text: /* ----------------------------------------------------------------------------    
  * Copyright (C) 2010-2014 ARM Limited. All rights reserved.    
  *    
  * $Date: 16/10/14 6:01p $Revision: 	V.1.4.5  
  *    
  * Project: 	    CMSIS DSP Library    
  * Title:		arm_float_to_q15.c    
  *    
  * Description:	Converts the elements of the floating-point vector to Q15 vector.    
  *    
  * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
  *  
  * Redistribution and use in source and binary forms, with or without 
  * modification, are permitted provided that the following conditions
  * are met:
  *   - Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  *   - Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in
  *     the documentation and/or other materials provided with the 
  *     distribution.
  *   - Neither the name of ARM LIMITED nor the names of its contributors
  *     may be used to endorse or promote products derived from this
  *     software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 
  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.    
  * ---------------------------------------------------------------------------- */
  
  #include "arm_math.h"
  
  /**    
   * @ingroup groupSupport    
   */
  
  /**    
   * @addtogroup float_to_x    
   * @{    
   */
  
  /**    
   * @brief Converts the elements of the floating-point vector to Q15 vector.    
   * @param[in]       *pSrc points to the floating-point input vector    
   * @param[out]      *pDst points to the Q15 output vector   
   * @param[in]       blockSize length of the input vector    
   * @return none.    
   *    
   * \par Description:    
   * \par   
   * The equation used for the conversion process is:    
   * <pre>    
   * 	pDst[n] = (q15_t)(pSrc[n] * 32768);   0 <= n < blockSize.    
   * </pre>    
   * \par Scaling and Overflow Behavior:    
   * \par    
   * The function uses saturating arithmetic.    
   * Results outside of the allowable Q15 range [0x8000 0x7FFF] will be saturated.    
   * \note   
   * In order to apply rounding, the library should be rebuilt with the ROUNDING macro     
   * defined in the preprocessor section of project options.     
   *    
   */
  
  
  void arm_float_to_q15(
    float32_t * pSrc,
    q15_t * pDst,
    uint32_t blockSize)
  {
    float32_t *pIn = pSrc;                         /* Src pointer */
    uint32_t blkCnt;                               /* loop counter */
  
  #ifdef ARM_MATH_ROUNDING
  
    float32_t in;
  
  #endif /*      #ifdef ARM_MATH_ROUNDING        */
  
  #ifndef ARM_MATH_CM0_FAMILY
  
    /* 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)
    {
  
  #ifdef ARM_MATH_ROUNDING
      /* C = A * 32768 */
      /* convert from float to q15 and then store the results in the destination buffer */
      in = *pIn++;
      in = (in * 32768.0f);
      in += in > 0.0f ? 0.5f : -0.5f;
      *pDst++ = (q15_t) (__SSAT((q31_t) (in), 16));
  
      in = *pIn++;
      in = (in * 32768.0f);
      in += in > 0.0f ? 0.5f : -0.5f;
      *pDst++ = (q15_t) (__SSAT((q31_t) (in), 16));
  
      in = *pIn++;
      in = (in * 32768.0f);
      in += in > 0.0f ? 0.5f : -0.5f;
      *pDst++ = (q15_t) (__SSAT((q31_t) (in), 16));
  
      in = *pIn++;
      in = (in * 32768.0f);
      in += in > 0.0f ? 0.5f : -0.5f;
      *pDst++ = (q15_t) (__SSAT((q31_t) (in), 16));
  
  #else
  
      /* C = A * 32768 */
      /* convert from float to q15 and then store the results in the destination buffer */
      *pDst++ = (q15_t) __SSAT((q31_t) (*pIn++ * 32768.0f), 16);
      *pDst++ = (q15_t) __SSAT((q31_t) (*pIn++ * 32768.0f), 16);
      *pDst++ = (q15_t) __SSAT((q31_t) (*pIn++ * 32768.0f), 16);
      *pDst++ = (q15_t) __SSAT((q31_t) (*pIn++ * 32768.0f), 16);
  
  #endif /*      #ifdef ARM_MATH_ROUNDING        */
  
      /* 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;
  
    while(blkCnt > 0u)
    {
  
  #ifdef ARM_MATH_ROUNDING
      /* C = A * 32768 */
      /* convert from float to q15 and then store the results in the destination buffer */
      in = *pIn++;
      in = (in * 32768.0f);
      in += in > 0.0f ? 0.5f : -0.5f;
      *pDst++ = (q15_t) (__SSAT((q31_t) (in), 16));
  
  #else
  
      /* C = A * 32768 */
      /* convert from float to q15 and then store the results in the destination buffer */
      *pDst++ = (q15_t) __SSAT((q31_t) (*pIn++ * 32768.0f), 16);
  
  #endif /*      #ifdef ARM_MATH_ROUNDING        */
  
      /* Decrement the loop counter */
      blkCnt--;
    }
  
  
  #else
  
    /* Run the below code for Cortex-M0 */
  
    /* Loop over blockSize number of values */
    blkCnt = blockSize;
  
    while(blkCnt > 0u)
    {
  
  #ifdef ARM_MATH_ROUNDING
      /* C = A * 32768 */
      /* convert from float to q15 and then store the results in the destination buffer */
      in = *pIn++;
      in = (in * 32768.0f);
      in += in > 0 ? 0.5f : -0.5f;
      *pDst++ = (q15_t) (__SSAT((q31_t) (in), 16));
  
  #else
  
      /* C = A * 32768 */
      /* convert from float to q15 and then store the results in the destination buffer */
      *pDst++ = (q15_t) __SSAT((q31_t) (*pIn++ * 32768.0f), 16);
  
  #endif /*      #ifdef ARM_MATH_ROUNDING        */
  
      /* Decrement the loop counter */
      blkCnt--;
    }
  
  #endif /* #ifndef ARM_MATH_CM0_FAMILY */
  
  }
  
  /**    
   * @} end of float_to_x group    
   */
  