Scalar Parameters and Enums¶

Many PTO intrinsics take scalar parameters in addition to tiles (e.g., comparison modes, rounding modes, atomic modes, or literal constants).

This document summarizes the scalar/enumeration types that appear in the public intrinsics in include/pto/common/pto_instr.hpp.

Scalar values¶

Some instructions take scalar values as plain C++ types:

• TADDS/TMULS/TDIVS/TEXPANDS: scalar is TileData::DType.
• TMINS: scalar is a template type T and must be convertible to the tile element type.
• TCI: scalar S is a template type T and must match TileData::DType (enforced by static_assert in the implementation).

PTO ISA type mnemonics (reference)¶

ISA documentation uses short type mnemonics (e.g., fp16, s8) when describing instruction semantics. Backends may support only a subset at any given time; see include/README.md for implementation status.

Integer types¶

Kind	Mnemonics
Signed	s4, s8, s16, s32, s64
Unsigned	u4, u8, u16, u32, u64

Floating-point types¶

Kind	Mnemonics
4-bit float families	fp4, hif4, mxfp4
8-bit float families	fp8, hif8, mxfp8
16-bit float families	bf16, fp16
32-bit float families	tf32, hf32, fp32
64-bit float	fp64

Bit-width (typeless) values¶

Kind	Mnemonics
Typeless bits	b4, b8, b16, b32, b64

Compatibility rules (ISA convention)¶

Two mnemonics are considered compatible when they have the same bit-width, and either:

• they are the same kind, or
• they are signed vs unsigned integers of the same width, or
• one side is a typeless bits type (b*) of the same width.

These are documentation-level rules used to describe instruction legality. Individual instructions may further restrict types.

Core enums¶

All enums below are available via #include <pto/pto-inst.hpp>.

pto::RoundMode¶

Defined in include/pto/common/constants.hpp. Used by TCVT to specify rounding behavior (e.g., RoundMode::CAST_RINT).

pto::CmpMode¶

Defined in include/pto/common/type.hpp. Used by TCMPS (and TCMP) for per-element comparisons (EQ/NE/LT/GT/GE/LE).

pto::MaskPattern¶

Defined in include/pto/common/type.hpp. Used by the mask-pattern TGATHER variant to select a predefined 0/1 mask pattern.

pto::AtomicType¶

Defined in include/pto/common/constants.hpp. Used as the template parameter to TSTORE<..., AtomicType::AtomicAdd> (or AtomicNone).

pto::AccToVecMode and pto::ReluPreMode¶

Defined in include/pto/common/constants.hpp. Used by TMOV overloads when moving from accumulator tiles with optional quantization and/or ReLU behavior.

pto::PadValue¶

Defined in include/pto/common/constants.hpp. Part of the Tile<...> template and used by some implementations to define how out-of-valid regions are treated (e.g., select/copy/pad paths).

Example¶

#include <pto/pto-inst.hpp>

using namespace pto;

void example(Tile<TileType::Vec, float, 16, 16>& dst,
             Tile<TileType::Vec, float, 16, 16>& src) {
  TCVT(dst, src, RoundMode::CAST_RINT);
  TMINS(dst, src, 0.0f);
}