godot/thirdparty/embree/kernels/common/stack_item.h

126 lines
3.2 KiB
C++

// Copyright 2009-2020 Intel Corporation
// SPDX-License-Identifier: Apache-2.0
#pragma once
#include "default.h"
namespace embree
{
/*! An item on the stack holds the node ID and distance of that node. */
template<typename T>
struct __aligned(16) StackItemT
{
/*! assert that the xchg function works */
static_assert(sizeof(T) <= 12, "sizeof(T) <= 12 failed");
__forceinline StackItemT() {}
__forceinline StackItemT(T &ptr, unsigned &dist) : ptr(ptr), dist(dist) {}
/*! use SSE instructions to swap stack items */
__forceinline static void xchg(StackItemT& a, StackItemT& b)
{
const vfloat4 sse_a = vfloat4::load((float*)&a);
const vfloat4 sse_b = vfloat4::load((float*)&b);
vfloat4::store(&a,sse_b);
vfloat4::store(&b,sse_a);
}
/*! Sort 2 stack items. */
__forceinline friend void sort(StackItemT& s1, StackItemT& s2) {
if (s2.dist < s1.dist) xchg(s2,s1);
}
/*! Sort 3 stack items. */
__forceinline friend void sort(StackItemT& s1, StackItemT& s2, StackItemT& s3)
{
if (s2.dist < s1.dist) xchg(s2,s1);
if (s3.dist < s2.dist) xchg(s3,s2);
if (s2.dist < s1.dist) xchg(s2,s1);
}
/*! Sort 4 stack items. */
__forceinline friend void sort(StackItemT& s1, StackItemT& s2, StackItemT& s3, StackItemT& s4)
{
if (s2.dist < s1.dist) xchg(s2,s1);
if (s4.dist < s3.dist) xchg(s4,s3);
if (s3.dist < s1.dist) xchg(s3,s1);
if (s4.dist < s2.dist) xchg(s4,s2);
if (s3.dist < s2.dist) xchg(s3,s2);
}
/*! use SSE instructions to swap stack items */
__forceinline static void cmp_xchg(vint4& a, vint4& b)
{
#if defined(__AVX512VL__)
const vboolf4 mask(shuffle<2,2,2,2>(b) < shuffle<2,2,2,2>(a));
#else
const vboolf4 mask0(b < a);
const vboolf4 mask(shuffle<2,2,2,2>(mask0));
#endif
const vint4 c = select(mask,b,a);
const vint4 d = select(mask,a,b);
a = c;
b = d;
}
/*! Sort 3 stack items. */
__forceinline static void sort3(vint4& s1, vint4& s2, vint4& s3)
{
cmp_xchg(s2,s1);
cmp_xchg(s3,s2);
cmp_xchg(s2,s1);
}
/*! Sort 4 stack items. */
__forceinline static void sort4(vint4& s1, vint4& s2, vint4& s3, vint4& s4)
{
cmp_xchg(s2,s1);
cmp_xchg(s4,s3);
cmp_xchg(s3,s1);
cmp_xchg(s4,s2);
cmp_xchg(s3,s2);
}
/*! Sort N stack items. */
__forceinline friend void sort(StackItemT* begin, StackItemT* end)
{
for (StackItemT* i = begin+1; i != end; ++i)
{
const vfloat4 item = vfloat4::load((float*)i);
const unsigned dist = i->dist;
StackItemT* j = i;
while ((j != begin) && ((j-1)->dist < dist))
{
vfloat4::store(j, vfloat4::load((float*)(j-1)));
--j;
}
vfloat4::store(j, item);
}
}
public:
T ptr;
unsigned dist;
};
/*! An item on the stack holds the node ID and active ray mask. */
template<typename T>
struct __aligned(8) StackItemMaskT
{
T ptr;
size_t mask;
};
struct __aligned(8) StackItemMaskCoherent
{
size_t mask;
size_t parent;
size_t child;
};
}