Diff: cmsis_dsp/MatrixFunctions/arm_mat_mult_fast_q15.c

Revision:

1:fdd22bb7aa52

Child:

2:da51fb522205

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cmsis_dsp/MatrixFunctions/arm_mat_mult_fast_q15.c	Wed Nov 28 12:30:09 2012 +0000
@@ -0,0 +1,361 @@
+/* ----------------------------------------------------------------------    
+* Copyright (C) 2010 ARM Limited. All rights reserved.    
+*    
+* $Date:        15. February 2012  
+* $Revision:     V1.1.0  
+*    
+* Project:         CMSIS DSP Library    
+* Title:        arm_mat_mult_fast_q15.c    
+*    
+* Description:     Q15 matrix multiplication (fast variant)    
+*    
+* Target Processor: Cortex-M4/Cortex-M3
+*  
+* 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 groupMatrix    
+ */
+
+/**    
+ * @addtogroup MatrixMult    
+ * @{    
+ */
+
+
+/**    
+ * @brief Q15 matrix multiplication (fast variant) for Cortex-M3 and Cortex-M4    
+ * @param[in]       *pSrcA points to the first input matrix structure    
+ * @param[in]       *pSrcB points to the second input matrix structure    
+ * @param[out]      *pDst points to output matrix structure    
+ * @param[in]        *pState points to the array for storing intermediate results    
+ * @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 difference between the function arm_mat_mult_q15() and this fast variant is that    
+ * the fast variant use a 32-bit rather than a 64-bit accumulator.    
+ * The result of each 1.15 x 1.15 multiplication is truncated to        
+ * 2.30 format. These intermediate results are accumulated in a 32-bit register in 2.30        
+ * format. Finally, the accumulator is saturated and converted to a 1.15 result.        
+ *        
+ * \par        
+ * The fast version has the same overflow behavior as the standard version but provides        
+ * less precision since it discards the low 16 bits of each multiplication result.        
+ * In order to avoid overflows completely the input signals must be scaled down.        
+ * Scale down one of the input matrices by log2(numColsA) bits to        
+ * avoid overflows, as a total of numColsA additions are computed internally for each        
+ * output element.        
+ *        
+ * \par    
+ * See <code>arm_mat_mult_q15()</code> for a slower implementation of this function    
+ * which uses 64-bit accumulation to provide higher precision.    
+ */
+
+arm_status arm_mat_mult_fast_q15(
+  const arm_matrix_instance_q15 * pSrcA,
+  const arm_matrix_instance_q15 * pSrcB,
+  arm_matrix_instance_q15 * pDst,
+  q15_t * pState)
+{
+  q31_t sum;                                     /* accumulator */
+  q15_t *pSrcBT = pState;                        /* input data matrix pointer for transpose */
+  q15_t *pInA = pSrcA->pData;                    /* input data matrix pointer A of Q15 type */
+  q15_t *pInB = pSrcB->pData;                    /* input data matrix pointer B of Q15 type */
+  q15_t *px;                                     /* Temporary output data matrix pointer */
+  uint16_t numRowsA = pSrcA->numRows;            /* number of rows of input matrix A    */
+  uint16_t numColsB = pSrcB->numCols;            /* number of columns of input matrix B */
+  uint16_t numColsA = pSrcA->numCols;            /* number of columns of input matrix A */
+  uint16_t numRowsB = pSrcB->numRows;            /* number of rows of input matrix A    */
+  uint16_t col, i = 0u, row = numRowsB, colCnt;  /* loop counters */
+  arm_status status;                             /* status of matrix multiplication */
+
+#ifndef UNALIGNED_SUPPORT_DISABLE
+
+  q31_t in;                                      /* Temporary variable to hold the input value */
+  q31_t inA1, inA2, inB1, inB2;
+
+#else
+
+  q15_t in;                                      /* Temporary variable to hold the input value */
+  q15_t inA1, inA2, inB1, inB2;
+
+#endif    /*    #ifndef UNALIGNED_SUPPORT_DISABLE    */
+
+#ifdef ARM_MATH_MATRIX_CHECK
+  /* Check for matrix mismatch condition */
+  if((pSrcA->numCols != pSrcB->numRows) ||
+     (pSrcA->numRows != pDst->numRows) || (pSrcB->numCols != pDst->numCols))
+  {
+    /* Set status as ARM_MATH_SIZE_MISMATCH */
+    status = ARM_MATH_SIZE_MISMATCH;
+  }
+  else
+#endif
+  {
+    /* Matrix transpose */
+    do
+    {
+      /* Apply loop unrolling and exchange the columns with row elements */
+      col = numColsB >> 2;
+
+      /* The pointer px is set to starting address of the column being processed */
+      px = pSrcBT + i;
+
+      /* 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(col > 0u)
+      {
+#ifndef UNALIGNED_SUPPORT_DISABLE
+        /* Read two elements from the row */
+        in = *__SIMD32(pInB)++;
+
+        /* Unpack and store one element in the destination */
+#ifndef ARM_MATH_BIG_ENDIAN
+
+        *px = (q15_t) in;
+
+#else
+
+        *px = (q15_t) ((in & (q31_t) 0xffff0000) >> 16);
+
+#endif /*    #ifndef ARM_MATH_BIG_ENDIAN    */
+
+        /* Update the pointer px to point to the next row of the transposed matrix */
+        px += numRowsB;
+
+        /* Unpack and store the second element in the destination */
+#ifndef ARM_MATH_BIG_ENDIAN
+
+        *px = (q15_t) ((in & (q31_t) 0xffff0000) >> 16);
+
+#else
+
+        *px = (q15_t) in;
+
+#endif /*    #ifndef ARM_MATH_BIG_ENDIAN    */
+
+        /* Update the pointer px to point to the next row of the transposed matrix */
+        px += numRowsB;
+
+        /* Read two elements from the row */
+        in = *__SIMD32(pInB)++;
+
+        /* Unpack and store one element in the destination */
+#ifndef ARM_MATH_BIG_ENDIAN
+
+        *px = (q15_t) in;
+
+#else
+
+        *px = (q15_t) ((in & (q31_t) 0xffff0000) >> 16);
+
+#endif /*    #ifndef ARM_MATH_BIG_ENDIAN    */
+
+        /* Update the pointer px to point to the next row of the transposed matrix */
+        px += numRowsB;
+
+        /* Unpack and store the second element in the destination */
+
+#ifndef ARM_MATH_BIG_ENDIAN
+
+        *px = (q15_t) ((in & (q31_t) 0xffff0000) >> 16);
+
+#else
+
+        *px = (q15_t) in;
+
+#endif /*    #ifndef ARM_MATH_BIG_ENDIAN    */
+
+#else
+
+        /* Read one element from the row */
+        in = *pInB++;
+
+        /* Store one element in the destination */
+        *px = in;
+ 
+        /* Update the pointer px to point to the next row of the transposed matrix */
+        px += numRowsB;
+
+        /* Read one element from the row */
+        in = *pInB++;
+
+        /* Store one element in the destination */
+        *px = in;
+ 
+        /* Update the pointer px to point to the next row of the transposed matrix */
+        px += numRowsB;
+
+        /* Read one element from the row */
+        in = *pInB++;
+
+        /* Store one element in the destination */
+        *px = in;
+ 
+        /* Update the pointer px to point to the next row of the transposed matrix */
+        px += numRowsB;
+
+        /* Read one element from the row */
+        in = *pInB++;
+
+        /* Store one element in the destination */
+        *px = in;
+
+#endif    /*    #ifndef UNALIGNED_SUPPORT_DISABLE    */
+        
+        /* Update the pointer px to point to the next row of the transposed matrix */
+        px += numRowsB;
+
+        /* Decrement the column loop counter */
+        col--;
+      }
+
+      /* If the columns of pSrcB is not a multiple of 4, compute any remaining output samples here.        
+       ** No loop unrolling is used. */
+      col = numColsB % 0x4u;
+
+      while(col > 0u)
+      {
+        /* Read and store the input element in the destination */
+        *px = *pInB++;
+
+        /* Update the pointer px to point to the next row of the transposed matrix */
+        px += numRowsB;
+
+        /* Decrement the column loop counter */
+        col--;
+      }
+
+      i++;
+
+      /* Decrement the row loop counter */
+      row--;
+
+    } while(row > 0u);
+
+    /* Reset the variables for the usage in the following multiplication process */
+    row = numRowsA;
+    i = 0u;
+    px = pDst->pData;
+
+    /* The following loop performs the dot-product of each row in pSrcA with each column in pSrcB */
+    /* row loop */
+    do
+    {
+      /* For every row wise process, the column loop counter is to be initiated */
+      col = numColsB;
+
+      /* For every row wise process, the pIn2 pointer is set        
+       ** to the starting address of the transposed pSrcB data */
+      pInB = pSrcBT;
+
+      /* column loop */
+      do
+      {
+        /* Set the variable sum, that acts as accumulator, to zero */
+        sum = 0;
+
+        /* Apply loop unrolling and compute 2 MACs simultaneously. */
+        colCnt = numColsA >> 2;
+
+        /* Initiate the pointer pIn1 to point to the starting address of the column being processed */
+        pInA = pSrcA->pData + i;
+
+        /* matrix multiplication */
+        while(colCnt > 0u)
+        {
+          /* c(m,n) = a(1,1)*b(1,1) + a(1,2) * b(2,1) + .... + a(m,p)*b(p,n) */
+#ifndef UNALIGNED_SUPPORT_DISABLE
+
+          inA1 = *__SIMD32(pInA)++;
+          inB1 = *__SIMD32(pInB)++;
+          inA2 = *__SIMD32(pInA)++;
+          inB2 = *__SIMD32(pInB)++;
+
+          sum = __SMLAD(inA1, inB1, sum);
+          sum = __SMLAD(inA2, inB2, sum);
+
+#else
+
+          inA1 = *pInA++;
+          inB1 = *pInB++;
+          inA2 = *pInA++;
+          sum += inA1 * inB1;
+          inB2 = *pInB++;
+
+          inA1 = *pInA++;
+          inB1 = *pInB++;
+          sum += inA2 * inB2;
+          inA2 = *pInA++;
+          inB2 = *pInB++;
+
+          sum += inA1 * inB1;
+          sum += inA2 * inB2;
+
+#endif    /*    #ifndef UNALIGNED_SUPPORT_DISABLE    */
+
+          /* Decrement the loop counter */
+          colCnt--;
+        }
+
+        /* process odd column samples */
+        colCnt = numColsA % 0x4u;
+
+        while(colCnt > 0u)
+        {
+          /* c(m,n) = a(1,1)*b(1,1) + a(1,2) * b(2,1) + .... + a(m,p)*b(p,n) */
+          sum += (q31_t) (*pInA++) * (*pInB++);
+
+          colCnt--;
+        }
+
+        /* Saturate and store the result in the destination buffer */
+        *px = (q15_t) (sum >> 15);
+        px++;
+
+        /* Decrement the column loop counter */
+        col--;
+
+      } while(col > 0u);
+
+      i = i + numColsA;
+
+      /* Decrement the row loop counter */
+      row--;
+
+    } while(row > 0u);
+
+    /* set status as ARM_MATH_SUCCESS */
+    status = ARM_MATH_SUCCESS;
+  }
+
+  /* Return to application */
+  return (status);
+}
+
+/**        
+ * @} end of MatrixMult group        
+ */