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Keep Bool4 in its native format instead of converting to a bitmask.

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This gives a small performance boost.
This commit is contained in:
Nathan Vegdahl 2019-06-28 22:56:51 +09:00
parent 2fddcae0fd
commit c5d23592b9
2 changed files with 32 additions and 16 deletions
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19
src/accel/bvh4_simd.rs
View File

@ -25,6 +25,7 @@ use super::{
};
use bvh_order::{calc_traversal_code, SplitAxes, TRAVERSAL_TABLE};
use float4::Bool4;
pub fn ray_code(dir: Vector) -> usize {
let ray_sign_is_neg = [dir.x() < 0.0, dir.y() < 0.0, dir.z() < 0.0];
@ -128,27 +129,25 @@ impl<'a> BVH4<'a> {
children,
traversal_code,
} => {
let mut all_hits = 0;
let mut all_hits = Bool4::new();
// Ray testing
ray_stack.pop_do_next_task(children.len(), |ray_idx| {
if rays.is_done(ray_idx) {
([0; 4], 0)
} else {
let hits = lerp_slice(bounds, rays.time(ray_idx))
.intersect_ray(
let hits = lerp_slice(bounds, rays.time(ray_idx)).intersect_ray(
rays.orig_local(ray_idx),
rays.dir_inv_local(ray_idx),
rays.max_t(ray_idx),
)
.to_bitmask();
);
if hits != 0 {
all_hits |= hits;
if !hits.all_false() {
all_hits = all_hits | hits;
let mut lanes = [0u8; 4];
let mut lane_count = 0;
for i in 0..children.len() {
if (hits >> i) & 1 != 0 {
if hits.get_n(i) {
lanes[lane_count] = i as u8;
lane_count += 1;
}
@ -161,14 +160,14 @@ impl<'a> BVH4<'a> {
});
// If there were any intersections, create tasks.
if all_hits > 0 {
if !all_hits.all_false() {
let order_code = traversal_table[traversal_code as usize];
let mut lanes = [0usize; 4];
let mut lane_count = 0;
for i in 0..children.len() {
let inv_i = (children.len() - 1) - i;
let child_i = ((order_code >> (inv_i * 2)) & 3) as usize;
if ((all_hits >> child_i) & 1) != 0 {
if all_hits.get_n(child_i) {
node_stack[stack_ptr + lane_count] = &children[child_i];
lanes[lane_count] = child_i;
lane_count += 1;

23
sub_crates/float4/src/lib.rs
View File

@ -620,6 +620,14 @@ mod x86_64_sse {
}
impl Bool4 {
#[inline(always)]
pub fn new() -> Bool4 {
use std::arch::x86_64::_mm_set1_ps;
Bool4 {
data: unsafe { _mm_set1_ps(0.0) },
}
}
/// Returns the value of the nth element.
#[inline(always)]
pub fn get_n(&self, n: usize) -> bool {
@ -637,24 +645,33 @@ mod x86_64_sse {
self.get_n(0)
}
/// Returns the value of the 1th element.
/// Returns the value of the 1st element.
#[inline(always)]
pub fn get_1(&self) -> bool {
self.get_n(1)
}
/// Returns the value of the 2th element.
/// Returns the value of the 2nd element.
#[inline(always)]
pub fn get_2(&self) -> bool {
self.get_n(2)
}
/// Returns the value of the 3th element.
/// Returns the value of the 3rd element.
#[inline(always)]
pub fn get_3(&self) -> bool {
self.get_n(3)
}
/// Returns whether all four bools are false.
///
/// This is the `OR` operation on all the contained bools. If even
/// one bool is true, this returns true.
pub fn all_false(&self) -> bool {
let a = unsafe { *(&self.data as *const __m128 as *const u128) };
a == 0
}
#[inline]
pub fn to_bitmask(&self) -> u8 {
let a = unsafe { *(&self.data as *const __m128 as *const u8).offset(0) };