Diff: cmsis_dsp/StatisticsFunctions/arm_max_q15.c

Revision:

1:fdd22bb7aa52

Child:

2:da51fb522205

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cmsis_dsp/StatisticsFunctions/arm_max_q15.c	Wed Nov 28 12:30:09 2012 +0000
@@ -0,0 +1,168 @@
+/* ----------------------------------------------------------------------    
+* Copyright (C) 2010 ARM Limited. All rights reserved.    
+*    
+* $Date:        15. February 2012  
+* $Revision:     V1.1.0  
+*    
+* Project:         CMSIS DSP Library    
+* Title:        arm_max_q15.c    
+*    
+* Description:    Maximum value of a Q15 vector.    
+*    
+* 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 groupStats    
+ */
+
+/**    
+ * @addtogroup Max    
+ * @{    
+ */
+
+
+/**    
+ * @brief Maximum value of a Q15 vector.    
+ * @param[in]       *pSrc points to the input vector    
+ * @param[in]       blockSize length of the input vector    
+ * @param[out]      *pResult maximum value returned here    
+ * @param[out]      *pIndex index of maximum value returned here    
+ * @return none.    
+ */
+
+void arm_max_q15(
+  q15_t * pSrc,
+  uint32_t blockSize,
+  q15_t * pResult,
+  uint32_t * pIndex)
+{
+#ifndef ARM_MATH_CM0
+
+  /* Run the below code for Cortex-M4 and Cortex-M3 */
+  q15_t maxVal1, maxVal2, out;                   /* Temporary variables to store the output value. */
+  uint32_t blkCnt, outIndex, count;              /* loop counter */
+
+  /* Initialise the count value. */
+  count = 0u;
+  /* Initialise the index value to zero. */
+  outIndex = 0u;
+  /* Load first input value that act as reference value for comparision */
+  out = *pSrc++;
+
+  /* Loop unrolling */
+  blkCnt = (blockSize - 1u) >> 2u;
+
+  /* Run the below code for Cortex-M4 and Cortex-M3 */
+  while(blkCnt > 0u)
+  {
+    /* Initialize maxVal to the next consecutive values one by one */
+    maxVal1 = *pSrc++;
+
+    maxVal2 = *pSrc++;
+
+    /* compare for the maximum value */
+    if(out < maxVal1)
+    {
+      /* Update the maximum value and its index */
+      out = maxVal1;
+      outIndex = count + 1u;
+    }
+
+    maxVal1 = *pSrc++;
+
+    /* compare for the maximum value */
+    if(out < maxVal2)
+    {
+      /* Update the maximum value and its index */
+      out = maxVal2;
+      outIndex = count + 2u;
+    }
+
+    maxVal2 = *pSrc++;
+
+    /* compare for the maximum value */
+    if(out < maxVal1)
+    {
+      /* Update the maximum value and its index */
+      out = maxVal1;
+      outIndex = count + 3u;
+    }
+
+    /* compare for the maximum value */
+    if(out < maxVal2)
+    {
+      /* Update the maximum value and its index */
+      out = maxVal2;
+      outIndex = count + 4u;
+    }
+
+    count += 4u;
+
+    /* Decrement the loop counter */
+    blkCnt--;
+  }
+
+  /* if (blockSize - 1u) is not multiple of 4 */
+  blkCnt = (blockSize - 1u) % 4u;
+
+#else
+
+  /* Run the below code for Cortex-M0 */
+  q15_t maxVal1, out;                            /* Temporary variables to store the output value. */
+  uint32_t blkCnt, outIndex;                     /* loop counter */
+
+  blkCnt = (blockSize - 1u);
+
+  /* Initialise the index value to zero. */
+  outIndex = 0u;
+  /* Load first input value that act as reference value for comparision */
+  out = *pSrc++;
+
+#endif /* #ifndef ARM_MATH_CM0 */
+
+  while(blkCnt > 0u)
+  {
+    /* Initialize maxVal to the next consecutive values one by one */
+    maxVal1 = *pSrc++;
+
+    /* compare for the maximum value */
+    if(out < maxVal1)
+    {
+      /* Update the maximum value and it's index */
+      out = maxVal1;
+      outIndex = blockSize - blkCnt;
+    }
+    /* Decrement the loop counter */
+    blkCnt--;
+
+  }
+
+  /* Store the maximum value and its index into destination pointers */
+  *pResult = out;
+  *pIndex = outIndex;
+}
+
+/**    
+ * @} end of Max group    
+ */