Question 1

The simplest instruction issue policy is to issue instructions in the exact order that would be achieved by sequential execution (in- order issue)and to write results in that same order (in-order completion).

Accepted Answer

The statement accurately describes the in-order issue policy, where instructions are issued and completed in the order they are encountered in program execution.

Question 2

ARM architecture has yet to implement superscalar techniques in the instruction pipeline.

Accepted Answer

ARM architecture has indeed implemented superscalar techniques in the instruction pipeline. Superscalar execution is a feature of ARM's Cortex-A processors that allows multiple instructions to be executed simultaneously.

Question 3

Machine parallelism exists when instructions in a sequence are independent and thus can be executed in parallel by overlapping.

Accepted Answer

False

Question 4

The situation where the second instruction needs data produced by the first instruction to execute is referred to as __________.
A)true data dependency
B)output dependency
C)procedural dependency
D)antidependency

Accepted Answer

A true data dependency occurs when the output of one instruction is used as input in another instruction. In this situation, the second instruction cannot execute until the first instruction produces its output. This is also known as a RAW (Read After Write) hazard. Option B, output dependency, is also a type of dependency but it occurs when the output of an instruction is used as input in a later instruction without any changes made to it. Option C, procedural dependency, is not a type of dependency in computer architecture. Option D, antidependency, occurs when the order of execution of instructions needs to be reversed to maintain correct output.

Question 5

The superscalar approach can be used on __________ architecture.
A)RISC
B)CISC
C)neither RISC nor CISC
D)both RISC and CISC

Accepted Answer

The superscalar approach can be used on both RISC and CISC architecture. Superscalar processors can execute multiple instructions simultaneously, and both RISC and CISC architectures support this kind of parallelism. However, the implementation of superscalar architecture may differ in RISC and CISC architectures.

Question 6

Which of the following is a fundamental limitation to parallelism with which the system must cope?
A)procedural dependency
B)resource conflicts
C)antidependency
D)all of the above

Accepted Answer

Procedural dependency, resource conflicts, and antidependency are all fundamental limitations to parallelism that must be addressed by the system for effective parallel processing. Therefore, the correct answer is D (all of the above).

Question 7

In-order completion requires more complex instruction issue logic than out-of-order completion.

Accepted Answer

In-order completion refers to the process where instructions are completed in the order they were issued, which is simpler to implement compared to out-of-order completion, where instructions can be completed in any order, requiring more complex logic to track dependencies and manage resources.

Question 8

The superscalar approach depends on the ability to execute multiple instructions in parallel.

Accepted Answer

Superscalar approach allows multiple instructions to be executed in parallel, therefore it depends on the ability to execute multiple instructions in parallel.

Question 9

Register renaming eliminates antidependencies and output dependencies.

Accepted Answer

Register renaming involves assigning independent physical registers to each instruction's operands, thereby eliminating antidependencies (also known as false dependencies) and output dependencies. This allows for better instruction scheduling and potentially higher performance in modern processors.

Question 10

The reorder buffer is temporary storage for results completed out of order that are then committed to the register file in program order.

Accepted Answer

This is an accurate description of the function of a reorder buffer.

Question 11

The instructions following a branch have a _________ on the branch and cannot be executed until the branch is executed.
A)resource dependency
B)procedural dependency
C)output dependency
D)true data dependency

Accepted Answer

Procedural dependency occurs because the instructions following a branch depend on the execution of the branch instruction to determine the correct execution path. This means they cannot be executed until the branch decision is made, indicating a procedural dependency on the branch.

Question 12

In effect,the Intel Core architecture implements a CISC instruction set architecture on a RISC microarchitecture.

Accepted Answer

The Intel Core architecture is based on a microarchitecture known as x86-64, which implements a CISC (Complex Instruction Set Computing) instruction set architecture. However, the microarchitecture itself is more RISC-like, with features such as pipelining, out-of-order execution, and register renaming.

Question 13

In the scalar organization there are multiple functional units,each of which is implemented as a pipeline and provides a degree of parallelism by virtue of its pipelined structure.

Accepted Answer

The answer of In the scalar organization there are multiple...

Question 14

The Cortex-A8 targets a wide variety of mobile and consumer applications including mobile phones,set-top boxes,gaming consoles and automotives navigation / entertainment systems.

Accepted Answer

The Cortex-A8 is designed to target a wide range of mobile and consumer applications such as mobile phones, set-top boxes, gaming consoles and automotive navigation/entertainment systems.

Question 15

The schedulers are responsible for retrieving micro-ops from the micro-op queues and dispatching these for execution.

Accepted Answer

The schedulers are responsible for retrieving micro-ops from the micro-op queues and dispatching these for execution.

Question 16

In a traditional scalar organization there is a single pipelined functional unit for integer operations and one for floating-point operations.

Accepted Answer

In a traditional scalar organization, there is typically one pipelined functional unit for integer operations and one for floating-point operations. This design helps to maximize the efficiency of the processor by allowing multiple instructions to be in various stages of execution at the same time.

Question 17

True data dependency is also called flow dependency or read after write (RAW)dependency.

Accepted Answer

True data dependency is also known as flow dependency or read after write (RAW) dependency.

Question 18

The superscalar approach has now become the standard method for implementing high-performance microprocessors.

Accepted Answer

The superscalar approach, which allows multiple instructions to be executed simultaneously, has indeed become the standard approach for high-performance microprocessors.

Question 19

The essence of the ________ approach is the ability to execute instructions independently and concurrently in different pipelines.
A)scalar
B)branch
C)superscalar
D)flow dependency

Accepted Answer

The ability to execute instructions independently and concurrently in different pipelines is a characteristic of superscalar architecture. Scalar architecture (A) uses a single pipeline for instruction execution. Branch (B) refers to a type of instruction that changes the flow of program execution. Flow dependency (D) refers to a type of hazard that arises when an instruction depends on the result of an instruction in a previous stage of the pipeline.

Question 20

Resources include: memories,caches,buses,and register-file ports.

Accepted Answer

These are commonly used computer architecture resources.

Quiz 16: Parallelism and Superscalar Processors

The simplest instruction issue policy is to issue instructions in the exact order that would be achieved by sequential execution (in- order issue)and to write results in that same order (in-order completion).

ARM architecture has yet to implement superscalar techniques in the instruction pipeline.

Machine parallelism exists when instructions in a sequence are independent and thus can be executed in parallel by overlapping.

The situation where the second instruction needs data produced by the first instruction to execute is referred to as __________.

The superscalar approach can be used on __________ architecture.

Which of the following is a fundamental limitation to parallelism with which the system must cope?

In-order completion requires more complex instruction issue logic than out-of-order completion.

The superscalar approach depends on the ability to execute multiple instructions in parallel.

Register renaming eliminates antidependencies and output dependencies.

The reorder buffer is temporary storage for results completed out of order that are then committed to the register file in program order.

The instructions following a branch have a _________ on the branch and cannot be executed until the branch is executed.

In effect,the Intel Core architecture implements a CISC instruction set architecture on a RISC microarchitecture.

In the scalar organization there are multiple functional units,each of which is implemented as a pipeline and provides a degree of parallelism by virtue of its pipelined structure.

The Cortex-A8 targets a wide variety of mobile and consumer applications including mobile phones,set-top boxes,gaming consoles and automotives navigation / entertainment systems.

The schedulers are responsible for retrieving micro-ops from the micro-op queues and dispatching these for execution.

In a traditional scalar organization there is a single pipelined functional unit for integer operations and one for floating-point operations.

True data dependency is also called flow dependency or read after write (RAW)dependency.

The superscalar approach has now become the standard method for implementing high-performance microprocessors.

The essence of the ________ approach is the ability to execute instructions independently and concurrently in different pipelines.

Resources include: memories,caches,buses,and register-file ports.