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Unformatted text preview: ins, indicating two series of computations that must be performed in sequence. The chain on the left processes the data, ﬁrst reading an array element from memory and then multiplying it times the accumulated product. The chain on the right processes the loop index i, ﬁrst incrementing it and then comparing it to length. The jump operation checks the result of this comparison to make sure the branch was correctly predicted. Note that there are no outgoing arrows 228 CHAPTER 5. OPTIMIZING PROGRAM PERFORMANCE
%edx.0 Execution Unit Operations load (%eax, %edx.0, 4) addl t.1, %ecx.0 incl %edx.0 cmpl %esi, %edx.1 jl-taken cc.1 load incl
%ecx.i +1 cmpl cc.1 %edx.1 t.1 %ecx.1 %edx.1 cc.1 load
%ecx.0 t.1 jl addl
%ecx.1 Figure 5.14: Operations for First Iteration of Inner Loop of combine4 for Integer Addition. Compared to multiplication, the only change is that the addition operation requires only one cycle. from the jump operation box. If the branch was correctly predicted, no other processing i...
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