Stuff about CISC/RISC Architecture.

(Remember that for this and the last two handouts, your answers to the ‘Why’ are the most important. Many of these questions can be answered both ways, if you have a good understanding of the ‘Why’)

1a. Name 1 CISC Implementation.___________________________________________________

1b. Name 5 RISC Implementations.___________________________________________________

1c. In the normal case, which type of architecture ….

i. has more complex instructions?______ Why?______________________________________

ii. requires fewer registers? ______ Why?______________________________________

iii. produces smaller code? ______ Why?______________________________________

iv. do compilers like less? ______ Why?______________________________________

v. do hand-coders like more? ______ Why?______________________________________

vi. is more portable? ______ Why?______________________________________

2a. In the normal case, which type of architecture will benefit more from…….

i more registers?_______Why?_________________________________________________

ii more pipelining?_______Why?_________________________________________________

iii bigger I-caches?_______Why?_________________________________________________

iv bigger D-caches?_______Why?_________________________________________________

v faster ‘Fetch’ stage?_______Why?_________________________________________________

vi faster ‘Decode’ stage?_______Why?_________________________________________________

vii faster ‘Register Read/Write’ stage?_______Why?______________________________________

viii faster ‘ALU’ stage?_______Why?_________________________________________________

ix faster ‘Memory Read/Write’ stage?_______Why?_______________________________________

3a. Consider P4 vs any RISC. Which implementation will….

i. be hurt more by a pieline stall?____ Why?________________________________________

ii. be hurt more by bad branch prediction?_____ Why?_________________________________

3b. If you had 10Million transistors to add to a P4, where would you put them?_____________________

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Why?_________________________________________________________________________

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3c. If you had 10Million transistors to add to a RISC, where would you put them?___________________

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Why?_________________________________________________________________________

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3d. Which machine is the way of the future (according to Berkeley CS)? _____ Why?________________

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