December 2016
Intermediate to advanced
440 pages
9h 44m
Japanese
Content preview from アルゴリズムクイックリファレンス 第2版
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3.4
浮動小数点計算
■
41
3.4.1
性能
整数値の計算は、浮動小数点の場合よりも効率的だと一般に受け止められている。
表3-1は、
1
千万回の演算の計算時間を示す。表には、（本書初版の）
Linux
の結果
と
1996
年製
SPARC Ultra-2
の結果を含めてある。ご覧の通り、個別演算の性能
は、プラットフォームごとに大きく異なる。この結果は、この
20
年間のプロセッサ
の驚異的な性能改善を示す。いくつかの結果は既存の計測メカニズムよりも速いた
めに、
0.0000
となっている。
表3-1 1千万回の演算の性能計算
演算 SparcUltra-2（秒） Linuxi686（秒） 最新（秒）
32
ビット整数
CMP 0.811 0.0337 0.0000
32
ビット整数
MUL 2.372 0.0421 0.0000
32
ビット単精度浮動小数点数
MUL 1.236 0.1032 0.02986
64
ビット倍精度浮動小数点数
MUL 1.406 0.1028 0.02987
32
ビット単精度浮動小数点数
DIV 1.657 0.1814 0.02982
64
ビット倍精度浮動小数点数
DIV 2.172 0.1813 0.02980
128
ビット倍精度浮動小数点数
MU 36.891 0.2765 0.02434
32
ビット整数
DIV 3.104 0.2468 0.0000
32
ビット倍精度浮動小数点数
SQRT 3.184 0.2749 0.0526
3.4.2
丸め誤差
浮動小数点値を使う計算では、浮動小数点表現の性質に ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.