Diff: src/Cortex-M4-M3/SupportFunctions/arm_q15_to_q31.c

Revision:

0:1014af42efd9

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/Cortex-M4-M3/SupportFunctions/arm_q15_to_q31.c	Thu Mar 10 15:07:50 2011 +0000
@@ -0,0 +1,100 @@
+/* ----------------------------------------------------------------------------  
+* Copyright (C) 2010 ARM Limited. All rights reserved.  
+*  
+* $Date:        29. November 2010  
+* $Revision: 	V1.0.3  
+*  
+* Project: 	    CMSIS DSP Library  
+* Title:		arm_q15_to_q31.c  
+*  
+* Description:	Processing function for the Conversion from Q15 to Q31  
+*  
+* 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 groupSupport  
+ */ 
+ 
+/**  
+ * @addtogroup q15_to_x  
+ * @{  
+ */ 
+ 
+/**  
+ * @brief Converts the elements of the Q15 vector to Q31 vector.   
+ * @param[in]       *pSrc points to the Q15 input vector  
+ * @param[out]      *pDst points to the Q31 output vector 
+ * @param[in]       blockSize length of the input vector  
+ * @return none.  
+ *  
+ * \par Description:  
+ *  
+ * The equation used for the conversion process is: 
+ * 
+ * <pre>  
+ * 	pDst[n] = (q31_t) pSrc[n] << 16;   0 <= n < blockSize.  
+ * </pre>  
+ * 
+ */ 
+ 
+ 
+void arm_q15_to_q31( 
+  q15_t * pSrc, 
+  q31_t * pDst, 
+  uint32_t blockSize) 
+{ 
+  q15_t *pIn = pSrc;                             /* Src pointer */ 
+  uint32_t blkCnt;                               /* loop counter */ 
+ 
+  /*loop Unrolling */ 
+  blkCnt = blockSize >> 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 = (q31_t)A << 16 */ 
+    /* convert from q15 to q31 and then store the results in the destination buffer */ 
+    *pDst++ = (q31_t) * pIn++ << 16; 
+    *pDst++ = (q31_t) * pIn++ << 16; 
+    *pDst++ = (q31_t) * pIn++ << 16; 
+    *pDst++ = (q31_t) * pIn++ << 16; 
+ 
+    /* Decrement the loop counter */ 
+    blkCnt--; 
+  } 
+ 
+  /* If the blockSize is not a multiple of 4, compute any remaining output samples here.  
+   ** No loop unrolling is used. */ 
+  blkCnt = blockSize % 0x4u; 
+ 
+  while(blkCnt > 0u) 
+  { 
+    /* C = (q31_t)A << 16 */ 
+    /* convert from q15 to q31 and then store the results in the destination buffer */ 
+    *pDst++ = (q31_t) * pIn++ << 16; 
+ 
+    /* Decrement the loop counter */ 
+    blkCnt--; 
+  } 
+ 
+} 
+ 
+/**  
+ * @} end of q15_to_x group  
+ */