Deduction Relationship

Deduction Rules

If aclTensor inputs of an API (such as aclnnAdd or aclnnMul) are of different data types, the API internally deduces a data type and converts the input data into this data type for computation.

Some data types supported by aclTensor meet the following deduction rules, which are similar to those of Type Promotion.

Note:

For ease of description, the data types used in the table are in abbreviated forms. The meanings of the data types are ACL_FLOAT(f32), ACL_FLOAT16(f16), ACL_DOUBLE(f64), ACL_BF16(bf16), ACL_INT8(s8), ACL_UINT8(u8), ACL_INT16(s16), ACL_UINT16(u16), ACL_INT32(s32), ACL_UINT32(u32), ACL_INT64(s64), ACL_UINT64(u64), ACL_BOOL(bool), ACL_COMPLEX32(c32), ACL_COMPLEX64(c64), and ACL_COMPLEX128(c128).

The table heading and the leftmost column in the table indicate the two input data types to be deduced. The corresponding intersections in the table indicate the deduced data types.

The cross sign (×) in the table indicates that the two types cannot be deduced.

Table 1 Data type deduction relationship

Data Type	f32	f16	f64	bf16	s8	u8	s16	u16	s32	u32	s64	u64	bool	c32	c64	c128
f32	f32	f32	f64	f32	f32	f32	f32	×	f32	×	f32	×	f32	c64	c64	c128
f16	f32	f16	f64	f32	f16	f16	f16	×	f16	×	f16	×	f16	c32	c64	c128
f64	f64	f64	f64	f64	f64	f64	f64	×	f64	×	f64	×	f64	c128	c128	c128
bf16	f32	f32	f64	bf16	bf16	bf16	bf16	×	bf16	×	bf16	×	bf16	c32	c64	c128
s8	f32	f16	f64	bf16	s8	s16	s16	×	s32	×	s64	×	s8	c32	c64	c128
u8	f32	f16	f64	bf16	s16	u8	s16	×	s32	×	s64	×	u8	c32	c64	c128
s16	f32	f16	f64	bf16	s16	s16	s16	×	s32	×	s64	×	s16	c32	c64	c128
u16	×	×	×	×	×	×	×	u16	×	×	×	×	×	×	×	×
s32	f32	f16	f64	bf16	s32	s32	s32	×	s32	×	s64	×	s32	c32	c64	c128
u32	×	×	×	×	×	×	×	×	×	u32	×	×	×	×	×	×
s64	f32	f16	f64	bf16	s64	s64	s64	×	s64	×	s64	×	s64	c32	c64	c128
u64	×	×	×	×	×	×	×	×	×	×	×	u64	×	×	×	×
bool	f32	f16	f64	bf16	s8	u8	s16	×	s32	×	s64	×	bool	c32	c64	c128
c32	c64	c32	c128	c32	c32	c32	c32	×	c32	×	c32	×	c32	c32	c64	c128
c64	c64	c64	c128	c64	c64	c64	c64	×	c64	×	c64	×	c64	c64	c64	c128
c128	c128	c128	c128	c128	c128	c128	c128	×	c128	×	c128	×	c128	c128	c128	c128

Deduction Example

When aclnnAdd is called, if the data types of the input parameters are different (one is float16 and the other is float32), the API converts float16 to float32 for computation.
When aclnnAdd is called, if the data types of the input parameters are different (one is float32 and the other is bool), the API converts bool to float32 for computation.