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Unformatted text preview: produced value Ú . Any operation waiting for Ø as a source will then use Ú as the source value. By this mechanism, values can be passed directly from one operation to another, rather than being written to and read from the register ﬁle. The renaming table only contains entries for registers having pending write operations. When a decoded instruction requires a register Ö , and there is no tag associated with this register, the operand is retrieved directly from the register ﬁle. With register renaming, an entire sequence of operations can be performed speculatively, even though the registers are updated only after the processor is certain of the branch outcomes. 5.7.2 Functional Unit Performance
Figure 5.12 documents the performance of some of basic operations for an Intel Pentium III. These timings are typical for other processors as well. Each operation is characterized by two cycle counts: the latency, indicating the total number of cycles the functional unit requires to complete the operation; and the issue...
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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
- The American