P.z);