Diff: src/Cortex-M4-M3/ComplexMathFunctions/arm_cmplx_dot_prod_q31.c

Revision:

0:1014af42efd9

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/Cortex-M4-M3/ComplexMathFunctions/arm_cmplx_dot_prod_q31.c	Thu Mar 10 15:07:50 2011 +0000
@@ -0,0 +1,118 @@
+/* ----------------------------------------------------------------------  
+* Copyright (C) 2010 ARM Limited. All rights reserved.  
+*  
+* $Date:        29. November 2010  
+* $Revision: 	V1.0.3  
+*  
+* Project: 	    CMSIS DSP Library  
+* Title:		arm_cmplx_dot_prod_q31.c  
+*  
+* Description:	Q31 complex dot product  
+*  
+* Target Processor: Cortex-M4/Cortex-M3
+*  
+* 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 */ 
+  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--; 
+  } 
+ 
+  /* Store the real and imaginary results in 16.48 format  */ 
+  *realResult = real_sum; 
+  *imagResult = imag_sum; 
+} 
+ 
+/**  
+ * @} end of cmplx_dot_prod group  
+ */