TRECIP

Instruction Diagram

Introduction

Performs element-wise reciprocal of a tile.

Mathematical Semantics

For each element (i, j) in the valid region:

$$\mathrm{dst}_{i,j} = \frac{1}{\mathrm{src}_{i,j}}$$

Assembly Syntax

Synchronous form:

%dst = trecip %src : !pto.tile<...>

AS Level 1 (SSA)

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

AS Level 2 (DPS)

pto.trecip ins(%src : !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 <auto PrecisionType = RecipAlgorithm::DEFAULT, typename TileDataDst, typename TileDataSrc,
          typename... WaitEvents>
PTO_INST RecordEvent TRECIP(TileDataDst &dst, TileDataSrc &src, WaitEvents &... events);

PrecisionType can specify the following values:

• RecipAlgorithm::DEFAULT: Normal algorithm, fast but with lower precision.
• RecipAlgorithm::HIGH_PRECISION: High-precision algorithm, slower.

Constraints

• Implementation check (NPU):
  • TileData::DType must be one of the following: float, half, int32_t, int16_t (the implementation delegates to TDIVS(dst, 1, src), which also allows integer 1/x).
  • The tile position must be a vector (TileData::Loc == TileType::Vec);
  • Static valid boundary: TileData::ValidRow <= TileData::Rows and TileData::ValidCol <= TileData::Cols.
  • Runtime: src.GetValidRow() == dst.GetValidRow() and src.GetValidCol() == dst.GetValidCol().
  • The tile layout must be row-major (TileData::isRowMajor).
  • The TRECIP instruction on Atlas A3 training products/Atlas A3 inference products does not support setting the source tile and destination tile to the same memory.
• Valid region:
  • This operation uses dst.GetValidRow()/dst.GetValidCol() as the iteration domain.
• Domain/NaN:
  • Division-by-zero behavior is target-defined; the CPU simulator asserts in debug builds.
• High-precision algorithm:
  • Valid only on Ascend 950PR/Ascend 950DT. The PrecisionType option is ignored on Atlas A3 training products/Atlas A3 inference products.

Examples

#include <pto/pto-inst.hpp>

using namespace pto;

void example() {
  using TileT = Tile<TileType::Vec, float, 16, 16>;
  TileT x, out;
  TRECIP(out, x);
  TRECIP<RecipAlgorithm::HIGH_PRECISION>(out, x);
}

ASM Examples

Automatic Mode

# Automatic mode: the compiler/runtime handles resource placement and scheduling.
%dst = pto.trecip %src : !pto.tile<...> -> !pto.tile<...>

Manual Mode

# Manual mode: explicitly bind resources first, then issue the instruction.
# Optional (when the instruction contains tile operands):
# pto.tassign %arg0, @tile(0x1000)
# pto.tassign %arg1, @tile(0x2000)
%dst = pto.trecip %src : !pto.tile<...> -> !pto.tile<...>

PTO Assembly Form

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