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ClampMax

Function Description

Replaces the number greater than scalar with scalar in srcTensor and retains the number less than or equal to scalar as the dstTensor output.

Prototype

  • Pass the temporary space through the sharedTmpBuffer input parameter.
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    template <typename T, bool isReuseSource = false>
__aicore__ inline void ClampMax(const LocalTensor<T>& dstTensor, const LocalTensor<T>& srcTensor, const LocalTensor<uint8_t>& sharedTmpBuffer, const T scalar, const uint32_t calCount)
  • Allocate the temporary space through the API framework.
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    template <typename T, bool isReuseSource = false>
__aicore__ inline void ClampMax(const LocalTensor<T>& dstTensor, const LocalTensor<T>& srcTensor, const T scalar, const uint32_t calCount)

Due to the complex mathematical computation involved in the internal implementation of this API, additional temporary space is required to store intermediate variables generated during computation. The temporary space can be passed by developers through the sharedTmpBuffer input parameter or allocated through the API framework.

  • When the sharedTmpBuffer input parameter is used for passing the temporary space, the tensor serves as the temporary space. In this case, the API framework is not required for temporary space allocation. This enables developers to manage the sharedTmpBuffer space and reuse the buffer after calling the API, so that the buffer is not repeatedly allocated and deallocated, improving the flexibility and buffer utilization.
  • When the API framework is used for temporary space allocation, developers do not need to allocate the space, but must reserve the required size for the space.

If sharedTmpBuffer is used, developers must allocate space for the tensor. If the API framework is used, developers must reserve the temporary space. To obtain the size of the temporary space (BufferSize) to be reserved, use the API provided in GetClampMaxMinTmpSize.

Parameters

Table 1 Parameters in the template

Parameter

Description

T

Data type of the operand.

isReuseSource

Whether the source operand can be modified. This parameter is reserved. Pass the default value false.
Table 2 API parameters

Parameter

Input/Output

Description

dstTensor

Output

Destination operand.

The type is LocalTensor, and the supported TPosition is VECIN, VECCALC, or VECOUT.

srcTensor

Input

Source operand.

The type is LocalTensor, and the supported TPosition is VECIN, VECCALC, or VECOUT.

The source operand must have the same data type as the destination operand.

sharedTmpBuffer

Input

Temporary buffer.

The type is LocalTensor, and the supported TPosition is VECIN, VECCALC, or VECOUT.

This parameter is used to store intermediate variables during complex computation in ClampMax and is provided by developers.

For details about how to obtain the temporary space size (BufferSize), see GetClampMaxMinTmpSize.

scalar

Input

Scalar data. The data type is the same as that of srcTensor. The supported data types are half and float.

calCount

Input

Number of actually computed data elements. The value range is [0, srcTensor.GetSize()].

Returns

None

Availability

Constraints

  • The source operand address must not overlap the destination operand address.
  • sharedTmpBuffer must not overlap the addresses of the source operand and destination operand.
  • For details about the alignment requirements of the operand address offset, see General Restrictions.

Example

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

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AscendC::TPipe pipe;
AscendC::TQue<AscendC::TPosition::VECCALC, 1> tmpQue;
pipe.InitBuffer(tmpQue, 1, bufferSize);
AscendC::LocalTensor<uint8_t> sharedTmpBuffer = tmpQue.AllocTensor<uint8_t>();
// The input shape information is 128.
AscendC::ClampMax<half>(dstLocal, srcLocal, sharedTmpBuffer, static_cast<half>(2), 128);
Result example:
Input data (srcLocal): [0 0 0 ...  3 3]
Output data (dstLocal): [0 0 0  ...  2 2]
Parent topic: Clamp