Proebsting's Law

Simon Wistow simon at
Tue Dec 13 17:27:44 GMT 2005

Proebsting's Law states
"Compiler Advances Double Computing Power Every 18 Years"

I claim the following simple experiment supports this depressing claim. 
Run your favorite set of benchmarks with your favorite state-of-the-art 
optimizing compiler. Run the benchmarks both with and without 
optimizations enabled. The ratio of of those numbers represents the 
entirety of the contribution of compiler optimizations to speeding up 
those benchmarks. Let's assume that this ratio is about 4X for typical 
real-world applications, and let's further assume that compiler 
optimization work has been going on for about 36 years. These 
assumptions lead to the conclusion that compiler optimization advances 
double computing power every 18 years. QED.

This means that while hardware computing horsepower increases at roughly 
60%/year, compiler optimizations contribute only 4%. Basically, compiler 
optimization work makes only marginal contributions.

Perhaps this means Programming Language Research should be concentrating 
on something other than optimizations. Perhaps programmer productivity 
is a more fruitful arena. 


it's the last line that interests me.

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