Diff: cmsis_dsp/MatrixFunctions/arm_mat_scale_q15.c

Revision:

1:fdd22bb7aa52

Child:

2:da51fb522205

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cmsis_dsp/MatrixFunctions/arm_mat_scale_q15.c	Wed Nov 28 12:30:09 2012 +0000
@@ -0,0 +1,181 @@
+/* ----------------------------------------------------------------------    
+* Copyright (C) 2010 ARM Limited. All rights reserved.    
+*    
+* $Date:        15. February 2012  
+* $Revision:     V1.1.0  
+*    
+* Project:         CMSIS DSP Library    
+* Title:        arm_mat_scale_q15.c    
+*    
+* Description:    Multiplies a Q15 matrix by a scalar.    
+*    
+* 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.    
+*    
+* Version 0.0.5  2010/04/26     
+*    incorporated review comments and updated with latest CMSIS layer    
+*    
+* Version 0.0.3  2010/03/10     
+*    Initial version    
+* -------------------------------------------------------------------- */
+
+#include "arm_math.h"
+
+/**    
+ * @ingroup groupMatrix    
+ */
+
+/**    
+ * @addtogroup MatrixScale    
+ * @{    
+ */
+
+/**    
+ * @brief Q15 matrix scaling.    
+ * @param[in]       *pSrc points to input matrix    
+ * @param[in]       scaleFract fractional portion of the scale factor    
+ * @param[in]       shift number of bits to shift the result by    
+ * @param[out]      *pDst points to output matrix structure    
+ * @return             The function returns either    
+ * <code>ARM_MATH_SIZE_MISMATCH</code> or <code>ARM_MATH_SUCCESS</code> based on the outcome of size checking.    
+ *    
+ * @details    
+ * <b>Scaling and Overflow Behavior:</b>    
+ * \par    
+ * The input data <code>*pSrc</code> and <code>scaleFract</code> are in 1.15 format.    
+ * These are multiplied to yield a 2.30 intermediate result and this is shifted with saturation to 1.15 format.    
+ */
+
+arm_status arm_mat_scale_q15(
+  const arm_matrix_instance_q15 * pSrc,
+  q15_t scaleFract,
+  int32_t shift,
+  arm_matrix_instance_q15 * pDst)
+{
+  q15_t *pIn = pSrc->pData;                      /* input data matrix pointer */
+  q15_t *pOut = pDst->pData;                     /* output data matrix pointer */
+  uint32_t numSamples;                           /* total number of elements in the matrix */
+  int32_t totShift = 15 - shift;                 /* total shift to apply after scaling */
+  uint32_t blkCnt;                               /* loop counters */
+  arm_status status;                             /* status of matrix scaling     */
+
+#ifndef ARM_MATH_CM0
+
+  q15_t in1, in2, in3, in4;
+  q31_t out1, out2, out3, out4;
+  q31_t inA1, inA2;
+
+#endif //     #ifndef ARM_MATH_CM0
+
+#ifdef ARM_MATH_MATRIX_CHECK
+  /* Check for matrix mismatch */
+  if((pSrc->numRows != pDst->numRows) || (pSrc->numCols != pDst->numCols))
+  {
+    /* Set status as ARM_MATH_SIZE_MISMATCH */
+    status = ARM_MATH_SIZE_MISMATCH;
+  }
+  else
+#endif //    #ifdef ARM_MATH_MATRIX_CHECK
+  {
+    /* Total number of samples in the input matrix */
+    numSamples = (uint32_t) pSrc->numRows * pSrc->numCols;
+
+#ifndef ARM_MATH_CM0
+
+    /* Run the below code for Cortex-M4 and Cortex-M3 */
+    /* Loop Unrolling */
+    blkCnt = numSamples >> 2;
+
+    /* 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(m,n) = A(m,n) * k */
+      /* Scale, saturate and then store the results in the destination buffer. */
+      /* Reading 2 inputs from memory */
+      inA1 = _SIMD32_OFFSET(pIn);
+      inA2 = _SIMD32_OFFSET(pIn + 2);
+
+      /* C = A * scale */
+      /* Scale the inputs and then store the 2 results in the destination buffer        
+       * in single cycle by packing the outputs */
+      out1 = (q31_t) ((q15_t) (inA1 >> 16) * scaleFract);
+      out2 = (q31_t) ((q15_t) inA1 * scaleFract);
+      out3 = (q31_t) ((q15_t) (inA2 >> 16) * scaleFract);
+      out4 = (q31_t) ((q15_t) inA2 * scaleFract);
+
+      out1 = out1 >> totShift;
+      inA1 = _SIMD32_OFFSET(pIn + 4);
+      out2 = out2 >> totShift;
+      inA2 = _SIMD32_OFFSET(pIn + 6);
+      out3 = out3 >> totShift;
+      out4 = out4 >> totShift;
+
+      in1 = (q15_t) (__SSAT(out1, 16));
+      in2 = (q15_t) (__SSAT(out2, 16));
+      in3 = (q15_t) (__SSAT(out3, 16));
+      in4 = (q15_t) (__SSAT(out4, 16));
+
+      _SIMD32_OFFSET(pOut) = __PKHBT(in2, in1, 16);
+      _SIMD32_OFFSET(pOut + 2) = __PKHBT(in4, in3, 16);
+
+      /* update pointers to process next sampels */
+      pIn += 4u;
+      pOut += 4u;
+
+
+      /* Decrement the numSamples 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 */
+
+    /* Initialize blkCnt with number of samples */
+    blkCnt = numSamples;
+
+#endif /* #ifndef ARM_MATH_CM0 */
+
+    while(blkCnt > 0u)
+    {
+      /* C(m,n) = A(m,n) * k */
+      /* Scale, saturate and then store the results in the destination buffer. */
+      *pOut++ =
+        (q15_t) (__SSAT(((q31_t) (*pIn++) * scaleFract) >> totShift, 16));
+
+      /* Decrement the numSamples loop counter */
+      blkCnt--;
+    }
+    /* Set status as ARM_MATH_SUCCESS */
+    status = ARM_MATH_SUCCESS;
+  }
+
+  /* Return to application */
+  return (status);
+}
+
+/**        
+ * @} end of MatrixScale group        
+ */