pto.tquant

pto.tquant is part of the Irregular and Complex tile instruction family.

Summary

Quantize a tile (e.g. FP32 to FP8) producing exponent/scaling/max outputs.

Mechanism

Quantize an FP32 tile into a lower-precision format (e.g. FP8), producing auxiliary exponent/scaling/max tiles. The quantization mode is a compile-time template parameter (mode). It belongs to the tile instructions and carries architecture-visible behavior that is not reducible to a plain elementwise compute pattern.

Unless otherwise specified, semantics are defined over the valid region. On A2/A3 and A5, the quantizer operates on the full valid region with target-specific quantization modes; the CPU simulator emulates the nearest available mode.

Syntax

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

AS Level 1 (SSA)

%dst = pto.tquant %src, %qp : (!pto.tile<...>, !pto.tile<...>) -> !pto.tile<...>

AS Level 2 (DPS)

pto.tquant ins(%src, %qp : !pto.tile_buf<...>, !pto.tile_buf<...>) outs(%dst : !pto.tile_buf<...>)

IR Level 1 (SSA)

%dst = pto.tquant %src, %qp : (!pto.tile<...>, !pto.tile<...>) -> !pto.tile<...>

IR Level 2 (DPS)

pto.tquant ins(%src, %qp : !pto.tile_buf<...>, !pto.tile_buf<...>) outs(%dst : !pto.tile_buf<...>)

C++ Intrinsic

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

template <auto quant_type, typename TileDataOut, typename TileDataSrc, typename TileDataExp, typename TileDataMax,
          typename... WaitEvents>
PTO_INST RecordEvent TQUANT(TileDataOut &dst, TileDataSrc &src, TileDataExp *exp, TileDataMax *max, TileDataSrc *scaling, WaitEvents &... events);

template <auto quant_type, auto store_mode, typename TileDataOut, typename TileDataSrc, typename TileDataExp,
          typename TileDataMax, typename TileDataIdx, typename... WaitEvents>
PTO_INST RecordEvent TQUANT(TileDataOut &dst, TileDataSrc &src, TileDataExp *exp, TileDataMax *max, TileDataSrc *scaling, TileDataExp *exp_zz, TileDataIdx *vgather_idx, WaitEvents &... events);

template <auto quant_type, typename TileDataOut, typename TileDataSrc, typename TileDataPara, typename... WaitEvents>
PTO_INST RecordEvent TQUANT(TileDataOut &dst, TileDataSrc &src, TileDataPara &scale, TileDataPara *offset = nullptr, WaitEvents &... events);

Inputs

  • src is the source tile to quantize.
  • qp is the quantization parameter tile.
  • exp (output): exponent tile.
  • max (output): max tile.
  • scaling (output): scaling tile.
  • dst names the destination tile. The operation iterates over src's valid region.

Expected Outputs

dst holds the quantized output. exp, max, scaling hold quantization metadata.

Side Effects

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

Constraints

Constraints

  • This instruction is currently implemented for specific targets (see include/pto/npu/*/TQuant.hpp).

  • Input type requirements and output tile types are mode/target-dependent.

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

  • pto.tquant preserves PTO-visible semantics across CPU simulation, A2/A3-class targets, and A5-class targets, but concrete support subsets may differ by profile.

  • Portable code must rely only on the documented type, layout, shape, and mode combinations that the selected target profile guarantees.

Examples

See related examples in docs/isa/ and docs/coding/tutorials/.

Auto Mode

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

PTO Assembly Form

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