FPU实验：BasicMathFunctions之求和

stm32f4

说明：基本函数里面做浮点数的运算很简单，该怎么算就怎么算，而定点数可能使用一些汇编指令

1. /**   
2. * @defgroup BasicAdd Vector Addition   
3. *   
4. * Element-by-element addition of two vectors.   
5. *   
6. * <pre>   
7. *     pDst[n] = pSrcA[n] + pSrcB[n],   0 <= n < blockSize.   
8. * </pre>   
9. *   
10. * There are separate functions for floating-point, Q7, Q15, and Q31 data types.   
11. */
13. /**   
14. * @addtogroup BasicAdd   
15. * @{   
16. */
18. /**   
19. * @brief Floating-point vector addition.   
20. * @param[in]       *pSrcA points to the first input vector   
21. * @param[in]       *pSrcB points to the second input vector   
22. * @param[out]      *pDst points to the output vector   
23. * @param[in]       blockSize number of samples in each vector   
24. * @return none.   
25. */
27. void arm_add_f32(
28.   float32_t * pSrcA,
29.   float32_t * pSrcB,
30.   float32_t * pDst,
31.   uint32_t blockSize)
32. {
33.   uint32_t blkCnt;                               /* loop counter */
35. #ifndef ARM_MATH_CM0
37. /* Run the below code for Cortex-M4 and Cortex-M3 */
39.   /*loop Unrolling */
40.   blkCnt = blockSize >> 2u;
42.   /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.   
43.    ** a second loop below computes the remaining 1 to 3 samples. */
44.   while(blkCnt > 0u)
45.   {
46.     /* C = A + B */
47.     /* Add and then store the results in the destination buffer. */
48.     *pDst++ = (*pSrcA++) + (*pSrcB++);
49.     *pDst++ = (*pSrcA++) + (*pSrcB++);
50.     *pDst++ = (*pSrcA++) + (*pSrcB++);
51.     *pDst++ = (*pSrcA++) + (*pSrcB++);
53.     /* Decrement the loop counter */
54.     blkCnt--;
55.   }
57.   /* If the blockSize is not a multiple of 4, compute any remaining output samples here.   
58.    ** No loop unrolling is used. */
59.   blkCnt = blockSize % 0x4u;
61. #else
63.   /* Run the below code for Cortex-M0 */
65.   /* Initialize blkCnt with number of samples */
66.   blkCnt = blockSize;
68. #endif /* #ifndef ARM_MATH_CM0 */
70.   while(blkCnt > 0u)
71.   {
72.     /* C = A + B */
73.     /* Add and then store the results in the destination buffer. */
74.     *pDst++ = (*pSrcA++) + (*pSrcB++);
76.     /* Decrement the loop counter */
77.     blkCnt--;
78.   }
79. }

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