[理工] 計組-data dependency

看板Grad-ProbAsk作者SiriusCloud (古月小楓)時間14年前 (2011/11/13 00:36)推噓3(3推 0噓 7→)

留言10則, 3人參與討論串1/2 (看更多)

Given 4 instructions , how many unique comparions (between register source and destinations) are necessary to find all of the RAW,WAR,WAW data dependences, Answer for the case of 4 instructions , and then derive a general equations for N instructions . Assume that all instructions have one register destination and two register source. (answer) For four instructions , the number of unique comparions: (2(3) + 2(2) + 2(1)) + (2(3) + 2(2) + 2(1)) + (3 + 2 + 1 ) = 30 ^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^ ↑RAW ↑WAR ↑WAW n-1 The general equation for N instructions = 5 * Σ i = (5*(n -1)*n) / 2 i=1 想請問的是4道指令答案是怎麼推導的呢？還有一般式如何推導出來？ -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 114.41.129.247

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CrazyBoss

11/13 01:26, , 1^F

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CrazyBoss

11/13 01:26, , 2^F

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CrazyBoss

11/13 01:26, , 3^F

11/13 01:26, 3^F