Primitive Attributes: accumulation modeΒΆ

Some applications can benefit from using lower precision accumulators to speed up computations without causing noticeable impacts on accuracy.

The default numerical behavior of oneDNN (described in Data Types) can be altered to allow the use of low precision accumulators. When passed to a primitive creation, the dnnl::accumulation_mode primitive attribute specifies which datatype can be used for accumulation purposes for that given primitive.

The dnnl::accumulation_mode primitive attribute accepts:

  • strict (default): For floating-point primitives (as defined in Data Types), the default accumulation datatype is f32 (or f64 for f64 primitives). For integral primitives (as defined in Data Types), the default accumulation datatype is s32.

  • relaxed : Same as strict except some partial accumulators can be rounded to the src/dst datatype in memory.

  • any : Uses the fastest implementation available with one of the src/dst datatypes or a higher precision accumulation datatype.

  • f32, f16 and s32 : Uses the specified accumulation datatype.

Primitive Attributes: floating-point math mode Primitive Attributes: rounding mode