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cfftf output -1.0#QNAN when measuring cycles

Question asked by Jhon on Jul 25, 2017
Latest reply on Aug 2, 2017 by Kader.M

CCES2.6.0, SC584

I use code like below to measure the speed of 1024-points cfftf, but the output in fft_buf_r and fft_buf_i are all -1.0#QNAN. When I comment out the CYCLES_xxx lines, I get the right answers.128-points cfftf don't have this problem.

 

#define DO_CYCLE_COUNTS
#include <cycles.h>
#include <sys/cache.h>

 

static cycle_stats_t cycles;

 

#pragma align 1024
static float dm fft_buf_r[1024];
#pragma align 1024
static float pm fft_buf_i[1024];

float dm twid_1024r[1024/2];
float pm twid_1024i[1024/2];

float dm temp_r[1024];
float pm temp_i[1024+1];

 

CYCLES_INIT(cycles);
CYCLES_START(cycles);

cfftf(fft_buf_r, fft_buf_i, temp_r, temp_i, twid_1024r, twid_1024i, 1024);

CYCLES_STOP(cycles);
printf("FFT1024: %"PRIu32" \n\n", (uint32_t)(cycles._cycles));

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