Frac

Function Description

Returns decimals element-wise. Examples:

Frac(-258.41888) = -0.41888428

Frac(5592.625) = 0.625

Prototype

  • Allocate the temporary space through the API framework.
    • All source operand tensors are involved in computation.
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      template <typename T, bool isReuseSource = false>
      __aicore__ inline void Frac(const LocalTensor<T>& dstTensor, const LocalTensor<T>& srcTensor)
      
    • All or part of the source operand tensors are involved in computation.
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      template <typename T, bool isReuseSource = false>
      __aicore__ inline void Frac(const LocalTensor<T>& dstTensor, const LocalTensor<T>& srcTensor, const uint32_t calCount)
      
  • Pass the temporary space through the sharedTmpBuffer input parameter.
    • All source operand tensors are involved in computation.
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      template <typename T, bool isReuseSource = false>
      __aicore__ inline void Frac(const LocalTensor<T>& dstTensor, const LocalTensor<T>& srcTensor, const LocalTensor<uint8_t>& sharedTmpBuffer)
      
    • All or part of the source operand tensors are involved in computation.
      1
      2
      template <typename T, bool isReuseSource = false>
      __aicore__ inline void Frac(const LocalTensor<T>& dstTensor, const LocalTensor<T>& srcTensor, const LocalTensor<uint8_t>& sharedTmpBuffer, 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 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.
  • 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 you 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.

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

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

dstLocal

Output

Destination operand.

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

srcLocal

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.

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

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

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

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.
  • For details about the alignment requirements of the operand address offset, see General Restrictions.

Example

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#include "kernel_operator.h"
template <typename srcType>
class KernelFrac
{
public:
    __aicore__ inline KernelFrac(){}
    __aicore__ inline void Init(GM_ADDR srcGm, GM_ADDR dstGm, uint32_t srcSize)
    {
        srcGlobal.SetGlobalBuffer(reinterpret_cast<__gm__ srcType *>(srcGm), srcSize);
        dstGlobal.SetGlobalBuffer(reinterpret_cast<__gm__ srcType *>(dstGm), srcSize);

        pipe.InitBuffer(inQueueX, 1, srcSize * sizeof(srcType));
        pipe.InitBuffer(outQueue, 1, srcSize * sizeof(srcType));
        bufferSize = srcSize;
    }
    __aicore__ inline void Process()
    {
        CopyIn();
        Compute();
        CopyOut();
    }

private:
    __aicore__ inline void CopyIn()
    {
        AscendC::LocalTensor<srcType> srcLocal = inQueueX.AllocTensor<srcType>();
        AscendC::DataCopy(srcLocal, srcGlobal, bufferSize);
        inQueueX.EnQue(srcLocal);
    }
    __aicore__ inline void Compute()
    {
        AscendC::LocalTensor<srcType> dstLocal = outQueue.AllocTensor<srcType>();
        AscendC::LocalTensor<srcType> srcLocal = inQueueX.DeQue<srcType>();
        AscendC::Frac<srcType, false>(dstLocal, srcLocal);
        outQueue.EnQue<srcType>(dstLocal);
        inQueueX.FreeTensor(srcLocal);
    }
    __aicore__ inline void CopyOut()
    {
        AscendC::LocalTensor<srcType> dstLocal = outQueue.DeQue<srcType>();
        AscendC::DataCopy(dstGlobal, dstLocal, bufferSize);
        outQueue.FreeTensor(dstLocal);
    }

private:
    AscendC::GlobalTensor<srcType> srcGlobal;
    AscendC::GlobalTensor<srcType> dstGlobal;

    AscendC::TPipe pipe;
    AscendC::TQue<AscendC::QuePosition::VECIN, 1> inQueueX;
    AscendC::TQue<AscendC::QuePosition::VECOUT, 1> outQueue;
    uint32_t bufferSize = 0;
};

template <typename dataType>
__aicore__ void kernel_frac_operator(GM_ADDR srcGm, GM_ADDR dstGm, uint32_t srcSize)
{
    KernelFrac<dataType> op;
    op.Init(srcGm, dstGm, srcSize);
    op.Process();
}

extern "C" __global__ __aicore__ void kernel_frac_operator(GM_ADDR srcGm, GM_ADDR dstGm, uint32_t srcSize)
{
    kernel_frac_operator<half>(srcGm, dstGm, srcSize);
}
Result example:
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Input data (srcLocal): [-258.41888  5592.625  -5312.416 ...  9423.014 -8336.825]
Output data (dstLocal): [-0.41888428 0.625  -0.41601562 ...  0.013671875 -0.8251953]