Fix npairloss bug

[supplyout]

PR types

Bug fixes

PR changes

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Describe

#49919
#49927

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[luotao1]

请问是和以下PR一个队么？

• fix zero bug of case18: paddle.logsumexp #51034

[supplyout]

请问是和以下PR一个队么？

• fix zero bug of case18: paddle.logsumexp #51034

是的,队名叫442power

[veyron95]

LGTM

[luotao1]

hi, @supplyout

• 非常感谢你对飞桨框架的贡献，我们正在运营一个PFCC组织，会通过定期分享技术知识与发布开发者主导任务的形式持续为飞桨框架做贡献，详情可见 /~https://github.com/luotao1 主页说明。
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