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explanations on compiler annotations needed

Question asked by vix on Oct 14, 2009
Latest reply on Oct 14, 2009 by SeanM

When I compile the following code

 

float ftemp, ftemp2=0.0, buf[20];

int i;

for(i=0; i<20; i++){
      ftemp = powf(buf[i], 2.0);
      ftemp2 += ftemp;
}

 

with VisualDSP++ 5.0 Update 6 for ADSP-BF527, I have the following compiler annotations (double clicking over the "i" on the for( ) line)

 

[Info] This loop executes 1 iteration of the original loop in estimated 27 cycles.
[Info] cycle count 27 excludes the cost of the inner function calls and it includes 7 stalls
[Info] This loop's resource usage is:
       //     Group 1             used  19 out of   27 ( 70.4%)
       //     16-bit Instruction  used  28 out of   54 ( 51.9%)
       //     32-bit Instruction  used   9 out of   27 ( 33.3%)
       //     Store               used   3 out of   27 ( 11.1%)

 

What does the resource usage mean?

Group 1 + 16-bit + 32-bit + Store = 59 (grater than 27 cycles)

70.4% + 51.9% + 33.3% + 11.1% = 166.7%!!!!

Could someone explain me what this [Info] lines mean?

 

Thanks

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