the float array in DDR3 channing (C6748)

Hello, experts,

My platform is  C6748.

It is puzzling that I define a float arrar in DDR3, code like below:

float data[100000];

//...other code
for(i=0; i<100000; i++)
{
    data[i] = 1.1;
}

but when I check the data[ ] array with emulator, I found it is not exactly 1.1. It become like below:

1.1

1.1 

1.1

1.099999

1.100001

1.099998

1.100002

1.099997

1.100003

...

Seems that the array was offset more and more with index adding.

This destroy my FFT resutl.

What's the problem?