Floating-Point Issue Queues

Figure 10-1 shows the five dispatch slots connected to issue queues for each of the functional units or groups of functional units. Figure 10-1 is actually oversimplified, since the true relationship between the dispatch slots, issue queues, and functional units is more complicated than depicted there. The actual physical issue queue configuration is a bit hard to explain in words, so Figure 10-4 shows how the floating-point issue queues really look.

The 970's floating-point issue queues

Figure 10-4. The 970's floating-point issue queues

Each of the floating-point execution units is fed by what I’ve called a logical issue queue. As you can see in Figure 10-4 ...

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