pto.tcmps

pto.tcmps is part of the Tile Scalar And Immediate instruction set.

Summary

Compare a tile against a scalar and write per-element comparison results.

Mechanism

Compare a tile against a scalar and write per-element comparison results. It operates on tile payloads rather than scalar control state, and its legality is constrained by tile shape, layout, valid-region, and target-profile support.

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

\[ \mathrm{dst}_{i,j} = \left(\mathrm{src}_{i,j}\ \mathrm{cmpMode}\ \mathrm{scalar}\right) \]

The encoding/type of dst is target-specific: on A2/A3 the predicate tile uses uint8_t with 1 bit per element (packed 8 elements per byte), and on A5 it uses uint32_t with 1 bit per element (packed 32 elements per DWORD).

Syntax

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

Synchronous form:

%dst = tcmps %src, %scalar {cmpMode = #pto.cmp<EQ>} : !pto.tile<...> -> !pto.tile<...>

AS Level 1 (SSA)

%dst = pto.tcmps %src, %scalar {cmpMode = #pto<cmp xx>} : (!pto.tile<...>, dtype) -> !pto.tile<...>

AS Level 2 (DPS)

pto.tcmps ins(%src, %scalar{cmpMode = #pto<cmp xx>}: !pto.tile_buf<...>, dtype) outs(%dst : !pto.tile_buf<...>)

IR Level 1 (SSA)

%dst = pto.tcmps %src, %scalar {cmpMode = #pto<cmp xx>} : (!pto.tile<...>, dtype) -> !pto.tile<...>

IR Level 2 (DPS)

pto.tcmps ins(%src, %scalar{cmpMode = #pto<cmp xx>}: !pto.tile_buf<...>, dtype) outs(%dst : !pto.tile_buf<...>)

C++ Intrinsic

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

template <typename TileDataDst, typename TileDataSrc0, typename T, typename... WaitEvents>
PTO_INST RecordEvent TCMPS(TileDataDst& dst, TileDataSrc0& src0, T src1, CmpMode cmpMode, WaitEvents&... events);

Inputs

  • src is the source tile.
  • scalar is the scalar value broadcast to all lanes; cmpMode selects comparison predicate.
  • dst names the destination predicate tile.
  • The operation iterates over dst's valid region.

Expected Outputs

dst carries the result tile or updated tile payload produced by the operation.

Side Effects

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

Constraints

Constraints

  • Common constraints:

    • Tile location must be vector (TileData::Loc == TileType::Vec).
    • Static valid bounds: TileData::ValidRow <= TileData::Rows and TileData::ValidCol <= TileData::Cols.
    • Runtime: src0 and dst must have the same valid row/col.

  • Valid region:

    • The op uses dst.GetValidRow() / dst.GetValidCol() as the iteration domain.

  • Comparison modes:

    • Supports CmpMode::EQ, CmpMode::NE, CmpMode::LT, CmpMode::GT, CmpMode::LE, CmpMode::GE.

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

  • Implementation checks (A2A3):

    • TileData::DType must be one of: int32_t, float, half, uint16_t, int16_t.
    • Tile layout must be row-major (TileData::isRowMajor).

  • Implementation checks (A5):

    • TileData::DType must be one of: int32_t, float, half, uint16_t, int16_t.
    • Tile layout must be row-major (TileData::isRowMajor).

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, uint8_t, 16, 32, BLayout::RowMajor, -1, -1>;
  SrcT src;
  DstT dst(16, 2);
  TCMPS(dst, src, 0.0f, CmpMode::GT);
}

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, uint8_t, 16, 32, BLayout::RowMajor, -1, -1>;
  SrcT src;
  DstT dst(16, 2);
  TASSIGN(src, 0x1000);
  TASSIGN(dst, 0x2000);
  TCMPS(dst, src, 0.0f, CmpMode::GT);
}

Auto Mode

# Auto mode: compiler/runtime-managed placement and scheduling.
%dst = pto.tcmps %src, %scalar {cmpMode = #pto<cmp xx>} : (!pto.tile<...>, dtype) -> !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.tcmps %src, %scalar {cmpMode = #pto<cmp xx>} : (!pto.tile<...>, dtype) -> !pto.tile<...>

PTO Assembly Form

%dst = tcmps %src, %scalar {cmpMode = #pto.cmp<EQ>} : !pto.tile<...> -> !pto.tile<...>
# AS Level 2 (DPS)
pto.tcmps ins(%src, %scalar{cmpMode = #pto<cmp xx>}: !pto.tile_buf<...>, dtype) outs(%dst : !pto.tile_buf<...>)