TROWPROD

Instruction Diagram

Introduction

Performs product reduction on each row of elements.

Mathematical Semantics

Assume R = src.GetValidRow() and C = src.GetValidCol(). For 0 <= i < R:

$$\mathrm{dst}_{i,0} = \prod_{j=0}^{C-1} \mathrm{src}_{i,j}$$

Assembly Syntax

Synchronous form:

%dst = trowprod %src : !pto.tile<...> -> !pto.tile<...>

Degradation may introduce an internal temporary tile; the C++ built-in function requires an explicit tmp operand.

AS Level 1 (SSA)

%dst = pto.trowprod %src, %tmp : (!pto.tile<...>, !pto.tile<...>) -> !pto.tile<...>

AS Level 2 (DPS)

pto.trowprod ins(%src, %tmp : !pto.tile_buf<...>, !pto.tile_buf<...>) outs(%dst : !pto.tile_buf<...>)

C++ Built-in APIs

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

The public include header is <pto/pto-inst.hpp>, and the internal declaration is located in pto/common/pto_instr.hpp.

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

Constraints

General Constraints or Checks

• Both dst and src must be TileType::Vec.
• src must use the standard ND layout: row-major and non-fractal (BLayout::RowMajor, SLayout::NoneBox).
• dst must use one of the following two non-fractal layouts:
  • ND layout (BLayout::RowMajor, SLayout::NoneBox), or
  • DN layout with the number of columns strictly equal to 1 (BLayout::ColMajor, SLayout::NoneBox, Cols == 1).
• The element types of dst and src must be identical.
• Runtime valid region checks:
  • src.GetValidRow() != 0
  • src.GetValidCol() != 0
  • src.GetValidRow() == dst.GetValidRow()
• The built-in API signature requires explicitly passing the tmp operand.

Implementation Check for Atlas A2/A3 Training Products/Atlas A2/A3 Inference Products

• Supported element types: half, float, int32_t, int16_t.

Ascend 950PR/Ascend 950DT Implementation Check

• Supported element types: half, float, int32_t, int16_t.
• In the currently checked implementation path, the actual constraints apply to src and dst.
• In the current implementation path, there is no additional requirement that tmp must satisfy specific shape/layout constraints.

Temporary Space

Atlas A2/A3 Training Products/Atlas A2/A3 Inference Products

tmp is used as a row-wise accumulator buffer. For each row, the implementation initializes tmp to 1.0, and then uses vmul to multiply each block of the src data into tmp. After all blocks are accumulated, the scalar-mode pipe reads the tmp elements and computes the final product.

• tmp must have the same element type as src/dst.
• tmp size: at least 1 row and BLOCK_BYTE_SIZE / sizeof(T) columns (that is, 1 block: 8 elements for float/int32_t, and 16 elements for half/int16_t).
• Safe default settings: set tmp to the same shape as src.

Ascend 950PR/Ascend 950DT

tmp is accepted by the API but not used by the Ascend 950PR/Ascend 950DT implementation. The Ascend 950PR/Ascend 950DT backend uses vector-register-based reduction (vmul + vintlv for tree reduction) and does not require temporary tile storage. tmp is retained in the C++ built-in API signature only for API compatibility with Atlas A2/A3 training products/Atlas A2/A3 inference products.

Examples

Automatic Mode

#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, 1, BLayout::ColMajor>;
  using TmpT = Tile<TileType::Vec, float, 16, 16>;
  SrcT src;
  DstT dst;
  TmpT tmp;
  TROWPROD(dst, src, tmp);
}

Manual Mode

#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, 1, BLayout::ColMajor>;
  using TmpT = Tile<TileType::Vec, float, 16, 16>;
  SrcT src;
  DstT dst;
  TmpT tmp;
  TASSIGN(src, 0x1000);
  TASSIGN(dst, 0x2000);
  TASSIGN(tmp, 0x3000);
  TROWPROD(dst, src, tmp);
}

ASM Examples

Automatic Mode

# Automatic mode: placement and scheduling managed by the compiler/runtime.
%dst = pto.trowprod %src, %tmp : (!pto.tile<...>, !pto.tile<...>) -> !pto.tile<...>

Manual Mode

# Manual mode: explicitly bind resources before issuing the instruction.
# Tile operands are optional:
# pto.tassign %arg0, @tile(0x1000)
# pto.tassign %arg1, @tile(0x2000)
%dst = pto.trowprod %src, %tmp : (!pto.tile<...>, !pto.tile<...>) -> !pto.tile<...>

PTO Assembly Form

%dst = trowprod %src : !pto.tile<...> -> !pto.tile<...>
# AS Level 2 (DPS)
pto.trowprod ins(%src, %tmp : !pto.tile_buf<...>, !pto.tile_buf<...>) outs(%dst : !pto.tile_buf<...>)