OPTIMIZING THE JAVA VIRTUAL MACHINE INSTRUCTION SET BY ...

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Chapter 1
Introduction
When Moore’s law [82] was originally published in 1965, it stated “The complexity for
minimum component costs has increased at a rate of roughly a factor of two per year.
Certainly over the short term this rate can be expected to continue, if not to increase.
Over the longer term, the rate of increase is a bit more uncertain, although there is
no reason to believe it will not remain nearly constant for at least 10 years.” In 1975,
Moore revised his estimate to a doubling in complexity every two years [83]. Moore
contends that he never said “every 18 months”. However, his law is commonly quoted
as such, and continued to accurately reflect the rate of micro-processor development
until 2002 [87].
While increasing processor complexity at this rate has lead to incredible gains in
processing power over the past four decades, developers’ and users’ appetite for this
power has kept pace. Each improvement in technology has been met with demands
for more features, the ability to solve larger problems and the ability for everything
to happen faster, quickly utilizing all of the performance gains that were achieved.
The Java programming language is packed with features that ease application
development. It provides a syntax familiar to developers that have worked with
earlier languages such as C and C++ while providing many additional features. These
include an extensive object oriented library, safety checks that catch runtime errors
in a graceful manner, a security model that allows users to safely execute code from
unknown sources, and object-code level platform independence.
While these features have reduced the burden of application development, they
have increased the burden on the computer. Object oriented programs often consist
of many small methods. Because Java provides polymorphism, the precise method to
invoke must often be determined at runtime, increasing the number of operations that
must be performed and inhibiting optimization. Runtime safety checks ensure that