函数说明
void DSPF_sp_fftSPxSP ( int N, float * ptr_x, float * ptr_w, float * ptr_y, unsigned char * brev, int n_min, int offset, int n_max )
The benchmark performs a mixed radix forwards fft.
Parameters:
N length of FFT in complex samples ptr_x pointer to complex data input ptr_w pointer to complex twiddle factor ptr_y pointer to complex output data brev pointer to bit reverse table containing 64 entries n_min should be 4 if N can be represented as Power of 4 else, n_min should be 2 offset index in complex samples of sub-fft from start of main fft n_max size of main fft in complex samples
Algorithm:
DSPF_sp_fftSPxSP_cn.c is the natural C equivalent of the optimized linear assembly code without restrictions. Note that the linear assembly code is optimized and restrictions may apply.
Assumptions:
N needs to be power of 28 <= N <= 131072, 32 <= N for linear assembly implementationArrays pointed by ptr_x, ptr_w, and ptr_y should not overlapArrays pointed by ptr_x, ptr_w, and ptr_y should align on the double words boundary
Implementation Notes:
Interruptibility: The code is interrupt-tolerant but not interruptible.Endian Support: The code supports both big and little endian modes.
但是我看到TI库里的例子却是#pragma DATA_ALIGN(x_i, 8); 这样写的8字节对齐,我的意思double Words 不就是4字节对齐么 为什么会写8???
Shine:
double数据类型是64bit的,所以double words boundary是8字节对齐。
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user5329195:
谢谢 !我原以为是2个WORDS类型的呢!!!
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user5352634:
如果用了数据地址对齐,在6748中,会报以下错误。请问有没有解决办法?
error #10099-D: program will not fit into available memory. placement wirh alignment fails for section ".text" size 0x8440. Available memory ranges:
SARAH size:0x1f000 unused:0x8478 maxhole:0x8478
error#10010:errors encountered during linking;