/* ----------------------------------------------------------------------------    
* Copyright (C) 2010 ARM Limited. All rights reserved.    
*    
* $Date: 13/10/11 2:55p $Revision: 	V1.1.0  
*    
* Project: 	    CMSIS DSP Library    
* Title:		arm_q7_to_q15.c    
*    
* Description:	Converts the elements of the Q7 vector to Q15 vector.    
*    
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
*  
* Version 1.1.0 2012/02/15 
*    Updated with more optimizations, bug fixes and minor API changes.  
*   
* Version 1.0.10 2011/7/15  
*    Big Endian support added and Merged M0 and M3/M4 Source code.   
*    
* Version 1.0.3 2010/11/29   
*    Re-organized the CMSIS folders and updated documentation.    
*     
* Version 1.0.2 2010/11/11    
*    Documentation updated.     
*    
* Version 1.0.1 2010/10/05     
*    Production release and review comments incorporated.    
*    
* Version 1.0.0 2010/09/20     
*    Production release and review comments incorporated.    
* ---------------------------------------------------------------------------- */

#include "arm_math.h"

/**    
 * @ingroup groupSupport    
 */

/**    
 * @addtogroup q7_to_x    
 * @{    
 */




/**    
 * @brief Converts the elements of the Q7 vector to Q15 vector.    
 * @param[in]       *pSrc points to the Q7 input vector    
 * @param[out]      *pDst points to the Q15 output vector   
 * @param[in]       blockSize length of the input vector    
 * @return none.    
 *    
 * \par Description:    
 *    
 * The equation used for the conversion process is:    
 *   
 * <pre>    
 * 	pDst[n] = (q15_t) pSrc[n] << 8;   0 <= n < blockSize.    
 * </pre>    
 *   
 */


void arm_q7_to_q15(
  q7_t * pSrc,
  q15_t * pDst,
  uint32_t blockSize)
{
  q7_t *pIn = pSrc;                              /* Src pointer */
  uint32_t blkCnt;                               /* loop counter */

#ifndef ARM_MATH_CM0
  q31_t in;
  q31_t in1, in2;
  q31_t out1, out2;

  /* Run the below code for Cortex-M4 and Cortex-M3 */

  /*loop Unrolling */
  blkCnt = blockSize >> 2u;

  /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.    
   ** a second loop below computes the remaining 1 to 3 samples. */
  while(blkCnt > 0u)
  {
    /* C = (q15_t) A << 8 */
    /* convert from q7 to q15 and then store the results in the destination buffer */
    in = *__SIMD32(pIn)++;

    /* rotatate in by 8 and extend two q7_t values to q15_t values */
    in1 = __SXTB16(__ROR(in, 8));

    /* extend remainig two q7_t values to q15_t values */
    in2 = __SXTB16(in);

    in1 = in1 << 8u;
    in2 = in2 << 8u;

    in1 = in1 & 0xFF00FF00;
    in2 = in2 & 0xFF00FF00;

#ifndef ARM_MATH_BIG_ENDIAN

    out2 = __PKHTB(in1, in2, 16);
    out1 = __PKHBT(in2, in1, 16);

#else

    out1 = __PKHTB(in1, in2, 16);
    out2 = __PKHBT(in2, in1, 16);

#endif

    *__SIMD32(pDst)++ = out1;
    *__SIMD32(pDst)++ = out2;

    /* Decrement the loop counter */
    blkCnt--;
  }

  /* If the blockSize is not a multiple of 4, compute any remaining output samples here.    
   ** No loop unrolling is used. */
  blkCnt = blockSize % 0x4u;

#else

  /* Run the below code for Cortex-M0 */

  /* Loop over blockSize number of values */
  blkCnt = blockSize;

#endif /* #ifndef ARM_MATH_CM0 */

  while(blkCnt > 0u)
  {
    /* C = (q15_t) A << 8 */
    /* convert from q7 to q15 and then store the results in the destination buffer */
    *pDst++ = (q15_t) * pIn++ << 8;

    /* Decrement the loop counter */
    blkCnt--;
  }

}

/**    
 * @} end of q7_to_x group    
 */
