Diff: cmsis_dsp/ComplexMathFunctions/arm_cmplx_dot_prod_q31.c

Revision:

1:fdd22bb7aa52

Child:

2:da51fb522205

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cmsis_dsp/ComplexMathFunctions/arm_cmplx_dot_prod_q31.c	Wed Nov 28 12:30:09 2012 +0000
@@ -0,0 +1,145 @@
+/* ----------------------------------------------------------------------    
+* Copyright (C) 2010 ARM Limited. All rights reserved.    
+*    
+* $Date:        15. February 2012  
+* $Revision:     V1.1.0  
+*    
+* Project:         CMSIS DSP Library    
+* Title:        arm_cmplx_dot_prod_q31.c    
+*    
+* Description:    Q31 complex dot product    
+*    
+* 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 groupCmplxMath    
+ */
+
+/**    
+ * @addtogroup cmplx_dot_prod    
+ * @{    
+ */
+
+/**    
+ * @brief  Q31 complex dot product    
+ * @param  *pSrcA points to the first input vector    
+ * @param  *pSrcB points to the second input vector    
+ * @param  numSamples number of complex samples in each vector    
+ * @param  *realResult real part of the result returned here    
+ * @param  *imagResult imaginary part of the result returned here    
+ * @return none.    
+ *    
+ * <b>Scaling and Overflow Behavior:</b>    
+ * \par    
+ * The function is implemented using an internal 64-bit accumulator.    
+ * The intermediate 1.31 by 1.31 multiplications are performed with 64-bit precision and then shifted to 16.48 format.    
+ * The internal real and imaginary accumulators are in 16.48 format and provide 15 guard bits.    
+ * Additions are nonsaturating and no overflow will occur as long as <code>numSamples</code> is less than 32768.    
+ * The return results <code>realResult</code> and <code>imagResult</code> are in 16.48 format.    
+ * Input down scaling is not required.    
+ */
+
+void arm_cmplx_dot_prod_q31(
+  q31_t * pSrcA,
+  q31_t * pSrcB,
+  uint32_t numSamples,
+  q63_t * realResult,
+  q63_t * imagResult)
+{
+  q63_t real_sum = 0, imag_sum = 0;              /* Temporary result storage */
+
+#ifndef ARM_MATH_CM0
+
+  /* Run the below code for Cortex-M4 and Cortex-M3 */
+  uint32_t blkCnt;                               /* loop counter */
+
+
+  /*loop Unrolling */
+  blkCnt = numSamples >> 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)
+  {
+    /* CReal = A[0]* B[0] + A[2]* B[2] + A[4]* B[4] + .....+ A[numSamples-2]* B[numSamples-2] */
+    /* Convert real data in 2.62 to 16.48 by 14 right shifts */
+    real_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14;
+    /* CImag = A[1]* B[1] + A[3]* B[3] + A[5]* B[5] + .....+ A[numSamples-1]* B[numSamples-1] */
+    /* Convert imag data in 2.62 to 16.48 by 14 right shifts */
+    imag_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14;
+
+    real_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14;
+    imag_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14;
+
+    real_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14;
+    imag_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14;
+
+    real_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14;
+    imag_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14;
+
+
+    /* Decrement the loop counter */
+    blkCnt--;
+  }
+
+  /* If the numSamples  is not a multiple of 4, compute any remaining output samples here.    
+   ** No loop unrolling is used. */
+  blkCnt = numSamples % 0x4u;
+
+  while(blkCnt > 0u)
+  {
+    /* CReal = A[0]* B[0] + A[2]* B[2] + A[4]* B[4] + .....+ A[numSamples-2]* B[numSamples-2] */
+    real_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14;
+    /* CImag = A[1]* B[1] + A[3]* B[3] + A[5]* B[5] + .....+ A[numSamples-1]* B[numSamples-1] */
+    imag_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14;
+
+    /* Decrement the loop counter */
+    blkCnt--;
+  }
+
+#else
+
+  /* Run the below code for Cortex-M0 */
+
+  while(numSamples > 0u)
+  {
+    /* outReal = realA[0]* realB[0] + realA[2]* realB[2] + realA[4]* realB[4] + .....+ realA[numSamples-2]* realB[numSamples-2] */
+    real_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14;
+    /* outImag = imagA[1]* imagB[1] + imagA[3]* imagB[3] + imagA[5]* imagB[5] + .....+ imagA[numSamples-1]* imagB[numSamples-1] */
+    imag_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14;
+
+    /* Decrement the loop counter */
+    numSamples--;
+  }
+
+#endif /* #ifndef ARM_MATH_CM0 */
+
+  /* Store the real and imaginary results in 16.48 format  */
+  *realResult = real_sum;
+  *imagResult = imag_sum;
+}
+
+/**    
+ * @} end of cmplx_dot_prod group    
+ */