Exp

Intel® Integrated Performance Primitives Developer Guide and Reference

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ID 790148

Date 11/07/2023

Version

Public

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Exp

Computes e to the power of each element of a vector.

Syntax

IppStatus ippsExp_32f(const Ipp32f* pSrc, Ipp32f* pDst, int len);

IppStatus ippsExp_64f(const Ipp64f* pSrc, Ipp64f* pDst, int len);

IppStatus ippsExp_32f_I(Ipp32f* pSrcDst, int len);

IppStatus ippsExp_64f_I(Ipp64f* pSrcDst, int len);

IppStatus ippsExp_16s_Sfs(const Ipp16s* pSrc, Ipp16s* pDst, int len, int scaleFactor);

IppStatus ippsExp_32s_Sfs(const Ipp32s* pSrc, Ipp32s* pDst, int len, int scaleFactor);

IppStatus ippsExp_16s_ISfs(Ipp16s* pSrcDst, int len, int scaleFactor);

IppStatus ippsExp_32s_ISfs(Ipp32s* pSrcDst, int len, int scaleFactor);

Include Files

ipps.h

Domain Dependencies

Headers: ippcore.h, ippvm.h

Libraries: ippcore.lib, ippvm.lib

Parameters

pSrc	Pointer to the source vector.
pDst	Pointer to the destination vector.
pSrcDst	Pointer to the source and destination vector pSrcDst for the in-place operation.
len	Number of elements in the vector
scaleFactor	Scale factor, refer to Integer Scaling.

Description

This function computes the exponential function of each element of the vector pSrc, and stores the result in pDst.

The computation is performed as follows:

pDst[n] = e^pSrc[n]

The in-place flavors of ippsExp compute the exponential function of each element of the vector pSrcDst and store the result in pSrcDst.

The computation is performed as follows:

pSrcDst[n] = e^pSrcDst[n]

When an overflow occurs, the function continues operation with the corresponding result value (see appendix A "Handling of Special Cases" for more information).

When computing the exponent of an integer number, the output result can exceed the data range and become saturated. The scaling retains the output data range but results in precision loss in low-order bits. The function ippsExp_32f64f computes the output result in a higher precision data range.

Application Notes

For the functions ippsExp and ippsLn the result is rounded to the nearest integer after scaling.

Return Values

ippStsNoErr	Indicates no error.
ippStsNullPtrErr	Indicates an error when the pSrc, pDst, or pSrcDst pointer is NULL.
ippStsSizeErr	Indicates an error when len is less than or equal to zero.

Example

Exp:

/*******************************************************************************
* Copyright 2015 Intel Corporation.
*
*
* This software and the related documents are Intel copyrighted materials, and your use of them is governed by
* the express license under which they were provided to you ('License'). Unless the License provides otherwise,
* you may not use, modify, copy, publish, distribute, disclose or transmit this software or the related
* documents without Intel's prior written permission.
* This software and the related documents are provided as is, with no express or implied warranties, other than
* those that are expressly stated in the License.
*******************************************************************************/

#include <stdio.h>
#include "ipp.h"

/* Next two defines are created to simplify code reading and understanding */
#define EXIT_MAIN exitLine:                                  /* Label for Exit */
#define check_sts(st) if((st) != ippStsNoErr) goto exitLine; /* Go to Exit if Intel(R) Integrated Primitives (Intel(R) IPP) function returned status different from ippStsNoErr */

/* Results of ippMalloc() are not validated because Intel(R) IPP functions perform bad arguments check and will return an appropriate status  */

int main()
{
    int len = 32;
    int i;
    Ipp16s *pSrc = ippsMalloc_16s(len * sizeof(Ipp16s));
    Ipp16s *pDst = ippsMalloc_16s(len * sizeof(Ipp16s));
    IppStatus status;
    int scale = 0;  //without scaling
    printf("\n\nSource vector\n");
    for (i = 0; i < len; i++)
    {
        pSrc[i] = 2 + i;
        printf("%d; ", pSrc[i]);
    }

    check_sts(status = ippsExp_16s_Sfs(pSrc, pDst, len, scale));

    printf("\n\nResult\n");
    for (i = 0; i < len; i++) printf("%d; ", pDst[i]);
    printf("\n\n");

EXIT_MAIN
    ippsFree(pSrc);
    ippsFree(pDst);
    printf("Exit status %d (%s)\n", (int)status, ippGetStatusString(status));
    return (int)status;
}

Exp_I:

/*******************************************************************************
* Copyright 2015 Intel Corporation.
*
*
* This software and the related documents are Intel copyrighted materials, and your use of them is governed by
* the express license under which they were provided to you ('License'). Unless the License provides otherwise,
* you may not use, modify, copy, publish, distribute, disclose or transmit this software or the related
* documents without Intel's prior written permission.
* This software and the related documents are provided as is, with no express or implied warranties, other than
* those that are expressly stated in the License.
*******************************************************************************/

#include <stdio.h>
#include "ipp.h"

/* Next two defines are created to simplify code reading and understanding */
#define EXIT_MAIN exitLine:                                  /* Label for Exit */
#define check_sts(st) if((st) != ippStsNoErr) goto exitLine; /* Go to Exit if Intel(R) Integrated Primitives (Intel(R) IPP) function returned status different from ippStsNoErr */

/* Results of ippMalloc() are not validated because Intel(R) IPP functions perform bad arguments check and will return an appropriate status  */

int main()
{
    int len = 32;
    int i;
    Ipp16s *pSrcDst = ippsMalloc_16s(len * sizeof(Ipp16s));
    IppStatus status;
    int scale = 0;  //without scaling
    printf("\n\nSource vector\n");
    for (i = 0; i < len; i++)
    {
        pSrcDst[i] = 2 + i;
        printf("%d; ", pSrcDst[i]);
    }

    check_sts(status = ippsExp_16s_ISfs(pSrcDst, len, scale));

    printf("\n\nResult\n");
    for (i = 0; i < len; i++) printf("%d; ", pSrcDst[i]);
    printf("\n\n");

EXIT_MAIN
    ippsFree(pSrcDst);
    printf("Exit status %d (%s)\n", (int)status, ippGetStatusString(status));
    return (int)status;
}

Parent topic: Arithmetic Functions

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