[WIP: Do not review] NanoVDB: VoxelBlockManager CPU port of decodeInverseMaps - #2186

Draft

sifakis wants to merge 110 commits into

AcademySoftwareFoundation:masterfrom

sifakis:vbm-cpu-port

Commits on Apr 2, 2026

VoxelBlockManager: add resolveWenoLeafPtrs and computeWenoStencil

sifakis
and
claude
committed
816901a
ex_voxelBlockManager_host_cuda: add host/CUDA VBM example

sifakis
and
claude
committed
c9906f4
VBMImplementationKnowledge: distill decodeInverseMaps design philosophy

sifakis
and
claude
committed
372b806
ex_voxelBlockManager_host_cuda: remove DecodeInverseMapsCPUPlan.md

sifakis
and
claude
committed
9a31aed
ex_voxelBlockManager_host_cuda: add StencilGather planning doc

sifakis
and
claude
committed
aae9b80
StencilGather: add stencil type interface and kernel/output design

sifakis
and
claude
committed
da91919
simd_test: add liftToSimd vectorization experiment and investigation notes

sifakis
and
claude
committed
57dec68

Commits on Apr 3, 2026

Commits on Apr 11, 2026

StencilGather.md: document CPU batch leaf-ptr design (probedMask, batchPtrs)

sifakis
and
claude
committed
42e54cc
ex_stencil_gather_cpu: prototype for CPU SIMD stencil gather Phase 1

sifakis
and
claude
committed
536467e

Commits on Apr 13, 2026

ex_stencil_gather_cpu: gather-site sentinel + AVX2 carry trick

sifakis
and
claude
committed
f5041df
BatchAccessor.md: design for SIMD batch leaf-neighborhood cache

sifakis
and
claude
committed
bf115e2

Commits on Apr 15, 2026

BatchAccessor: SIMD batch leaf-neighborhood cache (Phase 1)

sifakis
and
claude
committed
8db0c52
Simd.h + BatchAccessor: scalar_traits, uniform shifts, SWAR cleanup

sifakis
and
claude
committed
dce5240

Commits on Apr 16, 2026

Simd.h + BatchAccessor + Util.h: 2-arg where, util::reduce, countTrailingZeros

sifakis
and
claude
committed
515be21
BatchAccessor: SIMD gather chain for cachedGetValue ingredient fetch

sifakis
and
claude
committed
b15d2a0
BatchAccessor.md: document prefetch SIMD structure + assembly findings

sifakis
and
claude
committed
6a4711b

Commits on Apr 17, 2026

BatchAccessor: SWAR constant naming, ASCII cleanup, explicit parentheses

sifakis
and
claude
committed
d511842
BatchAccessor/Simd: scalar overloads, LeafIDVecT/LeafDataVecT class aliases

sifakis
and
claude
committed
87c3e1b
BatchAccessor: complete SIMD cachedGetValue pipeline (Steps 1-8)

sifakis
and
claude
committed
14c9db7
BatchAccessor.md: document GCC/Clang codegen findings for cachedGetValue

sifakis
and
claude
committed
16b43ac
BatchAccessor.md: document popcount alternatives and scalar popcnt tradeoffs

sifakis
and
claude
committed
1c93d78

Commits on Apr 18, 2026

StencilAccessor: SIMD batch stencil-index gatherer for CPU WENO5 Phase 1

sifakis
and
claude
committed
0b7524e
refactor: move Simd.h, BatchAccessor.h, StencilAccessor.h to nanovdb/util/

sifakis
and
claude
committed
c605ec2
refactor: move BatchAccessor.md, StencilAccessor.md, HaloStencilAccessor.md to nanovdb/util/

sifakis
and
claude
committed
432bec4
cleanup: remove simd_test/ scratchpad directory

sifakis
and
claude
committed
8db0218
cleanup: remove prefix-count sanity check from vbm_host_cuda_kernels.cu

sifakis
and
claude
committed
2610a11
StencilAccessor: end-to-end perf analysis + Legacy scalar oracle
sifakis
committed
6fce798
stencil_gather_cpu: add Legacy cost decomposition (framing / cache+leaf / tree-walk)
sifakis
committed
a05dce4
StencilAccessor/BatchAccessor: hybrid SIMD -> scalar-tail cachedGetValue
sifakis
committed
c90db49

Commits on Apr 19, 2026

Commits on Apr 20, 2026

ex_*stencil_cpu: prune diagnostic passes, keep just the two shipped paths

sifakis
and
claude
committed
24c2de7
ex_*stencil_cpu: add legacy-transposed pass; BatchAccessor: document §8l

sifakis
and
claude
committed
f3b53ed
Weno5Stencil: add center tap (19 total); BatchAccessor: document §11 WENO pipeline target

sifakis
and
claude
committed
cc073c1
ex_*stencil_cpu: batch-by-batch loops in legacy/framing/transposed

sifakis
and
claude
committed
5a92059
ex_narrowband_stencil_cpu: sidecar-legacy/stencil/transposed passes

sifakis
and
claude
committed
110d852
WenoStencil<W>: single-source scalar/SIMD stencil + out-of-band extrapolation

sifakis
and
claude
committed
a6b0871
WenoStencil.md + BatchAccessor.md §11.6: Stage 1-3 documentation

sifakis
and
claude
committed
0f8fccd

Commits on Apr 21, 2026

WenoStencil<W>: Simd-typed storage + normSqGrad; caller-owned fill buffers

sifakis
and
claude
committed
3c33d85
ex_narrowband_stencil_cpu: add sidecar-stencil-normsqgrad full-pipeline pass

sifakis
and
claude
committed
c00fe65
Simd + WenoStencil: [[gnu::always_inline]] on tiny wrappers + Phase-3 arithmetic

sifakis
and
claude
committed
1aa985b
ex_weno_nanovdb_cpu: full Phase-2+3 pipeline with scalar-reference validation

sifakis
and
claude
committed
8623483
ex_weno_nanovdb_cpu: remove stray emacs lock symlink

sifakis
and
claude
committed
3ffe1e7

Commits on Apr 23, 2026

WenoStencil: self-contained Taps tuple, no more Weno5Stencil policy dep

sifakis
and
claude
committed
2d8d94f
nanovdb: cleanup — remove hybrid StencilAccessor/BatchAccessor stack

sifakis
and
claude
committed
79004aa

Commits on Apr 27, 2026

nanovdb: drop HaloStencilAccessor design doc and cross-references

sifakis
and
claude
committed
412cd4b
nanovdb/util/Simd.h: remove unused gather and popcount

sifakis
and
claude
committed
4565d48

Commits on Apr 29, 2026

nanovdb/util/ForEach.h: drop hardware_concurrency()>>1 in std::thread fallback

sifakis
and
claude
committed
0c8b582

Commits on May 20, 2026

tools: introduce host-side MergeGrids + TopologyBuilder; add ex_merge_nanovdb_cpu
sifakis
committed
2b75d97

Commits on May 26, 2026

tools: document host-side topology-port plan
sifakis
committed
85c1098

Commits on May 27, 2026

Commits on May 28, 2026

tools::TopologyBuilder::processUpperNodes: inline BuildUpperNodesFunctor into a forEach lambda
sifakis
committed
729804d

Commits on Jun 10, 2026

util/Morphology.h: add host ProcessLowerNodes; route processLowerNodes through it

sifakis
and
claude
committed
4438dfe
util: add host-callable atomicMin/atomicMax; port TopologyBuilder::processBBox to host

sifakis
and
claude
committed
fe80448
tools::TopologyBuilder::postProcessGridTree: run PostProcessGridTreeFunctor on host

sifakis
and
claude
committed
28e0d65
tools::TopologyBuilder::processLeafOffsets: port to host forEach + util::inclusiveScan

sifakis
and
claude
committed
ed109dd
util/Morphology.h: add host MergeInternalNodes; route MergeGrids::mergeInternalNodes through it

sifakis
and
claude
committed
b7f41d2
util/Morphology.h: add host MergeLeafNodes; route MergeGrids::mergeLeafNodes through it

sifakis
and
claude
committed
a73eb2b
tools::MergeGrids::processGridTreeRoot: run on host (memcpy + BuildGridTreeRootFunctor)

sifakis
and
claude
committed
7e5f965
docs: record MergeGrids host-port completion state in plan + CLAUDE.md

sifakis
and
claude
committed
96415ce

Commits on Jun 11, 2026

tools::TopologyBuilder::postProcessGridTree: use host updateChecksum

sifakis
and
claude
committed
333c942
docs: record MergeGrids perf findings (§7.8) and mark updateChecksum done

sifakis
and
claude
committed
a5543f8
util/MorphologyHelpers.h: add host shuffleDown/shuffleUp + host MaskShift

sifakis
and
claude
committed
6e7401e
tools::DilateGrid: host DilateInternalNodes + transitional host operator + ex_dilate_nanovdb_cpu

sifakis
and
claude
committed
180b081
util/Morphology.h: add host DilateLeafNodes; route DilateGrid::dilateLeafNodes through it

sifakis
and
claude
committed
0110561
util/cuda/Morphology.cuh: replace UB reinterpret-view stencil in DilateLeafNodesFunctor<NN_FACE_EDGE_VERTEX>

sifakis
and
claude
committed
c199fcb
docs: TODO to share thread-centric leaf-dilation body via a __hostdev__ helper

sifakis
and
claude
committed
410dbb6
docs: record DilateGrid progress (§7.7) and mark Phase 4.8 in progress

sifakis
and
claude
committed
1494c80

Commits on Jun 12, 2026

tools::DilateGrid::processGridTreeRoot: run on host (memcpy + BuildGridTreeRootFunctor)

sifakis
and
claude
committed
ce25500
tools::DilateGrid::dilateRoot: read source root/uppers from managed grid (drop D2H copy)

sifakis
and
claude
committed
38fa025
tools::TopologyBuilder: drop __hostdev__ from the host-only detail functors

sifakis
and
claude
committed
517f94b
docs: DilateGrid now kernel-free (§7.7); record processGridTreeRoot/dilateRoot host + __hostdev__ cleanup

sifakis
and
claude
committed
a9ed2d7
tools::PruneGrid: host port + dilate->prune round-trip in ex_dilate_nanovdb_cpu

sifakis
and
claude
committed
e86cdee
ex_dilate_nanovdb_cpu: default to NN_FACE

sifakis
and
claude
committed
4af7084
docs: record PruneGrid host port (§7.7) and dilate->prune round-trip

sifakis
and
claude
committed
d59b32b
tools::TopologyBuilder: migrate scratch buffers UnifiedBuffer -> HostBuffer (cleanup step 1)

sifakis
and
claude
committed
db14618
tools: migrate mProcessedRoot DeviceBuffer -> HostBuffer (cleanup step 2)

sifakis
and
claude
committed
56f480b
tools::TopologyBuilder: drop Data::d_upperOffsets; read mUpperOffsets directly

sifakis
and
claude
committed
82f71cd
tools::TopologyBuilder: mData DeviceBuffer -> plain Data member (cleanup step 3)

sifakis
and
claude
committed
5fee27c
docs: record host-only cleanup steps 1-3 (§7.3)

sifakis
and
claude
committed
4db30f7
tools: MergeGrids runs on HostBuffer end-to-end; getBuffer made backend-agnostic (step 4, merge path)

sifakis
and
claude
committed
8d8993e
util/Injection.h: add host injectGridMask; use it in ex_dilate (validated in-place)

sifakis
and
claude
committed
7931906
tools: DilateGrid + PruneGrid run on HostBuffer end-to-end (step 4, dilate path)

sifakis
and
claude
committed
7eb3a50
tools: swap util::cuda::Timer -> host util::Timer in the operators (and examples)

sifakis
and
claude
committed
dae9740
tools: rip out the cudaStream_t plumbing (no async work remains)

sifakis
and
claude
committed
d5a962b
docs: record HostBuffer/stream cleanup (§7.3, §7.1); re-scope remaining work

sifakis
and
claude
committed
4c93f7c
docs(TopologyCpuPortPlan): record three-way OpenVDB/host/CUDA benchmark

sifakis
and
claude
committed
98cc34a

Commits on Jun 15, 2026

util/cuda/Morphology.cuh: fix prunedRoot/prunedTile copy-paste misnomer

sifakis
and
claude
committed
a4beab1
tools: host port of CoarsenGrid (2x topological coarsening)

sifakis
and
claude
committed
0bc2bce
tools: host port of RefineGrid (2x topological refinement)

sifakis
and
claude
committed
02411c0
tools: purge dead CUDA code and includes from the host topology headers

sifakis
and
claude
committed
c684bd3
examples/tools: flip topology _cpu examples to pure C++ (.cu -> .cpp)

sifakis
and
claude
committed
9728a1d
examples: fix stale warm-loop timer labels in merge/refine CUDA examples

sifakis
and
claude
committed
6c87781
util/Timer.h: report fractional milliseconds (match util::cuda::Timer)

sifakis
and
claude
committed
cb1d516
util/Injection.h: add host injectGridData (sidecar value injection)

sifakis
and
claude
committed
988e806