mulimoen/SummationByParts
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

simdify diff_op_col

Browse Source
This commit is contained in:
Magnus Ulimoen
2020-04-29 23:06:19 +02:00
parent cc5399a940
commit c4848ffd1a
1 changed files with 40 additions and 12 deletions
Download Patch File Download Diff File Expand all files Collapse all files

52
sbp/src/operators.rs
View File

@@ -192,10 +192,16 @@ pub(crate) fn diff_op_col(
};
let idx = 1.0 / dx;
fut.fill(0.0);
#[cfg(not(feature = "f32"))]
type SimdT = packed_simd::f64x8;
#[cfg(feature = "f32")]
type SimdT = packed_simd::f32x16;
let ny = prev.shape()[0];
// First block
for (bl, mut fut) in block.iter().zip(fut.axis_iter_mut(ndarray::Axis(1))) {
fut.fill(0.0);
debug_assert_eq!(fut.len(), prev.shape()[0]);
for (&bl, prev) in bl.iter().zip(prev.axis_iter(ndarray::Axis(1))) {
debug_assert_eq!(prev.len(), fut.len());
@@ -204,22 +210,44 @@ pub(crate) fn diff_op_col(
}
let half_diag_width = (diag.len() - 1) / 2;
assert!(half_diag_width <= block.len());
// Diagonal entries
for (ifut, mut fut) in fut
.axis_iter_mut(ndarray::Axis(1))
.enumerate()
.skip(block.len())
.take(nx - 2 * block.len())
{
for (id, d) in diag.iter().enumerate() {
let offset = ifut - half_diag_width + id;
fut.scaled_add(idx * d, &prev.slice(ndarray::s![.., offset]))
for ifut in block.len()..nx - block.len() {
let simdified = SimdT::lanes() * (ny / SimdT::lanes());
for j in (0..simdified).step_by(SimdT::lanes()) {
let index_to_simd = |(j, i)| unsafe {
// gets simd along stride 1, j never goes past end of slice
SimdT::from_slice_unaligned(std::slice::from_raw_parts(
prev.uget((j, i)),
SimdT::lanes(),
))
};
let mut f = SimdT::splat(0.0);
for (id, &d) in diag.iter().enumerate() {
let offset = ifut - half_diag_width + id;
f = f + d * index_to_simd((j, offset));
}
f = f * idx;
unsafe {
// puts simd along stride 1, j never goes past end of slice
f.write_to_slice_unaligned(std::slice::from_raw_parts_mut(
fut.uget_mut((j, ifut)),
SimdT::lanes(),
));
}
}
for j in simdified..ny {
let mut f = 0.0;
for (id, &d) in diag.iter().enumerate() {
let offset = ifut - half_diag_width + id;
f += d * prev[(j, offset)];
}
fut[(j, ifut)] = idx * f;
}
}
// End block
for (bl, mut fut) in block.iter().zip(fut.axis_iter_mut(ndarray::Axis(1)).rev()) {
fut.fill(0.0);
for (&bl, prev) in bl.iter().zip(prev.axis_iter(ndarray::Axis(1)).rev()) {
if symmetric {
fut.scaled_add(idx * bl, &prev);