[llvm-dev] '!annotation' type metadata and compiler optimisations

[Paul Heidekrüger via llvm-dev]

Hi all, 

I was looking for a mechanism for tracking instructions through compiler
optimisations, i.e. annotate before optimisations and check again after
optimisations. 

Am I correct in understanding that '!annotation' type metadata is, by design,
guaranteed to be left untouched by compiler optimisations if its corresponding
instruction doesn't get optimised away?

Many thanks,
Paul