Diff: src/Cortex-M4-M3/ComplexMathFunctions/arm_cmplx_mag_q31.c

Revision:

0:1014af42efd9

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/Cortex-M4-M3/ComplexMathFunctions/arm_cmplx_mag_q31.c	Thu Mar 10 15:07:50 2011 +0000
@@ -0,0 +1,123 @@
+/* ----------------------------------------------------------------------  
+* Copyright (C) 2010 ARM Limited. All rights reserved.  
+*  
+* $Date:        29. November 2010  
+* $Revision: 	V1.0.3  
+*  
+* Project: 	    CMSIS DSP Library  
+* Title:		arm_cmplx_mag_q31.c  
+*  
+* Description:	Q31 complex magnitude  
+*  
+* 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_mag  
+ * @{  
+ */ 
+ 
+/**  
+ * @brief  Q31 complex magnitude  
+ * @param  *pSrc points to the complex input vector  
+ * @param  *pDst points to the real output vector  
+ * @param  numSamples number of complex samples in the input vector  
+ * @return none.  
+ *  
+ * <b>Scaling and Overflow Behavior:</b>  
+ * \par  
+ * The function implements 1.31 by 1.31 multiplications and finally output is converted into 2.30 format.  
+ * Input down scaling is not required.  
+ */ 
+ 
+void arm_cmplx_mag_q31( 
+  q31_t * pSrc, 
+  q31_t * pDst, 
+  uint32_t numSamples) 
+{ 
+  q31_t real, imag;                              /* Temporary variables to hold input values */ 
+  q31_t acc0, acc1;                              /* Accumulators */ 
+  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) 
+  { 
+ 
+    /* C[0] = sqrt(A[0] * A[0] + A[1] * A[1]) */ 
+    real = *pSrc++; 
+    imag = *pSrc++; 
+    acc0 = (q31_t) (((q63_t) real * real) >> 33); 
+    acc1 = (q31_t) (((q63_t) imag * imag) >> 33); 
+    /* store the result in 2.30 format in the destination buffer. */ 
+    arm_sqrt_q31(acc0 + acc1, pDst++); 
+ 
+    real = *pSrc++; 
+    imag = *pSrc++; 
+    acc0 = (q31_t) (((q63_t) real * real) >> 33); 
+    acc1 = (q31_t) (((q63_t) imag * imag) >> 33); 
+    /* store the result in 2.30 format in the destination buffer. */ 
+    arm_sqrt_q31(acc0 + acc1, pDst++); 
+ 
+    real = *pSrc++; 
+    imag = *pSrc++; 
+    acc0 = (q31_t) (((q63_t) real * real) >> 33); 
+    acc1 = (q31_t) (((q63_t) imag * imag) >> 33); 
+    /* store the result in 2.30 format in the destination buffer. */ 
+    arm_sqrt_q31(acc0 + acc1, pDst++); 
+ 
+    real = *pSrc++; 
+    imag = *pSrc++; 
+    acc0 = (q31_t) (((q63_t) real * real) >> 33); 
+    acc1 = (q31_t) (((q63_t) imag * imag) >> 33); 
+    /* store the result in 2.30 format in the destination buffer. */ 
+    arm_sqrt_q31(acc0 + acc1, pDst++); 
+ 
+    /* 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) 
+  { 
+    /* C[0] = sqrt(A[0] * A[0] + A[1] * A[1]) */ 
+    real = *pSrc++; 
+    imag = *pSrc++; 
+    acc0 = (q31_t) (((q63_t) real * real) >> 33); 
+    acc1 = (q31_t) (((q63_t) imag * imag) >> 33); 
+    /* store the result in 2.30 format in the destination buffer. */ 
+    arm_sqrt_q31(acc0 + acc1, pDst++); 
+ 
+    /* Decrement the loop counter */ 
+    blkCnt--; 
+  } 
+} 
+ 
+/**  
+ * @} end of cmplx_mag group  
+ */