Two more examples, from ActiveState 5.8.2 build 808 and Strawberry 5.10.0.5, with identical output from both versions (note slightly greater precision used in  printf statement, and no negative zeros):

>perl -wMstrict -le
"for (-2.0,-1.9,-1.5,-1.1,-1.0,-0.9,-0.5,-0.1,-0) {
   my $v = $_ * 0;
   printf(qq{%5s -> %2s,%32.24e\n},$_,$v,$v);
   }
"
   -2 ->  0, 0.000000000000000000000000e+000
 -1.9 ->  0, 0.000000000000000000000000e+000
 -1.5 ->  0, 0.000000000000000000000000e+000
 -1.1 ->  0, 0.000000000000000000000000e+000
   -1 ->  0, 0.000000000000000000000000e+000
 -0.9 ->  0, 0.000000000000000000000000e+000
 -0.5 ->  0, 0.000000000000000000000000e+000
 -0.1 ->  0, 0.000000000000000000000000e+000
    0 ->  0, 0.000000000000000000000000e+000
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