Diff: cmsis_dsp/ComplexMathFunctions/arm_cmplx_mag_q31.c

Revision:

1:fdd22bb7aa52

Child:

2:da51fb522205

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cmsis_dsp/ComplexMathFunctions/arm_cmplx_mag_q31.c	Wed Nov 28 12:30:09 2012 +0000
@@ -0,0 +1,177 @@
+/* ----------------------------------------------------------------------    
+* Copyright (C) 2010 ARM Limited. All rights reserved.    
+*    
+* $Date:        15. February 2012  
+* $Revision:     V1.1.0  
+*    
+* Project:         CMSIS DSP Library    
+* Title:        arm_cmplx_mag_q31.c    
+*    
+* Description:    Q31 complex magnitude    
+*    
+* 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_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 */
+
+#ifndef ARM_MATH_CM0
+
+  /* Run the below code for Cortex-M4 and Cortex-M3 */
+  q31_t real1, real2, imag1, imag2;              /* Temporary variables to hold input values */
+  q31_t out1, out2, out3, out4;                  /* Accumulators */
+  q63_t mul1, mul2, mul3, mul4;                  /* Temporary variables */
+
+
+  /*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)
+  {
+    /* read complex input from source buffer */
+    real1 = pSrc[0];
+    imag1 = pSrc[1];
+    real2 = pSrc[2];
+    imag2 = pSrc[3];
+
+    /* calculate power of input values */
+    mul1 = (q63_t) real1 *real1;
+    mul2 = (q63_t) imag1 *imag1;
+    mul3 = (q63_t) real2 *real2;
+    mul4 = (q63_t) imag2 *imag2;
+
+    /* get the result to 3.29 format */
+    out1 = (q31_t) (mul1 >> 33);
+    out2 = (q31_t) (mul2 >> 33);
+    out3 = (q31_t) (mul3 >> 33);
+    out4 = (q31_t) (mul4 >> 33);
+
+    /* add real and imaginary accumulators */
+    out1 = out1 + out2;
+    out3 = out3 + out4;
+
+    /* read complex input from source buffer */
+    real1 = pSrc[4];
+    imag1 = pSrc[5];
+    real2 = pSrc[6];
+    imag2 = pSrc[7];
+
+    /* calculate square root */
+    arm_sqrt_q31(out1, &pDst[0]);
+
+    /* calculate power of input values */
+    mul1 = (q63_t) real1 *real1;
+
+    /* calculate square root */
+    arm_sqrt_q31(out3, &pDst[1]);
+
+    /* calculate power of input values */
+    mul2 = (q63_t) imag1 *imag1;
+    mul3 = (q63_t) real2 *real2;
+    mul4 = (q63_t) imag2 *imag2;
+
+    /* get the result to 3.29 format */
+    out1 = (q31_t) (mul1 >> 33);
+    out2 = (q31_t) (mul2 >> 33);
+    out3 = (q31_t) (mul3 >> 33);
+    out4 = (q31_t) (mul4 >> 33);
+
+    /* add real and imaginary accumulators */
+    out1 = out1 + out2;
+    out3 = out3 + out4;
+
+    /* calculate square root */
+    arm_sqrt_q31(out1, &pDst[2]);
+
+    /* increment destination by 8 to process next samples */
+    pSrc += 8u;
+
+    /* calculate square root */
+    arm_sqrt_q31(out3, &pDst[3]);
+
+    /* increment destination by 4 to process next samples */
+    pDst += 4u;
+
+    /* 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;
+
+#else
+
+  /* Run the below code for Cortex-M0 */
+  blkCnt = numSamples;
+
+#endif /* #ifndef ARM_MATH_CM0 */
+
+  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        
+ */