pto.set_loop1_stride_ubtoout

pto.set_loop1_stride_ubtoout is part of the DMA Copy instruction set.

Deprecated in PTO ISA v0.6

The v0.6 PTO micro-instruction surface no longer uses standalone loop / stride configuration registers for UB→GM DMA. The stride information previously carried by pto.set_loop1_stride_ubtoout is now expressed inline on the grouped transfer op as part of the inner nburst(%n_burst, %src_stride, %dst_stride) clause on pto.mte_ub_gm. New code should use the grouped form. This page is retained for historical reference and pre-v0.6 ports.

Summary

Configure the inner-loop pointer advance used by the UB→GM DMA engine.

Mechanism

This operation programs the loop1 stride registers for UB→GM DMA. After each inner-loop iteration, the DMA engine advances the UB source pointer by %src_stride bytes and the GM destination pointer by %dst_stride bytes before issuing the next burst row set.

Syntax

PTO Assembly Form

set_loop1_stride_ubtoout %src_stride, %dst_stride : i64, i64

AS Level 1 (SSA)

pto.set_loop1_stride_ubtoout %src_stride, %dst_stride : i64, i64

Inputs

Operand Type Description
%src_stride i64 UB source pointer advance per inner-loop iteration, in bytes
%dst_stride i64 GM destination pointer advance per inner-loop iteration, in bytes

Expected Outputs

Result Type Description
None — This form only updates the UB→GM DMA loop1-stride configuration state.

Side Effects

Programs the loop1 stride state consumed by subsequent UB→GM DMA copies. The configuration remains in effect until another loop1-stride operation overrides it.

Constraints

Constraints

  • UB stride values MUST obey the source-stride field width and alignment rules of the selected target profile.
  • GM stride values MUST be representable in the destination-stride field width of the selected target profile.
  • The configured strides apply only to later UB→GM DMA operations.

Exceptions

Exceptions

  • The verifier rejects illegal operand shapes, unsupported pipe or event identifiers, and attribute combinations that are not valid for the selected instruction set or target profile.
  • Any additional illegality stated in the constraints section is also part of the contract.

Target-Profile Restrictions

Target-Profile Restrictions
  • CPU simulation preserves the visible configuration contract but may not expose all hardware loop hazards.
  • A2/A3 and A5 may use different concrete register widths or reset behavior; portable code must follow the documented PTO contract plus the selected target profile.

Examples

pto.set_loop1_stride_ubtoout %src_stride, %dst_stride : i64, i64