The main purpose of my Ph.D. thesis
[41]
is to develop
a model enabling one to reason about various techniques for
program optimization,
in particular wrt. speedup and correctness.
Concerning speedup, some of the results are presented in
[29];
in particular
the reasons why a program transformation may yield more than
a constant speedup are factored out.
Concerning correctness, some results
(generalizing previous approaches from the literature)
about preservation of termination properties
for a logic language are presented in
[28].