Mini-optimization to AccuracyOp
Mini-optimization to AccuracyOp

Summary: For k-top accuracy, if the correct prediction does not make into the k-sized priority queue, it is not going to be in the top-K, so we can short circuit.

Reviewed By: Yangqing

Differential Revision: D4555637

fbshipit-source-id: 7f07787f853f1c6b4024e279dcc6920d28bdde3d

Yangqing/caffe2,sf-wind/caffe2,xzturn/caffe2,bwasti/caffe2,xzturn/caffe2,bwasti/caffe2,pietern/caffe2,xzturn/caffe2,Yangqing/caffe2,sf-wind/caffe2,davinwang/caffe2,pietern/caffe2,davinwang/caffe2,sf-wind/caffe2,bwasti/caffe2,pietern/caffe2,pietern/caffe2,Yangqing/caffe2,sf-wind/caffe2,bwasti/caffe2,caffe2/caffe2,bwasti/caffe2,davinwang/caffe2,davinwang/caffe2,pietern/caffe2,Yangqing/caffe2,sf-wind/caffe2,davinwang/caffe2,xzturn/caffe2,Yangqing/caffe2,xzturn/caffe2