Datatypes

MIOpen contains several datatypes at different levels of support. The enumerated datatypes are:

typedef enum {
    miopenHalf     = 0,
    miopenFloat    = 1,
    miopenInt32    = 2,
    miopenInt8     = 3,
    /* Value 4 is reserved. */
    miopenBFloat16 = 5,
    miopenDouble   = 6,
    miopenFloat8   = 7,
    miopenBFloat8  = 8
} miopenDataType_t;

Of these types only miopenFloat and miopenHalf are fully supported across all layers in MIOpen. Refer to the individual Modules in the API library for specific datatype support and limitations.

Type descriptions:

• miopenHalf: 16-bit floating point

• miopenFloat: 32-bit floating point

• miopenInt32: 32-bit integer, used primarily for int8 convolution outputs

• miopenInt8: 8-bit integer; supported by int8 convolution forward path, tensor set, tensor copy, tensor cast, tensor transform, tensor transpose, and im2col

• miopenBFloat16: brain float fp-16 (8-bit exponent, 7-bit fraction); supported by convolutions, tensor set, and tensor copy

• miopenDouble: 64-bit floating point; supported by reduction, layerNorm, and batchNorm

• miopenFloat8: 8-bit floating point (layout 1.4.3, exponent bias 7); supported by convolutions

• miopenBFloat8: 8-bit floating point (layout 1.5.2, exponent bias 15); supported by convolutions

In addition to these standard datatypes, pooling also contains its own indexing datatypes:

typedef enum {
    miopenIndexUint8  = 0,
    miopenIndexUint16 = 1,
    miopenIndexUint32 = 2,
    miopenIndexUint64 = 3,
} miopenIndexType_t;