Empirical Evaluation of Some Features
of Instruction Set Processor Architectures
This paper presents methods for empirical evaluation
of features of Instruction Set Processors 
(ISPs).  ISP features are evaluated in terms of the time
used or saved by having or not having the feature. 
 The methods are based on analysis of traces of program
executions.  The concept of a register life is 
in troduced, and used to answer questions like: How many
registers are used simultaneously? How many would 
be sufficient all of the time? Most of the time? What
would the overhead be if the number of registers 
were reduced? What are registers used for during their
lives? The paper also discusses the problem of 
detecting desirable but non-existing instructions. Other
problems are briefly discussed.  Experimental 
results are presented, obtained by analyzing 41
programs running on the DEC system 10 ISP.
CACM March, 1977
Lunde, A.
