TPREFETCH¶

Tile Operation Diagram¶

TPREFETCH tile operation

Introduction¶

Prefetch data from global memory into a tile-local cache/buffer (implementation-defined). This is typically used to reduce latency before a subsequent TLOAD.

Note: unlike most PTO instructions, TPREFETCH does not implicitly call TSYNC(events...) in the C++ wrapper.

Assembly Syntax¶

PTO-AS form: see PTO-AS Specification.

Synchronous form:

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

IR Level 1 (SSA)¶

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

IR Level 2 (DPS)¶

pto.tprefetch ins(%src : !pto.global<...>) outs(%dst : !pto.tile_buf<...>)

C++ Intrinsic¶

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

template <typename TileData, typename GlobalData>
PTO_INST RecordEvent TPREFETCH(TileData &dst, GlobalData &src);

Constraints¶

Semantics and caching behavior are target/implementation-defined.
Some targets may ignore prefetches or treat them as hints.

Math Interpretation¶

Unless otherwise specified, semantics are defined over the valid region and target-dependent behavior is marked as implementation-defined.

Examples¶

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

ASM Form Examples¶

Auto Mode¶

# Auto mode: compiler/runtime-managed placement and scheduling.
%dst = pto.tprefetch %src : !pto.global<...> -> !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.tprefetch %src : !pto.global<...> -> !pto.tile<...>

PTO Assembly Form¶

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