TROWARGMIN

Tile Operation Diagram

Introduction

Get the column index of the minimum element for each row.

Math Interpretation

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

$${\mathrm{d}\mathrm{s}\mathrm{t}}_{i,0}=\underset{0\le j<C}{\min }{j}_i$$

Assembly Syntax

PTO-AS form: see docs/grammar/PTO-AS.md.

Synchronous form:

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

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

IR Level 1 (SSA)

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

IR Level 2 (DPS)

pto.trowargmin ins(%src, %tmp : !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 TROWARGMIN(TileDataOut& dst, TileDataIn& src, TileDataTmp& tmp, WaitEvents&... events);

Constraints

Implementation checks (NPU):

• A2A3:
  • Tile location: dst and src must be TileType::Vec.
  • Tile layout of src: ND fractal (isRowMajor and SLayout::NoneBox).
  • Tile layout of dst:
    • Only support DN layout Tile of 1D, e.g., Tile<TileType::Vec, T, ROWS, 1, BLayout::ColMajor, ValidRows, 1>
    • ROWS muse be 32b aligned.
  • Source data types: half or float.
  • Destination data types: uint32_t.
  • Runtime valid checks:
    • srcValidCol != 0 and srcValidRow != 0.
• A5:
  • Source data types: half or float.
  • Destination data types: uint32_t.
  • No explicit runtime assertions on validRow/validCol in the implementation; the loops use src.GetValidRow() and src.GetValidCol().
  • tmp temporary tile is not used, only for compatibility use.

About temporary tile tmp for A3

• Temporary tile is not used when srcValidCol <= ElementPerRepeat, used when srcValidCol > ElementPerRepeat.
• tmp tile's rows is the same as src.
• Simply set tmp tile size the same as src when src is small.
• Use the following equation to get the minimum stride required by tmp tile, so as to save UB space:

$$stride=\frac{validCol/elementPerRepeat\ast 2+elementPerBlock-1}{elementPerBlock}\ast elementPerBlock+\frac{validCol/elementPerRepeat+elementPerBlock-1}{elementPerBlock}\ast elementPerBlock$$

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, uint32_t, 16, 1, BLayout::ColMajor>;
  using TmpT = Tile<TileType::Vec, float, 16, 16>;
  SrcT src;
  DstT dst;
  TmpT tmp;
  TROWARGMIN(dst, src, tmp);
}

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, uint32_t, 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);
  TROWARGMIN(dst, src, tmp);
}

ASM Form Examples

Auto Mode

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

Manual Mode

# Manual mode: resources must be bound explicitly before issuing the instruction.
# Optional for tile operands:
# pto.tassign %arg0, @tile(0x1000)
# pto.tassign %arg1, @tile(0x2000)
%dst = pto.trowargmin %src, %tmp : (!pto.tile<...>, !pto.tile<...>) -> !pto.tile<...>

PTO Assembly Form

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