Unformatted text preview: consisting of various patterns of of ·½s and ½s. For regular patterns (e.g., all ·½s, all ½s, or alternating ·½ and ½s), we ﬁnd the function requires between 13.01 and 13.41 cycles. We use this as our estimate of the performance with perfect branch condition. On an array set to random patterns of ·½s and ½s, we ﬁnd that the function requires 20.32 cycles. One principle of random processes is that no matter what strategy one uses to guess a sequence of values, if the underlying process is truly random, then we will be right only 50% of the time. For example, no matter what strategy one uses to guess the outcome of a coin toss, as long as the coin toss is fair, our probability of success is only 0.5. Thus, we can see that a mispredicted branch with this processor incurs a penalty of around 14 clock cycles, since a misprediction rate of 50% causes the function to run an average of 7 cycles slower. This means that calls to absval require between 13 and 27 cycles depending on the success of the branch pre...
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This note was uploaded on 09/02/2010 for the course ELECTRICAL 360 taught by Professor Schultz during the Spring '10 term at BYU.
 Spring '10
 Schultz
 The American, Gulliver's Travels, 2.2.5 2.2.6 2.2.7 2.3 2.3.1 2.3.2 2.3.3 2.3.4 2.3.5

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