Analogy To Branch Prediction
Memory dependence prediction for loads and stores is analogous to branch prediction for conditional branch instructions. In branch prediction, the branch predictor predicts which way the branch will resolve before it is known. The processor can then speculatively fetch and execute instructions down one of the paths of the branch. Later, when the branch instruction executes, it can be determined if the branch instruction was correctly predicted. If not, this is a branch misprediction, and a pipeline flush is necessary to throw away instructions that were speculatively fetched and executed.
Branch prediction can be thought of as a two step process. First, the predictor determines the direction of the branch (taken or not). This is a binary decision. Then, the predictor determines the actual target address. Similarly, memory dependence prediction can be thought of as a two step process. First, the predictor determines whether there is a dependence. Then it determines which this dependence is.
Read more about this topic: Memory Dependence Prediction
Famous quotes containing the words analogy to, analogy, branch and/or prediction:
“The whole of natural theology ... resolves itself into one simple, though somewhat ambiguous proposition, That the cause or causes of order in the universe probably bear some remote analogy to human intelligence.”
—David Hume (1711–1776)
“The analogy between the mind and a computer fails for many reasons. The brain is constructed by principles that assure diversity and degeneracy. Unlike a computer, it has no replicative memory. It is historical and value driven. It forms categories by internal criteria and by constraints acting at many scales, not by means of a syntactically constructed program. The world with which the brain interacts is not unequivocally made up of classical categories.”
—Gerald M. Edelman (b. 1928)
“When I am finishing a picture I hold some God-made object up to it—a rock, a flower, the branch of a tree or my hand—as a kind of final test. If the painting stands up beside a thing man cannot make, the painting is authentic. If there’s a clash between the two, it is bad art.”
—Marc Chagall (1889–1985)
“Recent studies that have investigated maternal satisfaction have found this to be a better prediction of mother-child interaction than work status alone. More important for the overall quality of interaction with their children than simply whether the mother works or not, these studies suggest, is how satisfied the mother is with her role as worker or homemaker. Satisfied women are consistently more warm, involved, playful, stimulating and effective with their children than unsatisfied women.”
—Alison Clarke-Stewart (20th century)