TGATHERB¶

Tile Operation Diagram¶

Introduction¶

Gather elements using byte offsets.

Math Interpretation¶

For each element in the valid region:

Exact bounds behavior is implementation-defined.

Assembly Syntax¶

PTO-AS form: see PTO-AS Specification.

Synchronous form:

%dst = tgatherb %src, %offsets : !pto.tile<...> -> !pto.tile<...>

IR Level 1 (SSA)¶

%dst = pto.tgatherb %src, %offsets : (!pto.tile<...>, !pto.tile<...>) -> !pto.tile<...>

IR Level 2 (DPS)¶

pto.tgatherb ins(%src, %offsets : !pto.tile_buf<...>, !pto.tile_buf<...>) outs(%dst : !pto.tile_buf<...>)

C++ Intrinsic¶

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

template <typename TileDataDst, typename TileDataSrc, typename TileDataOffset, typename... WaitEvents>
PTO_INST RecordEvent TGATHERB(TileDataDst& dst, TileDataSrc& src, TileDataOffset& offset, WaitEvents&... events);

Constraints¶

• Implementation checks (A2A3):
• Destination layout must be row-major (TileDataDst::isRowMajor).
• Destination element size must be 1, 2, or 4 bytes (enforced via static_assert in the helper).
• SrcTileData::DType/DstTileData::DType must be int8_t or uint8_t or int16_t or uint16_t or int32_t or uint32_t or half or bfloat16_t or float.
• Implementation checks (A5):
• Destination element size must be 1, 2, or 4 bytes.
• SrcTileData::DType/DstTileData::DType must be int8_t or uint8_t or int16_t or uint16_t or int32_t or uint32_t or half or bfloat16_t or float.
• Offset interpretation:
• Offsets are interpreted as uint32_t values (byte offsets) by the implementation.
• Offset bounds are not validated by explicit runtime assertions; out-of-range offsets are target-defined.

Examples¶

Auto¶

#include <pto/pto-inst.hpp>

using namespace pto;

void example_auto() {
  using SrcT = Tile<TileType::Vec, uint8_t, 1, 256>;
  using OffT = Tile<TileType::Vec, uint32_t, 1, 256>;
  using DstT = Tile<TileType::Vec, uint8_t, 1, 256>;
  SrcT src;
  OffT off;
  DstT dst;
  TGATHERB(dst, src, off);
}

Manual¶

#include <pto/pto-inst.hpp>

using namespace pto;

void example_manual() {
  using SrcT = Tile<TileType::Vec, uint8_t, 1, 256>;
  using OffT = Tile<TileType::Vec, uint32_t, 1, 256>;
  using DstT = Tile<TileType::Vec, uint8_t, 1, 256>;
  SrcT src;
  OffT off;
  DstT dst;
  TASSIGN(src, 0x1000);
  TASSIGN(off, 0x2000);
  TASSIGN(dst, 0x3000);
  TGATHERB(dst, src, off);
}

ASM Form Examples¶

Auto Mode¶

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

PTO Assembly Form¶

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