arm_float_to_q31.c

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/* ----------------------------------------------------------------------------      
* Copyright (C) 2011 ARM Limited. All rights reserved. 
*      
* $Date:        15. December 2011   
* $Revision:    V2.0.0  
*      
* Project:      Cortex-R DSP Library 
* Title:        arm_float_to_q31.c      
*      
* Description:  Converts the elements of the floating-point vector to Q31 vector.      
*      
* Target Processor:          Cortex-R4/R5
*
* Version 1.0.0 2011/03/08
*     Alpha release.
*
* Version 1.0.1 2011/09/30
*     Beta release.
*
* Version 2.0.0 2011/12/15
*     Final release. 
* 
* ---------------------------------------------------------------------------- */     
#include "arm_math.h"     
     
void arm_float_to_q31(     
  float32_t * pSrc,     
  q31_t * pDst,     
  uint32_t blockSize)     
{     
  float32_t *pIn = pSrc;                         /* Src pointer */     
  uint32_t blkCnt;                               /* loop counter */     
     
#ifdef ARM_MATH_ROUNDING     
     
  float32_t in;     
     
#endif     
     
     
  /*loop Unrolling */     
  blkCnt = blockSize >> 3u;     
     
  /* First part of the processing with loop unrolling.  Compute 48 outputs at a time.      
   ** a second loop below computes the remaining 1 to 7 samples. */     
  while(blkCnt > 0u)     
  {     
#ifdef ARM_MATH_ROUNDING     
    /* C = A * 32768 */     
    /* convert from float to Q31 and then store the results in the destination buffer */     
    in = *pIn++;     
    in = (in * 2147483648.0f);     
    in += in > 0 ? 0.5 : -0.5;     
    *pDst++ = clip_q63_to_q31((q63_t) (in));     
     
    in = *pIn++;     
    in = (in * 2147483648.0f);     
    in += in > 0 ? 0.5 : -0.5;     
    *pDst++ = clip_q63_to_q31((q63_t) (in));     
     
    in = *pIn++;     
    in = (in * 2147483648.0f);     
    in += in > 0 ? 0.5 : -0.5;     
    *pDst++ = clip_q63_to_q31((q63_t) (in));     
     
    in = *pIn++;     
    in = (in * 2147483648.0f);     
    in += in > 0 ? 0.5 : -0.5;     
    *pDst++ = clip_q63_to_q31((q63_t) (in));     
   
    in = *pIn++;     
    in = (in * 2147483648.0f);     
    in += in > 0 ? 0.5 : -0.5;     
    *pDst++ = clip_q63_to_q31((q63_t) (in));     
     
    in = *pIn++;     
    in = (in * 2147483648.0f);     
    in += in > 0 ? 0.5 : -0.5;     
    *pDst++ = clip_q63_to_q31((q63_t) (in));     
     
    in = *pIn++;     
    in = (in * 2147483648.0f);     
    in += in > 0 ? 0.5 : -0.5;     
    *pDst++ = clip_q63_to_q31((q63_t) (in));     
     
    in = *pIn++;     
    in = (in * 2147483648.0f);     
    in += in > 0 ? 0.5 : -0.5;     
    *pDst++ = clip_q63_to_q31((q63_t) (in));     
     
#else     
     
    /* C = A * 2147483648 */     
    /* convert from float to Q31 and then store the results in the destination buffer */     
    *pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0f));     
    *pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0f));     
    *pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0f));     
    *pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0f));     
    *pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0f));     
    *pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0f));     
    *pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0f));     
    *pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0f));     
     
#endif     
     
    /* Decrement the loop counter */     
    blkCnt--;     
  }     
     
  /* If the blockSize is not a multiple of 8, compute any remaining output samples here.      
   ** No loop unrolling is used. */     
  blkCnt = blockSize % 0x8u;     
     
  while(blkCnt > 0u)     
  {     
#ifdef ARM_MATH_ROUNDING     
     
    /* C = A * 2147483648 */     
    /* convert from float to Q31 and then store the results in the destination buffer */     
    in = *pIn++;     
    in = (in * 2147483648.0f);     
    in += in > 0 ? 0.5 : -0.5;     
    *pDst++ = clip_q63_to_q31((q63_t) (in));     
     
#else     
     
    /* C = A * 2147483648 */     
    /* convert from float to Q31 and then store the results in the destination buffer */     
    *pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0f));     
     
#endif     
     
    /* Decrement the loop counter */     
    blkCnt--;     
  }     
}