pto.trowexpandexpdif

pto.trowexpandexpdif is part of the Reduce And Expand instruction set.

Summary

Row-wise exp-diff: compute exp(src0 - src1) with per-row scalars.

Mechanism

Row-wise exp-diff: compute exp(src0 - src1) where src1 provides one scalar per row.

Let R = dst.GetValidRow() and C = dst.GetValidCol(). Let s_i be the per-row scalar taken from src1 (one value per row).

For 0 <= i < R and 0 <= j < C:

\[ \mathrm{dst}_{i,j} = \exp(\mathrm{src0}_{i,j} - s_i) \]

Syntax

Textual spelling is defined by the PTO ISA syntax-and-operands pages.

Synchronous form:

%dst = trowexpandexpdif %src0, %src1 : !pto.tile<...>, !pto.tile<...> -> !pto.tile<...>

AS Level 1 (SSA)

%dst = pto.trowexpandexpdif %src0, %src1 : !pto.tile<...>, !pto.tile<...> -> !pto.tile<...>

AS Level 2 (DPS)

pto.trowexpandexpdif ins(%src0, %src1 : !pto.tile_buf<...>, !pto.tile_buf<...>) outs(%dst : !pto.tile_buf<...>)

C++ Intrinsic

Declared in include/pto/common/pto_instr.hpp:

template <typename TileDataDst, typename TileDataSrc0, typename TileDataSrc1, typename... WaitEvents>
PTO_INST RecordEvent TROWEXPANDEXPDIF(TileDataDst &dst, TileDataSrc0 &src0, TileDataSrc1 &src1, WaitEvents &... events);

template <typename TileDataDst, typename TileDataSrc0, typename TileDataSrc1, typename TileDataTmp,
          typename... WaitEvents>
PTO_INST RecordEvent TROWEXPANDEXPDIF(TileDataDst &dst, TileDataSrc0 &src0, TileDataSrc1 &src1, TileDataTmp &tmp, WaitEvents &... events);

Inputs

  • src0 is the first source tile (the tile to be modified).
  • src1 is the second source tile providing per-row scalar values.
  • tmp (optional): temporary tile for intermediate storage.
  • dst names the destination tile. The operation iterates over dst's valid region.

Expected Outputs

dst[i,j] = exp(src0[i,j] - src1[i,0]) (row-wise exp-diff of per-row scalar).

Side Effects

No architectural side effects beyond producing the destination tile. Does not implicitly fence unrelated traffic.

Constraints

Constraints

  • TileDataDst::DType == TileDataSrc0::DType == TileDataSrc1::DType

  • TileDataDst::DType, TileDataSrc0::DType, TileDataSrc1::DType must be one of: half, float.

  • Tile shape/layout constraint (compile-time): TileDataDst::isRowMajor.

  • Mode 1: src1 is expected to provide one scalar per row (i.e., its valid shape must cover R values).

  • Mode 2: src1 is expected to provide 32 bytes data per row.

  • Exact layout/fractal constraints are target-specific; see backend headers under include/pto/npu/*/TRowExpand*.hpp.

Exceptions

Exceptions

  • Illegal operand tuples, unsupported types, invalid layout combinations, or unsupported target-profile modes are rejected by the verifier or by the selected backend instruction set.
  • Programs must not rely on behavior outside the documented legal domain of this operation, even if one backend currently accepts it.

Target-Profile Restrictions

Target-Profile Restrictions

  • pto.trowexpandexpdif preserves PTO-visible semantics across CPU simulation, A2/A3-class targets, and A5-class targets, but concrete support subsets may differ by profile.

  • Portable code must rely only on the documented type, layout, shape, and mode combinations that the selected target profile guarantees.

Examples

Auto

#include <pto/pto-inst.hpp>

using namespace pto;

void example_auto() {
  using SrcT = Tile<TileType::Vec, float, 16, 16>;
  using DstT = Tile<TileType::Vec, float, 16, 16>;
  using RowVecT = Tile<TileType::Vec, float, 16, 1, BLayout::ColMajor>;
  SrcT src0;
  DstT dst;
  RowVecT src1;
  // Row-expand-expdif: each row of dst = exp(src0.row - src1.row_scalar)
  TROWEXPANDEXPDIF(dst, src0, src1);
}

Manual

#include <pto/pto-inst.hpp>

using namespace pto;

void example_manual() {
  using SrcT = Tile<TileType::Vec, float, 16, 16>;
  using DstT = Tile<TileType::Vec, float, 16, 16>;
  using RowVecT = Tile<TileType::Vec, float, 16, 1, BLayout::ColMajor>;
  SrcT src0;
  DstT dst;
  RowVecT src1;
  TASSIGN(src0, 0x1000);
  TASSIGN(dst, 0x2000);
  TASSIGN(src1, 0x3000);
  // Row-expand-expdif in manual mode
  TROWEXPANDEXPDIF(dst, src0, src1);
}

Auto Mode

# Auto mode: compiler/runtime-managed placement and scheduling.
%dst = pto.trowexpandexpdif %src0, %src1 : !pto.tile<...>, !pto.tile<...> -> !pto.tile<...>

Manual Mode

# Manual mode: bind resources explicitly before issuing the instruction.
# Optional for tile operands:
# pto.tassign %arg0, @tile(0x1000)
# pto.tassign %arg1, @tile(0x2000)
%dst = pto.trowexpandexpdif %src0, %src1 : !pto.tile<...>, !pto.tile<...> -> !pto.tile<...>

PTO Assembly Form

%dst = trowexpandexpdif %src0, %src1 : !pto.tile<...>, !pto.tile<...> -> !pto.tile<...>
# AS Level 2 (DPS)
pto.trowexpandexpdif ins(%src0, %src1 : !pto.tile_buf<...>, !pto.tile_buf<...>) outs(%dst : !pto.tile_buf<...>)