HELP: MIPS PC Relative Addressing

[Maciej W. Rozycki]

On Thu, 4 Mar 2021, Jiaxun Yang wrote:

> >   I'm not sure though why you try to avoid composed relocations given we've
> > had them for 20+ years now.  Relocations are just calculation operators
> > for expressions evaluated at link time rather than assembly or high-level
> > language compilation time.  And just like we don't invent single operators
> > for complex combinations of `+', `&', `%', `<<', etc. and instead compose
> > the exiting ones in expressions used in various programming languages to
> > get the desired calculation, we don't need to do that for relocation and
> > we can just have a collection of simple relocation operators to choose
> > from and combine.
> 
> Well just because binutils code drives me crazy:-(
> I tired very hard to understand those stuff but when I trying to modify them
> I just got endless assert failure or other unreasonable errors :-/

 The code certainly has decades of baggage, it can be complicated and even 
hairy at places.  I guess nobody knows it all or understands all parts 
right away.  However you'll get better with getting around it as you work 
with it longer and get experience, you just need patience.  Nobody says 
learning tough stuff is easy.

 But difficulty with understanding one particular implementation mustn't
drive psABI design decisions!

  Maciej