TCOLSUM¶

Tile Operation Diagram¶

Introduction¶

Reduce each column by summing across rows.

Math Interpretation¶

Let R = src.GetValidRow() and C = src.GetValidCol(). For 0 <= j < C:

isBinary selects the implementation path (binary-tree accumulation vs. sequential accumulation).

Assembly Syntax¶

PTO-AS form: see PTO-AS Specification.

Synchronous form:

%dst = tcolsum %src {isBinary = false} : !pto.tile<...> -> !pto.tile<...>

Lowering may introduce internal scratch tiles; the C++ intrinsic requires an explicit tmp operand.

IR Level 1 (SSA)¶

%dst = pto.tcolsum %src : !pto.tile<...> -> !pto.tile<...>
%dst = pto.tcolsum %src, %tmp {isBinary = false} : (!pto.tile<...>, !pto.tile<...>) -> !pto.tile<...>

IR Level 2 (DPS)¶

pto.tcolsum ins(%src : !pto.tile_buf<...>) outs(%dst : !pto.tile_buf<...>)
pto.tcolsum ins(%src, %tmp {isBinary = false} : !pto.tile_buf<...>, !pto.tile_buf<...>) outs(%dst : !pto.tile_buf<...>)

C++ Intrinsic¶

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

template <typename TileDataOut, typename TileDataIn, typename TileDataTmp, typename... WaitEvents>
PTO_INST RecordEvent TCOLSUM(TileDataOut& dst, TileDataIn& src, TileDataTmp& tmp, bool isBinary,
                             WaitEvents&... events);

Constraints¶

Implementation checks (NPU):

• Tile location: dst, src, tmp must be TileType::Vec.
• Tile layout: all tiles must be ND fractal (isRowMajor and SLayout::NoneBox).
• DType consistency:
• A2A3: src.DType must be one of half, float, int16_t, int32_t, and dst.DType == tmp.DType == src.DType.
• A5: dst.DType == src.DType is required by TColReduceCheck; the exact supported src.DType set is target-defined (see include/pto/npu/a5/TColReduceOps.hpp).
• Runtime valid checks:
• A2A3: src.GetValidCol() == dst.GetValidCol(); returns early if src.GetValidRow() == 0 or src.GetValidCol() == 0.
• A5: srcValidRow and srcValidCol must be non-zero; srcValidCol == dstValidCol is asserted by TColReduceCheck.

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, 1, 16>;
  using TmpT = Tile<TileType::Vec, float, 16, 16>;
  SrcT src;
  DstT dst;
  TmpT tmp;
  TCOLSUM(dst, src, tmp, /*isBinary=*/false);
}

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, 1, 16>;
  using TmpT = Tile<TileType::Vec, float, 16, 16>;
  SrcT src;
  DstT dst;
  TmpT tmp;
  TASSIGN(src, 0x1000);
  TASSIGN(dst, 0x2000);
  TASSIGN(tmp, 0x3000);
  TCOLSUM(dst, src, tmp, /*isBinary=*/false);
}

ASM Form Examples¶

Auto Mode¶

# Auto mode: compiler/runtime-managed placement and scheduling.
%dst = pto.tcolsum %src : !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.tcolsum %src : !pto.tile<...> -> !pto.tile<...>

PTO Assembly Form¶

%dst = tcolsum %src {isBinary = false} : !pto.tile<...> -> !pto.tile<...>
# IR Level 2 (DPS)
pto.tcolsum ins(%src : !pto.tile_buf<...>) outs(%dst : !pto.tile_buf<...>)