{"id":206958,"date":"2025-07-08T09:52:55","date_gmt":"2025-07-08T01:52:55","guid":{"rendered":"https:\/\/server.hk\/cnblog\/206958\/"},"modified":"2025-07-08T09:52:55","modified_gmt":"2025-07-08T01:52:55","slug":"%e4%bb%8e%e6%8c%87%e6%95%b0%e5%92%8c%e6%9c%89%e6%95%88%e6%95%b0%e5%88%9b%e5%bb%ba%e6%b5%ae%e7%82%b9%e6%95%b0","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/206958\/","title":{"rendered":"\u4ece\u6307\u6570\u548c\u6709\u6548\u6570\u521b\u5efa\u6d6e\u70b9\u6570"},"content":{"rendered":"

<\/b> <\/p>\n

\u5f53\u524d\u4f4d\u7f6e\uff1a ><\/span> ><\/span> ><\/span> ><\/span> \u4ece\u6307\u6570\u548c\u6709\u6548\u6570\u521b\u5efa\u6d6e\u70b9\u6570<\/span><\/p>\n

\u6765\u6e90\uff1astackoverflow<\/span>
\n2024-04-19 08:09:37<\/span>
\n<\/i>0\u6d4f\u89c8<\/span>
\n<\/i>\u6536\u85cf<\/span> <\/p>\n

\u4eca\u5929\u5c06\u7ed9\u5927\u5bb6\u5e26\u6765\u300a\u4ece\u6307\u6570\u548c\u6709\u6548\u6570\u521b\u5efa\u6d6e\u70b9\u6570\u300b<\/span>\uff0c\u611f\u5174\u8da3\u7684\u670b\u53cb\u8bf7\u7ee7\u7eed\u770b\u4e0b\u53bb\u5427\uff01\u4ee5\u4e0b\u5185\u5bb9\u5c06\u4f1a\u6d89\u53ca\u5230<\/span>\u7b49\u7b49\u77e5\u8bc6\u70b9\uff0c\u5982\u679c\u4f60\u662f\u6b63\u5728\u5b66\u4e60Golang<\/span>\u6216\u8005\u5df2\u7ecf\u662f\u5927\u4f6c\u7ea7\u522b\u4e86\uff0c\u90fd\u975e\u5e38\u6b22\u8fce\u4e5f\u5e0c\u671b\u5927\u5bb6\u90fd\u80fd\u7ed9\u6211\u5efa\u8bae\u8bc4\u8bba\u54c8~\u5e0c\u671b\u80fd\u5e2e\u52a9\u5230\u5927\u5bb6\uff01<\/p>\n

\u95ee\u9898\u5185\u5bb9
\n <\/p>\n

\u7ed9\u5b9a\u6574\u6570 exp<\/code> \u548c 0<=sig<2^52<\/code>\uff0c\u5982\u4f55\u521b\u5efa\u4ee5 exp<\/code> \u4f5c\u4e3a\u6307\u6570\u4e14\u5176\u6709\u6548\u4f4d\u6570\u4e0e sig<\/code> \u7684\u4e8c\u8fdb\u5236\u8868\u793a\u5f62\u5f0f\u76f8\u540c\u7684 float64\uff08\u5728 Go \u4e2d\uff09\uff1f<\/p>\n

<\/p>\n

\u89e3\u51b3\u65b9\u6848<\/h2>\n

<\/p>\n

\u5b9a\u4e49\u4e86 go \u7528\u4e8e\u6d6e\u70b9\u6570\u7684\u6d6e\u70b9\u7b97\u672f\uff0c\u4f8b\u5982 float32<\/code> \u548c float64<\/code> \uff08\u5c31\u50cf\u51e0\u4e4e\u4efb\u4f55\u5176\u4ed6\u8bed\u8a00\u4e00\u6837\uff09\u3002<\/p>\n

\u7531\u4e8e\u60a8\u7684\u6709\u6548\u6570\u5b57\u53ef\u80fd\u9ad8\u8fbe 52 \u4f4d\uff0c\u56e0\u6b64\u663e\u7136\u5b83\u53ea\u80fd\u4f7f\u7528 float64<\/code> \u503c\u6765\u8868\u793a\u3002<\/p>\n

\u4e2d\u63cf\u8ff0\u4e86 float64<\/code> \u503c\u7684\u5185\u5b58\u5e03\u5c40\uff08\u4f4d\uff09\u3002<\/p>\n

\u8fd9\u662f float64<\/code> \u503c\u7684\u4f4d\u56fe\u7247\uff08\u53d6\u81ea\u7ef4\u57fa\u767e\u79d1\uff09\uff1a<\/p>\n

\u60a8\u58f0\u79f0\u60a8\u6709\u6307\u6570\u503c\u548c\u6709\u6548\u6570\uff08\u5373\u5c0f\u6570\u90e8\u5206\uff09\u3002<\/p>\n

\u60a8\u53ef\u4ee5\u4f7f\u7528\u7b80\u5355\u7684\u6309\u4f4d\u7b97\u672f\u6765\u6784\u9020\u6d6e\u70b9\u6570\u7684 64 \u4f4d\u503c\uff0c\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n

bits := exp<<52 | sig<\/pre>\n
\uff08\u6ce8\u610f\uff1aexp<\/code> \u548c sig<\/code> \u7684\u7c7b\u578b\u5e94\u4e3a uint64<\/code>\u3002\u5982\u679c\u4e0d\u662f\uff0c\u8bf7\u4f7f\u7528\u7c7b\u578b\u8f6c\u6362\u3002\uff09<\/p>\n
\u83b7\u5f97\u8fd9\u4e9b\u4f4d\u540e\uff0c\u60a8\u53ef\u4ee5\u4f7f\u7528 \u51fd\u6570\u5c06\u5176\u83b7\u53d6\u4e3a float64<\/code> \u503c\uff1a<\/p>\n
f := math.Float64frombits(bits)<\/pre>\n
\u8bf7\u6ce8\u610f\uff0c\u5185\u5b58\u5e03\u5c40\u7684\u6307\u6570\u503c\u4e0d\u662f\u60a8\u5728\u8ba1\u7b97\u6570\u5b57\u503c\u65f6\u5fc5\u987b\u4f7f\u7528\u7684\u201c\u76f4\u63a5\u201d\u6570\u5b57\uff0c\u800c\u662f\uff1a<\/p>\n
\u53cc\u7cbe\u5ea6\u4e8c\u8fdb\u5236\u6d6e\u70b9\u6307\u6570\u91c7\u7528\u8868\u793a\u5f62\u5f0f\u7f16\u7801\uff0c\u96f6\u504f\u79fb\u91cf\u4e3a1023\uff1b\u5728 ieee 754 \u6807\u51c6\u4e2d\u4e5f\u79f0\u4e3a\u6307\u6570\u504f\u5dee\u3002<\/p>\n
\u56e0\u6b64\uff0c\u4ee5\u4e0a\u8ff0\u53cc\u7cbe\u5ea6\u683c\u5f0f\u7f16\u7801\u7684\u6570\u5b57\u7684\u8ba1\u7b97\u65b9\u5f0f\u5982\u4e0b\uff1a<\/p>\n
(-1)\u7b26\u53f7<\/sup> x 2e-1023<\/sup> x 1.fraction<\/p>\n
\u4ee5\u4e0a\u5c31\u662f\u300a\u4ece\u6307\u6570\u548c\u6709\u6548\u6570\u521b\u5efa\u6d6e\u70b9\u6570\u300b\u7684\u8be6\u7ec6\u5185\u5bb9\uff0c\u66f4\u591a\u5173\u4e8e\u7684\u8d44\u6599\u8bf7\u5173\u6ce8\u516c\u4f17\u53f7\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"
\u5f53\u524d\u4f4d\u7f6e\uff1a > > ...<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4925],"tags":[],"class_list":["post-206958","post","type-post","status-publish","format-standard","hentry","category-4925"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/206958","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=206958"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/206958\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=206958"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=206958"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=206958"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}