pto.mte_l0c_ub

pto.mte_l0c_ub is part of Cube Data Movement Ops. It is one of the three FIXPIPE writeback ops; see FIXPIPE Model for the shared writeback pipeline. This is also the architectural basis for 1→2 Cube-to-Vector tile distribution.

Summary

FIXPIPE writeback from l0c to UB. The data transform clauses match pto.mte_l0c_l1; UB-specific operands select single-destination or dual-destination (split-M / split-N) behavior.

Syntax

pto.mte_l0c_ub %src, %dst, %m, %n, %src_stride, %dst_stride,
    dst_mode(%sub_blockid | split_m | split_n)
    [, unit_flag(check_only | check_and_clear)]?
    [, pre_quant(%payload, mode = <quant_pre_mode>)]?
    [, pre_relu([%payload, ]mode = <relu_pre_mode> [, clip = %clip])]?
    [, nz2nd | nz2dn(%loop0_src_stride) | nz2nz(%split)?]
    [, loop3(%count, %src_stride3, %dst_stride3)]?
    [, sat | sat(preserve_nan) | nosat]?
  : ...

Inputs

Parameter Width Description
%src, %m, %n, %src_stride — Same as pto.mte_l0c_l1
%dst buffer-like UB destination
%dst_stride i64 UB destination stride in destination elements
dst_mode(%sub_blockid) i64 operand Single-destination mode. %sub_blockid selects UB sub-block 0 or 1; the value may be dynamic.
dst_mode(split_m) keyword Dual-destination mode that splits the logical tile along M.
dst_mode(split_n) keyword Dual-destination mode that splits the logical tile along N.
other optional clauses — Same as pto.mte_l0c_l1; atomic(...) is not supported

In dst_mode(%sub_blockid), the whole logical result tile is written to the selected UB sub-block using the selected layout mode and %dst as that sub-block's base destination pointer.

In dst_mode(split_m), the logical tile is split into two M ranges: [0, m/2) and [m/2, m). The first range is written to UB sub-block 0 and the second range is written to UB sub-block 1. Each sub-block sees its own destination origin at %dst; within each sub-block, the written logical tile has shape (m / 2) x n.

In dst_mode(split_n), the logical tile is split into two N ranges: [0, n/2) and [n/2, n). The first range is written to UB sub-block 0 and the second range is written to UB sub-block 1. Each sub-block sees its own destination origin at %dst; within each sub-block, the written logical tile has shape m x (n / 2).

Expected Outputs

Result Type Description
None — Writes converted M x N result to UB, possibly split between AIV0 / AIV1 sub-blocks.

Side Effects

Reads L0C; writes UB. Engages the AIC FIXP pipe and (for dual-destination modes) the dedicated 1→2 cube-to-vector data path. UB-side consumers on the AIV blocks must synchronize via cross-block sema primitives.

Constraints

Constraints

  • atomic(...) is not supported on pto.mte_l0c_ub.
  • dst_mode(%sub_blockid) writes the whole logical tile to one UB sub-block. Runtime %sub_blockid values must be 0 or 1; constant values are checked statically when available.
  • dst_mode(split_m) splits the logical tile along M into two equal-height sub-block regions. %m must be even; each sub-block receives an (m / 2) x n tile.
  • dst_mode(split_n) splits the logical tile along N into two equal-width sub-block regions. %n must be a multiple of 32; each sub-block receives an m x (n / 2) tile.
  • Dual-destination split modes are valid only for target-supported normal or nz2nd writeback cases with pre-quant, pre-ReLU/clip, and other transform clauses omitted.
  • Other constraints match pto.mte_l0c_l1.

Examples

pto.mte_l0c_ub %l0c, %ub_out, %c16_i64, %c32_i64, %c16_i64, %c32_i64,
  dst_mode(%c1_i64),
  nz2nd
  : !pto.ptr<f32, l0c>, !pto.ptr<f32, ub>, i64, i64, i64, i64, i64