godot/thirdparty/embree/kernels/bvh/bvh_traverser1.h

467 lines
17 KiB
C++

// Copyright 2009-2021 Intel Corporation
// SPDX-License-Identifier: Apache-2.0
#pragma once
#include "bvh.h"
#include "node_intersector1.h"
#include "../common/stack_item.h"
#define NEW_SORTING_CODE 1
namespace embree
{
namespace isa
{
/*! BVH regular node traversal for single rays. */
template<int N, int types>
class BVHNNodeTraverser1Hit;
#if defined(__AVX512VL__) // SKX
template<int N>
__forceinline void isort_update(vint<N> &dist, const vint<N> &d)
{
const vint<N> dist_shift = align_shift_right<N-1>(dist,dist);
const vboolf<N> m_geq = d >= dist;
const vboolf<N> m_geq_shift = m_geq << 1;
dist = select(m_geq,d,dist);
dist = select(m_geq_shift,dist_shift,dist);
}
template<int N>
__forceinline void isort_quick_update(vint<N> &dist, const vint<N> &d) {
dist = align_shift_right<N-1>(dist,permute(d,vint<N>(zero)));
}
__forceinline size_t permuteExtract(const vint8& index, const vllong4& n0, const vllong4& n1) {
return toScalar(permutex2var((__m256i)index,n0,n1));
}
__forceinline float permuteExtract(const vint8& index, const vfloat8& n) {
return toScalar(permute(n,index));
}
#endif
/* Specialization for BVH4. */
template<int types>
class BVHNNodeTraverser1Hit<4, types>
{
typedef BVH4 BVH;
typedef BVH4::NodeRef NodeRef;
typedef BVH4::BaseNode BaseNode;
public:
/* Traverses a node with at least one hit child. Optimized for finding the closest hit (intersection). */
static __forceinline void traverseClosestHit(NodeRef& cur,
size_t mask,
const vfloat4& tNear,
StackItemT<NodeRef>*& stackPtr,
StackItemT<NodeRef>* stackEnd)
{
assert(mask != 0);
const BaseNode* node = cur.baseNode();
/*! one child is hit, continue with that child */
size_t r = bscf(mask);
cur = node->child(r);
BVH::prefetch(cur,types);
if (likely(mask == 0)) {
assert(cur != BVH::emptyNode);
return;
}
/*! two children are hit, push far child, and continue with closer child */
NodeRef c0 = cur;
const unsigned int d0 = ((unsigned int*)&tNear)[r];
r = bscf(mask);
NodeRef c1 = node->child(r);
BVH::prefetch(c1,types);
const unsigned int d1 = ((unsigned int*)&tNear)[r];
assert(c0 != BVH::emptyNode);
assert(c1 != BVH::emptyNode);
if (likely(mask == 0)) {
assert(stackPtr < stackEnd);
if (d0 < d1) { stackPtr->ptr = c1; stackPtr->dist = d1; stackPtr++; cur = c0; return; }
else { stackPtr->ptr = c0; stackPtr->dist = d0; stackPtr++; cur = c1; return; }
}
#if NEW_SORTING_CODE == 1
vint4 s0((size_t)c0,(size_t)d0);
vint4 s1((size_t)c1,(size_t)d1);
r = bscf(mask);
NodeRef c2 = node->child(r); BVH::prefetch(c2,types); unsigned int d2 = ((unsigned int*)&tNear)[r];
vint4 s2((size_t)c2,(size_t)d2);
/* 3 hits */
if (likely(mask == 0)) {
StackItemT<NodeRef>::sort3(s0,s1,s2);
*(vint4*)&stackPtr[0] = s0; *(vint4*)&stackPtr[1] = s1;
cur = toSizeT(s2);
stackPtr+=2;
return;
}
r = bscf(mask);
NodeRef c3 = node->child(r); BVH::prefetch(c3,types); unsigned int d3 = ((unsigned int*)&tNear)[r];
vint4 s3((size_t)c3,(size_t)d3);
/* 4 hits */
StackItemT<NodeRef>::sort4(s0,s1,s2,s3);
*(vint4*)&stackPtr[0] = s0; *(vint4*)&stackPtr[1] = s1; *(vint4*)&stackPtr[2] = s2;
cur = toSizeT(s3);
stackPtr+=3;
#else
/*! Here starts the slow path for 3 or 4 hit children. We push
* all nodes onto the stack to sort them there. */
assert(stackPtr < stackEnd);
stackPtr->ptr = c0; stackPtr->dist = d0; stackPtr++;
assert(stackPtr < stackEnd);
stackPtr->ptr = c1; stackPtr->dist = d1; stackPtr++;
/*! three children are hit, push all onto stack and sort 3 stack items, continue with closest child */
assert(stackPtr < stackEnd);
r = bscf(mask);
NodeRef c = node->child(r); BVH::prefetch(c,types); unsigned int d = ((unsigned int*)&tNear)[r]; stackPtr->ptr = c; stackPtr->dist = d; stackPtr++;
assert(c != BVH::emptyNode);
if (likely(mask == 0)) {
sort(stackPtr[-1],stackPtr[-2],stackPtr[-3]);
cur = (NodeRef) stackPtr[-1].ptr; stackPtr--;
return;
}
/*! four children are hit, push all onto stack and sort 4 stack items, continue with closest child */
assert(stackPtr < stackEnd);
r = bscf(mask);
c = node->child(r); BVH::prefetch(c,types); d = *(unsigned int*)&tNear[r]; stackPtr->ptr = c; stackPtr->dist = d; stackPtr++;
assert(c != BVH::emptyNode);
sort(stackPtr[-1],stackPtr[-2],stackPtr[-3],stackPtr[-4]);
cur = (NodeRef) stackPtr[-1].ptr; stackPtr--;
#endif
}
/* Traverses a node with at least one hit child. Optimized for finding any hit (occlusion). */
static __forceinline void traverseAnyHit(NodeRef& cur,
size_t mask,
const vfloat4& tNear,
NodeRef*& stackPtr,
NodeRef* stackEnd)
{
const BaseNode* node = cur.baseNode();
/*! one child is hit, continue with that child */
size_t r = bscf(mask);
cur = node->child(r);
BVH::prefetch(cur,types);
/* simpler in sequence traversal order */
assert(cur != BVH::emptyNode);
if (likely(mask == 0)) return;
assert(stackPtr < stackEnd);
*stackPtr = cur; stackPtr++;
for (; ;)
{
r = bscf(mask);
cur = node->child(r); BVH::prefetch(cur,types);
assert(cur != BVH::emptyNode);
if (likely(mask == 0)) return;
assert(stackPtr < stackEnd);
*stackPtr = cur; stackPtr++;
}
}
};
/* Specialization for BVH8. */
template<int types>
class BVHNNodeTraverser1Hit<8, types>
{
typedef BVH8 BVH;
typedef BVH8::NodeRef NodeRef;
typedef BVH8::BaseNode BaseNode;
#if defined(__AVX512VL__)
template<class NodeRef, class BaseNode>
static __forceinline void traverseClosestHitAVX512VL8(NodeRef& cur,
size_t mask,
const vfloat8& tNear,
StackItemT<NodeRef>*& stackPtr,
StackItemT<NodeRef>* stackEnd)
{
assert(mask != 0);
const BaseNode* node = cur.baseNode();
const vllong4 n0 = vllong4::loadu((vllong4*)&node->children[0]);
const vllong4 n1 = vllong4::loadu((vllong4*)&node->children[4]);
vint8 distance_i = (asInt(tNear) & 0xfffffff8) | vint8(step);
distance_i = vint8::compact((int)mask,distance_i,distance_i);
cur = permuteExtract(distance_i,n0,n1);
BVH::prefetch(cur,types);
mask &= mask-1;
if (likely(mask == 0)) return;
/* 2 hits: order A0 B0 */
const vint8 d0(distance_i);
const vint8 d1(shuffle<1>(distance_i));
cur = permuteExtract(d1,n0,n1);
BVH::prefetch(cur,types);
const vint8 dist_A0 = min(d0, d1);
const vint8 dist_B0 = max(d0, d1);
assert(dist_A0[0] < dist_B0[0]);
mask &= mask-1;
if (likely(mask == 0)) {
cur = permuteExtract(dist_A0,n0,n1);
stackPtr[0].ptr = permuteExtract(dist_B0,n0,n1);
*(float*)&stackPtr[0].dist = permuteExtract(dist_B0,tNear);
stackPtr++;
return;
}
/* 3 hits: order A1 B1 C1 */
const vint8 d2(shuffle<2>(distance_i));
cur = permuteExtract(d2,n0,n1);
BVH::prefetch(cur,types);
const vint8 dist_A1 = min(dist_A0,d2);
const vint8 dist_tmp_B1 = max(dist_A0,d2);
const vint8 dist_B1 = min(dist_B0,dist_tmp_B1);
const vint8 dist_C1 = max(dist_B0,dist_tmp_B1);
assert(dist_A1[0] < dist_B1[0]);
assert(dist_B1[0] < dist_C1[0]);
mask &= mask-1;
if (likely(mask == 0)) {
cur = permuteExtract(dist_A1,n0,n1);
stackPtr[0].ptr = permuteExtract(dist_C1,n0,n1);
*(float*)&stackPtr[0].dist = permuteExtract(dist_C1,tNear);
stackPtr[1].ptr = permuteExtract(dist_B1,n0,n1);
*(float*)&stackPtr[1].dist = permuteExtract(dist_B1,tNear);
stackPtr+=2;
return;
}
/* 4 hits: order A2 B2 C2 D2 */
const vint8 d3(shuffle<3>(distance_i));
cur = permuteExtract(d3,n0,n1);
BVH::prefetch(cur,types);
const vint8 dist_A2 = min(dist_A1,d3);
const vint8 dist_tmp_B2 = max(dist_A1,d3);
const vint8 dist_B2 = min(dist_B1,dist_tmp_B2);
const vint8 dist_tmp_C2 = max(dist_B1,dist_tmp_B2);
const vint8 dist_C2 = min(dist_C1,dist_tmp_C2);
const vint8 dist_D2 = max(dist_C1,dist_tmp_C2);
assert(dist_A2[0] < dist_B2[0]);
assert(dist_B2[0] < dist_C2[0]);
assert(dist_C2[0] < dist_D2[0]);
mask &= mask-1;
if (likely(mask == 0)) {
cur = permuteExtract(dist_A2,n0,n1);
stackPtr[0].ptr = permuteExtract(dist_D2,n0,n1);
*(float*)&stackPtr[0].dist = permuteExtract(dist_D2,tNear);
stackPtr[1].ptr = permuteExtract(dist_C2,n0,n1);
*(float*)&stackPtr[1].dist = permuteExtract(dist_C2,tNear);
stackPtr[2].ptr = permuteExtract(dist_B2,n0,n1);
*(float*)&stackPtr[2].dist = permuteExtract(dist_B2,tNear);
stackPtr+=3;
return;
}
/* >=5 hits: reverse to descending order for writing to stack */
distance_i = align_shift_right<3>(distance_i,distance_i);
const size_t hits = 4 + popcnt(mask);
vint8 dist(INT_MIN); // this will work with -0.0f (0x80000000) as distance, isort_update uses >= to insert
isort_quick_update<8>(dist,dist_A2);
isort_quick_update<8>(dist,dist_B2);
isort_quick_update<8>(dist,dist_C2);
isort_quick_update<8>(dist,dist_D2);
do {
distance_i = align_shift_right<1>(distance_i,distance_i);
cur = permuteExtract(distance_i,n0,n1);
BVH::prefetch(cur,types);
const vint8 new_dist(permute(distance_i,vint8(zero)));
mask &= mask-1;
isort_update<8>(dist,new_dist);
} while(mask);
for (size_t i=0; i<7; i++)
assert(dist[i+0]>=dist[i+1]);
for (size_t i=0;i<hits-1;i++)
{
stackPtr->ptr = permuteExtract(dist,n0,n1);
*(float*)&stackPtr->dist = permuteExtract(dist,tNear);
dist = align_shift_right<1>(dist,dist);
stackPtr++;
}
cur = permuteExtract(dist,n0,n1);
}
#endif
public:
static __forceinline void traverseClosestHit(NodeRef& cur,
size_t mask,
const vfloat8& tNear,
StackItemT<NodeRef>*& stackPtr,
StackItemT<NodeRef>* stackEnd)
{
assert(mask != 0);
#if defined(__AVX512VL__)
traverseClosestHitAVX512VL8<NodeRef,BaseNode>(cur,mask,tNear,stackPtr,stackEnd);
#else
const BaseNode* node = cur.baseNode();
/*! one child is hit, continue with that child */
size_t r = bscf(mask);
cur = node->child(r);
BVH::prefetch(cur,types);
if (likely(mask == 0)) {
assert(cur != BVH::emptyNode);
return;
}
/*! two children are hit, push far child, and continue with closer child */
NodeRef c0 = cur;
const unsigned int d0 = ((unsigned int*)&tNear)[r];
r = bscf(mask);
NodeRef c1 = node->child(r);
BVH::prefetch(c1,types);
const unsigned int d1 = ((unsigned int*)&tNear)[r];
assert(c0 != BVH::emptyNode);
assert(c1 != BVH::emptyNode);
if (likely(mask == 0)) {
assert(stackPtr < stackEnd);
if (d0 < d1) { stackPtr->ptr = c1; stackPtr->dist = d1; stackPtr++; cur = c0; return; }
else { stackPtr->ptr = c0; stackPtr->dist = d0; stackPtr++; cur = c1; return; }
}
#if NEW_SORTING_CODE == 1
vint4 s0((size_t)c0,(size_t)d0);
vint4 s1((size_t)c1,(size_t)d1);
r = bscf(mask);
NodeRef c2 = node->child(r); BVH::prefetch(c2,types); unsigned int d2 = ((unsigned int*)&tNear)[r];
vint4 s2((size_t)c2,(size_t)d2);
/* 3 hits */
if (likely(mask == 0)) {
StackItemT<NodeRef>::sort3(s0,s1,s2);
*(vint4*)&stackPtr[0] = s0; *(vint4*)&stackPtr[1] = s1;
cur = toSizeT(s2);
stackPtr+=2;
return;
}
r = bscf(mask);
NodeRef c3 = node->child(r); BVH::prefetch(c3,types); unsigned int d3 = ((unsigned int*)&tNear)[r];
vint4 s3((size_t)c3,(size_t)d3);
/* 4 hits */
if (likely(mask == 0)) {
StackItemT<NodeRef>::sort4(s0,s1,s2,s3);
*(vint4*)&stackPtr[0] = s0; *(vint4*)&stackPtr[1] = s1; *(vint4*)&stackPtr[2] = s2;
cur = toSizeT(s3);
stackPtr+=3;
return;
}
*(vint4*)&stackPtr[0] = s0; *(vint4*)&stackPtr[1] = s1; *(vint4*)&stackPtr[2] = s2; *(vint4*)&stackPtr[3] = s3;
/*! fallback case if more than 4 children are hit */
StackItemT<NodeRef>* stackFirst = stackPtr;
stackPtr+=4;
while (1)
{
assert(stackPtr < stackEnd);
r = bscf(mask);
NodeRef c = node->child(r); BVH::prefetch(c,types); unsigned int d = *(unsigned int*)&tNear[r];
const vint4 s((size_t)c,(size_t)d);
*(vint4*)stackPtr++ = s;
assert(c != BVH::emptyNode);
if (unlikely(mask == 0)) break;
}
sort(stackFirst,stackPtr);
cur = (NodeRef) stackPtr[-1].ptr; stackPtr--;
#else
/*! Here starts the slow path for 3 or 4 hit children. We push
* all nodes onto the stack to sort them there. */
assert(stackPtr < stackEnd);
stackPtr->ptr = c0; stackPtr->dist = d0; stackPtr++;
assert(stackPtr < stackEnd);
stackPtr->ptr = c1; stackPtr->dist = d1; stackPtr++;
/*! three children are hit, push all onto stack and sort 3 stack items, continue with closest child */
assert(stackPtr < stackEnd);
r = bscf(mask);
NodeRef c = node->child(r); BVH::prefetch(c,types); unsigned int d = ((unsigned int*)&tNear)[r]; stackPtr->ptr = c; stackPtr->dist = d; stackPtr++;
assert(c != BVH::emptyNode);
if (likely(mask == 0)) {
sort(stackPtr[-1],stackPtr[-2],stackPtr[-3]);
cur = (NodeRef) stackPtr[-1].ptr; stackPtr--;
return;
}
/*! four children are hit, push all onto stack and sort 4 stack items, continue with closest child */
assert(stackPtr < stackEnd);
r = bscf(mask);
c = node->child(r); BVH::prefetch(c,types); d = *(unsigned int*)&tNear[r]; stackPtr->ptr = c; stackPtr->dist = d; stackPtr++;
assert(c != BVH::emptyNode);
if (likely(mask == 0)) {
sort(stackPtr[-1],stackPtr[-2],stackPtr[-3],stackPtr[-4]);
cur = (NodeRef) stackPtr[-1].ptr; stackPtr--;
return;
}
/*! fallback case if more than 4 children are hit */
StackItemT<NodeRef>* stackFirst = stackPtr-4;
while (1)
{
assert(stackPtr < stackEnd);
r = bscf(mask);
c = node->child(r); BVH::prefetch(c,types); d = *(unsigned int*)&tNear[r]; stackPtr->ptr = c; stackPtr->dist = d; stackPtr++;
assert(c != BVH::emptyNode);
if (unlikely(mask == 0)) break;
}
sort(stackFirst,stackPtr);
cur = (NodeRef) stackPtr[-1].ptr; stackPtr--;
#endif
#endif
}
static __forceinline void traverseAnyHit(NodeRef& cur,
size_t mask,
const vfloat8& tNear,
NodeRef*& stackPtr,
NodeRef* stackEnd)
{
const BaseNode* node = cur.baseNode();
/*! one child is hit, continue with that child */
size_t r = bscf(mask);
cur = node->child(r);
BVH::prefetch(cur,types);
/* simpler in sequence traversal order */
assert(cur != BVH::emptyNode);
if (likely(mask == 0)) return;
assert(stackPtr < stackEnd);
*stackPtr = cur; stackPtr++;
for (; ;)
{
r = bscf(mask);
cur = node->child(r); BVH::prefetch(cur,types);
assert(cur != BVH::emptyNode);
if (likely(mask == 0)) return;
assert(stackPtr < stackEnd);
*stackPtr = cur; stackPtr++;
}
}
};
}
}