Question

Consider program P, which runs on a 1GHz machine M in 10 seconds. An optimization is made to P, replacing all instances of multiplying a value by 4 (mult X, X, 4) with two instructions that set x = x + x twice. Call this new optimized program, P'. The CPI of a multiply instruction is 4, and the CPI of an 'add' is 1. After recompiling, the program now runs in 9 seconds on machine M. How many multiplies were replaced by the new compiler?

Name: consider program p which runs on a 1ghz machine m in 10 seconds an optimization is made to p replacing all instances of multiplying a value by 4 mult x x 4 with two instructions that set x x 03408
Uploaded: 2022-07-06T11:24:01-08:00
Duration: 1 min 33 s
Channel: Shaiju T
Description: consider program p which runs on a 1ghz machine m in 10 seconds an optimization is made to p replacing all instances of multiplying a value by 4 mult x x 4 with two instructions that set x x 03408

          Consider program P, which runs on a 1GHz machine M in 10 seconds. An optimization is made to P, replacing all instances of multiplying a value by 4 (mult X, X, 4) with two instructions that set x = x + x twice. Call this new optimized program, P'. The CPI of a multiply instruction is 4, and the CPI of an 'add' is 1. After recompiling, the program now runs in 9 seconds on machine M. How many multiplies were replaced by the new compiler?

Added by Miranda G.

University Physics with Modern Physics

Hugh D. Young 14th Edition

Instant Answer

Solved by Expert Shaiju T

07/06/2022

Step 1

Given that program P runs on a 1GHz machine in 10 seconds, we can calculate the total number of cycles executed as follows: Total cycles = 1GHz * 10 seconds = 10^9 cycles Show more…

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Consider program P, which runs on a 1GHz machine M in 10 seconds. An optimization is made to P, replacing all instances of multiplying a value by 4 (mult X, X, 4) with two instructions that set x = x + x twice. Call this new optimized program, P'. The CPI of a multiply instruction is 4, and the CPI of an 'add' is 1. After recompiling, the program now runs in 9 seconds on machine M. How many multiplies were replaced by the new compiler?