perf: ibl opts: cmp-vs-literal, no collision cmp

[derekbruening]

From [email protected] on February 21, 2009 10:55:05

this was PR 215263

recording some things that other systems use to achieve performance on
ibs, and that we may want to try

driven by CGO07 paper "Evaluating Indirect Branch Handling
Mechanisms in Software Dynamic Translation Systems" though that's on
Strata where they cheat on returns and so don't consider them in their
study

• sieve == expand table into cmp-vs-literal, trading code for data
  footprint (HDTrans)
• inlined cmps (like my cgo03): 1st 2 targets for call* good, but jmp*
  needs profiling and in fact 1st 2 there is worse
• not in that paper but in a vmware paper: no collision check inline,
  instead jmp to resolution code, if no conflict jmp straight there

Original issue: http://code.google.com/p/dynamorio/issues/detail?id=32