GetAxpyMaxMinTmpSize

Function

To perform Axpy computation in the kernel, temporary space needs to be allocated. This API is used on the host to obtain the maximum and minimum sizes of the temporary space to be allocated. You can select a proper size within this range as a tiling parameter and pass it to the kernel.

To ensure correct functions, the temporary space to be allocated cannot be less than the minimum temporary space.
Within the range between the minimum and maximum, as the temporary space increases, the API computing performance in the kernel can be optimized to some extent. To achieve better performance, allocate the space based on the actual buffer usage.

Prototype

void GetAxpyMaxMinTmpSize(const ge::Shape& srcShape, const uint32_t typeSize, const bool isReuseSource, uint32_t& maxValue, uint32_t& minValue)

Parameters

**Table 1** API parameters
Parameter	Input/Output	Function
srcShape	Input	Input shape.
typeSize	Input	Size of the input data type, in bytes. For example, if the input data type is half, set this parameter to 2.
isReuseSource	Input	Whether to reuse the space of the source operand input, which must be the same as that of the Axpy API.
maxValue	Output	Maximum size of the temporary space required by Axpy computation. Any space exceeding this value will not be utilized by the API. Within the range between the minimum and maximum, as the temporary space increases, the API computing performance in the kernel can be optimized to some extent. To achieve better performance, allocate the space based on the actual buffer usage. If the maximum space size is 0, no temporary space is required. NOTE: maxValue is for reference only and may be larger than the available space of the Unified Buffer. In this case, select a proper temporary space size based on the remaining space of the Unified Buffer.
minValue	Output	Minimum size of the temporary space required by Axpy computation. To ensure correct functions, the size of the temporary space to be allocated during API computation cannot be less than the value of this parameter. If the minimum space size is 0, no temporary space is required.

Returns

None

Restrictions

None

Example

For details about the complete call example, see More Examples.

// The input shape is 1024. The operator input data is of the half type. The source operand cannot be modified.
std::vector<int64_t> shape_vec = {1024};
ge::Shape shape(shape_vec);
uint32_t maxValue = 0;
uint32_t minValue = 0;
AscendC::GetAxpyMaxMinTmpSize(shape, 2, false, maxValue, minValue);

Parent topic: Axpy APIs