Diff: cmsis_dsp/BasicMathFunctions/arm_shift_q31.c

Revision:

5:a912b042151f

Parent:

4:9cee975aadce

--- a/cmsis_dsp/BasicMathFunctions/arm_shift_q31.c	Mon Jun 23 09:30:09 2014 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,203 +0,0 @@
-/* ----------------------------------------------------------------------    
-* Copyright (C) 2010-2013 ARM Limited. All rights reserved.    
-*    
-* $Date:        17. January 2013
-* $Revision: 	V1.4.1
-*    
-* Project: 	    CMSIS DSP Library    
-* Title:		arm_shift_q31.c    
-*    
-* Description:	Shifts the elements of a Q31 vector by a specified number of bits.    
-*    
-* 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 groupMath        
- */
-/**        
- * @defgroup shift Vector Shift        
- *        
- * Shifts the elements of a fixed-point vector by a specified number of bits.        
- * There are separate functions for Q7, Q15, and Q31 data types.        
- * The underlying algorithm used is:        
- *        
- * <pre>        
- *     pDst[n] = pSrc[n] << shift,   0 <= n < blockSize.        
- * </pre>        
- *        
- * If <code>shift</code> is positive then the elements of the vector are shifted to the left.        
- * If <code>shift</code> is negative then the elements of the vector are shifted to the right.        
- *
- * The functions support in-place computation allowing the source and destination
- * pointers to reference the same memory buffer.
- */
-
-/**        
- * @addtogroup shift        
- * @{        
- */
-
-/**        
- * @brief  Shifts the elements of a Q31 vector a specified number of bits.        
- * @param[in]  *pSrc points to the input vector        
- * @param[in]  shiftBits number of bits to shift.  A positive value shifts left; a negative value shifts right.        
- * @param[out]  *pDst points to the output vector        
- * @param[in]  blockSize number of samples in the vector        
- * @return none.        
- *        
- *        
- * <b>Scaling and Overflow Behavior:</b>        
- * \par        
- * The function uses saturating arithmetic.        
- * Results outside of the allowable Q31 range [0x80000000 0x7FFFFFFF] will be saturated.        
- */
-
-void arm_shift_q31(
-  q31_t * pSrc,
-  int8_t shiftBits,
-  q31_t * pDst,
-  uint32_t blockSize)
-{
-  uint32_t blkCnt;                               /* loop counter */
-  uint8_t sign = (shiftBits & 0x80);             /* Sign of shiftBits */
-
-#ifndef ARM_MATH_CM0_FAMILY
-
-  q31_t in1, in2, in3, in4;                      /* Temporary input variables */
-  q31_t out1, out2, out3, out4;                  /* Temporary output variables */
-
-  /*loop Unrolling */
-  blkCnt = blockSize >> 2u;
-
-
-  if(sign == 0u)
-  {
-    /* 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 = A  << shiftBits */
-      /* Shift the input and then store the results in the destination buffer. */
-      in1 = *pSrc;
-      in2 = *(pSrc + 1);
-      out1 = in1 << shiftBits;
-      in3 = *(pSrc + 2);
-      out2 = in2 << shiftBits;
-      in4 = *(pSrc + 3);
-      if(in1 != (out1 >> shiftBits))
-        out1 = 0x7FFFFFFF ^ (in1 >> 31);
-
-      if(in2 != (out2 >> shiftBits))
-        out2 = 0x7FFFFFFF ^ (in2 >> 31);
-
-      *pDst = out1;
-      out3 = in3 << shiftBits;
-      *(pDst + 1) = out2;
-      out4 = in4 << shiftBits;
-
-      if(in3 != (out3 >> shiftBits))
-        out3 = 0x7FFFFFFF ^ (in3 >> 31);
-
-      if(in4 != (out4 >> shiftBits))
-        out4 = 0x7FFFFFFF ^ (in4 >> 31);
-
-      *(pDst + 2) = out3;
-      *(pDst + 3) = out4;
-
-      /* Update destination pointer to process next sampels */
-      pSrc += 4u;
-      pDst += 4u;
-
-      /* Decrement the loop counter */
-      blkCnt--;
-    }
-  }
-  else
-  {
-
-    /* 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 = A >>  shiftBits */
-      /* Shift the input and then store the results in the destination buffer. */
-      in1 = *pSrc;
-      in2 = *(pSrc + 1);
-      in3 = *(pSrc + 2);
-      in4 = *(pSrc + 3);
-
-      *pDst = (in1 >> -shiftBits);
-      *(pDst + 1) = (in2 >> -shiftBits);
-      *(pDst + 2) = (in3 >> -shiftBits);
-      *(pDst + 3) = (in4 >> -shiftBits);
-
-
-      pSrc += 4u;
-      pDst += 4u;
-
-      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 */
-
-
-  /* Initialize blkCnt with number of samples */
-  blkCnt = blockSize;
-
-#endif /* #ifndef ARM_MATH_CM0_FAMILY */
-
-
-  while(blkCnt > 0u)
-  {
-    /* C = A (>> or <<) shiftBits */
-    /* Shift the input and then store the result in the destination buffer. */
-    *pDst++ = (sign == 0u) ? clip_q63_to_q31((q63_t) * pSrc++ << shiftBits) :
-      (*pSrc++ >> -shiftBits);
-
-    /* Decrement the loop counter */
-    blkCnt--;
-  }
-
-
-}
-
-/**        
- * @} end of shift group        
- */