pto.pipe_barrier

pto.pipe_barrier is part of the Pipeline Sync instruction set.

Summary

Drain all previously issued work in one pipeline before allowing later work on that same pipeline to begin.

Mechanism

pto.pipe_barrier forces completion of the named pipeline's outstanding work. It is the simplest ordering primitive when the hazard is confined to one pipeline and no explicit cross-pipeline event identity is required.

Syntax

PTO Assembly Form

pipe_barrier "PIPE_*"

AS Level 1 (SSA)

pto.pipe_barrier "PIPE_*"

Inputs

Operand Type Description
PIPE_* pipe identifier Pipeline whose outstanding work must retire before later work begins

Expected Outputs

Result Type Description
None — This form does not return SSA values; it establishes an ordering point on the named pipeline.

Side Effects

Stalls the named pipeline until its previously issued operations retire. Later operations issued to that pipeline are ordered after the barrier.

Constraints

Constraints

  • The selected pipe identifier MUST be valid for the selected target profile.
  • This barrier orders work within one pipeline; cross-pipeline producer-consumer edges still require the appropriate event or buffer protocol.
  • Portable code SHOULD use the narrowest ordering primitive that matches the hazard.

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 ordering contract but may not expose every pipeline hazard that motivates the barrier on hardware.
  • A2/A3 and A5 may differ in the exact pipe set that can be named.

Examples

pto.pipe_barrier "PIPE_MTE3"