shikaku https://blog.hatena.ne.jp/shikaku/ shikaku's blog https://blog.systemjp.net/ C++ round()関数はめちゃ遅いらしい。試してないがSSE2で丸め処理 #include <xmmintrin.h> #include <emmintrin.h> float f; double d; int i; i = _mm_cvtss_si32(_mm_load_ss(&f)); i = _mm_cvtsd_si32(_mm_load_sd(&d)); ネタ元 http://nu-pan.hatenablog.com/entry/20140423/1398238518 190 <iframe src="https://hatenablog-parts.com/embed?url=https%3A%2F%2Fblog.systemjp.net%2Fentry%2F2018%2F07%2F06%2F093446" title="C/C++で四捨五入で浮動小数点を整数に丸める - shikaku&#39;s blog" class="embed-card embed-blogcard" scrolling="no" frameborder="0" style="display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;"></iframe> Hatena Blog https://hatena.blog 2018-07-06 09:34:46 rich https://blog.systemjp.net/entry/2018/07/06/093446 1.0 100%