pto.taddc

pto.taddc is part of the Elementwise Tile Tile instruction set.

Summary

Elementwise ternary add: src0 + src1 + src2.

Mechanism

Elementwise ternary add: src0 + src1 + src2.

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

\[ \mathrm{dst}_{i,j} = \mathrm{src0}_{i,j} + \mathrm{src1}_{i,j} + \mathrm{src2}_{i,j} \]

Syntax

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

Synchronous form:

%dst = taddc %src0, %src1, %src2 : !pto.tile<...>

AS Level 1 (SSA)

%dst = pto.taddc %src0, %src1, %src2 : (!pto.tile<...>, !pto.tile<...>, !pto.tile<...>) -> !pto.tile<...>

AS Level 2 (DPS)

pto.taddc ins(%src0, %src1, %src2 : !pto.tile_buf<...>, !pto.tile_buf<...>, !pto.tile_buf<...>) outs(%dst : !pto.tile_buf<...>)

C++ Intrinsic

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

template <typename TileData, typename... WaitEvents>
PTO_INST RecordEvent TADDC(TileData &dst, TileData &src0, TileData &src1, TileData &src2, WaitEvents &... events);

Inputs

Operand Role Description
%src0 First source tile First source tile; read at (i, j) for each (i, j) in dst valid region
%src1 Second source tile Second source tile; read at (i, j) for each (i, j) in dst valid region
%src2 Third source tile Third source tile; read at (i, j) for each (i, j) in dst valid region
WaitEvents... Optional synchronisation RecordEvent tokens to wait on before issuing the operation

Expected Outputs

Result Type Description
%dst !pto.tile<...> Destination tile; all (i, j) in its valid region contain src0[i,j] + src1[i,j] + src2[i,j] after the operation

Side Effects

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

Constraints

Constraints

  • The op iterates over dst.GetValidRow() / dst.GetValidCol().

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.taddc 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.

Performance

A2/A3 Throughput

TADDC compiles to CCE vector instructions via the TBinOp.hpp performance model. The throughput is identical to TADD (binary arithmetic):

Metric Value (FP) Value (INT)
Startup latency 14 14
Completion latency 19 17
Per-repeat throughput 2 2
Pipeline interval 18 18

Examples

#include <pto/pto-inst.hpp>

using namespace pto;

void example() {
  using TileT = Tile<TileType::Vec, float, 16, 16>;
  TileT a, b, c, out;
  TADDC(out, a, b, c);
}

Auto Mode

# Auto mode: compiler/runtime-managed placement and scheduling.
%dst = pto.taddc %src0, %src1, %src2 : (!pto.tile<...>, !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.taddc %src0, %src1, %src2 : (!pto.tile<...>, !pto.tile<...>, !pto.tile<...>) -> !pto.tile<...>

PTO Assembly Form

%dst = taddc %src0, %src1, %src2 : !pto.tile<...>
# AS Level 2 (DPS)
pto.taddc ins(%src0, %src1, %src2 : !pto.tile_buf<...>, !pto.tile_buf<...>, !pto.tile_buf<...>) outs(%dst : !pto.tile_buf<...>)