CCS/AWR1843BOOST: The initialization of variable j in the function arrangeTracksByAge

Rata Zhang

Part Number: AWR1843BOOST

Tool/software: Code Composer Studio

Hi,

There is a function called arrangeTracksByAge in kalman filtering algorithm of the MRR demo.

void arrangeTracksByAge(KFstate_t * restrict TrackList, const uint32_t numTracksTotal)
{
    KFstate_t * currTrackFwd = &TrackList[0];
    KFstate_t * currTrackRev = &TrackList[numTracksTotal-1];
    KFstate_t temp;
    uint32_t numTracks = numTracksTotal;
    uint32_t i, j;

    /* For each track, assign the newer tracks to the bottom of the list. Copy the older tracks
     * to the beginning. */
    for (i = 0; i < numTracksTotal; i++)
    {

.....

}

In this function the variable j is uninitialized. Is the default value for the uninitialized variable zero in the DSP system?If not, whether the variable j should be initialized as 0.

Thanks,

Regards,

Rata

over 5 years ago

0 Cesar over 5 years ago

TI__Guru*** 147894 points

Hi,

I checked the code. the variable J is initialized in the function as below

thank you

Cesar

    /* For each track, assign the newer tracks to the bottom of the list. Copy the older tracks
     * to the beginning. */
    for (i = 0; i < numTracksTotal; i++)
    {
        if ((currTrackFwd->validity == IS_VALID) && (currTrackFwd->tick < 10))
        {
            for (j = 0; j < numTracks-(i+1); j++)
            {
                if ((currTrackRev->tick >= 10) && (currTrackFwd->validity == IS_VALID))
                {
                    temp = * currTrackRev;
                    *currTrackRev = *currTrackFwd;
                    *currTrackFwd = temp;
                    currTrackRev--; j++;
                    break;
                }
                else
                {
                    currTrackRev--;
                }
            }
            numTracks -= j;
        }

        if (j >= numTracks)
        {
            break;
        }
        currTrackFwd ++ ;
    }
}

0 Rata Zhang over 5 years ago in reply to Cesar

Expert 2840 points

Hi Cesar,

Yes, it is. The function is as follows:

...

if (j >= numTracks)
        {
            break;
        }
        currTrackFwd ++ ;
    }
}

But there is one case that

(1) for i=0, the condition ((currTrackFwd->validity == IS_VALID) && (currTrackFwd->tick < 10)) is not satisfied,

(2) at the same time the default value of j is greater than or equal to numTracks (equal to numTracksTotal),

then the loop for (i = 0; i < numTracksTotal; i++) will be performed only once.

Then I think the variable j should be initialized as 0 when it is declared.

Thanks,

Regards,

Rata

0 Anil Mani over 5 years ago in reply to Rata Zhang

TI__Expert 4720 points

Hi Rata,

It looks like a corner case, and should be fixed. Thank you for finding it.

Regards

Anil

0 Rata Zhang over 5 years ago in reply to Anil Mani

Expert 2840 points

Hi Anil,

Thanks for your reply, I got it.

BR,

Rata

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CCS/AWR1843BOOST: The initialization of variable j in the function arrangeTracksByAge