Table of Contents

Enum NDIterFlags

Namespace
NumSharp.Backends.Iteration
Assembly
NumSharp.dll

Iterator-level flags. Conceptually matches NumPy's NPY_ITFLAG_* constants.

NOTE: Bit positions differ from NumPy's implementation:

  • NumPy uses bits 0-7 for IDENTPERM, NEGPERM, HASINDEX, etc.
  • NumSharp reserves bits 0-7 for legacy compatibility flags (SourceBroadcast, SourceContiguous, DestinationContiguous)
  • NumPy-equivalent flags are shifted to bits 8-15

This layout maintains backward compatibility with existing NumSharp code while adding NumPy parity flags. The semantic meaning of each flag matches NumPy, only the bit positions differ.

[Flags]
public enum NDIterFlags : uint
Extension Methods

Fields

None = 0
SourceBroadcast = 1

Source operand has broadcast dimensions (stride=0).

SourceContiguous = 2

Source operand is contiguous after coalescing.

DestinationContiguous = 4

Destination operand is contiguous after coalescing.

IDENTPERM = 256

The axis permutation is identity.

NEGPERM = 512

The permutation has negative entries (flipped axes).

HASINDEX = 1024

Iterator is tracking a flat index.

HASMULTIINDEX = 2048

Iterator is tracking a multi-index.

FORCEDORDER = 4096

Iteration order was forced on construction.

EXLOOP = 8192

Inner loop is handled outside the iterator.

RANGE = 16384

Iterator is ranged (subset iteration).

BUFFER = 32768

Iterator uses buffering.

GROWINNER = 65536

Grow the buffered inner loop when possible.

ONEITERATION = 131072

Single iteration, can specialize iternext.

DELAYBUF = 262144

Delay buffer allocation until first Reset.

REDUCE = 524288

Iteration includes reduction operands.

REUSE_REDUCE_LOOPS = 1048576

Reduce loops don't need recalculation.

CONTIGUOUS = 8

All operands are contiguous (SIMD eligible).

GATHER_ELIGIBLE = 16

Can use AVX2 gather for strided access.

PARALLEL_SAFE = 64

The iteration range can be split across parallel workers without write hazards. Set at construction when there is no REDUCE operand (cross-iteration accumulation on a shared slot) and either no WRITE operands at all, or exactly one WRITE operand whose potential overlap with the inputs was resolved by COPY_IF_OVERLAP processing (forced copy + write-back on Dispose). Consumed by the parallel ForEach work (roadmap Wave 6.2).

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