The branch processor can arrange the execution of up to 5 ipc. A superscalar processor can fetch, decode, execute, and retire, e. Chapter 16 instructionlevel parallelism and superscalar processors luis tarrataca luis. A typical superscalar processor fetches and decodes the incoming instruction. With this superscalar design, several instructions can execute at once. Superscalar processors exploit both forms of parallelism to squeeze out performance far exceeding that of our singlecycle and multicycle processors. A superscalar processor is one that is capable of sustaining an instruction execution rate of more than one instruction per clock cycle. Superscalar instruction execution in the 21164 alpha microprocessor. Actual computation overwhelmed by overhead of aggressive execution pipeline. Maintaining this execution rate is primarily a problem of scheduling processor resources such as functional units for highutilrzation. A typical superscalar processor fetches and decodes the incoming instruction stream several instructions at a time. Superscalar architecture exploit the potential of ilpinstruction level parallelism. A simultaneous multithreading processor 33, 32, 17, 35 holds the state of multiple threads execution contexts in hardware, allowing the execution of.
Work on execute of one instruction in parallel with decode of next. Chapter 16 instructionlevel parallelism and superscalar. Pdf superscalar execution with dynamic data forwarding. Definition and characteristics superscalar processing is the ability to initiate multiple instructions during the same clock cycle. Ibm announced this superscalar risc system in 1990. In the traditional processor pipeline model under ideal circumstances one new instruction enters the processors and one instruction completes execution each cycle. A superscalar processor is one that is capable of sustaining an instructionexecution rate of more than one instruction per clock cycle. Thus, for the best case the processor can have an average execution rate of one clock per instruction. Superscalar execution with dynamic data forwarding conference paper pdf available in parallel architectures and compilation techniques conference. Superscalar execution 11 a typical dualissue pipeline multiported register file larger area, latency, power, cost, complexity multiple execution units simple alus are easy, but bypass paths are expensive memory unit single load per cycle stall at decode probably okay for dual issue. Multiple execution units is a case of spatial parallelism.
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